FEATURES

Controls Boost Preregulator to Near-Unity

Power Factor

World Wide Line Operation

Over-Voltage Protection

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

10.8-V to 17-V Operation

Programmable Output Voltage (Tracking

Boost Topology)

DESCRIPTION

The UCC2819A/UCC3819A 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.

Designed in Texas Instrument’s BiCMOS process,

the UCC3819A offers new features such as lower

start-up current, lower power dissipation,

overvoltage protection, a shunt UVLO detect

circuitry and a leading-edge modulation technique

to reduce ripple current in the bulk capacitor.

The UCC3819A allows the output voltage to be

programmed by bringing out the error amplifier

noninverting input.