IL3843 Datasheet | IK Semicon

DESCRIPTION Fixed frequency current-mode PWM controller. It is specially designed for Off Line And DC-to-DC converter applications with minimal external ponent. This integrated circuit features a trimmed oscillator for precise duty cycle control. a temperature pensated reference, high gain arror amplifier, current sensing parator, and a high current totempole output ideally suited for driving a power MOSFET. Protection circuitry includes built in under-voltage lockout and current limiting. .. FEATURES - Automatic Feed Forward pensation - High Gain Totem Pole Output - Internally Trimmed Bandgap Reference - Undervoltage Lockout with Hysteresis - Low Start Up Current - Optimized for offline converter - Double pulse suppression - Current mode operation to 500KHz ORDERING INFORMATION Device IL3843 Operating Temperature Range TA=0° to +70°C Package DIP-8 Rev. 01 PIN FUNCTION DESCRIPTION Pin Function No. 1 pensation 2 3 4 5 7 8 Voltage Feedback Current Sense RT/CT GND Vcc VREF Description This pln is the Error Amplifier output and is made available for loop pensation This is the inverting input of the Error Amplifier. It is normally connected to the switching power supply outpul through a resistor divider. A voltage proportional to inductor current is connected to this input. The PWM uses this. information to terminate the output switch conduction The Oscillator frequency and maximum Output duty cycle are programmed by connecting resistor RT to VREF and capacitor CT to ground. Operation to 500k Hz is possible. This pin is the bined conlrol circuitry and power ground This output directly drives the gate of a power MOSFET. Peak currents up to 1,0A are sourced and sunk by this pin. This pin is the positive supply of the control IC. This is the reference output. It provides chsarging current for capacitor CT through resistor RT .. 6 Output ABSOLUTE MAXIMUM RATINGS Characteristic Total Power Supply and Zener Current Output Current Output Energy (Capacitive Load per...