SWRZ098 April 2021 AWR6443
LVDS Coupling to Clock System
AWR6443 ES2.0
The digital activity in the High-Speed Serial Interfaces (HSI) state machine can couple to the clock system/FMCW synthesizer and can cause spurs in its clock output. The spur frequency is HSI rate dependent (for example, for a 600-MHz HSI clock rate, 6.25-MHz and 12.5-MHz spurs can be observed on TX/RX output, and for a 900-MHz HSI clock rate, 7-MHz and 14-MHz spurs can be observed on the TX/RX output). The spur levels are low (near or below -65 dBc).
The spur will not be present, when the LVDS is not used.