Custom hardware has poor Low Power performance
Dear ST
As a follow up to my previous question (https://community.st.com/s/question/0D53W00001Tgf47SAB/high-power-consumption-in-low-power-examples:(
I'm using a custom board based on the STM32WB55CE6U MCU, design using the various application notes and Nucleo-WB datasheet/user manual.
The board does work, as I'm able to run my core BLE application with ADC/DMA and other functionality.
I've now started to implement Low Power (FreeRTOS tickless idle) using STOP2 mode.
The current consumption has dropped significantly (from 10mA --> 630uA during idle), but that is nowhere near the 3-6uA the BLE_HeartRate_FreeRTOS example uses on the Nucleo development board.
Digging in to the issue I've played around with the simple PWR_STOP2_RTC example, which uses ~3uA on the Nucleo.
Running the same (basically) software on my board, the consumption is never below ~80uA. I've literally soldered off all components but the basics - see pictures.
Are there some custom code, which need to be implemented for STOP2 to be optimal.
I've added code from the example in "stm32wbxx_hal_msp.c" and "main.c".
Running the binary from the example on my board yields the same result, so i do suspect my hardware.
All Capacitors are X5R or X7R and other components live of to standards in application notes.
Could it be bad PCB quality? Traces?
