SG3525A

1. Use an external transistor or open-collector comparator to pul down on the Comp terminal.  This will set the PWM latch turningoff both outputs.  If the shutdown signal is momentary, pulse-by-pulse protection can be accomplished as the PWM latch wil be reset with each clock pulse.

2. The same results can be accomplished by pulling down on the Soft-Start terminal with the difference that on this pin, shutdownwill not affect the amplifier compensation network but must discharge any Soft-Start capacitor.

3. Apply a positive-going signal to the Shutdown terminal.  This will provide most rapid shutdown of the outputs but will not immediately set the PWM latch if there is a Soft-Start capacitor.This capacitor will discharge but with a current of approxi-mately twice the charging current.

4. The shutdown terminal can be used to set the PWM latch on a pulse-by-pulse basis if there is no external capacitance on Soft-Start terminal.  Slow turn-on may still be accomplished by applying an external capacitor, blocking diode, and charging resistor to the comp terminal. (See SG1524 Application Note).