The evolution of intelligent electronic sensors is creating a revolution for IoT and Industrial IoT as companies bring new sensor-based, intelligent systems to market. These systems now incorporate processors and software and they include communication hardware in order to move data into the Cloud for analysis. While the sensor market continues to garner billions of dollars, the average selling price of a MEMS sensor, for example, is only 60 cents. How will vendors make money in the IoT intelligent systems market?

Usually, teams manage analog simulations manually or they use complex and expensive tools that require intricate setup and proprietary test plans before they can be deployed. What teams need is an easy way to manage analog verification in order to track the large number of simulations for each project. Tracking simulation results at all levels for each team member and project managers requires automation. This whitepaper introduces a painless solution for analog verification management.

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For many analog-to-digital converter (ADC) applications, a simple passive resistor/capacitor (RC) filter at the buffer input will provide adequate antialiasing filtering. However, an active filter is often needed for higher-resolution, low-noise applications that require higher-order filtering. The active component in that filter must have sufficient bandwidth, fast settling time, low noise, and low offset voltage so that it doesn’t corrupt the signal before it gets to the ADC.

This circuit uses a differential op amp optimized to drive a low-power successive-approximation-register (SAR) ADC, although it will work for other converters as well (Fig. 1). It provides a 30-kHz, third-order filter based on op amp U2 (LTC6363), which has 500-MHz gain-bandwidth product, 780-ns settling time to 4-ppm, 2.9-nV/√Hz input-referred noise, and a maximum offset voltage of 100 µV. U2 is optimized to drive U1 (LTC2380-24), a 1.5/2-Msample/s, low-power SAR ADC with an integrated digital filter that can average from 1 to 65,536 conversion results in real time, thus providing an increase in signal-to-noise ratio (SNR).

1. The 30-kHz, third-order active filter centered on op amp U2 drives the 24-bit ADC with the necessary bandwidth, fast settling time, low noise level, and low offset voltage.

The inputs of this circuit are driven differentially with a ±2.5-V p-p signal range via R3 and R5 (or one input can be grounded while the other input is driven with a signal that can range up to ±5 V p-p). The output of ultra-low-noise op amp U4 (LT6202) is applied to U2’s common-mode voltage input to establish its output common-mode reference voltage.

High-quality capacitors and resistors should be used in the RC filter network between U2 and U1 (C5, C6, C7, R6, and F7), since these components can add distortion. NP0 and silver-mica type dielectric capacitors have excellent linearity, and metal-film surface-mount resistors are much less susceptible than carbon surface-mount resistors to generating distortion, which can result from self-heating, as well as damage that may occur during soldering.

2. The combined frequency response of filter plus ADC is flat out to a 10-kHz input.

3. The PScope screen capture shows key parameters FFT, SNR, and THD of the circuit with N = 1.

Figure 2 shows the combined frequency response of the filter and ADC with a sample rate of 1.5 Msamples/s and number of averages (N) set to 1 and 8. Figure 3 is a PScope screen capture that shows the fast Fourier transform (FFT), SNR, and total harmonic distortion (THD) for the circuit with N = 1. (PScope is a USB-based product demonstration and data-acquisition system for use with Linear Technology’s high-performance ADCs and signal-chain receiver family.)

4. Details of THD versus input frequency show that it’s always below −60 dB, even at 100-kHz input frequency, for both N = 1 and N = 8.

5. SNR is 100 dB and better out to 100-kHz input frequency, again for N = 1 and N = 8.

Figures 4 and 5 respectively show THD and SNR versus input frequency, with N equal to 1 and 8. At input frequencies below a few kilohertz, performance is close to the typical datasheet numbers for SNR and THD, and THD gracefully degrades as the input frequency increases beyond that range.

Guy Hoover is an applications engineer specializing in SAR ADC applications support at Analog Devices. He has over 30 years of experience at as a technician, an IC design engineer, and an applications engineer. He began his career at Linear Technology as a technician, learning from industry luminaries including Bob Dobkin, Bob Widlar, Carl Nelson, and Tom Redfern, while working on op amps, comparators, switching regulators, and ADCs, as well as designing SAR ADCs. Guy graduated from DeVry Institute of Technology (now DeVry University) with a BS in electronics engineering technology.

For many analog-to-digital converter (ADC) applications, a simple passive resistor/capacitor (RC) filter at the buffer input will provide adequate antialiasing filtering. However, an active filter is often needed for higher-resolution, low-noise applications that require higher-order filtering. The active component in that filter must have sufficient bandwidth, fast settling time, low noise, and low offset voltage so that it doesn’t corrupt the signal before it gets to the ADC.

This circuit uses a differential op amp optimized to drive a low-power successive-approximation-register (SAR) ADC, although it will work for other converters as well (Fig. 1). It provides a 30-kHz, third-order filter based on op amp U2 (LTC6363), which has 500-MHz gain-bandwidth product, 780-ns settling time to 4-ppm, 2.9-nV/√Hz input-referred noise, and a maximum offset voltage of 100 µV. U2 is optimized to drive U1 (LTC2380-24), a 1.5/2-Msample/s, low-power SAR ADC with an integrated digital filter that can average from 1 to 65,536 conversion results in real time, thus providing an increase in signal-to-noise ratio (SNR).

1. The 30-kHz, third-order active filter centered on op amp U2 drives the 24-bit ADC with the necessary bandwidth, fast settling time, low noise level, and low offset voltage.

Silicon carbide (SiC) and gallium nitride (GaN) are two major wide bandgap (WBG) power semiconductor materials capable of operating at higher voltages, temperatures, and switching frequencies. They offer great potential for enabling higher performance, as well as more compact and energy-efficient power systems. Over the years we have seen WBG devices used successfully in many applications where silicon-based solutions were previously employed. To cite one recent example, full SiC power modules for automotive applications have been announced by Rohm to be used by the Venturi Formula-E team in the fourth season of FIA Formula E.

Members of the power electronic industry realized there is a need for common standards to help WBG suppliers differentiate their solutions. Regulations and standards are important tools to encourage efficiency improvements in power electronics, defining product types and establishing minimum levels of quality and reliability. Standards help companies to invest more strategically in R&D rather than designing everything from scratch. Once common formats are established, companies can offer products based on standards, and focus R&D efforts on developing innovations to differentiate their products.

To that end, the Joint Electron Device Engineering Council (JEDEC) recently announced the formation of a new committee: JC-70 Wide Bandgap Power Electronic Conversion Semiconductors. The new JC-70 committee will initially have two subcommittees: JC-70.1 Subcommittee for GaN Power Electronic Conversion Semiconductor Standards and JC-70.2 Subcommittee for SiC Power Electronic Conversion Semiconductor Standards. The focus areas are on Reliability and Qualification Procedures; Datasheet Elements and Parameters; and Test and Characterization Methods.

The JC-70 is led by interim chairs from Infineon, Texas Instruments, and Wolfspeed, a Cree Company. “To meet the demand of today’s energy and product requirements, this team is helping to create the mature industry infrastructure that customers need to design power supplies,” says Dr. Stephanie Watts Butler, technology innovation architect at Texas Instruments. “The broad academic and industry participation is indicative of the importance of wide bandgap for complying with these requirements.”

“Our consensus is that JEDEC is the logical home for the continuation of these efforts in a public forum, and the team is delighted to invite industry participation in this new JEDEC committee,” adds Dr. Jeff Casady, Wolfspeed’s business development and programs manager. “Creating clear, universal standards is a key step in advancing the adoption of wide bandgap technologies. These new parameters will enable users to design SiC and GaN devices into the systems of tomorrow, thus creating a more energy efficient future."

At the moment, reducing energy consumption is a common goal in the power electronic industry where SiC and GaN materials had begun to thrive. The creation of the J-70 committee is a step forward in driving the adoption of GaN and SiC technologies while also helping wideband gap markets to growth at faster speed.

Types of Magnets

There are four main types of magnets: ceramic (ferrite), AlNiCo, Samarium Cobalt (SmCo), and Neodymium (NdFeB). The latter is one of the most commonly used in motors for hybrids vehicles and EVs. Neodymium magnets have higher remanence, along with much higher coercivity and energy production, but often lower Curie temperature than other types.

Special neodymium magnet alloys that include terbium and dysprosium have been developed with higher Curie temperature, allowing them to tolerate higher temperatures of up to 200°C. Because of the RE magnet properties, no other magnet material can match their high strength performance. “You cannot really replace RE magnets,” says Da Vukovich, president of Alliance LLC. “This is what it would look like if you try to replace the material to build a motor using a ferrite magnet instead of a RE magnet (Fig. 1).”

1. This is a comparison of sizes using pieces of a motor ferrite magnet instead of a RE magnet. (Courtesy of Alliance LLC)

Magnets are divided into two categories:  Light Rare Earth (LRE) and Heavy Rare Earth (HRE). The global RE reserves consist of approximately 85% LRE and 15% HRE. The latter are the ones providing magnets rated at high temperature that are suitable in many automotive applications.

2011 Crisis and Disruptions

Six years ago, manufacturers worried that there would be a RE shortage after China cut its exports to the rest of the world to meet its own demands, triggering fears of a global shortage. Rare earth magnet values skyrocketed accordingly: They reached a high point of $2,200/kg from an earlier $130/kg. (Fig. 2). Manufacturers building loud speakers and electric motors had to requote entire products just because of the rise of the magnet price. After the elimination of export quotas and taxes the following years (2012-2013), China saw an increase of about 35,000 MT due to the 2011 crisis.

2. Shown are prices of rare earth elements in 2011 (Courtesy of Alliance LLC)

China’s desire to dominate green industries like wind turbines and electronic vehicles is setting a high demand for its own rare earth metals, so there is no guarantee that another world crisis will start one more time.

Production Outside of China

Even though China is the largest producer, there are other countries mining rare earth minerals:

Mining rare earth elements is very toxic; it is very expensive to do it in a way that doesn’t contaminate the environment. State-of-the-art equipment is necessary to comply with environmental and labor regulations. Molycorp had invested more than $1.5 billion into a mine located in Mountain Pass, Calif.  (Fig. 3), but it was shut down in 2015 because it could not compete with lower RE prices.

3. Molycorp was the U.S.’s only miner and processor of rare earths (Courtesy of mining.com)

Recently the U.S. Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) has found high rare earth element (REE) concentrations in coal samples taken from the Illinois, Northern Appalachian, Central Appalachian, Rocky Mountain Coal Basins, and the Pennsylvania Anthracite region. These highly concentrated samples are greater than 300 parts per million (ppm).

“Rare Earth Elements are vital to the development and manufacturing of high-tech devices such as computers, cell phones, and our national defense systems,” says U.S. Secretary of Energy Rick Perry. “The current difficulties and high expenses associated with REE extraction has left the U.S. dependent on foreign REE imports. Supporting innovative research and development to establish efficient, cost-effective REE extraction methods is critical to our country’s energy and national security.”

