IR 公司的IR11672AS是智能整流器控制器,用来驱动隔离反激和谐振半桥转换器中同步整流器的N沟功率MOSFET,最大开关频率为500kHz,关断驱动电流峰值为7A,栅极驱动电压10.7V,具有抗跳动逻辑和UVLO保护,Vcc电压从11.3V到20V,和0.3W待机功耗,能源之星,CECP等标准兼容, 典型应用为LCD和PDP TV,通信SMPS,AC/DC适配器,ATX SMPS,服务器SMPS等.本文介绍IR11672AS主要特性, 功能方框图, 典型连接图和在LLC半桥中的应用电路.

    IR11672AS: ADVANCED SMART RECTIFIER TM CONTROL IC

    IR11672A is a smart secondary-side driver IC designed to drive N-Channel power MOSFETs used as synchronous rectifiers in isolated Flyback and resonant half-bridge converters. The IC can control one or more paralleled N-MOSFETs to emulate the behavior of Schottky diode rectifiers. The drain to source voltage is sensed differentially to determine the polarity of the current and turn the power switch on and off in proximity of the zero current transition. The cycle-by-cycle MOT protection circuit can automatically detect no load condition and turn off gate driver output to avoid negative current flowing through the MOSFETs.

    Ruggedness and noise immunity are accomplished using an advanced blanking scheme and double-pulse suppression which allow reliable operation in all operating modes.

    IR11672AS主要特性:

    Secondary side high speed SR controller

    DCM, CrCM flyback and Resonant half-bridge topologies

    200V proprietary IC technology

    Max 500KHz switching frequency

    Anti-bounce logic and UVLO protection

    7A peak turn off drive current

    Micropower start-up & ultra low quiescent current

    10.7V gate drive clamp

    50ns turn-off propagation delay

    Vcc range from 11.3V to 20V

    Direct sensing of MOSFET drain voltage

    Enable function synchronized with MOSFET VDS transition

    Cycle by Cycle MOT Check Circuit prevents multiple false trigger GATE pulses

    Lead-free

    Compatible with 0.3W Standby, Energy Star, CECP,etc.

    IR11672AS典型应用:

    LCD & PDP TV, Telecom SMPS, AC-DC adapters, ATX SMPS, Server SMPS

    图3.IR11672AS在LLC半桥中的应用电路