current measurement is not the same when do as the 51822 DK user guide

[Alice]

Hi All,

I use the 51822 DK to do the current measurement and do as the DK user guide 5.1.8 current measurement.

I just use the __WFI() to make the 51822 get into idle mode and I use jumper P7 in the motherboard to do the current measurement,I find that the current is 2.5uA.

However,when I use the CSM to do it,the curent is 10uA.I have do as the user guide and the voltage is 1 mv,that is to say,I=10mv/100=10uA.

I donn;t know why.I use the same test code.

[Håkon Alseth]

Hi Alice,

The comparator on the dev-kit is not accurate when measuring in the sub-mA area. We recommend that you rather use the P7 jumper for more accurate measuring of sleep currents.

Best regards Håkon