If a pre-charge condition occurs (a voltage exists on the output at turn-on) a resulting undervoltage lockout of the BOOT pin activates an internal, 5-mA (typical) pulldown. The pulldown reduces the time required to bring the output voltage low enough to charge the BOOT capacitor and begin operation. The device activates this strong pulldown any time undervoltage lockout of the BOOT pin occurs. However, in most situations the diode turn-on does most of the work to lower the switch node voltage. The pulldown will not act as a synchronous FET.