using LPCOMP to measure vdd

RE: using LPCOMP to measure vdd

inya_lake — Thu, 27 Aug 2020 14:58:55 GMT

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

RE: using LPCOMP to measure vdd

Jørgen Holmefjord — Thu, 27 Aug 2020 14:45:50 GMT

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

RE: using LPCOMP to measure vdd

inya_lake — Thu, 27 Aug 2020 13:56:49 GMT

No, I'm looking to detect when vdd cross certain value (low battery) using Lpcomp instead of ADC. More of a low battery indicator without using ADC

RE: using LPCOMP to measure vdd

Turbo J — Thu, 27 Aug 2020 13:35:50 GMT

If you only want a power fail indicator, there is a power fail comperator in the POWER block: POFCON register.

When using SD, use SD functions to set the POF threshold value (POWER is a restricted peripherial).