JAJSJT6A August 2020 – July 2021 TPS65994AD
PRODUCTION DATA
The application firmware enables the OVP and
configures it based on the expected Px_VBUS
voltage. If the voltage on Px_VBUS surpasses
the configured threshold VOVP4VSYS = VOVP4RCP/rOVP,
then Px_GATE_VSYS is automatically disabled
within tPx_GATE_VSYS_FSD
to protect the system. If the voltage on Px_VBUS surpasses the configured threshold
VOVP4RCP then Px_GATE_VBUS is
automatically disabled within tPx_GATE_VBUS_OVP. When VPx_VBUS falls below
VOVP4RCP - VOVP4RCPH
Px_GATE_VBUS is automatically re-enabled
within
tPx_GATE_VBUS_ON since the OVP condition has cleared. This
allows two sinking power paths to be enabled simultaneously and Px_GATE_VBUS will be disabled when necessary
to ensure that VPx_VBUS remains
below VOVP4RCP.
While the TPS65994AD is in the 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 Px_GATE_VBUS and Px_GATE_VSYS are disabled. Once the OVP condition clears, both Px_GATE_VBUS and Px_GATE_VSYS are re-enabled (unless ADCINx are configured in SafeMode). Since this is a dead-battery condition, the TPS65994AD will be drawing approximately IVIN_3V3,ActSnk from PA_VBUS or PB_VBUS during this time to help discharge it.