The PCM1809EVM can be powered with a single 5V power supply connected to J6. Onboard low dropout regulators convert the 5V supply to the 3.3V and 1.8V rails used by the ADC. The analog supply, AVDD, is fixed at 3.3V. The digital supply, IOVDD, can be set to either 1.8V or 3.3V with J5. To power the ADC directly, remove J9 and J5 and apply a voltage directly to the AVDD and IOVDD test points. Note that if this is done, then keep J10 populated (or make sure there is a path between the pins if the supply current is being monitored) as this jumper connects the applied IOVDD to the mode selection pins and other circuitry that relies on IOVDD.

Figure 2-1 PCM1809 Power Supply