Some implementations (especially those paired with the MAX97220 OpAmp) reported a noticeable hiss when no audio was playing. This is often a circuit implementation issue rather than a chip defect.
Here is how you apply the Datasheet Fix. Cx31993 Datasheet Fix
While a direct PDF download for a "datasheet fix" is not publicly hosted by Synaptics, technical parameters are widely documented by manufacturers like and Audiocular who implement the chip: Key Technical Specifications DAC Sampling Rate: Up to 32-bit / 384kHz. Cx31993 Datasheet Fix