Rare Earth Magnets in Hybrids and EVs

Around 9,200 gr of RE materials are used in Hybrid & EV which 8,900 gr is Nd. Here are some of the RE magnets found in hybrid and EV vehicles:

Usage of magnetic rare earth in such vehicles is expected to grow from about 2,000 metric tons last year to 7,000 tons by 2020 and 12,000 tons by 2024, according to a presentation dated last month from Lynas Corp., the biggest rare earths miner outside China. The United States through exploration and research will keep looking for other sources of rare earth elements in other to not obstruct productiveness and competitiveness in green technologies.

The most common method for sharing data between devices is via a digital means of communications. Several standard buses implement such methods, with the main differences between them being data rate and noise sensitivity. When it comes to industrial applications or high-noise environments, communications systems suffer from noise interference. Thus, differential buses are often the best option as a result of their significantly reduced sensitivity to noise.

RS-485, also known as TIA-485(-A) or EIA-485, is a standard defined by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA). It’s based on balanced electrical signaling (a differential bus) that can be used effectively over long distances and in electrically noisy environments such as industrial environments.

RS-422, also known as TIA/EIA-422, specifies electrical characteristics of a digital balanced signaling circuit. This bus is very similar to RS-485, with the main difference being that the RS-485 can implement linear bus topologies with only a twisted pair of cables.

These buses are commonly used with embedded systems that implement half-duplex asynchronous serial communications. To do this, a conversion from single-ended buses to differential buses must be used.

Several different brands of commercial ICs implement the single-ended to differential bus conversion. These offer a simple way to convert RS-232-compatible buses to RS-422/RS-485 bus. Such ICs are called RS-422/RS-485 transceivers.

In this article, the required digital logic to implement an integrated transceiver for RS-422/RS-485 protocols converting single-ended to differential data when transmitting, or differential to single-ended data when receiving—managed by control signals—is used. To achieve this, we (at ADOM Ingieneria) used a Silego GreenPAK SLG46533.

The system has two differential input/outputs as the interface to the RS-422/RS-485 bus—one control signal for flow data control and one serial data input (Tx to the bus) and one serial data output (Rx from the bus) as the interface to the singe-ended bus. With this implementation, the SLG46533V will work as a transceiver and is able to replace commercial ICs.

Differential Communications

Two basic forms of data-transmission circuits exist on serial communication buses: a single-ended bus and differential bus.

1. Single-ended or unbalanced circuit.

A single-ended or unbalanced circuit (Fig. 1) determines the bus state through the voltage difference between the signal line and common local ground. Fig. 1 shows the electrical schematic diagram of a single-ended transmission circuit, as well as the noise sources V_N and V_G. Noise voltages are added directly to the signal voltage (V_S)_.

A differential or balanced circuit is shown in Figure 2. In this case, the bus state is determined by the voltage difference between two complementary signal lines. Fig. 2 illustrates the electrical schematic diagram of a single-ended transmission circuit and the noise sources V_N and V_G. Noise voltages V_N and V_G are added to each signal line and are common to both signals.

2. Differential or balanced circuit.

In this case, input voltages to the receiver stage are calculated with the equations:

V_IA = V_SA + V_N + V_G

V_IB = V_SB + V_N + V_G

The differential receiver measures the difference between the two lines. The received signal voltage is calculated as follows:

V_RX = V_IB– V_IA = V_SB− V_SA

From Fig. 1, it can be seen that single-ended buses are susceptible to external noise influences. Also, due to the lack of any complementary signal presence, the electromagnetic fields created by the single-ended signal aren’t canceled, so it radiates much more noise than differential circuits. Electromagnetic-noise susceptibility and emissions relegate single-ended interfaces to low signaling rates and short transmission lines.

It can be seen that the differential receiver rejects the common voltage of the signals. If this bus type is used with closely coupled lines, the complementary signals cancel each other’s noise, resulting in high immunity and low noise emissions.

This immunity to external noise influence is the main reason for choosing differential signaling when relatively high signaling rates and long distance are required in electrically noisy, or noise-sensitive, applications. The disadvantage of differential buses is the additional cost of the line driver, receiver, and interconnection, versus the cost of single-ended transmission buses.

RS-422/RS-485 Bus

As mentioned, RS-422 and RS-485 are very similar differential bus standards. The first published standard was RS-422. But it lacked bidirectional capabilities allowing for multipoint connections, which led to the creation of RS-485.

RS-485—or TIA-485(-A) or EIA-485—defines the electrical characteristics of the interconnection, including driver, line, and receiver. It allows data rates up to 35 Mb/s and line lengths of up to 1200 m. As to be expected, both limits can’t be reached at the same time. There are several recommendations about wiring and termination; the standard doesn’t specify the connector or any protocol requirements.

A half-duplex and differential transmission method defined by RS-485 is designed for twisted-pair cables and other balanced media. The standard requires drivers to deliver a minimum differential output voltage of 1.5 V with up to 32 unit loads of about 12-kΩ each, plus termination resistors at each end of the bus.

Unlike RS-422 with its single driver circuit that can’t be switched off, RS-485 drivers use three-state logic that enables deactivation of individual transmitters. This allows RS-485 to implement multipoint linear bus topologies using only two wires. The linear bus topology is often based in a master-slave arrangement, where one device (the master device) initiates all communication activity.

As mentioned earlier, due to its differential transmission form, RS-485 is very robust against electrical noise. Due to its wide common-mode voltage range, it’s tolerant to ground potential shifts between nodes. These two characteristics are the main reasons for using RS-485 in applications that require low noise emissions and susceptibility.

3. RS-485 network schematic.

In most applications, the signaling rate and long distance lines are sufficient to control a process line or share data in industrial environments. Figure 3 shows an RS-485 network schematic.

The RS-485 standard doesn’t define particular protocols for communications with the bus; it only specifies electrical characteristics of the interconnection. Thus, RS-485 is used with many communication protocols as the physical layer of the communication system.

Due to the differential nature of the RS-485 bus, transceivers are used to convert single-ended buses to differential versions. That’s because typical communications systems or microcontroller serial communications peripherals are single-ended. This is implemented using the logic shown in Figure 4.

4. RS-485 transceiver logic schematic.

Since RS-485 communications are half-duplex, a flow-control input called /RE DE is used. When flow control is low, the Rx stage is active; therefore, the A and B lines are input lines. Data at the differential bus is decoded by the Rx stage, and the result appears at the R output pin.

When flow control is high, the Tx stage is active, which means the A and B lines are output lines. Data at the single-ended input D is converted to differential data by the Tx stage so that it can be transmitted via the differential bus connected to pins A and B.

One protocol that often uses RS-485 as the electrical layer is RS-232, a serial communication protocol. RS-422/RS-485 is used because of its single-ended nature and the full-duplex scheme of the RS-232 serial data transmission. Typically, low bit rates are employed, such as 19,200 or 38,400 bits/s, due to the industrial environments that install RS-485 buses.

Implementation

Implementation of the RS-422/RS-485 transceiver is accomplished with a SLG46533V GreenPAK. This configurable mixed-signal IC (CMIC) has four analog comparators and GPIOs that can be used as a simultaneous input/output by configuring it with a control signal. The outputs at this stage are two square waveforms, one for each group.

The flow-control input is implemented with Pin 3, which is configured as a digital input (/RE DE).

5. Analog comparator configuration.

To implement the transceiver’s receiver mode, SLG46533 must convert a differential input to a single-ended output. This was done using an analog comparator. Figure 5 shows the ACMP3 configuration. The analog comparator is configured with 25-mV hysteresis and without low bandwidth in order to obtain higher-speed communications.

The selection of the ACMP is made based on the idea of using the same pins for differential input and differential output, as is required by a RS-485 transceiver. This is the main reason for choosing ACMP3, because it can have input pins with I/O control signals to configure them as an input or output for receiving or transmitting data.

The inputs of the analog comparator are the differential inputs of the transceiver, called A and B. To do this, positive input of the ACMP is connected to Pin 13 (ACMP2 In+ source) and the negative input is connected to Pin 14 (the external V_REF of the ACMP3).

When the transceiver flow-control bit is low, the transceiver works as a receiver of data. In this case, Pin 13 and Pin 14 are configured as analog inputs and the analog comparator processes both inputs to define a high or low level at its output. The output of the ACMP is connected to Pin 5, called R, which represents the received data. Figures 6 and 7 show the configurations of Pin 13 and Pin 14, respectively.

6. Pin 13 configuration.

7. Pin 14 configuration.

When the transceiver flow-control bit is high, the transceiver works as a data transmitter of data. In this case, Pin 13 and Pin 14 are configured as digital outputs. The single-ended serial data input to the transceiver is implemented with Pin 4, called D.

8. LUT0 configuration.

In order to obtain differential data at the outputs, LUT0 uses a NOT gate to obtain the inverse of the data input. Two signals (Data and its inverse) are connected to outputs A and B so that the differential data is transmitted to the bus. Figure 8 illustrates the LUT0 configuration.

The table above shows the logic states of inputs and outputs as well as the functionalities of the RS-422/RS-485 transceiver. The entire implementation is depicted in Figure 9.

9. RS-422/RS-485 block diagram.

Testing Results

To test the implementation, the transceiver was used as a receiver and a transmitter in separate cases. Therefore, the inputs and the outputs could be registered with a logic analyzer.

As a receiver, the RS-485 transceiver received a binary stream via the differential bus and the logic analyzer registered the differential inputs and the single-ended data output. The binary stream sent to the transceiver was:

1101001010

Figure 10 shows the received stream data at the inputs A and B, and the data output pin R. Furthermore, it can be seen that the flow-control signal /RE DE is set to a low logic level in order to configure the RS-485 transceiver as a data receiver.

10. RS-422/RS-485 transceiver in receiver mode.

As a transmitter, the RS-485 transceiver transmitted a binary stream (corresponding to the single-ended binary stream at the D input) via the differential bus. The logic analyzer registered the differential inputs and the single-ended data input. The binary stream sent by the transceiver was:

1001101010

Figure 11 shows the transmitted stream data by outputs A and B and the data input pin D. Also, the flow-control signal /RE DE was set to a high logic level in order to configure the RS-485 transceiver as a data transmitter.

11. RS-422/RS-485 transceiver in transmitter mode.

Conclusion

In this article, we implemented a RS-422/RS-485 transceiver with the SLG46533. RS-422/RS-485 transceivers are found in many applications that use this industrial bus because of its differential nature, which isn’t compatible with the single-ended nature of binary communication systems.

Several commercial ICs implement this type of transceiver. We created a compatible transceiver with the RS-485 specifications with respect to input differential voltage sensitivity, differential output voltage, typical data transfer rates, and typical common-mode voltages. Our system complies with RS-485 specifications, with the added benefit of much smaller IC size.

ADOM Ingenieria specializes in professional design, development, support and consulting in analog and digital electronic requirements.

