• 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-µA 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

(1) Additional temperature ranges are available - contact factory Unitrode Is a trademark of Texas Instruments.

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.