How to design bootstrap capacitor for MOSFET Gate driver

[Beffo]

bootstrap mosfet

I use IR2136 MOSFET Gate driver to drive a bridge of 6 transistors... for BLDC motor drive.

How do I know the size of bootstrap capacitor that I should use?

Frequency: 20kHz
Feeding IR2136 with PWM-signal of 20kHz and Duty 20-90%

https://www.alldatasheet.com/datasheet-pdf/pdf/91153/IRF/IR2136.html

 

[max0412]

mosfet bootstrap

Check page 7 of this AN from Allegro.

www.allegromicro.com/datafile/3946.pdf

 

[Beffo]

bootstrap capacitor calculation

Thank you!

Very helpful...

 

[burhanqamar]

can you please refresh the link!

 

[leandrorondon]

https://www.allegromicro.com/~/media/Files/Datasheets/A3946-Datasheet.ashx