For low-power products, after entering the sleep state WFI, the standard power consumption is 10uA, and the current power consumption is 50uA. Where might the 40uA come from?

一沙一世

For low-power products, after entering the sleep state WFI, the standard power consumption is 10uA, and the current power consumption is 50uA. Where might the 40uA come from? [Copy link]

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A low-power product designed for STM32 MCU, after entering the sleep state WFI, the standard power consumption is 10uA, and the current power consumption is 50uA. Which component or port setting may cause this 40uA? Please help analyze it. Thank you.

vincentc543

It should be caused by current consumption when the IO peripheral rises or pulls down the IO pin.

This 40uA current may be consumed by the MCU internal or external resistor.

vincentc543

You can first check the pins whose IO output is set to low.

vincentc543

Peripherals are also checked because they are still working in sleep mode.

wangerxian

Are you measuring the power consumption of the chip or the whole board with the 50uA?

chunyang

Insufficient information to make a judgement.

hjl2832

To measure low power consumption, first, you need to check whether you are measuring the power consumption of the chip alone or the overall power consumption of the board. If it is the overall power consumption, you need to look up the circuit diagram to see if there is a resistor that directly forms a loop from the power supply to the ground. There are also circuits similar to the bias of the BE pole of the transistor, such as the forward direction of the diode that can form a loop with the ground. In addition, check whether the IO state of the microcontroller will form a loop current as described above when it is in sleep mode. In many cases, the high current is because the state of the IO port forms a current loop after sleep mode.

一沙一世

hjl2832 posted on 2022-6-8 08:35 To measure low power consumption, first of all, you need to see whether you are measuring the power consumption of a single chip or the overall power consumption of the board. If it is the overall power consumption, you need to look up the circuit diagram to see if there is...

grateful.