ML4823

REV. 1.0 10/12/2000

7

SOFT START AND CURRENT LIMIT

The ML4823 employs two current limits. When the

REF, the outputs are immediately shut off and the cycle is

terminated for the remainder of the oscillator period by

resetting the RS flip flop.

If the output current is rising quickly (usually due to

transformer saturation) such that the voltage on pin 9

reaches 1.4V before the outputs have turned off, a soft

start cycle is initiated. The soft start capacitor is discharged

and outputs are held “off” until the voltage at SS reaches

1V, ensuring a complete soft start cycle. The duty cycle on

start up is limited by limiting the output voltage of the

error amplifier voltage to the voltage at the SS pin.