PPKII Output low-frequency oscillation/ripple caused by PC data connection - Option to use USB power only?

RE: PPKII Output low-frequency oscillation/ripple caused by PC data connection - Option to use USB power only?

Kenneth — Mon, 15 Sep 2025 11:29:12 GMT

Okey, then I unfortunately don't have any better suggestions.

Kenneth

RE: PPKII Output low-frequency oscillation/ripple caused by PC data connection - Option to use USB power only?

mh@mxc — Mon, 15 Sep 2025 11:25:50 GMT

Hi - Thanks for the reply

As mentioned I have tried to use the PPKII in Amp meter mode with a clean external supply. I do still see a slight 0.5Hz signature in the measurement results - much less than when I use it in source more, but still enough to corrupt my measurement.

When using the external supply without the PPKII in between I see no low-frequency noise.

So the Amp meter mode is better, but does not solve the fundamental problem.

Thanks

RE: PPKII Output low-frequency oscillation/ripple caused by PC data connection - Option to use USB power only?

Kenneth — Mon, 15 Sep 2025 09:57:54 GMT

Hello,

When you use ampere meter mode, you don't need to use P22 VDD_nRF' as VIN, you can use a power supply, batteries etc.
https://docs.nordicsemi.com/bundle/ug_ppk2/page/UG/ppk/measure_current_ampere_meter.html

Does that solve your problem?

Kenneth