Through either the adoption or expansion of technologies, many power electronics markets are expected to grow and undergo further development in 2018 and beyond. In fact, the technologies that have started to trend this year will continue to do so—especially technologies to combat greenhouse gas emissions in the automotive and alternative energy markets. Of course, power electronics investment also will come from the Internet of Things (IoT), energy storage, wide-bandgap materials, and wireless charging, as detailed below:

Electrification of Vehicles

2017 was a good year for electric vehicles and the future of this market looks very promising. Just a few weeks ago, 12 countries around the globe had set goals to end sales of gas- and diesel-powered vehicles starting in 2040. This action will accelerate the growth of sales on hybrid vehicles and electric vehicles, directly increasing the demand for automotive power-semiconductor devices. Power electronics is no longer just concerned with heating a cooling system in cars. Nowadays, it involves systems like on-board charging, battery management systems, infotainment, electric motors, etc. The adoption of electric vehicles in 2018 will lead to an increase in technology developments and competition and a reduction of costs for automotive semiconductor technologies.

Even Lamborghini is getting on board the electric vehicle bandwagon with its Terzo Millennio electric super sports concept car.

Wireless Charging

In 2017, we saw how wireless charging technology has been adopted by many consumer electronic devices. Apple was the latest company to add the technology to its iPhone X. But wireless charging is not just for smartphones; we have seen the benefits in harvesting systems, too. The automotive industry has also started to adopt the technology. Some luxury automotive makers had incorporated in-car wireless charging systems for electronic gadgets. In the future, we might be able to wirelessly charge an electric vehicle while driving it.

There are still many challenges ahead (e.g., standardization, safety, and skepticism). But many automotive suppliers and semiconductor companies are recognizing the advantages that this technology can offer. They will keep working together to develop better solutions. Further developments in fast charging and freedom of alignment will make possible an increase in adoption of automotive wireless charging technology.

Apple introduced wireless charging in its new iPhone in 2017, opening the floodgates for more wireless charging innovations from a wide range of manufacturers and developers in 2018.

Wide-Bandgap Materials

Wide-bandgap semiconductor materials like gallium nitride (GaN) and silicon carbide (SiC) are anticipated to be used in many more applications in 2018. At the moment, the number of applications for those materials is steadily increasing in the automotive and military industry. We will continue to see this trend. In the automotive market in particular, expect to see more adoption of SiC and GaN materials due to their efficient performance under high temperatures and power. We also will see more applications using wide-bandgap materials in on-board chargers (OBCs), dc-dc converters, bidirectional inverters, and dc-ac inverters. Even though the adoption of GaN and SiC is rising, however, expect to see them coexisting with silicon across markets for a long time. Each of those three material choices might perform better, depending on the application and budget restrictions.

Energy Storage

According to Bloomberg New Energy Finance (BNEF), the global energy-storage market will double six times between 2016 and 2030, rising to a total of 125 G/305 gigawatt-hours. In 2018, energy-storage systems will continue proliferating to provide backup power to the electric grid. We will continue to see more projects integrating energy storage and renewable energy solutions. The demand on energy storage is also increasing the use of smart grids around the world. 2018 will see a rise in the production of lithium-batteries, due to the creation and expansion of battery cell factories. Supercapacitors have found a niche in the automotive market with start-stop technologies. Their adoption will continue in other sectors in the renewable energy market (e.g., wind turbine applications).  

IoT

All IoT devices require semiconductors, such as microcontrollers and sensors, to perform their tasks. IC Insights expects sales for IoT system to reach $31.1 billion in 2020. IoT has touched many industries, but in the next years will see the increasing use of smart farming technologies. In fact, IoT device installations in the agriculture world are projected to experience a compound annual growth rate of 20 percent.

The power-electronics market is expected to be valued at USD $41.73 billion by 2022, growing at a CAGR of 2.4% between 2016 and 2022 according to markets&markets. It cites the principal factors driving this growth as the following: increasing demand for energy-efficient, battery-powered portable electronic gadgets; the rising trend of wireless charging technologies; the development of new and advanced defense technologies; and the growing focus toward using renewable power sources. Watch for all of these technologies and applications to evolve and improve continuously for the foreseeable future.

Celebrating Bob Pease
It’s hard to believe it has been five years since the analog industry lost one of its most highly respected gurus, Bob Pease.

Celebrating Bob Pease

We all remember Bob Pease fondly—for his analog design expertise as well as his sense of humor. We were lucky he shared his wit and knowledge with us for years with his special column for Electronic Design, “Pease Porridge.” Earlier this year we released Vol. 1 in a series of two eBooks to commemorate this legendary engineer. Vol. 2 of Electronic Design’s special collection of articles written by Bob is now ready for download.

Mobile and portable devices continue to shrink the space available for the audio system, but high-quality sound continues to be a point of differentiation for manufacturers. Ever wondered how you can get those bone-crushing, “all the way to eleven” sounds out of a 15- × 11-mm speaker with technology that’s barely changed in almost 100 years (Fig. 1)?

1. Early attempts to enhance the mobile audio experience may have improved the sound, but presented problems for the packaging group. (Source: Etsy)

It all begins with the old injunction “First, do no harm.”

Where Speakers Go to Die

A speaker consists of a cylindrical voice coil connected to a diaphragm made of paper or a composite material. The coil assembly is located between the poles of a permanent magnet and constrained to move in the axial direction. The larger end of the cone attaches to the loudspeaker frame. A flexible inner suspension (the spider) centers the coil assembly in the gap.

Download this article in PDF format.

Mobile and portable devices continue to shrink the space available for the audio system, but high-quality sound continues to be a point of differentiation for manufacturers. Ever wondered how you can get those bone-crushing, “all the way to eleven” sounds out of a 15- × 11-mm speaker with technology that’s barely changed in almost 100 years (Fig. 1)?

1. Early attempts to enhance the mobile audio experience may have improved the sound, but presented problems for the packaging group. (Source: Etsy)

It all begins with the old injunction “First, do no harm.”

 Sponsored Resources: 

• Innovations in Smart Amps
• Smart Amp Quick Start Guide
• Smart Amp Quick Start – How to characterize your speaker

Where Speakers Go to Die

A speaker consists of a cylindrical voice coil connected to a diaphragm made of paper or a composite material. The coil assembly is located between the poles of a permanent magnet and constrained to move in the axial direction. The larger end of the cone attaches to the loudspeaker frame. A flexible inner suspension (the spider) centers the coil assembly in the gap.

What kills a speaker?  Figure 2 tells the tale.

2. Excessive heat and excessive movement are the two primary causes of speaker failure. (Source: TI “Audio – Smart Amp”)

Thermal failure occurs when the amplifier supplies more power to the speaker than it can handle, causing the voice coil to get too hot. Up to 95% of the energy input to the loudspeaker is turned into heat. The coil can melt or burn the wires and cause an open circuit, or the coil can come apart as the adhesives holding it together start to soften.

Mechanical failure can occur when the drive signal demands excessive movement from the speaker coil. At one end, the coil may strike the speaker assembly backplate and cause an audible clicking sound. At the other end, the coil may pop completely out of its housing and fail to return correctly, resulting in a permanent misalignment. Excessive excursion can also tear the fabric spider that centers the coil in the gap, cause stretching and vibration of the cone, or even break the coil connecting wires.

Speaker Protection and Smart Amplifier Technology

Protecting the speaker requires both controlling the voice-coil temperature and keeping the cone excursion within safe limits.

In traditional analog audio design, the speaker protection methods are relatively crude. In high-power systems, the output can include a fuse or polyswitch (PPTC device) that interrupts the loudspeaker current when it exceeds a safe level. This method isn’t practical in portable applications, so the prevailing approach has been to limit the amplifier output to a guaranteed safe level under all operating conditions. It prevents damage, but restricts the loudspeaker output across its whole performance envelope, too.

Unfortunately, imposing a hard limit on speaker output also suppresses audio peaks and reduces clarity.  A more sophisticated approach uses an in-depth understanding of speaker behavior to protect it from failure while simultaneously increasing loudness and preserving audio quality.

A speaker is a complex electromechanical system. Electrically, it’s a combination of resistive, capacitive, and inductive elements; a full lumped-parameter model also includes elements that represent acoustic and mechanical properties. The electrical parameters can be measured, but the others must be calculated based on acoustic tests that measure the speaker’s sound pressure level (SPL, a measure of loudness) over its full range.

The new method therefore begins with a detailed characterization in the laboratory of the particular speaker to be used. This allows the engineer to fine-tune a speaker model with a set of calibration parameters that represent the speaker’s specific capabilities. The data set is then utilized in conjunction with a smart amplifier to model the real-time speaker response during operation.

3. A Smart Amplifier (Smart Amp) includes DSP blocks that modify its response based on sensor inputs and a stored model of speaker performance. (Source: TI “Audio – Smart Amp” Feedback Smart Amp architecture)

The smart amplifier is a hybrid analog/digital device that includes several digital-signal-processing (DSP) blocks (Fig. 3).

The digital signal processor runs an adaptive control algorithm with both performance-enhancement and protection blocks:

• Smart EQ automatically modifies high-frequency performance to achieve a flat response or match a target curve.
• Smart SOA establishes the maximum speaker diaphragm excursion and the maximum voice-coil temperature based on the electromechanical-thermal model.
• Smart Sense provides inputs from system and system-level sensors, including temperature, speaker voltage and current, supply voltage, etc.
• Smart Bass automatically modifies the bass response to accommodate larger excursions as the signal amplitude increases.
• Smart Protection models the current state of the speaker to adaptively change amplifier characteristics to avoid over-temperature and over-excursion.

The Characterization and Optimization Process

Texas Instruments offers a comprehensive set of hardware and software tools to help developers characterize a selected speaker and then optimize Smart Amp performance. The information gathered during characterization allows the user to determine speaker performance characteristics and then calculate the allowable excursion and reproducible SPL.

4. The PPC3 development environment includes a specialized Learning Board that facilitates speaker characterization. (Source: TI Training: “Smart Amp Quick Start – How to characterize your speaker”)

Figure 4 shows the typical hardware used for speaker characterization. The main components are:

• A Smart Amp evaluation module (EVM)
• A Smart Amp Learning Board 2 (LB2)
• A digital or analog reference microphone
• A laser to measure speaker diaphragm excursion
• The PurePath Console 3 software suite

The EVM contains the Smart Amp device itself, support circuitry, a USB port, and an LB2 interface.

The LB2 includes a digital audio generator and precision circuitry to measure speaker parameters. During a speaker characterization, the LB2 captures the speaker voltage and current from the EVM, the speaker audio output, plus the movement of the speaker membrane over the complete operating envelope.

Using these measurements and calculations, the LB2 can compensate for SPL variation over frequency by safely overdriving the speaker. This results in greater output level and enhanced low-frequency response.

5. Here’s the PPC3 dashboard for the TAS2557. (Source: TI “Smart Amp Quick Start Guide” PDF, p. 3)

The PurePath Console 3 (PPC3) controls the LB2 and other hardware (Fig. 5). It’s an intuitive graphical user interface (GUI) for characterizing and tuning speakers. The program includes a step-by-step procedure that guides developers through speaker characterization and system calibration.

