The UVP, OVP and POR circuits of the TPA3223 fully protect the device in any power-up/down and brownout situation, and also in overvoltage situation with PVDD not exceeding the values stated in Section 7.1. While powering up, the POR circuit ensures that all circuits are fully operational when the AVDD supply voltage reaches the value stated in Section 7.5. Although AVDD is independently monitored, a supply voltage drop below the UVP threshold on AVDD pin results in all half-bridge outputs immediately being set in the high-impedance (Hi-Z) state. The device automatically resumes operation when all supply voltages have increased above their UVP threshold. In case of an OVP event, all half-bridge outputs are immediately set in the high-impedance (Hi-Z) state and FAULT is asserted low until PVDD is below the OVP threshold.