The UCC3818N is a BiCMOS Power Factor Preregulator offers new 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 (±2mV) current amplifier to reduce distortion at light load conditions. It provides all the functions necessary for active power factor corrected pre-regulators. This 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. It offers an on-chip shunt regulator with low start-up current, suitable for applications utilizing a bootstrap supply.
Controls boost pre-regulator to near-unity power factor
