STELPD01 datasheet(11/27 Pages) STMICROELECTRONICS

11 / 27 page

Figure 7. EN/Fault driver circuit

5 V

STELPD01

30 μA

Fault driver

Fault signal

GND

VI(INT)ref

UVLO

EN/Fault

ON/OFF Comparator

To the logic control block

GND

Pull down block

VREF

6.8

External gate driver function for reverse blocking

The STELPD01 provides a dedicated gate drive signal on the VG pin which can be used to control an external

blocking MOSFET for reverse-current protection (RCP). See Figure 4.

When the internal control circuitry is enabled to perform output start-up ramp, the Vgate pin is pulled up by

External FET charging current IFET to the charge pump voltage referred to the Vin voltage in order to guarantee

the activation of external FET.

If the input voltage reaches Vclamp threshold the Vgate voltage is also clamped to a safe value of Vout + 5.5 V. See

Figure 23.

Reverse current protection is activated in case VIN falls below the undervoltage lockout (UVLO), the enable (EN)

voltage falls below the low-level threshold, or a fault event occurs.

For example, as VCC drops during input power removal, the device turn off internal FET and it sinks current from

the gate of the external FET to quickly turn it off, therefore blocking any current flow from the load to the input

side.

STELPD01

External gate driver function for reverse blocking

DS13254 - Rev 1

page 11/27

STELPD01 Datasheet(PDF) 11 Page - STMicroelectronics