Posts: 118
Registered: ‎12-27-2016

EM2 current draw 150uA with only main()

The measured current draw on my board in EM2 is way too high. To help isolate the problem I have no user initialization code at all. Instead, I call "EMU_EnterEM2(0)" as the first code in main(). As I understand it, the default clock configuration should be HFRCO at 19MHZ, all HF and LF perpherails turned off, DC-DC in bypass mode. Although this won't be the lowest power configuration possible, I would expect it to be < 10uA. Certainly not 150uA.


If I lift the output pin on my 3V LDO, current drops to 1uA (which is the IQ of the LDO). So the current draw is on the 3V side.  All of the micro output pins (5 of them) have 3.01Meg pull-downs on them. But there is only a few milli-volts across them, so this is not where the current is going. There are several GPIO pins that are used for analog functions which are "open". But grounding them made no difference in current draw. 


DVDD and AVDD, and IOVDD are all 3V. As far as I can tell, the current draw is from the micro.


Any suggestions ?

Posts: 2,384
Registered: ‎10-14-2014

Re: EM2 current draw 150uA with only main()

[ Edited ]


Do you tried to disconnect the debugger?

are you using the EFM32PG1 STK board to test this.

I suggest you try to reset the board before you measure the energy to see if there is difference.

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