FULL-BRIDGE SYNCHRONOUS RECTIFIER INTEGRATED WITH CURRENT DETECTION

摘要

Disclosed in the present invention is a full-bridge synchronous rectifier integrated with current detection, comprising a rectifier bridge, a switch control circuit, and a current detection circuit integrated onto one CMOS process substrate. The rectifier bridge receives an input alternating current voltage, performs rectification, and then outputs the rectified voltage; the switch control circuit is configured to control the rectifier bridge to operate in a synchronous rectification mode; the current detection circuit detects a current flowing through a first lower MOS transistor and a second lower MOS transistor in the rectifier bridge, proportionally decreases the current according to a current attenuation ratio, and then converts the current into a voltage signal to be output; the current decrease ratio of the current detection circuit is set by forming a proportional relationship using identical MOS transistor internal resistors having the same type and same unit feature size as the first lower MOS transistor and the second lower MOS transistor in the rectifier bridge. The present invention has the advantages of low power consumption, less PCB area, high detection precision, and strong interference resistance.