High Voltage High Efficiency Power Factor Correction Controller

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.

General Features
• 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

Safety Features
• 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 Protectio

Typical Applications
• PC Power Supplies
• Off Line Appliances Requiring Power Factor Correction
• LED Drivers
• Flat TVs