TPS25751AS datasheet(36/85 Pages) TI2

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8.3.3.2.3 VBUS UVLO

The TPS25751A monitors VBUS voltage and detects when the voltage falls below VVBUS_UVLO. When the

UVLO condition is detected, GATE_VBUS is disabled within tPPHV_RCP. When the UVLO condition is cleared,

GATE_VBUS is re-enabled within tPPHV_ON.

8.3.3.2.4 Discharging VBUS to Safe Voltage

The TPS25751A has an integrated active pulldown (IDSCH) on VBUS for discharging from high voltage to

VSAFE0V (0.8V). This discharge is applied when the device is in an Unattached Type-C state.

8.3.3.3 External Powerpath Control PP_EXT

The TPS25751AS has two N-ch gate drivers designed to control a sinking path from VBUS to VSYS and

a sourcing path from VSYS to VBUS. The charge pump for these gate drivers requires VBUS to be above

VVBUS_UVLO. When a sink path is enabled, the circuitry includes a slew rate control loop to make sure that

external switches do not turn on too quickly (SS).The TPS25751AS senses the VSYS and VBUS voltages to

control the gate voltages to enable or disable the external FETs.

The high voltage power path control includes overvoltage protection (OVP), and reverse current protection

(RCP). Adding resistance in series with a GATE pin of the TPS25751AS and the gate pin of the N-ch MOSFET

slows down the turnoff time when OVP or RCP occurs. Any such resistance must be minimized, and not allowed

to exceed 3Ω.

PP_EXT

Figure 8-16. PP_EXT External Powerpath Control

Details of the VSYS Gate Driver shows the GATE_VSYS gate driver in more detail.

TPS25751A

SLVSJG7 – MAY 2026

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TPS25751AS Datasheet(PDF) 36 Page - Texas Instruments