The UCC3818N provides all the functions necessary for active power factor corrected preregulators. The controller achieves near unity power factor by shaping the ac input line current waveform to correspond to that of the ac input line voltage. Average current mode control maintains stable, low distortion sinusoidal line current. The UCC3818N offers features such as lower start-up current, lower power dissipation, overvoltage protection, a shunt UVLO detect circuitry, a leading-edge modulation technique to reduce ripple current in the bulk capacitor and an improved, low-offset (±2 mV) current amplifier to reduce distortion at light load conditions.
Controls Boost Preregulator to Near-Unity Power Factor
Limits Line Distortion
World Wide Line Operation
Accurate Power Limiting
Average Current Mode Control
Improved Noise Immunity
Improved Feed-Forward Line Regulation
Leading Edge Modulation
150-µA Typical Start-Up Current
Low-Power BiCMOS Operation
12-V to 17-V Operation
16 pin DIP. Manufactured by Unitrode.