UC3854N High Power Factor Preregulator  DataSheet

Description

The UC3854 provides active power factor correction for power systems that otherwise would draw non-sinusoidal current from sinusoidal power lines. This device implements all the control functions necessary to build a power supply capable of optimally using available power-line current while minimizing line-current distortion. To do this, the UC3854 contains a voltage amplifier, an analog multiplier/divider, a current amplifier, and a fixed-frequency PWM. In addition, the UC3854 contains a power MOSFET compatible gate driver, 7.5V reference, line anticipator, load-enable comparator, low-supply detector, and over-current comparator.

The UC3854 uses average current-mode control to accomplish fixed-frequency current control with stability and low distortion

Features Control Boost PWM to 0.99 Power Factor Limit Line Current Distortion To <5% World-Wide Operation Without Switches Feed-Forward Line Regulation Average Current-Mode Control Low Noise Sensitivity Low Start-Up Supply Current Fixed-Frequency PWM Drive Low-Offset Analog Multiplier/Divider 1A Totem-Pole Gate Driver Precision Voltage Reference Compatibility: UC1854, UC2854

Specifications: UVLO Thresholds On/Off (V) 16/10 Operating Supply (Max) (V) 30 Startup Current (mA) 1.5 Operating Supply Current (mA) 10 Vref (V) 7.5 Vref tol (%) 1.3 Duty Cycle (Max) (%) 95 Practical Operating Frequency (Max) (MHz) 0.2 Pin / Package 16PDIP Update on www.tme.vn   12 / 04 / 2012