PCM5100A-Q1: PCM5100A-Q1 schematic review

Hi Sherry,

A few comments:

1. Capacitors C6122 and C6123 seem pretty large.  The low-pass filter created by this RC would have a cutoff-frequency of about 150Hz, which would be most of the audible range.  These are more commonly 2.2nF.

2. They should verify the voltage rating of C6111 and C6112.  These should be about 2.2uF at 3.3V, but most capacitors suffer from a voltage-coefficient of capacitance, where the capacitance of the device reduces as the voltage on the cap approaches it's rating.  As customer desire smaller caps, they use smaller ratings, such as 6.3V, but it is common for the capacitance value to be <60% at 3.3V with a 6.3V rating.  See the example curve below:

The other capacitor values are somewhat less critical as they are for decoupling and noise filtering.

Thanks,

Paul