MOSFET WITH GATE PULL-DOWN

摘要

A pull-down MOSFET (110) is coupled between a drain and gate of a MOSFET main switch transistor (102) in a switching type DC-to-DC power converter. A gate of the pull-down MOSFET (110) is coupled to the drain of the main switch transistor (102) by a capacitor 118 and is connected to a source of the main switch transistor (102) by a resistor (120). The pull-down MOSFET (110) is operated by capacitive coupling to the voltage drop across the main switch transistor (102) and can be used to hold the gate of the main switch transistor (102) at or near its source potential to avoid or reduce unintentional turn-on of the main switch transistor (102) by the Miller effect.