FEATURES
· Controls Boost Preregulator to Near-Unity
Power Factor
· Limits Line Distortion
· World-Wide Line Operation
· Overvoltage Protection
· Accurate Power Limiting
· Average Current Mode Control
· Improved Noise Immunity
· Improved Feed-Forward Line Regulation
· Leading Edge Modulation
· 150-mA Typical Start-Up Current
· Low-Power BiCMOS Operation
· 12-V to 17-V Operation

SUPPORTS DEFENSE, AEROSPACE,
AND MEDICAL APPLICATIONS
· Controlled Baseline
· One Assembly/Test Site
· One Fabrication Site
· Available in Military (–55°C/125°C)
Temperature Range(1)
· Extended Product Life Cycle
· Extended Product-Change Notification
· Product Traceability

DESCRIPTION/ORDERING INFORMATION
The UCC2817 and UCC2818 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 with TI's BiCMOS process, the UCC2817 and UCC2818 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 (±2-mV) current
amplifier to reduce distortion at light load conditions.
The UCC2817 offers an on-chip shunt regulator with low start-up current suitable for applications utilizing a
bootstrap supply. The UCC2818 is intended for applications with a fixed supply (VCC).
The devices are available in a 16-pin D package.