Current Mode PWM Controller

3

PIN FUNCTION

N

FUNCTION

DESCRIPTION

1

COMP

This pin is the Error Amplifier output and is made for loop compensation.

2

This is the inverting input of the Error Amplifier. It is normally connected to the

switching power supply output through a resistor divider.

3

A voltage proportional to inductor current is connected to this input. The PWM

uses this information to terminate the output switch conduction.

4

The oscillator frequency and maximum Output duty cycle are programmed by

5

GROUND

This pin is the combined control circuitry and power ground.

6

OUTPUT

This output directly drives the gate of a power MOSFET. Peak currents up to 1A

are sourced and sink by this pin.

7

This pin is the positive supply of the integrated circuit.

8

APPLICATION INFORMATION

Figure 1. Error Amp Configuration

Figure 2. Undervoltage Lockout

KA3843A(AM)

WS

WS