The PCM175x devices are designed to operate from a 4.5-V to 5.5-V power supply. Ensure that the power supply is clean and use high-quality decoupling capacitors to reduce noise. The bulk capacitances can be from either tantalum or aluminum capacitors.
Separate power supplies are recommended for the digital and analog sections of the board. This prevents the switching noise present on the digital supply from contaminating the analog power supply and degrading the dynamic performance of the PCM175x devices. In cases where a common 5-V supply must be used for the analog and digital sections, an inductance (RF choke, ferrite bead) should be placed between the analog and digital 5-V supply connections to avoid coupling of the digital switching noise into the analog circuitry. Figure 39 shows the recommended approach for single-supply applications.