On Semi NCP1219通用AC输入非绝缘6W电表降压电源方案
On Semi 公司的NCP1219是有动态自偏压电源的PWM控制器,具有极好的待机功耗,采用带斜率补偿的固定频率电流模式运作,频率在65kHz和100kHz选择,不需要辅助绕组,峰值源/沉电流驱动能力500mA/800mA,主要用在笔记本电脑,LCD监视器的AC/DC适配器,离线电池充电器,消费类电子如STB,DVD,DVDR电源.本文介绍了NCP1219主要特性,功能方框图,应用电路图以及通用AC输入非绝缘6W电表降压电源参考设计主要特性与指标,电路图和材料清单.
NCP1219: PWM Controller Featuring Dynamic Self Supply
The NCP1219 represents a new, pin to pin compatible, generation of the successful 7−pin current mode NCP12XX product series. The controller allows for excellent standby power consumption by use of its adjustable skip mode and integrated high voltage startup FET. Internal frequency jittering, ramp compensation, timer−based fault detection and a latch input make this controller an excellent candidate for converters where ruggedness and component cost are the key constraints.
The Dynamic Self Supply (DSS) drastically simplifies the transformer design in avoiding the use of an auxiliary winding to supply the NCP1219. This feature is particularly useful in applications where the output voltage varies during operation (e.g. battery chargers). Due to its high voltage technology, the IC can be directly connected to the high voltage dc rail.
NCP1219主要特性:
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