Noise on Channel 1 - Analog Discovery Pro

[Piotr]

On the first channel, there is significant noise. I tried calibrating the device, but it didn't help. Overall, the channel measures correctly, but because of this, there is significant noise in impedance measurements. Is there any way to switch channel 2 as the reference channel instead of channel 1? Maybe I have something turned on? Inputs are connected to GND.

Edited October 4, 2023 by Piotr

[attila]

Hi @Piotr

Notice that warning "Channel 1 range will be extended !"
You have set the trigger to C1 30V, so the C1 is set to high range 50V pk2pk (lower resolution) and the other channels are at low range (higher resolution).
The channel range is adjusted not only by the specified Range but also according the trigger level if needed to make sure it captures that value and it switches also to higher range if offset exceeds +/-1V. See the Help tab / ADP3450

The next software version will also bring channel option for Impedance Analyzer.

[attila]

Hi @Piotr

Is it working now correctly ?
Looking at this again, to be able to set the trigger level to 30V with 0V offset, you probably have also set 10x? Attenuation for Channel 1, so signal and noise are both visually amplified, with 10X you have 500Vpk2pk range.