JAJSRT8A October 2023 – March 2024 TPS25751
PRODUCTION DATA
The application firmware enables the OVP and configures it based on the expected VBUS voltage. If the voltage on VBUS surpasses the configured threshold VOVP4VSYS = VOVP4RCP/rOVP, then GATE_VSYS is automatically disabled within tPPHV_FSD to protect the system. If the voltage on VBUS surpasses the configured threshold VOVP4RCP, then GATE_VBUS is automatically disabled within tPPHV_OVP. When VVBUS falls below VOVP4RCP - VOVP4RCPH, GATE_VBUS is automatically re-enabled within tPPHV_ON because the OVP condition has cleared. This action allows two sinking power paths to be enabled simultaneously and GATE_VBUS disables when necessary to ensure that VVBUS remains below VOVP4RCP.
While the TPS25751D is in BOOT mode in a dead-battery scenario (that is VIN_3V3 is low), it handles an OVP condition slightly differently. As long as the OVP condition is present, GATE_VBUS and GATE_VSYS are disabled. Once the OVP condition clears, both GATE_VBUS and GATE_VSYS are re-enabled. Because this is a dead-battery condition, the TPS25751D draws approximately IVIN_3V3, ActSnk from VBUS during this time to help discharge it.