KA3524 Voltage Mode PWM Control Circuit IC

The KA3524 regulating pulse width modulator designed of all control circuit necessary to implement switching regulators of either polarity, transformer-coupled DC to DC converters, transformerless polarity converters and voltage doublers, as well as other power control applications. This KA3524 device comes with a 5V voltage regulator capable of supplying a current up to 50mA to an external circuit, a control amplifier, an oscillator, a pulse width modulator, a phase splitting flip-flop, dual alternating output switch transistors, and current limiting and shut-down circuit. Both the regulator output transistor and each output switch of the device internally current limiting.  And to limit junction temperature, an internal thermal shutdown circuit employed.

This Complete PWM power control circuit allows their operation beyond 100KHz with 2% frequency stability with temperature. Meanwhile, it offers a total quiescent current less than 10mA. This Voltage mode PWM control circuit provides  Single-ended or push-pull outputs along with the  current limit amplifier provides external component protection. In addition to it, the  On-chip protection provided against excessive junction temperature and output current. Thus provides a 5V, 50mA linear regulator output  to user.

The oscillator in KA3524 uses an external resistor (RT) to establish a constant charging current into an external capacitor (CT). While this uses more current than a series connected PC, it provides a linear ramp voltage on the capacitor.  This is also used as a reference for the comparator. In order to provide external synchronization,  the KA3524 given to an external clock.  A pulse of = +3 volts applied to oscillator output terminal with RTCT set slightly greater than clock period.