Measuring current consumption of STM32L496ZG MCU on an STM32-Nucleo board

[Ans]

I'm using Nordic's Power Profiler Kit II to measure current of STM32L496ZG MCU on STM32 Nucleo board. I've tried to measure current using JP5 (IDD) as mentioned in the datasheet but current consumption is too high (163uA) considering the fact that I'm using tickless idle mode example (freertos low power).

I've been following this tutorial: https://www.youtube.com/watch?v=nSLN_WM2TOc&t=929s&ab_channel=STMicroelectronics

As far as connections are concerned, I've connected Vin of PPK II to one pin and Vout to other pin of JP5 of Nucleo board. I don't know if I'm doing anything wrong? 

[jiangfan]

I also do brief test for STOP2: ~1uA current at JP5 seen for the MB1312 NUCLEO-L496ZG.

[Ans]

Can you please share the code? and also how did you measure the current exactly on JP5? Another thing, how are you powering up the board while measuring current?

[jiangfan]

put current meter between 2 pin of JP5 to measure current, and the board is powered up in normal state from CN1 (STLINK side), current meter will display STOP mode current after 1 second.

[Ans]

what about jumpers configuration? I'm still trying to figure out why my board is drawing current ~160uA if I'm doing exactly similar procedure for stop modes.
It would be better if you could share the complete main.c file so that I can see what configurations of freq, gpios you're using. Thanks 

[jiangfan]

I should use default jumper configuration and I suppose no significant difference with different jumper setting as no many jumpers on board. it is complete main.c except GPIO variable (GPIO_InitStruct), and no configuration for frequency as HAL_RCC_DeInit() is called to use default clock setting. You may try the .bin file on your board.

[Ans]

So, your bin file works fine. Meter is showing current of ~2uA. Also, it shows current of 10uA when I try to run your program. 

[Ans]

It works fine on stm32 nucleo board but when I try to integrate this into my device code, it doesn't work as expected. Current is too high (95uA) when using only this code on my device. It goes up to 700uA when I'm integrating the STOP mode code into my main application code. 

[jiangfan]

good to know your MB1312 NUCLEO-L496ZG works find in terms of STOP mode current. Regarding your own device, or other board different than NUCLEO-L496ZG, one point to be care: keep GPIO at stable state, or say, avoid clock signal connected to STM32 GPIO pins so as to avoid leakage/extra current for low power mode such as STOP.

[Ans]

@jiangfan 
Just a question, Would you recommend using the similar configuration of low power modes with freeRTOS. Like if I use this configuration (without freeRTOS), I'm getting current as low as 2 uA. But it jumps to 160uA as soon as I integrate freeRTOS with it. 

I'm using this configuration in one of the task. And yes I've tried tickless mode but for some reason it didn't work. 

[jiangfan]

I did not try your case. I think user should get same STOP mode current with use of freeRTOS. what is the wakeup source (from STOP mode) for your case? RTC? button?

I suppose it is better to try in bare metal mode with same wakeup source.