On Semi公司的NCP1611是采用創新的電流控制頻率折返(CCFF)方法的驅動PFC升壓級,功率因素接近1, 高驅動能力為 −500 mA / +800 mA, VCC范圍從9.5V到35V,具有非閉鎖和過壓保護,電壓檢測,軟起動和過流限制,主要用在PC電源,需要PFC的所有離線電器電源.本文介紹了NCP1611主要特性,方框圖,通用應用電路以及160W PFC電源評估板指標,電路圖和材料清單.

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典型應用:

??PC Power Supplies

??All Off Line Appliances Requiring Power Factor Correction

圖1.NCP1611方框圖

圖2.NCP1611通用應用電路圖

160W電源評估板

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.


圖3.160W電源評估板外形圖

160W電源評估板指標:


圖4.160W電源評估板電路圖:電源部分

圖5.160W電源評估板電路圖:控制部分
160W電源評估板材料清單:

詳情請見:
http://www.onsemi.cn/pub_link/Collateral/NCP1611-D.PDF
和
http://www.onsemi.cn/pub_link/Collateral/AND9062-D.PDF
以及
http://www.onsemi.cn/pub_link/Collateral/NCP1611GEVB_BOM_ROHS.PDF