It has been found that the PCM4220 has the possibility to create an idle tone when there is no input into the device. Not all devices exhibit the behavior, but it is possible for a PCM4220 to produce an idle tone in the audio band. Depending on the temperature of the device, this artifact can change amplitude and frequency. This issue can be solved with a workaround that is detailed below.
Workaround:
It is possible to reduce this idle tone and even eliminate it by increasing the Vcc supply to the part from 4 V up to 4.35 V. The trade off for the increase in Vcc will be that the THD performance of the part will be reduced by about 2 dB if Vcc is increased to 4.35 V. This will go above the specified limit of Vcc in the data sheet, this will not damage the part, but will degrade the THD performance from what is specified in the data sheet.
