原标题：On Semi NCP1654电源功率因素控制方案

　　On Semi 公司的NCP1654是电源功率因素控制器,与IEC61000−3−2兼容,平均电流连续导通模式(CCM),具有快速瞬态响应特性和非常少的外接元件,起动电流低于75uA,关断电流小于400uA,主要应用于平板电视,台式计算机,AC适配器,白色家电和其它离线开关电源(SMPS).本文介绍了NCP1654的主要特性,功能方框图, 软起动方框图, 300W 65kHz功率因素修正电路以及NCP1654EVB评估板主要特性,电路图和所用材料清单.

　　NCP1654 Power Factor Controller for Compact and Robust, Continuous Conduction Mode Pre-Converters

　　The NCP1654 is a controller for Continuous Conduction Mode (CCM) Power Factor Correction step−up pre−converters. It controls the power switch conduction time (PWM) in a fixed frequency mode and in dependence on the instantaneous coil current.

　　Housed in a SO8 package, the circuit minimizes the number of external components and drastically simplifies the PFC implementation. It also integrates high safety protection features that make the NCP1654 a driver for robust and compact PFC stages like an effective input power runaway clamping circuitry.

　　NCP1654主要特性:

　　IEC61000−3−2 Compliant

　　Average Current Continuous Conduction Mode

　　Fast Transient Response

　　Very Few External Components

　　Very Low Startup Currents (<75 uA)

　　Very Low Shutdown Currents (< 400uA)

　　Low Operating Consumption

　　1.5 A Totem Pole Gate Drive

　　Accurate Fully Integrated 65/133/200 kHz Oscillator

　　Latching PWM for cycle−by−cycle Duty−Cycle Control

　　Internally Trimmed Internal Reference

　　Undervoltage Lockout with Hysteresis

　　Soft−Start for Smoothly Startup Operation

　　Shutdown Function

　　Pin to Pin Compatible with Industry Standard

　　This is a Pb−Free Device

　　NCP1654安全特性:

　　Inrush Currents Detection

　　Overvoltage Protection

　　Undervoltage Detection for Open Loop Detection or Shutdown

　　Brown−Out Detection

　　Soft−Start

　　Accurate Overcurrent Limitation

　　Overpower Limitation

　　NCP1654典型应用:

　　Flat TVs, PC Desktops

　　AC Adapters

　　White Goods, other Off−line SMPS

　　图1.NCP1654功能方框图

　　图2.NCP1654 OVP和快速瞬态响应特性

　　图3.NCP1654软起动方框图

　　图4.NCP1654应用电路:300W 65kHz功率因素修正电路

　　NCP1654EVB评估板

　　The NCP1654EVB is a Power Factor Controller to efficiently drive Continuous Conduction Mode (CCM) step-up pre-converters. The NCP1654 allows operation in Follower Boost mode to drastically lower the pre-converter size and cost, in a straight-forward manner. The NCP1654 is a continuous conduction mode and fixed frequency controller (65kHz). The coil (650 uH) is selected to limit the peak to peak current ripple in the range of 36 % at the sinusoid top, in full load and low line conditions.

　　NCP1654EVB评估板主要特性:

　　Fast Transient Response

　　Low Operating Consumption

　　Inrush Currents Detection

　　Overvoltage Protection

　　Brown-Out Detection

　　图5.NCP1654EVB评估板外形图

　　图6.NCP1654EVB评估板电路图

　　NCP1654EVB评估板材料清单: