case about nRF52820 COMP precision with mode "CROSS event on VIN+ and VIN- crossing"

RE: case about nRF52820 COMP precision with mode "CROSS event on VIN+ and VIN- crossing"

peter.min — Thu, 10 Mar 2022 01:04:31 GMT

Hi Karl Ylvisaker，
This response is very useful to the customer.
Thank you very much.
Kind regards,
Peter.Min

RE: case about nRF52820 COMP precision with mode "CROSS event on VIN+ and VIN- crossing"

Karl Ylvisaker — Thu, 03 Mar 2022 08:45:28 GMT

Hello again Peter.Min,

With no hysteresis enabled and with the differential configuration it is simply a comparator comparing the two signals - the output will change immediately upon a change in the voltage exceeding the other pin. If your signal fluctuates it may therefore trigger a barrage of events as it approaches the threshold if you do not have hysteresis enabled.

Best regards,
Karl

RE: case about nRF52820 COMP precision with mode "CROSS event on VIN+ and VIN- crossing"

peter.min — Thu, 03 Mar 2022 08:15:26 GMT

Hi Karl Ylvisaker,

You should understand the question as described below

First I set CPMP to work in differential mode

Then I tested that when the input voltage changes by 0.1mV, the output will change.

Based on the above Settings and tests, I would like to know the following questions

COMP input voltage accuracy?

Thank you for all your assistance.
Kind regards,
Peter.Min

RE: case about nRF52820 COMP precision with mode "CROSS event on VIN+ and VIN- crossing"

Karl Ylvisaker — Wed, 02 Mar 2022 08:55:29 GMT

Hello Peter.Min,

[quote user=""]2. When the input voltage changes to the minimum, the output terminal will change[/quote]

Do I understand you correctly that the issue you are seeing is that the CROSS event is generated anytime the voltage goes above 0 V, regardless of the threshold you have set?
If so, I suspect that your configuration of the COMP peripheral might be the issue.

Could you show me how you have configured your COMP peripheral, and elaborate on which levels you had intended for it to trigger on?

Best regards,
Karl