UC1854B Datasheet PDF

FEATURES

● Controls Boost PWM to Near Unity Power Factor
● Limits Line Current Distortion To <3%
● World-Wide Operation Without Switches
● Accurate Power Limiting
● Fixed Frequency Average Current Mode Control
● High Bandwidth (5MHz), Low Offset Current Amplifier
● Integrated Current and Voltage Amp Output Clamps
● Multiplier Improvements: Linearity, 500mV VAC Offset (eliminates external resistor), 0-5V Multout Common Mode Range
● VREF "GOOD" Comparator
● Faster and Improved Accuracy ENABLE Comparator
● UVLO Threshold Options (16/10V / 10.5/10V)
● 300µA Startup Supply Current UVLO Turn on UVLO Turn off UC1854A 16V 10V UC1854B 10.5V 10V

DESCRIPTION

The UC1854A/B products are pin compatible enhanced versions of the UC1854. Like the UC1854, these products provide all of the functions necessary for active power factor corrected preregulators. The controller achieves near unity power factor by shaping the AC input line current waveform to correspond to the AC input line voltage. To do this the UC1854A/B uses average current mode control.