On Semi NCP1129 25W离线电源解决方案
On Semi公司的NCP1129是集成了低导通电阻650V MOSFET的固定频率65kHz或100kHz的峰值电流模式控制器,外接电阻可调整限流值,提升轻载和待机能效的频率反走及跳周期模式，符合美国“能源之星”EPS 2.0,待机功耗小于100mW, 非常适用于家用电器、DVD播放机及机顶盒的电源系统设计.本文介绍了NCP112x主要特性, NCP1129功能框图和应用电路, 25W离线电源评估板NCP1129DIPGEVB主要特性,电路图和材料清单.
The NCP112x products integrates a fixed−frequency peak current mode controller with a low on−resistance, 650 V MOSFET. Available in a PDIP−7 package, the NCP112x offers a high level of integration, including soft−start, frequency−jittering, short−circuit protection,thermal shutdown protection, frequency foldback mode and skip−cycle to reduce power consumption in light load condition, peak current mode control with adjustable internal ramp compensation and adjustable peak current set point.
During nominal load operation, the part switches at one of the available frequencies (65 or 100 kHz). When the output power demand diminishes, the IC automatically enters frequency foldback mode and provides excellent efficiency at light loads. When the power demand reduces further, it enters into a skip mode to reduce the standby consumption down to no load condition.
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