Sorry I have no idea about the Adafruit board so best to ask them. But in the meantime the PCM5102A is only rated for 3.3V so don't go giving it any higher voltage. However there may be a 5V->3.3V regulator on the Adafruit board so as to give the DAC a clean supply. Again best to check with the manufacturer.Hi,
Thanks for replying. I admit I'm quite new to embedded engineering so forgive me if anything comes across as stupid. In short, I don't know the answer to your question![:oops:]( "Embarrassed")
The PCM5102 card I have is an Adafruit model, and I thought it combined analog and digital voltage into one pin - the VIN pin. And I'm powering VIN from a shared 3.3V VCC across the whole circuit. But I've left the PCM's 3V output pin floating. I've read that the PCM's 3V pin is a regulator pin... do I need to tie that pin to something?
Another idea is powering the PCM at 5V from the Pico's VBUS pin, which might keep the on-chip charge pump happier, so it might power to audio output better... let me know what you think.
That said combining digital and analogue supply on one pin sounds a recipe for poor performance. We use totally different regulators from a 6.5V source to keep all digital noise well away from the DAC analogue sections.
Statistics: Posted by MikeDB — Thu Oct 02, 2025 10:42 am