HIGH-SIDE N-TYPE POWER TRANSISTOR GATE DRIVING TECHNIQUES WITHOUT A BOOTSTRAP CAPACITOR

Techniques and apparatus for driving the gate of a high-side transistor in a switched-mode power supply (SMPS) circuit, such as an inverting buck-boost converter or a buck converter. One example technique to pull down the gate voltage of the high-side transistor involves a multi-step approach, in which the gate voltage is initially discharged to a lower voltage level, and once the gate voltage falls below a certain level, an auxiliary switch can take over to completely turn off the high-side transistor. One example SMPS circuit generally includes a high-side transistor, a pulldown gate driver having an output coupled to a gate of the high-side transistor, a pulse generator having an output coupled to an input of the pulldown gate driver, and a first switch coupled between the gate and a source of the high-side transistor.