LPCOMP: start-up time and REFSEL while running

[Tobias Schneider]

Hi,

two quick questions (nRF52832):

1. What is the value of t_LPCOMP,STARTUP (I didn't find it in the PS).

2. Can PSEL be modified while LPCOMP is running? What is the expected delay until the output is stable again?

Regards Tobias

[MartinBL]

Hi, I have asked the LPCOMP architects. It might take a few days before I have an answer for you though.

[MartinBL]

Hi,

My apologies for the long wait. Busy days here at Nordic.

1. The value of nRF52832's t_LPCOMP,STARTUP is 25us. This is the time delay from the LPCOMP is started until the READY event is generated. However, please be aware of this errata: [76] LPCOMP: READY event is set sooner than it should. This implies that the comparator may need another 115us before it really can be trusted. A firmware workaround for this is suggested in the link above.
2. No it can't. LPCOMP (and all other peripherals) shall be stopped before modifying PSEL or any other configuration register.