STM32WLE5 high current consumption in Stop2 (RAK3172-SIP)

[YDOVG.11]

Hello

I am trying to implement low power mode with STM32WLE5 MCU (as a part of RAK3172-SIP).

However, the current consumption is unreasonably high.

I measure around 200uA with 3.6V and around 150uA with 3.3V.

Did many tests with different configurations, checked the RF switches. I use TXCO, but even if I run with internal clock - no changes. Debug mode is disabled.

How can I debug it further?

I even tried to go into Stop2 mode directly before HAL_Init() - still the same 200uA (at 3.6V) consumption. So even before all periphery is initialized I cannot get the lower consumption.

I did similar test with Wio-e5 module just to check that the HW is not an issue, and there I 've got around 300uA (at 3.6V). So I have no questions to HW.

Regarding the HW, there I have one 100k resistor to BOOT0 to GND and one 100k pullup to nRST. The rest is caps and inductors for supply lines, nothing else is connected to the module.

I was thinking this is because of SMPS - but I checked that it is not running in Stop2.

Please guide me how to debug this.

[YDOVG.11]

Well.... I found the reason why the consumption was too high.

The simple answer RTC.

If you configure date/time, alarm and timestamp in MX_RTC_Init then the consumption will be on those 200uA.

Seems like one should not initiate alarms or date.

Now I am around 1.5uA.