I’m getting some problems when setting up a CD4051B multiplexer with 8 pots for a custom test cirtcuit of mine. I’ve quite some crosstalk from one channel to the next. It’s ok when those channels are for example volumes, but for a frequency pot, the previous read can influence the frequency pot read by something like a semi-tone when the pot is log-mapped over 20-10kHz for a frequency at around 500Hz.
We don’t have the BOM for the Daisy Field, but I guess it’s a CD4051B as well, and given the low power supply of 3V3, there should be a RON of around 500Ω, which for reasons I don’t fully understand for now, maybe because of some equivalent parasite capacitance of the ADC thus forming a RC filter, could make bad readings, that is the current reading is influenced by the tension of the previous reading.
Is this something the Daisy Field is also suffering from? Looking at the forum, it doesn’t seem at all, so I was wondering what could be wrong in my design.
My design is hosted here:
(I’ve removed the 1n cap to get to the semi-tone result, before it was even worse)
Thanks for any information on that matter,