High Voltage SEPIC Converter

摘要

A SEPIC converter with over-voltage protection includes a high-side inductor that connects a node Vw to a node Vx. The node Vx is connected, in turn to ground by a power MOSFET. The node Vx is also connected to a node Vy by a first capacitor. The node Vy is connected to ground by a low-side inductor. A rectifier diode further connects the node Vy and a node Vout and an output capacitor is connected between the node Vout and ground. A PWM control circuit is connected to drive the power MOSFET. An over-voltage protection MOSFET connects an input supply to the PWM control circuit and the node Vw. A comparator monitors the voltage of the input supply. If that voltage exceeds a predetermined value Vref the comparator output causes the over-voltage protection MOSFET to disconnect the node Vw and the PWM control circuit from the input supply.