Hello,
I have a PCB with just an SWD connector and an STM32L053R8T6 populated.
I'm running example code to measure standby and stop currents. For standby, I'm reading 0.5 uA, which is within the limits given in the datasheet.
I am not getting the expected results in STOP mode: the current is ~14 uA instead of the expected <1 uA.
The code I am using is from PWR/PWR_STOP/Src/main.c (attached), where it just enters STOP mode after a 2s delay. I have not configured any wake up sources.
The current measurements are shown below. One thing to notice is that some peripheral seems to be waking up every 2 minutes. I ruled out the system tick and the watchdog. The debugger is not attached to the connector when collecting these measurements.
Below are the same measurements taken after changing the code as:
- HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFE);
+ HAL_PWR_EnterSTANDBYMode();
In standby mode the average current drops to 0.42 uA and there are no periodic wake ups.
I have looked at this great post on low power modes and I think I'm addressing all the potential errors it describes.
Can anyone suggest what could be the cause for the excess consumption? Or whether this periodic wake up is normal/expected?
Thank you!