After setting up the hardware for the chosen Smart Amp and specifying the type of speaker and enclosure, the PPC3 performs the following actions:

1. Exercise the speaker over its frequency range (IV measurement) and generate a graph of speaker impedance versus frequency.

2. Characterize the acoustic response using an accurate reference microphone. The output is an SPL versus frequency curve (Fig. 6) that’s used in the SmartEQ function to correct for peaks and dips in the speaker response.

3. Set up the SOA parameters (excursion limit and thermal limit) and perform the thermal characterization test.

4. Download the speaker characterization parameters to the selected Smart Amp. These are contained in a ppc3 file.

6. The PPC3 produces a measured SPL plot as part of the speaker characterization process. Frequencies <100 Hz represent room noise and are ignored by the Smart Amp (Source: TI “Smart Amp Quick Start Guide” PDF, p. 17)

Following the speaker characterization, the developer can use the PPC3 GUI to tune the Smart Amp—i.e., optimize the sound quality and SPL for a given application. Consult this Application Report for a detailed discussion of the Smart Amp tuning process.

Smart Amp Products

Texas Instruments has built Smart Amp technology into a family of products designed for low-power applications. These include portables and wearables such as smartphones and tablets; and Internet of Things (IoT) devices such as video doorbells, voice-enabled thermostats, and Bluetooth speakers. The design support tools include EVMs for use with the PPC3 as discussed above. The table summarizes the available low-power parts. 

These devices integrate several blocks into a system-on-a-chip (SoC) solution. Each family member has a different feature set, but common features include a low-noise audio DAC; a Class-D power amplifier with speaker voltage and current-sensing feedback; and an I²C and I²S interface. Separate tuning for different speakers allows customers to add value while maintaining a common form factor between designs. Two devices can combine for a stereo implementation.

The TAS2552 and TAS2560 require an external DSP to run their Smart Amp speaker protection algorithms, but the TAS2555, TAS2557, and TAS2559 feature an integrated, low-latency DSP. These devices download the PPC-generated characterization data on boot-up. An adaptive control algorithm combines this data with real-world temperature readings to control Smart Bass and Smart DRP (Dynamic Range Preservation). The protection side of the algorithm is also used for thermal protection and mechanical-excursion protection. Figure 7 shows the internal functional block diagram of the TAS2559.

7. The TAS25xx family of Smart Amps provides an SoC solution for low-power audio applications. The TAS2559 is shown. (Source: TAS2559 PDF, p. 18)

The TAS2559 contains an internal look-ahead algorithm that monitors the battery voltage and digital audio data stream. When the speaker voltage nears the supply voltage, the device activates a multilevel boost function to increase the available headroom. When the audio signal only requires the lower Class-D output power, the boost deactivates, and VBAT supplies the Class-D amplifier directly for greater efficiency. When higher audio output power is needed, the boost function activates and tracks the signal to provide additional voltage to the load.

Two boost modes are available (Fig. 8). Class-H boost adjusts the voltage dynamically as the signal changes for maximum efficiency, but has a high inrush current as the voltage transitions between levels. Class-G is on-off and requires less inrush current; however, it’s also less efficient.

8. The TAS2559 features two selectable boost functions. (Source: TAS2559 PDF, p. 24)

The TAS2559 supports separate dynamic tuning modes for voice and audio, too. Its low idle-channel noise (ICN) figure of 15.9 µV eliminates audible speaker noise when using a smartphone in a receiver or pause mode, and eliminates the need for external noise-reduction components.

Smart Amp Technology at Higher Power Levels

Low-power applications aren’t the only ones that can benefit from the Smart Amp approach. Suitable medium-power applications include active speakers, digital TV sound bars, Bluetooth audio docks, and larger PCs such as notebooks, desktops, and all-in-one computers.

A range of mid-power Smart Amps addresses these applications.The TAS5766M, for example, is a 20-W Class-D stereo Smart Amp that delivers up to 2x50 W peak into 4 Ω.  Operating from a supply voltage of 4.5 to 26 V, the device is available in TSSOP and QFN packages.

The TAS5780M and TAS5782M Smart Amps feature 96-kHz processor sampling for HD audio applications. Both stereo devices offer 20 W into 4 Ω with a 12-V supply voltage, and up to 50 W into 4 Ω with 24-V supply voltage.

The primary difference between the two devices lies in their DSP configurations. The TAS5780 has a fixed-function DSP process flow that features multiple functions, including twelve bi-quad filters, a parametric equalizer (PEQ), a two-band dynamic ranger control (DRC), automatic gain limiter (AGL), and more.

With the TAS5782’s flexible DSP process flows, designers are able to select between different tasks. The PPC3 GUI currently includes six process flows that support a variety of popular use cases—mono, stereo, bi-amped, etc. 

The process flows have different feature sets to accommodate standard or Smart Amp applications. Flow 2, for example, targets 96-kHz sampling and Smart Amp processing. It includes process blocks such as left and right biquad EQ filters; Smart Amp features such as Smart Thermal Protection and Smart Bass; an input mixer; and an output clipper.

Find out more about these flexible process flows in Application Report SLAA737B.

Conclusion

With the trend toward accomplishing more in a smaller space, audio engineers are turning to advanced digital modeling and smart amplifiers to generate more sound from smaller speakers, while still maintaining high audio quality.

Texas Instruments’ portfolio of Smart Amp products, in conjunction with the Pure Path Console 3 development environment, can help designers get the most of small speakers in both low- and medium-power applications.

 Sponsored Resources: 

• Innovations in Smart Amps
• Smart Amp Quick Start Guide
• Smart Amp Quick Start – How to characterize your speaker

Back in 2007, Jim Williams and Mark Thoren wrote Linear Technology application note AN-112. Titled “Developments in Battery Stack Voltage Measurement,” the note deals with the thorny problem of monitoring each individual battery cell in a high-voltage stack, such as those used in electric cars. Analog engineers know Jim Williams from his prolific article writing. Mark Thoren is an equally brilliant and dedicated analog engineer who works more on the data converter side of applications.

I happened to visit Williams while he was writing the app note. He proudly showed me one of his famous copper-clad prototype circuit boards (Fig. 1). I was pleased to see that Williams used the same PanaVise circuit board vise to hold his circuits as I do. The circuit uses cheap pulse transformers to isolate the individual battery cells from the measurement circuits. Professor Kent Lundberg has a nice post regarding the app note on his “Reading Jim Williams” blog.

1. This is the prototype circuit board built by Jim Williams for AN-112, an app note about monitoring individual cells in a battery stack.

I agree with Lundberg that Williams’ circuit was certainly no over-complicated prank. While the prototype circuit looks complicated (Fig. 2), the analog principles behind it are quite elegant. Transformers are a great way to isolate the cells from the measurement circuit and from each other. I have a friend that works on large lithium-ion battery arrays for electric-grid power storage. He tried one of the early automotive battery-stack monitor ICs from a major analog company. The part worked fine in laboratory conditions. When the company’s assemblers put the pack together, they did not hook up the cells to the monitor circuit in ascending order. This blew up the chip.

2. A close-up of Jim Williams’ prototype shows the Pulse brand pulse transformer, the ICs, and the switches and potentiometers he used to develop and understand the circuit.

Subsequent versions of the battery-stack monitor ICs have more design considerations for real-world automotive use. They often have completely redundant circuits. In addition, a separate bunch of independent circuitry usually monitors the measurement circuit. The entire automotive industry has responded to the requirements of automotive battery systems. In addition to the plethora of existing automotive battery standards, the SAE (Society of Automotive Engineers) has released standards like J2929 crafted specifically for lithium-ion battery stacks.

Williams may have been a bit naive about the concern for product liability amongst automotive engineers. When I was a student at GMI (General Motor’s Institute, now Kettering University), they made us all take a business law class. One case study was how a person modified the seat in his VW bus, propping it up with a couple of 2×4 pieces of wood. He got into a crash and the seat came loose, injuring him. He sued VW, and he won. The judge said that VW was responsible for anticipating that people would try to modify the seats. The judge gave no guidance on how VW was supposed to deal with this, though.

When every fire in a Tesla becomes international news, it’s easy to see why the automotive industry is so cognizant of liability issues. It doesn’t matter that a rational assessment shows little cause for concern. A jury judging the death of a young woman versus a billion-dollar corporation will not be rational.

Before you scoff at using transformers to isolate battery-stack cells, check out this app note from Analog Devices. The company uses tiny transformers inside its chips to achieve remarkable isolation levels and common-mode rejection. Perhaps it’s no coincidence that Analog Devices bought Linear Technology last year. They are both analog powerhouses, and we can expect more good things in the future.

If you are looking to monitor a battery stack, besides ADI and Linear Tech, also check out offerings from AMS and Maxim Integrated. Texas Instruments has a large series of battery monitor chips, too. Its battery expertise goes back decades from when they acquired Benchmarq via their acquisition of Unitrode.

3. The battery-stack monitor circuit waveforms precisely match those Williams placed in his AN-112 app note. Williams put a “Genuine Intel 32-bit microprocessor inside” sticker on his trusty Tek analog scope. The man had a great sense of humor.

In addition to taking pictures of Jim Williams’ prototype circuit, I also snapped a picture of his trusty Tektronix oscilloscope (Fig. 3). The waveforms are an exact match to the scope photo in AN-112. I like this photo, since it shows the signals in context, on that faceplate that Williams must have spent many, many hours looking at.

Silicon’s 20th Century dominance in power electronics applications has been eroding for some time now. As engineers extract dwindling amounts of additional performance from silicon ICs, they are looking to wide-bandgap (WBG) materials to develop next-generation power electronics. Examples include silicon carbide (SiC) and gallium nitride (GaN). Materials that have a wide bandgap are inherently applicable in high-power electronics, as they have a higher breakdown voltage and are able to run at higher temperatures when compared to materials with narrow bandgaps, such as silicon.

SiC and GaN also offer the potential for smaller, more robust power devices, which switch faster and are more energy-efficient than Si-based devices. SiC and GaN products, in demand for electric-car and mobile-device applications, perform much better than Si in reducing on-state resistance and shrinking package size. This results in faster charging, lower power consumption, and more efficient energy conversion. Generally speaking, SiC power semiconductor devices are being specified for applications with high power capacity (in excess of 600 V) and GaN for applications involving medium to low-power capacities.

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Silicon’s 20th Century dominance in power electronics applications has been eroding for some time now. As engineers extract dwindling amounts of additional performance from silicon ICs, they are looking to wide-bandgap (WBG) materials to develop next-generation power electronics. Examples include silicon carbide (SiC) and gallium nitride (GaN). Materials that have a wide bandgap are inherently applicable in high-power electronics, as they have a higher breakdown voltage and are able to run at higher temperatures when compared to materials with narrow bandgaps, such as silicon.

SiC and GaN also offer the potential for smaller, more robust power devices, which switch faster and are more energy-efficient than Si-based devices. SiC and GaN products, in demand for electric-car and mobile-device applications, perform much better than Si in reducing on-state resistance and shrinking package size. This results in faster charging, lower power consumption, and more efficient energy conversion. Generally speaking, SiC power semiconductor devices are being specified for applications with high power capacity (in excess of 600 V) and GaN for applications involving medium to low-power capacities.

