STM32H7: Excessive VBAT consumption

[AndreaTW]

Hello everyone

In my application using an STM32H7, I noticed that the VBAT pin, with VDD off, draws 1.9 mA. This is excessive current draw.
I'm using a CR2032 battery in series with a 100R battery connected to the microcontroller's VBAT pin.
What could be the cause?
Is there any way to understand why it's drawing so much current?
NB: The datasheet states that the RTC draws 225 nA at 1.2 V, including the LSE's power consumption.

Thanks

[KDJEM.1]

Hello @AndreaTW ;

Could you please precise which STM32H7 you are using?

Could you please share your code?

Thank you.

Kaouthar

[Danish1 · Accepted solution]

Some stm32 have a few (very few) gpio pins in the VBat domain - see the data sheet and reference manual for your stm32 to check which apply to your stm32.

If you have one such pin set as GPIO output high then it will continue as logic high output when Vdd is removed, drawing current from VBat.

[AndreaTW]

Thank you all.
Your answers helped me.
I checked and found a pin on my ST32H7 that stayed high when the VDD was off.
So, as a result (as you indicated), the VBAT pin was drawing more current.
Thank you so much.