This document describes the interface issues between the PFC stage and PWM controllers in switch mode power supplies with power factor correction, and provides examples of how to interface the L4981A with other PWM controllers.
The document describes synchronization techniques for Switched Mode Power Supply (SMPS) systems using power factor correction. It addresses potential interference issues when two different switch mode controllers operate close to each other.
The note provides specific circuit examples and wiring configurations for interfacing the L4981A master or slave with the L4990 and UC3842 PWM controllers, ensuring proper oscillation frequency settings.
Yes, the device is provided with an input/output (I/O) synchronization pin which allows it to be used both as a master or a slave.
The master oscillator frequency must be higher than the slave one in any condition.