UC3875: UC3875 max delay time

Arman Bzishkyan

Part Number: UC3875

I am developing high power PSFB DC/DC stetp up converter with switching freq. 16 khz. One of the low freq. phase shift pwm contolers is UC3875 wich i am using in project, it gives max delay time 2,2 us which is

not enough because of snubber capacitors 45 nF across IGBT, high-side IGBT closes almost at the same time low-side opens. (snubbers due to welding mode of the converter),

Is there any other pwm contoler with longer delay time, excluding DSP or microconrollers.?

over 6 years ago

0 Yunsheng Qu over 6 years ago

TI__Genius 9790 points

Hi, Arman

could you let us know where is the 2.2us delay time from? it should between two signals, could you let us know this two signals?

regards,
Yunsheng

0 Arman Bzishkyan over 6 years ago in reply to Yunsheng Qu

Prodigy 90 points

HI Yunsheng, aprox. 2.2-2,4 us is between two gate signals A and B of UC3875 for one half bridge. But due capacitance IGBT this delay not enough

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UC3875: UC3875 max delay time