Texas Instruments UC3854BDW, Power Factor Pre-Regulator Circuit, 115 kHz, 20 V 16-Pin, SOIC

Texas Instruments integrated controllers for Power Factor Correction (PFC) in pre-regulators and PFC converters can achieve near unity power factor and give stable, low distortion sinusoidal line currents. They utilise advanced features and innovative processes such as quantized voltage feed-forward, current synthesis, frequency dithering and slew rate enhancement to provide significant performance enhancements.

The Texas Instruments UC3843 series of control integrated circuits provide the features that are necessary to implement off-line or DC-to-DC fixed-frequency current-mode control schemes, with a minimum number of external components. The internally implemented circuits include an under voltage lockout(UVLO), featuring a start-up current of less than 1 mA, and a precision reference trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (PWM) comparator that also provides current-limit control, and totem-pole output stage that is designed to source or sink high-peak current. The output stage, suitable for driving N-channel MOSFETs, is low when it is in the off state.

Optimized for off-line and DC-to-DC converters
Low start-up current (< 1 mA)
Automatic feedforward compensation
Pulse-by-pulse current limiting
Enhanced load-response characteristics
Under voltage lockout with hysteresis
Double-pulse suppression
High-current totem-pole output
Internally trimmed bandgap reference
Up to 500-kHz operation
Error amplifier with low output resistance

Power Factor Correction (PFC), Texas Instruments

Texas Instruments Power Factor Correction (PFC) controllers meet IEC61000-3-2 harmonic current limit standards. PFC controllers are designed for AC-DC applications and provide high Power Factor (PF), low current distortion (iTHD), high efficiency and high power density.