Part UC3855B
Description High Performance Power Factor Preregulator
Manufacturer UNITRODE
Size 1.28 MB
UNITRODE
UC3855B

Overview

The UC3855A/B provides all the control features necessary for high power, high frequency PFC boost converters. The average current mode control method allows for stable, low distortion AC line current programming without the need for slope compensation.

  • Controls Boost PWM to Near Unity Power Factor
  • Fixed Frequency Average Current Mode Control Minimizes Line Current Distortion
  • Built-in Active Snubber (ZVT) allows Operation to 500kHz, improved EMI and Efficiency
  • Inductor Current Synthesizer allows Single Current Transformer Current Sense for Improved Efficiency and Noise Margin
  • Accurate Analog Multiplier with Line Compensator allows for Universal Input Voltage Operation
  • High Bandwidth (5MHz), Low Offset Current Amplifier
  • Overvoltage and Overcurrent protection
  • Two UVLO Threshold Options
  • 150µA Startup Supply Current Typical
  • Precision 1% 7.5V Reference