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 DIP8 or 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.

FEATUREs
•IEC1000−3−2 Compliant
•Average Current Continuous Conduction Mode
•Fast Transient Response
•Very Few External Components
•Very Low Startup Currents (<75 A)
•Very Low Shutdown Currents (< 400 A)
•Low Operating Consumption
•±1.5 A Totem Pole Gate Drive
•Accurate Fully Integrated 65 kHz Oscillator
•Latching PWM for cycle−by−cycle Duty−Cycle Control
•Internally Trimmed Internal Reference
•2 versions of Undervoltage Lockout with Hysteresis
•Soft−Start for Smoothly Startup Operation (B version only)
•Shutdown Function

Safety Features
•Inrush Currents Detection
•Overvoltage Protection
•Undervoltage Detection for Open Loop Detection (shutdown)
•Brown−Out Detection
•Soft−Start
•Accurate Overcurrent Limitation
•True Overpower Limitation

Typical Applications
•TV, Monitors, PC Desktop SMPS
•AC Adapters SMPS
•White Goods, other Off−line SMPS