Simple way to convert Buck to Buck boost

[grittinjames]

Hi,

Its very usefull info.


Thanks
Grittin

 

[manojdharap]

I am not able to understand how it will step up the voltage? can you please explain in detail?

 

[grittinjames]

Hi,

In usual practice primary switch of Buck converter allows current to flow through inductor series with load.
But here when Primary switch is on we have one more switch which allows to store energy only in Inductor. And when both switches are open stored energy is delivered to load.

Hope now working of circuit is clear
Thanks
Grittin

 

[manojdharap]

Yes. clear. thanks for clarification... I think this is called synchronous power supply, where we will use both switches synchronously..

 

[grittinjames]

I believe Synchronous is used for reducing Diode drope at higer current rating or for high effeciency.
Their we keep a switch parrellel to BUck diode so when ever primary switch is off this switch will turn on. and the drop will will be much lesser than traditional .7V

 

[Prototyp_V1.0]

Question is - will it work? Anybody tried to design it on a board or simulated it?

 

[grittinjames]

Question is - will it work? Anybody tried to design it on a board or simulated it?

Hi no doubt. I have tried. But I am not very sure about calculations for same

 

[Prototyp_V1.0]

I have had some thaughts about this.
I made up a simple schematic that show current path when the switch is on and off. It seems that it should work. However, calculating voltage out may be very difficult.
Another thing to have in mind is that the gate voltage may be too high for the mosfet and maximum Vgs should be protected with a zener.