using LPCOMP to measure vdd

[inya_lake]

Hi, is it possible to measure NRF52832 vdd voltage using LPcomp. I know I can do it with ADC but it draws a lot of current. I'm thinking if I can compare VDD to lpcomp reference voltage, it will let me know once it goes below certain value. I don't get exact battery level like measuring with SAADC but at least it will let me know if it goes below certain voltage value.

Thanks,

[Jørgen Holmefjord]

Hi,

The LPCOMP peripheral does not have any internal static reference voltage. You need to either provide an external reference, or you can choose an internal reference as a fraction of the VDD voltage. This makes it hard to use for measurement of VDD.

Note that the Average current of the SAADC does not need to be that high, see this example. But of course, this depends on the power requirement of your application.

Best regards,
Jørgen

[inya_lake]

Thank you. I can follow your example and get VDD voltage with minimal current consumption.