Hello Experts,
I am using the STM32L476QEI6 in one of my projects. The system VDD is 3.3V, and VBAT is supplied by a 1.55V coin cell battery (Murata SR621SW).
The tamper pin (PC13) is connected to an anti-tamper switch normally closed (NC) — meaning the switch is open only when the box is closed. I’ve configured the tamper detection in level detection mode, using:
Sampling frequency: 1 Hz
Precharge duration: 8 cycles
External capacitor: 2.2 nF (C0G)
Tamper is triggered on low level
What I’m concerned about is the behavior on
RTC when VDD is shut down — for example, due to a power failure or brownout. Let's say I’ve configured the BOR level 4,
So, when the RTC switches from VDD to VBAT (1.55V), is there a risk of a false tamper detection being triggered due to the voltage transition?
Best regards,
ZHIYAR TAHIR
