RE: nRF52832 SAADC configuration effects on calibration

Jørgen Holmefjord — Thu, 07 Feb 2019 14:06:02 GMT

Hi again,

I'm forwarding reply from our HW developers:

1) Calibration can be improved by setting oversample, but the accuracy is limited by internal DAC.

2) TACQ should not affect the offset calibration accuracy. Even TACQ at 3µs will allow the sampling network to settle fully.

3) No, the only effect we've seen is that offset will drift over temperature. The SAADC has been designed such that GAIN and REFSEL will not affect the offset. The MODE will affect the offset, as you in single ended will get twice the offset error referred to the input (single ended mode is really differential mode with N input grounded).

Best regards,
Jørgen

RE: nRF52832 SAADC configuration effects on calibration

Jørgen Holmefjord — Thu, 07 Feb 2019 10:00:11 GMT

Hi,

I have forwarded your questions to our HW engineers. I will get back to you when I get an answer.

Best regards,
Jørgen