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.