The SG3525A PWM Controller offers improved performance and_lower external parts count_when implemented for controlling all types of switching power supplies. The on-chip +5.1 V reference is trimmed to +/-1%_and_the error amplifier has an input common-mode voltage range that includes the reference voltage, thus eliminating the need for external divider resistors. A sync input to the oscillator enables multiple units to be slaved or a single unit to be synchronized to an external system clock. A wide range of deadtime can be programmed by a single resistor connected between the CT and_Discharge pins. This device also features built-in soft-start circuitry, requiring only an external timing capacitor. A shutdown pin controls both the soft-start circuitry and_the output stages, providing instantaneous turn off through the PWM latch with pulsed shutdown, as well as soft-start recycle with longer shutdown commands. The under voltage lockout inhibits the outputs and_the changing of the soft-s tart capacitor when VCC is below nominal. The output stages are totem-pole design capable of sinking and_sourcing in excess of 200 mA. The output stage of the SG3525A features NOR logic resulting in a low output for an off-state.

characteristic

8.0V to 35V Operation

5.1 V +/- 1.0%_Trimmed Reference

100 Hz to 400 kHz Oscillator Range

Separate Oscillator Sync Pin

Adjustable Deadtime Control

Input Undervoltage Lockout

Latching PWM to Prevent Multiple Pulses

Pulse-by-Pulse Shutdown

Dual Source/Sink Outputs: +/- 400 mA Peak

Pb-Free Packages are Available*_

application

Half Bridge

Push-Pull