Current consumption in VBAT mode

[Vel]

Hi,

I am using STM32H753 controller in my design, I am measuring the current consumption in vbat mode with the battery and found it to be around 1uA. The RTC Configuration was RTC_Alarm_A enabled.

But disable the Alarm_A in the RTC configuration, the current value is pulsating from 4 uA to 25uA.

Herewith I have attached the main.c file for your reference and the measured current value. I don't understand why the current value is pulsating. Please help me with it.

Thanks,

[waclawek.jan]

Is this a "known good" board such as EVAL or NUCLEO, or your own? If the latter, how are exactly wired up the power/ground pins (including VDDA/VSSA) and the LSE oscillator; and did you verify that there are not bad solder joints and/or shorts around them? Does the RTC run normally, i.e. do you see normal time? While you measure the VBAT current, are all other VDD (including VDDA) pins at 0V? Do you have BOR set up?

JW

[Vel]

It's own board. connected ammeter in VBAT .Assembly wise there are no issues.

Yes the RTC runs normally with exact time.

VDD,VDDA are in 0V.

We connected supervisory ic for VDD supply for a proper reset.

Thanks

[waclawek.jan]

I'm out of ideas at this point, except that you could perhaps try the same code on a Nucleo, if you have one at hand.

JW