Silicon carbide has become an attractive alternative to Si in applications requiring efficient high-voltage, high-frequency power conversions. SiC power devices operate at higher switching speeds and higher temperatures with lower losses than conventional silicon. In addition, SiC allows inverters and other energy-conversion systems to be built with improved power density and energy efficiency at lower cost. Almost all the OEMs and Tier-1s are using or testing SiC devices in electric and hybrid electric vehicles (EVs and HEVs).

Similarly, GaN possesses high breakdown voltage and low conduction resistance characteristics, thereby enabling high-speed switching and miniaturization. Unlike conventional Si transistors, which require bigger chip areas to reduce on-resistance, GaN devices have smaller sizes (and lower parasitic capacitance) for high-speed switching. Miniaturization is possible in part because of the smaller passive components needed.

As evidence of the growing maturity of WBG materials, JEDEC—a global leader in developing open standards for the microelectronics industry—just formed a new committee: JC-70 “Wide Bandgap Power Electronic Conversion Semiconductors.” This team is helping to create the mature industry infrastructure that customers need to design power supplies. Led by interim chairs from Infineon, Texas Instruments, and Wolfspeed, the new JC-70 committee will initially have two subcommittees (yes, you guessed it): Gallium Nitride and Silicon Carbide. Both will focus on Reliability and Qualification Procedures, Datasheet Elements and Parameters, and Test and Characterization Methods. Let’s now look at recent developments in SiC and GaN one at a time.

GaN: Servo Motors, Laptop Adapters, Radar, PAs, and High-Speed Wireless

According to a new report from MarketsandMarkets, “Gallium Nitride Semiconductor Device Market—Global Forecast to 2023,” the GaN semiconductor device market is expected to reach $22.47 billion by 2023. It will chalk up a CAGR of 4.6% between 2017 and 2023. In 2016, optoelectronic devices held the largest market share. (GaN LEDs are widely used in laptops and notebooks, televisions, and signs). Yet the market for GaN-based inverters for motor drives is expected to grow significantly during the forecast period. Indeed, another market research firm, Yole Développement, is even more optimistic. While the power-supply segment will remain the biggest application for GaN, it suggests that the data-center market is adopting GaN solutions as well—driving a 114% CAGR for power supplies through to 2022.

The advantages of high-voltage GaN field-effect transistors (FETs) are best seen when used in power electronics systems including power supplies, servo motors, and photovoltaic inverters. Yaskawa Electric Corp.’sΣ-7 F is the first servo motor to use high-voltage (HV) GaN, in this case provided by Transphorm (and precipitated by a $15 million investment in Transphorm from Yaskawa Electric). The AEC-Q101-qualified, 650-V GaN semiconductors enabled Yaskawa to develop an integrated servo motor half the size of a similar design using Si technology. The key achievement here is that the Σ-7 F integrates the servo amplifier with the servo motor itself. According to Yaskawa, the topology will be deployed across its full Σ-7 F product line, which currently includes three servo motors ranging from 100 to 400 W.

By integrating the driver in the same package, as Texas Instruments has done with its TIDA-00915 reference design, it’s possible to reduce parasitic inductances and optimize switching performance. This approach reduces power loss, allowing the designer to downsize the heat sink. Such space savings are beneficial for compact servo drives and motor-integrated drives. Operating the inverter at a high switching frequency of 100 kHz reduces the current ripple, which improves torque ripple when used with low-inductance motors. The three-phase inverter design for driving 200-V AC servo motors (with 2 kWPEAK) is built around six of TI's LMG3410 600-V, 12-A GaN power modules. They allow switching up to five times faster than silicon FETs, while achieving efficiency levels said to be greater than 98% at 100 kHz and 99% at 24 kHz pulse width modulation (PWM).

Designed to help engineers evaluate USB power-delivery (PD) adapters and dongle solutions featuring power and data, Navitas Semiconductor has developed what is reportedly the smallest 65-W USB-PD laptop adapter. It minimized the size, weight, and cost of transformers, filters, and heatsinks through the use of AllGaN Power ICs. The part delivers 65 W in only 2.7 in.3 and weighs only 60 g.  By contrast, existing silicon-based designs can require 6 to 7 in.3 and weigh over 300 g. The new reference design uses its GaN power ICs in an active-clamp-flyback (ACF) topology running 3x to 4x faster and with 40% lower loss than typical adapter designs. The firm says that its AllGaN 650-V platform process design kit (PDK) monolithically integrates GaN power FETs with logic and analog circuits, enabling smaller, high-energy-efficiency and lower-cost power for mobile, consumer, enterprise, and new energy markets.

A promising approach to long-distance, high-capacity wireless communications is to utilize the 75 to 110 GHz W-band and increase output with a transmission power amplifier. Fujitsu has succeeded in developing a power amplifier for use in W-band transmissions that offers both high output power and high efficiency, improving transistor performance through the reduction of electrical current leakage and internal GaN high-electron-mobility-transistor (HEMT) resistance. The company has achieved 4.5 W per millimeter of gate width, which is said to be the world's highest output density in the W-band. In addition, it has confirmed a 26% reduction in energy consumption compared to conventional technology.

The latest GaN-on-SiC HEMTs from Cree’s Wolfspeed (Fig. 1) comprise a series of 28-V RF power devices that can operate to 8 GHz. The new devices were developed using Wolfspeed’s 0.25-µm GaN-on-SiC process. They are designed with the same package footprint as the previous-generation 0.4-µm devices, making it easy for RF design engineers to use them as drop-in replacements. The new GaN HEMTs are said to deliver 33% higher frequency operation to 8 GHz (from 6 GHz) as well as a 5% to 10% boost in operating efficiency compared to Wolfspeed’s earlier-generation devices. The higher efficiency and bandwidth capability make these devices well-suited for a range of RF power amplifier applications including military communications systems, radar equipment, electronic warfare (EW), and electronic countermeasures (ECMs).

1. Shown are the GaN HEMT MMIC semiconductor process components from Wolfspeed. On the subject of frequency bands per amplifier, the company’s literature says, and we kid you not, that it has “more bands than Woodstock.”

With the continuing development of GaN HEMTs, new topologies and control methods are challenging classic power-supply architectures. In soft switching applications, for instance, GaN HEMTs have the potential for very high switching frequencies. In contrast, silicon-based counterparts are limited to low and moderate switching frequencies. An example is satellite networks, which are used for high-speed communication during natural disasters and in areas where ground networks are difficult to construct. Currently, they are implemented mainly in the C-band (4 to 8 GHz) and Ku-band (12 to 18 GHz).

Higher frequencies are increasingly being explored, however. In response, Mitsubishi Electric has launched a Ka-band (26 to 40 GHz), 8-W GaN HEMT monolithic microwave integrated circuit (MMIC) amplifier for satellite earth stations (Fig. 2). Its new GaN-HEMT MMIC, which offers low distortion and an output power rating of 8 W, boasts a small footprint that will help to downsize power transmitters. Features include one-chip integration of amplifier transistor circuits, matching circuits, and a built-in distortion-reducing linearizer.

2. Solutions like the MGFG5H3001 Ka-band GaN-HEMT MMIC from Mitsubishi will help meet the growing demand for higher-frequency satellite deployments. The company began shipping samples in November.

SiC: Inverters, Server Power, and Photovoltaics

Today, SiC technology’s added value is widely understood and accepted by the power electronics community. Yole’s analysts peg CAGR at 28% through 2022 (Fig. 3). Part of the appeal of SiC comes from its physical properties. For example, where silicon has a breakdown electric field of 0.3 MV/cm, SiC can withstand up to 2.8 MV/cm. Its internal resistance is 100 times smaller than that of silicon. As a result, applications can handle the same level of current using a smaller chip and, in turn, smaller systems.

3. Yole Developpement analysts pull no punches. In 2016, they said the SiC power business was “concrete and real, with a promising outlook.” This year, they added,“The trend has not changed in 2017 and even more, the SiC industry is going further.”

Recently, Rohm developed an all-SiC, 1200-V, 600-A power module integrating SiC Schottky barrier diodes (SBDs) and MOSFETs. The module achieves a rated current of 600 A by utilizing a new package featuring a revised internal structure and optimized heat radiation design. In doing so, it enables support for higher-power applications. This half-bridge module is suitable for the following applications: motor drive, inverter, converter, photovoltaics, wind-power generation, and induction heating equipment. Compared to IGBTs, the SiC MOSFET offers much faster switching. At a chip temperature of 150°C, Rohm claims that the part offers a 64% reduction in switching losses (Fig. 4). A new package has a flatter baseplate that decreases contact resistance by 57% and inductance by 23% (compared to earlier products) by optimizing the placement of the SiC device inside the package. According to the company, the “G Type” package decreases switching loss by 24% under the same surge-voltage drive conditions.

4. According to Rohm, SiC power modules equipped with its SiC SBDs and MOSFETs make it possible to reduce switching loss by 64% (at a chip temperature of 150°C) vs. IGBTs at the same current rating. (Source: Rohm)

The Infineon 650-V G6, as the name implies, represents the sixth generation of the company’s CoolSiC Schottky diodes. These devices are built upon the characteristics of its G5 series, but feature a new layout, cell structure, and proprietary Schottky metal system. The G6 diodes are designed to complement Infineon’s 600-V and 650-V CoolMOS 7 families. Aimed at current and future applications in server and PC power, telecom power, and photovoltaic inverters, the CoolSiC 650-V G6 boasts an industry benchmark V F (1.25 V), and a Q c x V F figure of merit (FOM), which is 17% lower than the previous generation, according to Infineon. In addition, the new G6 diode leverages two of silicon carbide’s strong characteristics: temperature-independent switching behavior and no reverse recovery charge.

SiC Schottky diodes have approximately 40 times lower reverse leakage current than PN silicon Schottky diodes. Littelfuse, which got into the SiC game through its acquisition of Monolith Semiconductor, has come out with a new generation of 1200-V SiC Schottky diodes with current ratings from 5 to 40 A. With negligible reverse recovery, the LSIC2SD120 Series—the Monolith/Littelfuse partnership's first product introduction--reduces switching losses (compared to Si bipolar diodes) to boost system efficiency.  The switching behavior of the diodes is temperature-independent and the operating junction temperature is 175°C. These aspects enable a larger design margin and reduced thermal management requirements. Target applications are EV charging stations, solar inverters, and switch-mode power supplies.

Using its second-generation SiC MOSFET technology, STMicroelectronics has introduced a 650-V, 22-mΩ (typically at 150 °C) SiC power device. The main features of this product include low on-resistance per unit area and better switching performance. The variation of both RDS(on) and switching losses are said by ST to be almost independent from junction temperature. When employed in the EV/HEV main inverter, the company reports that the part increases efficiency by up to 3% compared with an equivalent IGBT solution. This translates into longer battery life and a lighter power unit. ST’s SiC MOSFETs also feature what the company claims is the industry’s highest junction-temperature rating of 200°C.  This leads to higher system efficiency, which reduces cooling requirements and PCB form factors, simplifying thermal management.

