| 描述 | Fairchild 公司的FAN9612是隔行扫描的双临界工作模式(BCM) BFC控制器,采用并行连接的180度反相输出进行控制,控制功率从300W到800W.和连续导通模式(CCM)技术不同,BCM使得升压二极管在零电流开关,因此降低了成本和损耗.可应用于100-1000W离线电源,大屏幕LCD-TV,PDP-TV,RP-TV的电源以及高端台式计算机和服输器点名源,获得80+证书的设备.本文介绍了FAN9612的主要特性,方框图,典型应用电路图以及采用FAN9612隔行扫描的BCM PFC电路图.
FAN9612: Interleaved Dual BCM PFC Controller
The FAN9612 Interleaved Dual Boundary-Conduction-Mode (BCM)
Power-Factor-Correction Controller operates two parallel-connected boost power trains 180º out of phase. Interleaving extends the maximum practical power level of the control technique from about 300W to greater than 800W. Unlike the continuous conduction mode (CCM) technique often used at higher power levels, BCM offers inherent zero-current switching of the boost diodes (no reverse-recovery losses), which permits the use of less expensive diodes without sacrificing efficiency. Furthermore, the input and output filters can be made smaller due to ripple current cancellation and effective doubling of the switching frequency.
The converters operate with variable frequency which is a function of the load and the instantaneous input / output voltages. The switching frequency is limited between 18kHz .. |
