We mounted a TRF7962A on a PCB with a ABM3C-13.560MHZ-D4Y-T crystal. The TRF always output a stable 13MHz waveform on OSC_OUT. Sometimes SYS_CLK started immediately, sometimes it took several seconds, and sometimes it never started. We verified that the TRF always had power, gnd and EN directly on the pins.
We thought the problem might be the oscillator so we switched to a 13.56MHz 3V CMOS oscillator. It outputs the correct waveform but now SYS_CLK never comes up at all.
The datasheet says that Pin 31 (OSC_IN) is a "crystal or oscillator input". Is there some issue with connecting a CMOS osc to Pin 31? Has anyone else had these extensive clocking problems?
Thanks