• Resolved

PCM2912A: 1 KHz USB packet frame noise.

Prodigy 235 points

Replies: 3

Views: 17

Part Number: PCM2912A

I built a prototype board with the PCM2912A. Works beautifully. One thing I noticed though was the coupling of the 1KHz USB packet frame (and its harmonics) to the Analog Mic signal. 

Could this be mitigated simply by putting a ferrite between AGND pin of the chip and my GND plane (I have a single GND plane that all circuitry connects to, and my analog and digital sections are isolated), or is this considered common mode noise on the USB that needs a common mode choke.

Thank you.