uc3823

david navon

Other Parts Discussed in Thread: UC3823

hello'

I want drive two mosfet and i using uc3823 for that, the freq must to be 50Khz.

I need help how determine the freq by Ct Rt and ramp input. I using voltage mode at fixe duty cycle 50% and fix freq.

I try to find help at web but I didn't find guide to design the ic,

best regard

david

0 JohnTucker over 8 years ago

There is a crude frequency vs Rt and Ct graph on sheet 6 of the datasheet. It is an old device.

0 JohnTucker over 8 years ago in reply to JohnTucker

Did you try to calculate the R and C values per the graph?

0 david navon over 8 years ago in reply to JohnTucker

thank u john abut quickly answer,

I simulate the ic but at different ic module (ltc3723),

but I dont know how change duty cycle if I work in open loop' I didn't wire the output to INV input.

I wire the out REF to NINV input with resistor, but I don't shore about it?

thank u abut your help

david

Power management forum