ZXLD1360

ZXLD1360

Document number: DS33471 Rev. 3 - 2

15 of 25

www.diodes.com

December 2010

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Diodes Incorporated

Shutdown Mode

Taking the ADJ pin to a voltage below 0.2V for more than approximately 100µs will turn off the output and supply current to a

low standby level of 20µA nominal.

100% nominal average value. (See graphs for details).

Soft-start

The device has inbuilt soft-start action due to the delay through the PWM filter. An external capacitor from the ADJ pin to

ground will provide additional soft-start delay, by increasing the time taken for the voltage on this pin to rise to the turn-on

threshold and by slowing down the rate of rise of the control voltage at the input of the comparator. With no external

capacitor, the time taken for the output to reach 90% of its final value is approximately 500

μs. Adding capacitance increases

this delay by approximately 0.5ms/nF. The graph below shows the variation of soft-start time for different values of capacitor.

Soft-start operation. Output current (Ch2) and LX voltage (Ch1)

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