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.