DESCRIPTION

The UC3842A-BW/43A-BW/44A-BW/45A-BW are fixed frequency current mode PWM controller. They are specially designed for OFF−Line and DC to DC converter applications with a minimal external components. Internally implemented circuits include a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totempole output ideally suited for driving a power MOSFET. Protection circuitry includes built undervoltage lockout and current limiting.

FEATURES

• Low Start-Up and Operating Current

• High Current Totem Pole Output

• Undervoltage Lockout With Hysteresis

• Operating Frequency Up To 500KHz