The NCP1612 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 NCP1612 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 stand-by losses are reduced to a minimum.

General Features

? 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

? Six Versions: NCP1612A, B, A1, A2, A3 and B2 (see Table 1)

? Line Range Detection

? pfcOK Signal

? This is a Pb-Free Device

Safety Features

? Separate Pin for Fast Over-voltage Protection (FOVP) for Redundancy

? Soft Over-voltage Protection

? Brown-out Detection

? Soft-start for Smooth Start-up Operation (A, A1, A2 and A3 Versions)

? Over Current Limitation

? Disable Protection if the Feedback is Not Connected

? Thermal Shutdown

? Latched Off Capability

? Low Duty-cycle Operation if the Bypass Diode is shorted

? Open Ground Pin Fault Monitoring

? Saturated Inductor Protection

? Detailed Safety Testing Analysis (Refer to Application Note AND9079/D)

Typical Applications

? PC Power Supplies

? All Off Line Appliances Requiring Power Factor Correction

NCP1612A1DR2G屬于集成電路（IC） > PFC（功率因數(shù)校正）。安森美半導(dǎo)體公司制造生產(chǎn)的NCP1612A1DR2GPFC（功率因數(shù)校正）功率因數(shù)校正 (PFC) 是用于調(diào)整交流電路中的電壓和電流之間的相位角，使之趨近于零的半導(dǎo)體器件。不同模式包括平均電流、邊界導(dǎo)通、連續(xù)導(dǎo)通、臨界導(dǎo)通、電流控制式頻率折返、不連續(xù)和不連續(xù)導(dǎo)通，開關(guān)頻率從 6 kHz 至 1.7 MHz 可調(diào)。