TK83854

Control Boost PWM to 0.99 Power Factor
Limit Line Current Distortion to < 5%
Worldwide Operation without Switches
Feed-Forward Line Regulation
Low Noise Sensitivity
Pin Compatible with UC2854, and UC3854 (Licensed Source)
 Low Start-Up Supply Current
Fixed-Frequency PWM Drive
Low-Offset Analog Multiplier/Divider
1 Amp Totem-Pole Gate Driver
Precision Voltage Reference

The TK83854 family of integrated circuits provide active power factor correction for power systems that otherwise would draw non-sinusoidal current from sinusoidal power lines. These parts implement all the control functions necessary to build a power supply preregulator capable of optimally using available power-line current while minimizing line-current distortion. To do this, the TK83854 contains a voltage amplifier, a precision analog multiplier/ divider, a current amplifier, and a fixed-frequency PWM. In addition, the TK83854 contains a power MOSFET gate driver, 7.5 V reference, line anticipator, load-enable comparator, low supply detector, and overcurrent comparator.

The TK83854 family uses average current-mode control to accomplish fixed-frequency current control with stability and low distortion. Unlike peak current-mode control, average current control accurately maintains sinusoidal line current without slope compensation.

The TK83854's high reference voltage and high oscillator amplitude minimize noise sensitivity while fast PWM elements permit chopping frequencies above 200 kHz. The TK83854 can be used in systems with line voltages that vary from 75 to 275 V and with line frequencies across the 50 Hz to 400 Hz range. To reduce the burden on the circuitry that supplies power to this device, the TK83854 family features low start-up supply current.

These devices are available in 16-pin plastic dual in-line (DIP) and 16-pin surface mount (SOP) packages.