pcm512x charge capacitor value
I'm guessing you are looking out the "Layout Example" section, where the data sheet has a couple of problems, which you have found!  First, there is no reason for an NPO or COG capacitor on the charge pump; a 2.2 uF X7R will be fine here, since the charge pump is not in the audio circuit.  COG caps are only required on the output filter to prevent the filter roll-off from moving around with temperature.  Second, the output filter cap values (which should be NP0) are recommended to be 2.2 nF (much easier to find), not 2.2 uF.  This is mentioned several places elsewhere in the document.  The "Layout Example" is a typo.  Good luck!