原标题：On Semi NCP1615高压高效PFC电源控制解决方案

　　On Semi公司的NCP1615是高压高效功率因素修正(PFC)控制器,采用创新的电流控制频率折返(CCFF)方法,在正常和轻负载时最大化效率,特别是待机功耗降低到最低,而功率因素接近一.器件集成了高压起动电流不需要外接元件,并具有多种安全特性,主要用在PC电源,需要PFC的离线电器电源,LED驱动器和平板TV等.本文介绍了NCP1615主要特性和安全特性, 功能框图,典型应用电路以及评估板NCP1615GEVB电路图和材料清单.

　　The NCP1615 is a high voltage PFC controller designed to drive PFC boost stages based on an innovative Current Controlled frequency Foldback (CCFF) method. In this mode, the circuit operates in critical conduction mode (CrM) when the inductor current exceeds a programmable value. When the current is below this preset level, the NCP1615 linearly decays the frequency down to a minimum of about 26 kHz at the sinusoidal zero−crossing. CCFF maximizes the efficiency at both nominal and light load. In particular, the standby losses are reduced to a minimum. Innovative circuitry allows near−unity power factor even when the switching frequency is reduced.

　　The integrated high voltage start−up circuit eliminates the need for external start−up components and consumes negligible power during normal operation. Housed in a SOIC−14 or SOIC−16 package, the NCP1615 incorporates the features necessary for robust and compact PFC stages, with few external components.

　　NCP1615主要特性:

　　• High Voltage Start−Up Circuit with Integrated Brownout Detection

　　• Input to Force Controller into Standby Mode

　　• Restart Pin Allows Adjustment of Bulk Voltage Hysteresis in Standby Mode

　　• Skip Mode Near the Line Zero Crossing

　　• Fast Line / Load Transient Compensation

　　• Valley Switching for Improved Efficiency

　　• High Drive Capability: −500 mA/+800 mA

　　• Wide VCC Range: from 9.5 V to 28 V

　　• Input Voltage Range Detection

　　• Input X2 Capacitor Discharge Circuitry

　　• Power Saving Mode (PSM) Enables < 30 mW No−load Power Consumption

　　• This is a Pb and Halogen Free Device

　　NCP1615安全特性:

　　• Adjustable Bulk Undervoltage Detection (BUV)

　　• Soft Overvoltage Protection

　　• Line Overvoltage Protection

　　• Overcurrent Protection

　　• Open Pin Protection for FB and FOVP/BUV Pins

　　• Internal Thermal Shutdown

　　• Bi−Level Latch Input for OVP and OTP

　　• Bypass/Boost Diode Short Circuit Protection

　　• Open Ground Pin Protection

　　NCP1615典型应用:

　　• PC Power Supplies

　　• Off Line Appliances Requiring Power Factor Correction

　　• LED Drivers

　　• Flat TVs

　　图1. NCP1615功能框图

　　图2. NCP1615C/D典型应用电路

　　图3. NCP1615A/B典型应用电路

　　NCP1615评估板NCP1615GEVB

　　NCP1615GEVB: High Voltage PFC Controller with Current Controlled Frequency Foldback Evaluation Board

　　图4. 评估板NCP1615GEVB外形图

　　图5. 评估板NCP1615GEVB电路图

　　评估板NCP1615GEVB材料清单: