NUCLEO-L433RC-P: Why is the shutdown current so high (1mA) ?

[freeflyer]

I have measured the MCU current on the NUCLEO-L433RC-P dev board by removing JP6 and connecting a multimeter.

 

The current in shutdown is ~1mA, why is this so high ?  

 

The shutdown current should be nA or uA at most...

 

 

To shutdown I call "HAL_PWREx_EnterSHUTDOWNMode();" and have PC13 (the blue top button) set to SYS_WKUP2 to wake up.

 

Looking at the dev board schematic, it appears that the only other load on the 3.3V supply are two level shifters (SN74LVC2T45DCUT) but the datasheet says that these have a low power consumption, 4-μA maximum ICC.

 

[mƎALLEm]

Hello,

Debugger connected?

See this thread: How to measure power consumption for Nucleo-144 board?

[freeflyer]

The debugger as in the ST Link ? 

I haven't broken the ST Link part of the board to disconnect the ST Link, if that's what you mean ?

The USB is not connected to a computer, the USB connector is only powered with 5V and GND from an external 5V supply.

 

Looking at the schematics, the ST Link MCU is powered by a different supply rail (3V3_ST_LINK)...

 

 

JP6 jumper is a different power rail only used by the target MCU (STM32L433RCT6P) and level shifters...

 

Presumably it was designed this way so that you can measure the current of the target MCU without it being affected by the ST-Link MCU