Gaining Momentum

Efficiency, power density, and the reduction of system cost are key drivers behind the use of the WBG materials SiC and GaN.  While some application areas tend to be early adopters for new technology (if benefits outweigh risks), many others are now following as these materials move into more mainstream applications. As additional suppliers enter the market, increased production will drive down costs. Those cost benefits—taken together with quality and reliability gains—will push the rapidly maturing SiC- and GaN-based topologies to the tipping point, even in cost-sensitive applications.

Gallium-nitride (GaN) is becoming increasingly attractive in power electronics because the low switching losses of GaN enable high-frequency operation, which reduces the size of passive components without adversely impacting efficiency.

By employing a vertical FinFET GaN transistor design—for higher-voltage, higher-current switches, a vertical structure is preferred since its die area does not depend on the breakdown voltage—researchers from MIT, Cardiff, IQE (a Wales-based wafer and substrate maker), IBM, Columbia University, and the Singapore-MIT Alliance for Research and Technology have reported on development of a switch that handles voltages up to 1,200 V.

What’s more, the researchers report that with further work their FinFET device holds the promise of boosting capacity to the 3,300 V to 5,000 V range needed to bring the efficiencies of GaN to power electronics in the electrical grid itself.

Even at 1,200 V, the GaN device already has enough capacity to be considered alongside silicon-carbide (SiC) in addressing the power conversion needs of electric vehicles (EVs), but the researchers, who presented their paper at the IEEE International Electron Devices Meeting (San Francisco, Dec. 4-6), emphasize that they have thus far only produced a first prototype manufactured in an academic lab.

The leading GaN device architecture today is the High Electron Mobility Transistor (HeMT), which is a lateral device, meaning the entire device is fabricated on the top surface of the gallium-nitride wafer. While the resultant semiconductor is good for low-power applications like laptop chargers, the current and voltage demands for high-power conversion applications makes the chip area in a lateral topology so large that it becomes difficult to manufacture.

Schematic of the proposed GaN vertical fin power FET and its starting epi-structure. (Source MIT Technology  Licensing Office)

Other drawbacks of lateral GaN FETs include (among other things): high leakage current; the larger dimensions and cost needed to yield higher voltage breakdown limits; non-uniform heat generation; the careful management of electric field profiles required in the lateral dimension between contacts (particularly in high voltage applications); the difficulties entailed in trying to make a normally-off device; reliability;  maximum current limited by wire routing; and the lack of avalanche breakdown properties.

According to MIT professor of electrical engineering and computer science Tomás Palacios, senior author of the new paper, vertical devices are much better in terms of how much voltage they can manage and how much current they control. In these devices the current, instead of flowing through the surface of the semiconductor, flows through the wafer and across the semiconductor. This provides more space for input and output wires, enabling higher current loads, higher voltages, and higher efficiencies.

With lateral devices, on the other hand, all the current flows through a very narrow slab of material where the gate’s electric field can exert an influence on it; this area may be only 50nm in thickness and close to the surface. All the heat is being generated in this very narrow region and it gets extremely hot. In a vertical device, the current flows through the entire wafer, so heat dissipation is much more uniform.

In the past, researchers had attempted to build vertical transistors by embedding physical barriers in the gallium nitride to direct current into a channel beneath the gate. The barriers, however, were built from a costly material that’s difficult to produce, and integrating it with the surrounding gallium nitride in a way that doesn’t disrupt the transistor’s electronic properties proved challenging.

Rather than using an internal barrier to route current into a small region of a larger device, Palacios and his team used a narrower device. Their vertical gallium nitride transistors have bladelike protrusions known as “fins.” On both sides of each fin are electrical contacts that together act as a gate. Current enters the transistor through another contact, on top of the fin, and exits through the bottom of the device. The narrowness of the fin ensures that the gate electrode will be able to switch the transistor on and off.

Palacio attributes the clever idea of changing the geometry of the transistor—and thus confining the current geometrically by removing material from those regions where they don’t want the current to flow—to first authors Yuhao Zhang, a post-doctorate researcher in Palacios’ lab, and Min Sun, who received his MIT Ph.D. in the Department of Electrical Engineering and Computer Science (EECS). Other members of the team include Jie Hu, a postdoc in Palacios’s group; Zhihong Liu of the Singapore-MIT Alliance for Research and Technology; Xiang Gao of IQE; and Columbia’s Ken Shepard.

The fabricated transistor demonstrated a threshold voltage of 1 V and a specific on resistance of 0.36 mΩcm². By proper electric field engineering, 800 V blocking voltage was achieved at a gate bias of 0V, the researchers reported.

The amount of electronic waste  – refrigerators, televisions, computers, smartphones, and other devices thrown out or recycled – produced worldwide increased to 49.3 million tons over the last year, up from 46.1 million tons in 2014, according to a new report from the United Nations.

But only around a fifth of that digital debris was collected and the precious metals inside recovered through formal recycling programs, even though that percentage increased from 15.5% in 2014. The rest falls through cracks in the rules and regulations meant to stem – and document – the flow of harmful e-waste across the globe.

The fate of around 76% of the world’s e-waste is unknown, according to The Global E-Waste Monitor. The report is the result of a partnership between the U.N., the International Telecommunications Union and the International Solid Waste Association on charting global levels of e-waste, which the report classifies as anything with a battery or cord.

The e-waste unaccounted for could be shipped out to other countries, where it collects in vast junkyards like Agbogbloshie, Ghana, and Guiyu, China, an infamous dumping ground where conditions have allegedly improved after an international outcry. The workers in these cities pour acid over electronics to extract precious metals like gold, cook circuit boards to liberate chips, and melt plastic packaging, causing severe health risks and environmental harm.

The largely self-employed recyclers compete to wring out the gold, silver, copper, platinum, palladium, and other valuable materials used in devices. The United Nations estimated that all the raw materials left inside e-waste would have been worth around $55 billion had they been recovered, or around $1,100 for every ton of e-waste.

The last 4% of e-waste is thrown out in higher-income countries with the trash, which will be incinerated or buried in landfills, allowing toxins to leech into the air, water and ground. That percentage is up from around 1.7% of all e-waste in 2014.

The problem of electronic waste is not going away any time soon. As more of the population connects to the internet and incomes growing worldwide, companies constantly churn out devices, particularly smartphones, which companies like Apple and Samsung redesign with faster processors and new features almost every year.

The report predicts that 57.5 million tons of used electronics will be thrown out globally in 2021.

Furthermore, companies have been less than enthusiastic about giving customers the right to repair broken electronics. While Apple has been praised for flushing out conflict minerals from its supply chain, it has faced criticism for making its phones and other products extremely hard to fix, unlike Dell and Hewlett Packard, which go so far as selling replacement parts.

The shadowy fate of e-waste is particularly evident in the United States, which has not passed federal rules regulating the recycling of personal computers and other devices, even though it goes through so many of them. Last year, it generated 6.95 million tons of e-waste, but the United Nations report estimates that only 1.5 million tons were collected.

“The whereabouts of the remainder of the e-waste is largely unknown in the U.S., which reflects a larger lack of data about the global flow of e-waste,” the report said. It is legal to export almost all electronic waste in the United States to developing countries because of federal exemptions to laws that classify circuit boards and other electronics as hazardous waste.

The United Nations report is not all negative, though. Today, two-thirds of the world’s population is covered by e-waste management laws, up from 44% of the global population in 2014. Importantly, India, the world’s fifth largest producer of electronic waste, passed new rules last year for recycling the analog and digital detritus.

On the other hand, there is insufficient data to track the amount of used electronics shipped from richer to poor countries, the report said. In addition, the report cautioned that countries that have enacted national electronic waste laws do not always enforce them, and many lack the resources required to collect data or set realistic recycling targets.

“We live in a time of transition to a more digital world, where automation, sensors and artificial intelligence are transforming industry and society,” said Antonis Mavropoulos, president of the International Solid Waste Association, in a statement. “E-waste is the most emblematic by-product of this transition."

Designing medical devices is a complicated task, largely because of all of the standards that have to be met. To a design engineer it may seem as if the products need as much certification as the physicians who will use them. But there is logic behind all the paperwork: Someone’s life may depend on a steady power supply to a critical medical device.

The good news is that—design difficulty and serpentine approval process notwithstanding—clever engineers at CUI, RECOM, and Powerbox have recently come up with new supplies that meet the latest IEC 60601-1 standards for medical applications.

To better understand what’s involved, let’s take a moment to review the relevant standards and how they are applied. We’ll start with the umbrella standard IEC 60601-1. It provides general requirements that address the basic safety and effectiveness of medical electrical equipment. And it has undergone substantial revision since being first published in 1977.

For example, the second edition of IEC 60601-1 (1988) established risk guidelines in the “patient vicinity” that applied when a device was within a 6-ft. radius from the patient. Three use categories of increasing severity were defined:

• Type B (body) equipment operates within this vicinity, but without patient
• contact. Examples include x-ray machines, hospital beds, and MRI scanners.
• Type BF (body floating) equipment makes physical contact with the patient. Examples include thermometers, blood pressure monitors, and ultrasound equipment.
• Type CF (cardiac floating) equipment makes physical contact with the heart (e.g., defibrillators).

The 3rd Edition of IEC 60601-1, released in 2005, included a greater emphasis on risk management. It extended the patient focus to require an overall means of protection (MOP) that combines one or more “means of operator protection” (MOOP) and “means of patient protection” (MOPP). IEC 60601-1 (Edition 3.1) serves to ensure that no single electrical, mechanical, or functional failure poses an unacceptable risk to patients and/or operators.

The United States and Canada currently require compliance with Edition 3.1. At the same time, however, the FDA has already accepted the 4^th edition (2014) in the U.S. This includes EMC standards, and prefers products to be tested to 4^th edition standards.

The power products we will discuss all meet these standards. Here, then, are the specifics:

CUI’s Power Group has introduced five new open-frame series to its line of internal ac-dc medical power supplies. Ranging from 180 W up to 550 W and certified to the medical 60601-1 edition 3.1 safety standards for 2 × MOPP applications and 4^th edition EMC requirements, the VMS-180, VMS-225, VMS-275, VMS-350, and VMS-550 series feature efficiency up to 94% and power densities up to 30 W/in³. The new models are housed in 2 × 4 in. (50 × 101 mm) and 3 × 5 in. (76 × 127 mm) packages, with profiles measuring as low as 0.75 in. (19 mm).

CUI’s medical ac-dc power supplies range from 180 W to 550 W, featuring efficiency up to 94% and power density up to 30 W/in³.

A compact, high-density solution for medical diagnostic equipment, monitoring devices, and dental application, the new VMS series provides output voltage options from 12 to 58 V dc, have universal input voltage ranges from 80 to 264 V ac, and boast no-load power consumption as low as 0.5 W. The new models also carry an input-to-output isolation of 4,200 V ac, with leakage current ratings as low as 0.3 mA at 230 V ac. Operating temperatures range at full load from −40°C  up to +50°C with forced air cooling, derating to 50% load at +70°C. Additional features include protections for over-voltage, over-current, and short circuit; power factor correction; and a 12 V dc/500 mA fan output.

