expected current for saadc low power mode

[carlche]

Dear Nordic support,

I need to clarify a few points using SAADC for battery measurement - running the ble_app_proximity application without modification. I measured the power using PPK on 52840 DK and get around 1mA back ground current. After some googling, it says using Low power of SAADC should help. 

However,  after I change the config.h file to enable low power mode of SAADC, the current measured is still close to 1mA. Is this expected?

The following post (2 years old):

https://devzone.nordicsemi.com/f/nordic-q-a/27070/saadc-battery-measurement-current-consumption

suggest that the following has to be done for each read to reduce current, is it still relevant in SDK 15.2 or 15.3? What's the SAADC low power mode is for if it cannot reduce power consumption? What's the expected current using LP (low power) SAADC mode? 

Thanks,

Lichang

[carlche]

Sorry, should have included the quote from the above link:

-------------------------------------------

What might not be obvious in the sample code is that you need to turn off the SAADC when you are done with it. So in your handler once you are done reading the buffer, turn off the saadc and clear pending irq.

nrf_drv_saadc_uninit();
    NRF_SAADC->INTENCLR = (SAADC_INTENCLR_END_Clear << SAADC_INTENCLR_END_Pos);
    NVIC_ClearPendingIRQ(SAADC_IRQn);

-------------------------