onsemi NCP1622BCCSNT1G

The 6−pin PFC controller NCP1622 is designed to drive PFC boost stages. It is based on an innovative Valley Synchronized Frequency Fold−back (VSFF) method. In this mode, the circuit classically operates in Critical conduction Mode (CrM) when V_control voltage exceeds a programmable value V_ctrl,FF. When V_control is below this preset level V_ctrl,FF, the NCP1622 (versions [B**] and [D**]) linearly decays the frequency down to about 30 kHz until V_control reaches the SKIP mode threshold. VSFF maximizes the efficiency at both nominal and light load. In particular, the stand−by 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 TSOP6 package, the circuit also incorporates the features necessary for robust and compact PFC stages, with few external components.

• Near−Unity Power Factor
• Critical Conduction Mode (CrM)
• Valley Synchronized Frequency Fold−back (VSFF): Low Frequency Operation is Forced at Low Current Levels (9 Pre−programmed Settings)
• Works With or Without a Transformer w/ ZCD Winding (Simple Inductor)
• On−time Modulation to Maintain a Proper Current Shaping in VSFF Mode
• Skip Mode at Very Low Load Current (versions [B**] and [D**])
• 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 30 V
• Low Start−up Consumption for: [**C] Version: Low Vcc Start−up level (10.5 V) [**A] Version: High Vcc Start−up level (17.0 V)
• Line Range Detection for Reduced Crossover Frequency Spread
• This is a Pb−Free Device
• Thermal Shutdown
• Non−latching, Over−Voltage Protection
• Second Over−Voltage Protection
• Brown−Out Detection
• Soft−Start for Smooth Start−up Operation ([**C] Version)
• Over Current Limitation
• Disable Protection if the Feedback Pin is Not Connected
• Low Duty−Cycle Operation if the Bypass Diode is Shorted
• Open Ground Pin Fault Monitoring

• PC Power Supplies
• Lighting Ballasts (LED, Fluorescent)
• Flat TV
• All Off Line Appliances Requiring Power Factor Correction