Hi, I am trying to build a half wave inverter and drive 2 IRF530 MOSFETS using IR2110. I looked at the application note (an-978) for the ic and found the formula for the capacitor design but I am not sure if I am substituting with the correct values. So here are the values I am using:

Qg=26nF
Iqbs=230uA
QLs=5nC
Icbs (I didn't know how to get this value so I neglected it , I am using ceramic capacitors)
Vmin=10v (I am also not sure about this value)

My Vcc is 15v , Vf is 0.7v , Vls =20/150*0.16=0.02v (inverter supply=20v and the load is 150 ohms)

So by substituting in the above formula I get C>36nF. Is this value correct?

 

Welcome to AAC!

Qg=26nF

Gate charge is measured in nC, not nF.
Fairchild's datasheet gives Qg as max 30nC (where did you get '26'?), so if you are driving two IRF530 in parallel your driver will be faced with providing max 60nC.

 

Is this what you are looking for?
https://www.silabs.com/tools/Pages/bootstrap-calculator.aspx
Max.

 

Ok thanks a lot.