Fairchild FAN6208 LLC电源同步整流控制方案 - 软件编程/OS - 电子工程网
Fairchild 公司的FAN6208是用于绝缘的LLC或LC谐振转换器的同步整流(SR)控制器,能驱动两个单独 SRMOSFET,通过监测每个SR的漏-源极电压来测量每个开关周期的SR导通时间,从而确定SR栅极驱动的最佳时间.具有先进的输出短路/过载保护以及超温保护(OTP),主要用在 LCD TV, PC电源和开架开关电源.本文介绍了FAN6208主要特性,方框图,应用电路图以及FEBFAN6208_CP433v1评估板主要指标,电路图,材料清单和PCB布局图.
FAN6208 is a synchronous rectification (SR) controller for isolated LLC or LC resonant converters that can drive two individual SR MOSFETs emulating the behavior of rectifier diodes. FAN6208 measures the SR conduction time of each switching cycle by monitoring the drain-to-source voltage of each SR and determines the optimal timing of the SR gate drive. FAN6208 uses the change of opto-coupler diode current to adaptively shrink the duration of SR gate drive signals during load transients to prevent shoot-through. To improve lightload efficiency, Green-Mode operation is employed, which disables the SR drive signals, minimizing gate drive power consumption at light-load condition.
Optimal timing circuits and protection functions are integrated in an 8-pin SOP package, which allows highefficiency power supply design with fewer components.
Specialized SR Controller for LLC or LC Resonant Converters
Secondary-Side Timing Detection with Timing Estimator
Gate-Shrink Function to Prevent Shoot-Through During Load and Line Transient
Green-Mode Function for Higher Efficiency at Light- Load Condition
Programmable Dead Time between Primary-Side Gate Drive Signal and SR Drive Signal
Advanced Output-Short / Overload Protection Based on the Feedback Information
Internal Over-Temperature Protection (OTP)
VDD Pin Over-Voltage Protection (OVP)