原标题：Fairchild FAN6240同步整流控制解决方案

　　Fairchild公司的FAN6240是用于反激拓扑转换器和正向续流整流的同步整流(SR)控制器,输出电压5V-24V,超低绿色模式工作电路,典型值为1.1mA,带次级绕组电压检测的PWM频率跟踪,主要用在AC/DC 笔记本电脑适配器,开架开关电源和电池充电器.本文介绍了FAN6240主要特性,方框图以及两种典型应用电路.

　　FAN6204: Synchronous Rectification Controller for Flyback and Forward Freewheeling Rectification

　　FAN6204 is a secondary-side synchronous rectification (SR) controller to drive SR MOSFET for improving efficiency. The IC is suitable for flyback converters and forward free-wheeling rectification.

　　FAN6204 can be applied in continuous or discontinuous conduction mode (CCM and DCM) and quasi-resonant (QR) flyback converters based on the proprietary innovative linear-predict timing-control technique. The benefits of this technique include a simple control method without current-sense circuitry to accomplish noise immunity.

　　With PWM frequency tracking and secondary-side winding voltage detection, FAN6204 can operate in both fixed- and variable-frequency systems.

　　In Green Mode, the SR controller stops all SR switching operation to reduce the operating current. Power consumption is maintained at minimum level in lightload condition.

　　FAN6240主要特性:

　　SR Controller

　　Suited for Flyback Converter in QR, DCM, and CCM Operation

　　Suited for Forward Freewheeling Rectification

　　Internal Green Mode for Lower No-Load Power Consumption and Higher Light-Load Efficiency

　　PWM Frequency Tracking with Secondary-Side Winding Voltage Detection

　　Ultra-Low VDD Operating Voltage for Various Output Voltage Applications (5V~24V)

　　Ultra-Low Green Mode Operating Current:

　　1.1mA Typical

　　VDD Pin Over-Voltage Protection (OVP)

　　12V (Typical) Gate Driver Clamp

　　8-Pin SOP Package

　　FAN6240应用:

　　AC/DC NB Adapters

　　Open-Frame SMPS

　　Battery Charger

　　图1.FAN6240方框图

　　图2.FAN6240反激转换器典型应用电路图

　　图3.FAN6240正向续流整流典型应用电路图