Other Parts Discussed in Thread: PCM3070
The TLV320AIC FAQ says:
The recommendation for unused inputs on TI's Audio ADCs and CODECs is to provide
an AC termination to GND through a ~0.47uF capacitor to prevent noise-pickup on
an un-terminated input. The analog inputs have a DC bias on them so they should
not be shorted directly to GND.
however the FAQ also says:
Whenever any of the analog input terminals are not used in an application, it is
recommended to short the unused input terminals together and connect them to ground
using a small capacitor (example 0.1μF).
Can this be clarified (one recommendation says 0.47uF per unused input, the other seems
to suggest 0.1uF per unused input pair)? Is it along the lines of:
When an input is being used single-ended, then the unused minus input should have
an AC termination to GND through a ~0.47uF capacitor to prevent noise-pickup.
When an input is not being used at all, then both the plus and minus input terminals
should be shorted together and be AC terminated to ground using a small capacitor