nRF52840 LPCOMP abnormal power consumption?

[hgm-ble]

Calling of nrf_drv_lpcomp_enable() increases custom device's power consumption from less than 50 uA to 600 uA.

[hgm-ble]

It seems to be the same issue as in Errata 3.12 [89] "TWI: Static 400 μA current while using GPIOTE" and with the same workaround... But I don't use GPIOTE itself. In the part of code with this issue there is:

a number of GPIO pins init,
TWI init, exchange with external IC to set it to PD, TWI uninit.
SPI init, exchange with another external IC to set it to PD, SPI uninit.
then lpcomp init as in lpcomp example.

I tried to tie different analog inputs to lpcomp and commented a handler for doing nothing, but only the function nrf_drv_lpcomp_enable() have an influence to power consumption. When nrf_drv_lpcomp_enable() is commented, there's no abnormal consumption. I can't exactly test it without twi and spi usage because a power consumption of external ICs is higher when not in PD mode. Applying workaround as in Errata 3.12 [89] has solved this question.

[Bjørn Kvaale]

Great! Good to hear that you figured it out!