illustrate

This UC3854A/B product is a compatible enhanced version of pin UC3854. Like the UC3854, these products provide all the features needed for an active power factor correction preconditioner. The controller achieves a voltage close to the unit power factor corresponding to the AC input line voltage by shaping the AC input current waveform. To do this UC3854A / B adopts average current mode control. The average current mode control remains stable, and the low-distortion sine line is not like the peak current mode control without the need for slope compensation current.

A 1%, 7.5 V reference, fixed frequency oscillator, pulse width modulation, voltage amplifierwith soft start, line voltage feedforward (V RMS squared), input supply voltage clamp, over lilst feataures are currently relatively round.

characteristic

• ThePWM controls the boost to near power factor
• 限制线电流失真
• Global action, no switch
• Precise power limits
• Fixed frequency average current mode control
• High bandwidth (5 MHz), low bias current amplifier
• Integrated current and voltage amplifier output wire clamps
• Multiplier improvements: linear, 500 mV AC offset (no external resistor required), 0 V to 5 V Multout common mode range
• A good comparison of V REF
• Faster, improved accuracy allows comparison
• UVLO options (V/10, 16, V/10 V or 10.5 V).
• 300μA start-up supply current