Patent ID: 7521878
Filing Date: 2009-04-21
Classification: H02M,H05B,Y02B

Abstract:
1. A power supply circuit for powering a load, comprising: a half-bridge comprising a pair of high-side and low-side switching devices arranged in series between a high-side supply circuit and a common return circuit; a connection point between said switching devices providing a switched output for powering said load; an integrated circuit, including a high-side driver and a low-side driver for respectively providing drive signals to control terminals of said high- and low-side switching devices, said high- and low-side drivers being controlled by an oscillator and timing and logic elements in the integrated circuit; and a protective circuit which responds to high dv/dt at the switched output by delivering a voltage peak to a current sense terminal of said IC; wherein the protective circuit comprises a capacitor and a resistor connected in series to said switched output, and a diode with its cathode connected to a node of said capacitor and resistor, and its anode connected to said current sense terminal.