Issue with Current Consumption in STM32L4 STOP2 Mode

[JIN3473]

Hello,

I am attempting to measure the current consumption of an STM32L4 before and after entering STOP2 mode using a DC power supply. I expected the initial current of 165mA to drop down to the $\mu A$ range upon entering STOP2 mode, but it only decreased by 5mA.

For my configuration, I have only enabled System Core - SYS - Debug - Serial Wire and a single GPIO pin for toggling to monitor the status via an oscilloscope. When STOP2 mode is activated, I confirmed with the oscilloscope that the GPIO toggling stops completely, indicating the CPU has halted. However, the power supply current remains high.

I have attached my main.c file for reference. Could you please check if I have missed any necessary configurations or if I am doing something wrong?

Thank you in advance for your help.

[Gyessine]

hello @JIN3473 
Do you use an ST board or a custom PCB?
The 165mA consumption in normal mode is already very high; it should not exceed a few milliamperes.
If you use a custom PCB, I suspect that there is a short circuit or another issue, especially since your code enters stop mode and you notice a reduction in consumption.
Also, can you specify which STM32L4 product you are using?
to exclude all software related issues, can you try a firmware example and give feedback about the visualized behavior. here is an example using STM32L476RG
BR
Gyessine