IR2117 for the Buck Converter

[ravi_xmas]

Hello,

Can anybody tell me, how to calculate the Bootstarp components for the following spec. of DC-DC Buck converter.

Power stage:
Input Voltage: 80-130 DC
Output Voltage :30V DC
Output Current: 20A
Switching Frequency: 200Khz

Control stageIR2117 with SG3524)

I am not getting proper PWM pulse after the certain Input voltage, is it bootstarp issue?
Regards,
Ravi

 

[hanif]

try this pdf, it seems contains some useful info regarding your problem

application note

http://www.irf.com/technical-info/appnotes/an-978.pdf

 

[ravi_xmas]

Hello hanif,

Thanks for your replay. But I have designed the Bootstrap capacitor as per the application notes only, but still having problem.

Kindly let me know, is there is any high side driver for the Buck converter or shall we use IR2110 (high alone ) for this application?

Thanks,

Ravi

 

[FvM]

There's no functional difference between 2117 and 2110 HS driver, both should work. You have to limit the duty cycle
below 100%, this shouldn't be a problem with 3524.

P.S.: With no output load, bootstrap operation most likely isn't maintained.