ZHCSLY5A August 2020 – July 2021 TPS65994AD
PRODUCTION DATA
The VSYS gate control circuit monitors the VSYS and Px_VBUS voltages and detects reverse current when the VVSYS surpasses VPx_VBUS by more than VRCP. When the reverse current condition is detected, Px_GATE_VBUS is disabled within tPx_GATE_VBUS_RCP. When the reverse current condition is cleared, Px_GATE_VBUS is re-enabled within tPx_GATE_VBUS_ON. This limits the amount of reverse current that may flow from VSYS to Px_VBUS through the external N-ch MOSFETs.
In reverse current protection mode, the power switch controlled by Px_GATE_VBUS is allowed to behave resistively until the current reaches VRCP/ RON and then blocks reverse current from VSYS to Px_VBUS, where RON is the resistance of the external back-to-back N-ch MOSFET. Figure 8-14 shows the behavior of the switch.