Introduction
TI’s LMK05318 device is an ultra-high performance clock generator, jitter cleaner, and clock synchronizer with advanced reference clock selection and hitless switching feature to meet the stringent requirements of telecom and industrial applications. The device features a single channel synchronizer or digital PLL (DPLL) that can synchronize to one of two differential or single-ended reference clock inputs. The synchronizer is accompanied by an analog PLL (APLL) domain that features TI’s proprietary Bulk Acoustic Wave (BAW) resonator as a VCO and generates 50-fs, rms jitter. There is an additional APLL domain that can be used to generate unrelated frequencies either locked to the reference clock input or the free-run XO input and generates 120-fs, rms jitter. The LMK05318 can generate up to eight high performance output clocks with up to six different frequencies. Apart from usage as a clock synchronizer in telecom applications, the LMK05318 can also be used a jitter cleaner in any application where single or multiple frequencies with low jitter needs to be generated from a dirty system clock. Utilizing the ability to set low loop bandwidth either on the DPLL or the APLL with BAW VCO, the LMK05318 offers the ability to clean reference clock jitter while simplifying the overall PCB design by relying on standard off-the-shelf inexpensive components around the device.