原标题：On Semi NCP1611 160W PFC电源解决方案

　　On Semi公司的NCP1611是采用创新的电流控制频率折返(CCFF)方法的驱动PFC升压级,功率因素接近1, 高驱动能力为 −500 mA / +800 mA, VCC范围从9.5V到35V,具有非闭锁和过压保护,电压检测,软起动和过流限制,主要用在PC电源,需要PFC的所有离线电器电源.本文介绍了NCP1611主要特性,方框图,通用应用电路以及160W PFC电源评估板指标,电路图和材料清单.

　　The NCP1611 is designed to drive PFC boost stages based on an innovative Current Controlled frequency Fold−back (CCFF) method. In this mode, the circuit classically operates in Critical conduction Mode (CrM) when the inductor current exceeds a programmable value. When the current is below this preset level, the NCP1611 linearly decays the frequency down to about 20 kHz when the current is null. CCFF maximizes the efficiency at both nominal and light load. In particular, the standby losses are reduced to a minimum.

　　Like in FCCrM controllers, internal circuitry allows near−unity power factor even when the switching frequency is reduced. Housed in a SO−8 package, the circuit also incorporates the features necessary for robust and compact PFC stages, with few external components.

　　NCP1611主要特性:

　　Near−Unity Power Factor

　　Critical Conduction Mode (CrM)

　　Current Controlled Frequency Fold−back (CCFF): Low Frequency Operation is Forced at Low Current Levels

　　On−time Modulation to Maintain a Proper Current Shaping in CCFF Mode

　　Skip Mode Near the Line Zero Crossing

　　Fast Line / Load Transient Compensation (Dynamic Response Enhancer)

　　Valley Turn on

　　High Drive Capability: −500 mA / +800 mA

　　VCC Range: from 9.5 V to 35 V

　　Low Start−up Consumption

　　A Version: Low VCC Start−up Level (10.5 V), B Version: High VCC Start−up level (17.0 V)

　　Line Range Detection

　　This is a Pb−Free Device

　　NCP1611安全特性:

　　Non−latching, Over−Voltage Protection

　　Brown−Out Detection

　　Soft−Start for Smooth Start−up Operation (A version)

　　Over Current Limitation

　　Disable Protection if the Feedback Pin is Not Connected

　　Thermal Shutdown

　　Low Duty−Cycle Operation if the Bypass Diode is Shorted

　　Open Ground Pin Fault Monitoring

　　NCP1611典型应用:

　　PC Power Supplies

　　All Off Line Appliances Requiring Power Factor Correction

　　图1.NCP1611方框图

　　图2.NCP1611通用应用电路图

　　160W电源评估板

　　The NCP1611 is active power factor corrected (PFC) controller specifically designed for use as a boost preconverter in ac-dc adapters, flat TVs, lighting ballasts and other medium powered offline applications. The controller is based on an innovative Current Controlled Frequency Foldback(CCFF) method. In this mode, the circuit classically operates in Critical conduction Mode (CrM) when the inductor current exceeds a programmable value. When the current is below this preset level, the NCP1611 linearly reduces the frequency down to about 20 kHz when the current is at a null. CCFF maximizes the efficiency at both nominal and light load. In particular, the standby losses are reduced to a minimum. The controller features a robust suite of protection features to properly handle an array of power supply operating and fault conditions.

　　图3.160W电源评估板外形图

　　160W电源评估板指标:

　　图4.160W电源评估板电路图:电源部分

　　图5.160W电源评估板电路图:控制部分

　　160W电源评估板材料清单: