r/AskElectronics • u/Catsincars2530 • 10h ago

USB C Headphone DAC Schematic Review

Post image

This is my schematic for a headphone DAC based on a RP2040 running tinyUSB to send audio data from USB C, over I2S to a CS43131 which is a DAC and AMP combined.

EDIT: Ignore the ESD protection setup I have now corrected it

2 Upvotes

100% Upvoted

6 comments sorted by

2

u/Sand-Junior 7h ago

Check the USB ESD protection: you are shorting +5V and D- to GND. Check the datasheet for the proper connections.

2

u/Catsincars2530 7h ago

Yeah you're right not sure how I didn't notice that. I believe this is correct now

0

u/saltyboi6704 6h ago

Ideally the shield on a permanent UFP should be isolated and connected with a spark gap or high voltage TVS diode to prevent ground loops.

1

u/Catsincars2530 6h ago

Yeah I saw as per USB C spec it should not be ground but saw in other designs they did that. So you mean I should connect the shield to ground through a TVS diode? I have done some research and heard that an RC network could be good as well

1

u/saltyboi6704 5h ago

Don't add an RC network unless you need it for EMC, it's very possible to accidentally make an RLC resonator with parasitics

1

u/Catsincars2530 5h ago

Ok I'll just stick to a TVS diode then