Buck converter components

[jayce3390]

Hi,

I want to design a buck converter. My specs are :

Vin = 70V
Vout = 65V
freq = 10 MHz
Iout = 1.5A
Ripple : 5%

How to get L & C values from those values? I found different equations on the web leading on different results...

 

[SimonB]

You will have great difficulty. At such a high frequency your switching losses will be high. can you bring the frequency down to something more humane, like 300kHz. this tends to be the sweet spot trading off inductor size against switching loses.

Look at LT and Power Integrations for high input voltage switchers. You might be able to use one of these... if you do not mind a lower switching frequency

 

[jayce3390]

SimonB,

Yes the frequency is high, but I don't use MOSFETs, I m using GaN RF power transistor, it's faster than a MOSFET.
My switching device is able to run at 10 MHz easily, I tested it. But now I have to get my components values.

 

[jayce3390]

anybody?

 

[jayce3390]

This topic is in the proper section or not?

If not could you tell me?