Developed for medical PCB designs, RECOM’s RACM18 and RACM30 (18W and 30W, respectively) ac-dc converters are certified to the latest 60601 medical standards, as well as the EN60335 household and the IEC/EN60950 ITE standards.

RECOM’s RACM8 and RACM30 take up less than 2 × 2 in. on the PCB, and their round shape allows them to be fitted into flush mount wall installations.

IP68 waterproof encapsulation enables the modules to withstand harsh operating conditions allowing for versatile uses in medical, household and industrial applications. The modules take up less than 2-in.x 2-in. on the PCB and their round shape also allows them to be fitted into flush mount wall installations. With a certified operation up to 5000m altitude (the altitude rating is important as countries in South America as well as China are bringing healthcare to mountainous region-based populations) and temperature ranges from -20°C up to +80°C, these modules are built to power compact applications in medical healthcare, household, smart building and automation appliances.

Powerbox has launched a new series of power supplies for medical applications requiring BF (Body Floating) class insulation and full operation up to 5,000 meters altitude to power medical healthcare facilities and equipment. The OBR04 series of 600-650 W (with a peak power level of up to 720 W) single-output ac-dc Medical SMPSs comply with the latest EMI coexistence standard IEC 60601-1-2:2014 (4th edition), and are available in 12 different voltages from 12 V to 58 V with an efficiency rating up to 91%.

The power supply is designed for global operation with an input frequency range of 47 to 63 Hz. The input current at 115 V ac and 60 Hz is 8.4 A (RMS), and 4.2 A (RMS) at 230 V ac, 50 Hz.

The Powerbox VMS-180 series is a 180 W high-density, open-frame, ac-dc power supply certified to the medical 60601-1 (edition 3.1) safety standard.

Input-to-output isolation is 4,000 V ac (2× MOPP), input to ground is 1,500 V ac (1×MOPP) and output-to-ground is 1,500 V ac; Powerbox points out that conventional products frequently offer only 500 V dc isolation. All products are available in single, dual, triple, or quad outputs.

Housed in an aluminum chassis, dimensions are 165.8 mm × 101.6 mm × 62.5 mm (6.53 × 4.0 × 1.95-in.) and the series is available in a “U” shape chassis or an enclosed box with built-in fan. The power supply can be safely operated within a temperature range of −10°C to +70 °C and can be stored at −40°C up to +85°C.

Back in 1989, engineer Reginald Neale wrote Bob Pease a letter complimenting him on his troubleshooting book. He agreed with Pease’s observation that modern test equipment has complicated menu structures. Neale then recommended Pease read the book "The Psychology of Everyday Things" by Don Norman.

A few months later in 1990, Pease replied in a handwritten letter:

“Okay, Reginald, I went out and bought the book, ‘The Psychology of Everyday Things’. Read it. Enjoyed it. I was confused because at the top of page 170 he thinks there’s confusion about those one-lever faucets. I think they are neat and natural. I can’t imagine how he or anybody else might be confused.

“I got another book in December, Systemantics, by John Gall. The plane running out of oil on pages 44 and 45 of Norman’s book is a perfect example. I’d love to tell there’s a lot more good stuff in Systemantics, but I think John Carroll excerpted about 40% of the better items. Still, about worth buying. I was disappointed that neither Norman nor Gall mentions the problems and solutions from the railroads of the 1890s. For example, a guy pulls a switch lever. He thinks the rail switch is thrown so the oncoming train won’t go into the siding full of cars of dynamite. But the cable broke and it didn’t move, crash. The solution was to set up a repeater. If you pull the lever and the tell-tale moves, you know the switch did move. It’s kinda fail-safe.

“Another example, the engineers kept screwing down the adjustments on the safety valve to get a little more steam pressure. Keep it up, and ‘boom.’ The solution was to set up two or three safety valves having two or three different designs. Put them inside and under a dome, so they are not accessible or adjustable. Another problem was a train going over a switch, and as soon as it’s through, the guy throws the switch to send the next train on the other route. But the guy blinks and throws the switch too early. The first train gets ripped apart. The solution was a sort of treadle to lock out the switch from being thrown until there is nothing on it.

“I mean, people figured out this kind of interlock 100 years ago. Now, at 3-mile Island, there was one valve closed that was required to be open, and its closure was largely responsible for the inability to understand and control the mess. They should have had an interlock, a repeater, on that kind of important valve. Neither author mentioned that. When systems get big and important, ya gotta plan ahead, and not just fix the accident after the crash. I mean, 70 years ago, the best way to fix airplane design was to wait for crashes and then make improvements. These days, it’s too expensive to be so dumb. PS: Neither author mentioned the special system for making sure parachute riggers do a perfect job.”

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Back in 1989, engineer Reginald Neale wrote Bob Pease a letter complimenting him on his troubleshooting book. He agreed with Pease’s observation that modern test equipment has complicated menu structures. Neale then recommended Pease read the book "The Psychology of Everyday Things" by Don Norman.

A few months later in 1990, Pease replied in a handwritten letter:

“Okay, Reginald, I went out and bought the book, ‘The Psychology of Everyday Things’. Read it. Enjoyed it. I was confused because at the top of page 170 he thinks there’s confusion about those one-lever faucets. I think they are neat and natural. I can’t imagine how he or anybody else might be confused.

“I got another book in December, Systemantics, by John Gall. The plane running out of oil on pages 44 and 45 of Norman’s book is a perfect example. I’d love to tell there’s a lot more good stuff in Systemantics, but I think John Carroll excerpted about 40% of the better items. Still, about worth buying. I was disappointed that neither Norman nor Gall mentions the problems and solutions from the railroads of the 1890s. For example, a guy pulls a switch lever. He thinks the rail switch is thrown so the oncoming train won’t go into the siding full of cars of dynamite. But the cable broke and it didn’t move, crash. The solution was to set up a repeater. If you pull the lever and the tell-tale moves, you know the switch did move. It’s kinda fail-safe.

“Another example, the engineers kept screwing down the adjustments on the safety valve to get a little more steam pressure. Keep it up, and ‘boom.’ The solution was to set up two or three safety valves having two or three different designs. Put them inside and under a dome, so they are not accessible or adjustable. Another problem was a train going over a switch, and as soon as it’s through, the guy throws the switch to send the next train on the other route. But the guy blinks and throws the switch too early. The first train gets ripped apart. The solution was a sort of treadle to lock out the switch from being thrown until there is nothing on it.

“I mean, people figured out this kind of interlock 100 years ago. Now, at 3-mile Island, there was one valve closed that was required to be open, and its closure was largely responsible for the inability to understand and control the mess. They should have had an interlock, a repeater, on that kind of important valve. Neither author mentioned that. When systems get big and important, ya gotta plan ahead, and not just fix the accident after the crash. I mean, 70 years ago, the best way to fix airplane design was to wait for crashes and then make improvements. These days, it’s too expensive to be so dumb. PS: Neither author mentioned the special system for making sure parachute riggers do a perfect job.”

Puzzling Products

I completely agree with Pease and Neale. Many modern products are more of a puzzle than a useful appliance. Pease responded to the puzzle of computers by throwing one off the roof. Companies hire stylists and engineers, but no usability people.

1. The Schwinn Airdyne exercise bike has a control panel mounted between two swinging handlebars. The panel is hard to read and hard to understand.

I go to the local gym, and use a Schwinn exercise bike (Fig. 1). It is a complete abomination. Schwinn put the control panel between the two handlebars that swing back-and-forth while you pedal. If you need to press any buttons or change any settings, the metal arms are so close to each other that they beat your forearms away before you can touch the panel. Just as bad, the panel has minuscule printing. Pro-tip to exercise equipment designers: People don’t wear reading glasses when they exercise.

After three months, I managed to figure out you hit the lower center button to turn the dang thing on. Then you go to the button under the top display and press it so that it displays “level,” which is a little less arbitrary than “RPM.” Then you go to the button under the lower display and press that button until it shows time, not distance, which is completely arbitrary as far as I am concerned.

Not done yet, often the time is set to some non-zero value. So you use the far-left bottom button to zero out the time. Wait, wait… now you have to press the button to the right of it so that the timer starts to count up. The buttons are those cheap, carbon printed-circuit-board (PCB) types and some don’t work anymore. I never did understand what the two right-most buttons were until I took a picture, where I could blow it up and see those are “up” and “down.” There may have been paint on the embossed names once, but it has been worn off long ago.

2. The older Schwinn Airdyne exercise bike had a simple mechanical speedometer and odometer. (Courtesy of terapeak.com)

The really sad thing is the older versions of the Airdyne control box looks much more passive and far more understandable (Fig. 2). It had a mechanical speedometer with a mechanical odometer. I get that. I grew up seeing that in every car in the neighborhood. The LCD display is probably some type of time readout. The real horror is when I look at newer Airdyne models (Fig. 3). That control box looks like you are launching an Atlas rocket, not pedaling to go nowhere. What I really want is one of those mechanical egg timers (Fig. 4). Mount it nice and high so I can set it to five or ten minutes even when I’m pedaling. It will ding when I’m done.

3. The latest Schwinn Airdyne exercise bike has a control panel that is absurdly complicated. Like the older model at my gym, the panel is mounted between the swinging handlebars so you can’t touch it while you are pedaling. (Courtesy thefitnesssuperstore.com)

4. The Lux kitchen timer. I wish Schwinn would mount this on its Airdyne exercise bikes rather than some complex electronic control panel. (Courtesy Amazon.com)

Then there is the batch of Sharpie pens I bought (Fig. 5). They have a narrow tip on one end and a bold tip on the other. Sharpie calls it the Twin Tip, and sells them to this day. Problem is that when you go to put the bigger cap over the other end as you use the bold side, it wedges the little cap inside of it. If you have a dental tool handy, you can pry the little cap out. I have decided to lower my blood pressure by throwing my whole batch of Twin Tips into the garbage.

5. When you put the bigger cap on the back of a Sharpie Twin Tip marker, it wedges the smaller cap inside it.

I can’t believe the intelligent and successful people at Sharpie sat around a conference table and did not see that this marker has a serious design flaw. Just make the smaller cap a few millimeters less in diameter and the big cap won’t captivate it anymore. I guess those expensive injection-molding tools were already made and they dare not scrap them. Finance types have no forgiveness when it comes to their precious, precious money.

Pathetic Products

So many products are shabby or deficient these days. I think this has to do with the buyers at the retail companies. Decades ago, you could tell the products in the Sears catalog were decided on by people pretty much like you and me. They actually used the air compressors and garden tools and clothes, and they picked the best ones for the catalog. Now the buyers are just lowly peons in the eyes of the finance idiots that run companies. I don’t know who the buyers are, but they are not middle-class working people choosing things for other middle-class working people. If some Chinese knock-off is cheaper, then that’s what they buy. Keeping the finance clowns happy is more important than keeping customers happy.

