ZHCSFF4C February 2016 – August 2021 TPS65981
PRODUCTION DATA
VIN_3V3 takes precedence over VBUS, meaning that when both supply voltages are present the TPS65981 will power from VIN_3V3. Refer to The Figure 9-40 for a diagram showing the power supply path block. There are two cases in with a power supply switch-over will occur. The first is when VBUS is present first and then VIN_3V3 becomes available. In this case, the supply will automatically switch-over to VIN_3V3 and brown-out prevention is verified by design. The other way a supply switch-over will occur is when both supplies are present and VIN_3V3 is removed and falls below 2.85 V. In this case, a hard reset of the TPS65981 occurs prompting a re-boot.