I plan to use i.MX6ULL and PF3000 and want to confirm that I need to add a protection circuit between VSNVS and VDD_SNVS_IN.
We connects to VSNVS and VDD_SNVS_IN.
Furthermore, coin batteries may not be installed in some cases, and the VIN power to be supplied to the PF3000 is not a battery but an AC adapter, so there are situations where the power supply at the base can be suddenly cut off.
Here is the description in the Hardware Development Guide.
When VDD_HIGH_IN > VDD_SNVS_IN
VDD_HIGH_IN supplies all SNVS domain current and current flows into VDD_SNVS_IN to charge a coin cell battery.
From the above description, I think that user need to have a protection circuit for backflow prevention.
Am I correct ?