6. The Arris DOCSIS modem has nine blue LEDs on the side. Some have completely cryptic labels.

My internet service is provisioned with an Arris DOCSIS modem (Fig. 6). The edge is peppered with little blue LEDs. They have jargon-cryptic labels like “MoCA” and “US/DS.” The labels are too small to read easily. It gives a little flashing light show as it hooks to the internet. The top has a mysterious button labeled “WPS.” There is an LED labeled “Power.” What is not clear is that the box has a battery. When the power light flashes, it means I accidentally flipped the wall switch and the box has lost ac power. It will work about a day, and then die. Cable company support misery ensues.

An SLJSoHID Approach

I would like to propose we start the Samuel L. Jackson School of Human Interface Design, or the SLJSoHID. Note that neither Mr. Jackson or his cadre of high-powered Hollywood lawyers knows or approves of this. Let’s hope his sense of humor exceeds his sense of brand protection. Samuel L. Jackson is known for playing characters who tell it like it is. He is a straight, if somewhat profane, talker.

The Arris DOCSIS modem designed at the SLJSoHID would have just one light and no power switch. When you plugged it in, that light would say “This %*&^ thing is plugged in.” It would say that in big, clear, high-contrast type that I could read across the room. When it’s doing all of its DHCP negotiations, I don’t want to see cryptic little blue lights flashing. I want the big lighted panel that said it was plugged in to now say, “This *~^%$ thing is warming up.” Yes, it’s like we have regressed to the vacuum tube age, as if electrical appliances have to heat up the filaments before they can work.

When the modem finally does actually hook me to the internet, I want that big lighted panel to now read, “This *&^%$ thing is working.” Spare me the jargon, spare me the gibberish. Just tell me if it’s working. For now I get that from the Ooma VoIP (voice over internet protocol) telephone box I plug into the modem. It has a big backlit daisy logo. When it flashes red, the internet is dead. When it turns blue, it’s connected.

7. The Ooma VoIP phone box has no explanatory text on it. The “buttons” are just touchpads that will go off if your hand gets even close to them. Apologies for the dust, but it’s impossible to clean unless you turn it off.

That Ooma VoIP phone box has another exasperating user interface (Fig. 7). Like modern hip and edgy designs, nothing is clearly written to tell you how to use it. Worse yet, it has hair-trigger touch buttons, so if you even brush near them, the phone goes off into some obscure function or mode. I routinely erase messages accidentally. I have yet to figure out some of the buttons, since I’m so terrified of turning the whole thing into a brick. It’s so touchy, it seems more like a training device for a bomb-disposal unit.

Hellish Handhelds

Speaking of bomb-disposal training devices, there are all of these handheld devices with buttons paving the sides. Designers must not realize that we all pick things up by the sides. My cheap flip phone has buttons at the lower part of its sides. My Nook tablet has buttons toward the upper part of its sides. Please, please put buttons in the top and bottom edge or the front, where we don’t grab to pick the dang thing up. I have yet to use my phone where I don’t somehow change the ring tone or vibrate mode, or change the volume.

That brings to mind an old Motorola phone I had. It blessedly used a standard USB connector. Then the engineers made it whereby the charger needed a resistor in the USB circuit, so you had to buy a Motorola charger. Modern industrial designers are all sadists or rent-seeking opportunists. Frank Zappa had an appropriate saying, "If there is a Hell, it waits for them."

Some usability issues are courtesy of the sociopath-in-chief, Steve Jobs. He pioneered the thinking that our products have to be so sleek and stupid they are impossible to understand. I also blame him for the widespread adoption of tiny dark gray text on black backgrounds for the few labels our products do have. Please universe, we are all aging. Please put some contrast in the labels as well as making displays that we can read without a magnifying glass. I hate having to take food packages to my 5-diopter reading lamp to read ingredients, nutrition info, or cooking instructions.

User-Unfriendly Interface

I don’t have to do any thinking or deep research to find miserable user interfaces. All I have to do is glance around the room. I have two 70-in. Sharp TVs. The remotes are obviously identical electrically. However, some sadistic genius has decided to take plain, simple English words off the newer remote (Fig. 8).

8. My older Sharp TV remote (left) has English labels like “2D/3D, MENU, Smart Central, ENTER, EXIT, and RETURN.”  I defy anyone to understand the icons Sharp uses on the new remote (right). At least the Netflix button is more readable on the new remote.

When I worked at Ford Motor in the 1980s, we were forced into this kind of misery. The government had decided that we could only use icons to label heater controls, light switches, and other knobs. Ford argued that a word is a very handy icon, but the government refused. We tried to get permission to print the word under the mandated icon. The regulators denied that. Maybe by now everyone knows what the silly squiggly lines mean, but I would still prefer “Heat,” “Defrost,” and “De-Ice” than goofy little cartoons.

The Sharp TVs have their own menu exasperation. When I had a Samsung 46-in. TV in California, the optical-out audio jack would play 5.1 surround into my home-theater speaker system. In Florida, I have the exact same Denon receiver hooked to the exact same speakers. I could not get surround sound for a year.

The Denon manual is overly complicated and unclear to begin with. Even the hardware is goofy. The rear speakers might connect to the “Surround” jacks, or perhaps they are supposed to plug into the “Surr. Back/Amp Assign” jacks. It was the fact that I was not even getting the Dolby light on the receiver that tipped me off the TVs were not sending 5.1 over the optical-out cable. This was especially infuriating since the channel information overlay on the TV would say “5.1CH Dolby D.”

I plowed through the menus on the 4K TV and under the “audio” sub-menu found a setting titled “Surround.” When that didn’t work, I realized Sharp decided it was what they would name a pointless feature that simulates surround. They probably do phasing tricks on the built-in speakers to fake surround sound.

I use the older Sharp as a VGA computer monitor. I hooked it to a TV antenna so I could troubleshoot the surround sound while digging through its menu system. Its menus were cruder, but better-organized. Only then did I see that there was a “Devices” sub-menu. You had to go to the “Audio Out” sub-sub menu and then select “Optical,” which then let me choose between “PCM” and “Bitstream.” A tour through Google showed PCM tends to be a stereo standard, so I changed it to Bitstream. It only took me a year to figure this out.

The 4K TV had the same concept. I never noticed the “Devices” sub-menu since the new Sharp does not launch you into the top-level menu, but one level down in the “TV Setup” menu. Whoever designed this menu system must worship Satan. He must be trying to punish the world for teasing him in junior high school. Dear TV engineers, send 5.1 out the optical jack by default. People with optical input home-theater receivers do not want stereo. Also, please make setting up the TV part of the “TV setup” menu.

9. For a product that you use from 10 feet away, home-theater receivers have stupidly small displays. In addition, they display cryptic abbreviations and codes. The indicator labels were too tiny to read even up close. I solved this with masking-tape labels I can read from across the room. The old Sony stereo is the sub-woofer amplifier. At least its display is readable from across the room. Note the Alpha Five clock from Evil Mad Scientist. I can read that from across the house.

That Denon AVR-1609 receiver has its own exasperation. Like many other receivers, it’s huge. It measures over 6 by 17 in., yet the vacuum-florescent display text that tells you what the thing is doing is less than a quarter of an inch tall. Worse yet, the labels for some of the buttons are so minuscule I had to use a magnifying glass to read them. I solved that issue by putting masking tape on the panel. I wrote labels on the tape with the same Sharpie that so infuriated me earlier (Fig. 9). All of this was part of the chain of dependencies in troubleshooting why I didn’t have surround sound.

Image Unconscious

Years ago, I saw a Craigslist ad for a DSLR camera. The listing said “Brand new, too complicated to use.” I bought a cheap Dimage camera because it turns on with an actual switch, not a pushbutton. You slide the lens cover and it turns on. I adored this after my first experience with a little digital box camera in 2000. I pressed the “Power” button and nothing happened. Fortunately my young protégé Francis Lau was nearby. Being younger and hipper to the ways of user interface evil, he showed me that you had to hold down the power button for about a half-second before it would turn on. Of course, if you held it down for too long, it would turn on, see that you were pressing the power button, and then turn off.

While the Dimage slide on-off switch is great, the menu system on the Dimage is laughable. The default selections are almost all wrong. One default is to turn the camera off after a minute. Another default is to reset any setting you may have laboriously set when it does turn off. My fancy 4K Panasonic GH4 has a gigantic menu system and assignable pushbuttons peppering the back. It’s beyond bad and gets to the point of absurdity.

From the Sublime to the Refrigerator

I bought a Roundup-brand sprayer (Fig. 10). It drives me nuts. The plastic plunger is cheap and flimsy. There is no pressure-release valve. The sprayer valve is horrific. It takes about a second to turn off. You have to be sure the chemical spray has stopped or you accidentally kill large swathes of grass. If you are not careful, it locks, so it never turns off.

10. This Roundup-brand sprayer has a flimsy pump that makes an awful squeak when you use it. The spray valve sticks so it takes a second to stop spraying. There is no pressure-release for when you want to store it or add chemicals. If you lock the handle 180 degrees off, the wand holder interferes with the hose outlet.

When I went to buy more Roundup chemical, a helpful store employee noted that HDX Weed and Grass Killer was half the price, and you use half the amount to make a gallon of spray chemical. I promptly bought it. It was not so much to save money, but to punish the otherwise fine folks at Monsanto for selling that junk sprayer.

Meanwhile, my 2300-dollar Samsung refrigerator has Wi-Fi so I can spend a couple hours setting it up to communicate with a smart electric meter. This might save 20 cents of electricity a month. I don’t want to turn off my refrigerator at peak usage times. Food safety is more important to me than saving less than three bucks a year. If Samsung has to go high tech, they should put in a barometric pressure sensor so that you can set the refrigerator temperature to 0.2°C above freezing, no matter the altitude or weather.

Many of my pals collect old test equipment, ham gear, and consumer electronics. The old stuff just has a more intuitive user interface, augmented by clear labels. I have an old Sharp microwave from the 1970s that has a mechanical timer dial and a start button. When you open the door, it turns off. It’s blessedly analog and blessedly simple.

Software usability is atrocious, but I recently downloaded FreeCommander to use instead of Windows Explorer. I did this after noting that Windows Explorer would just close by itself. It turns out that if I left it pointed to a USB device that shuts off, like that Dimage camera, Windows Explorer just goes “poof.” FreeCommander just hops up a level. I love it. Things can be intuitive and usable even in this day and age.

Since the Baby Boom has aged, maybe we can look forward to products with clear and simple interfaces. Let’s hope designers learn we are longing for big print with sharp contrast. We want switches, not pushbuttons that might turn the gizmo on, or might turn it off. At the least, use two push-buttons, one for on and one for off, like Denon does on its remote. Maybe if we all rise up and complain, the billion-dollar multinational product companies will fire the stylists and interior decorators and hire some usage architects. Then we won’t need to read 60-page manuals every day to remind us how to operate our household appliances.