Buck converter using the UC3843 driving a N-Chanel Mosfet

[SAMIR_SBG]

uc3843

Hi,
I am Samir, I am a electronic engineer.

I have made successfully a DC-DC boost converter (12 to 19V/5A) with the UC3843,
but i found a problem to make a Buck converter with N-Chanel Mosfet.

If someone have an idea about how to drive a N-Chanel Mosfet with UC3843 in Buck topology, please help me.
Thanks.
SAMIR.

 

[Tahmid]

buck converter mosfet

Hi,
Please spell out regarding the particular of a buck circuit you want to indulge with. Input voltage, output power and voltage requirement etc. then help can be provided.Even a detail circuit also can be provided. Thanks.

 

[Dmitron]

uc3843 buck

look how drivers IC are supplied

 

[FvM]

uc3843 buck converter

There are two points contradicting usage of UC3843 and similar in this case.
- A level shifting driver with boostrap function would be needed
- There's no simple way to connect the current measurement, that is expected for current mode operation.

In my opinion, it's much simpler to use one of various available buck converter controllers for an external NFET switch.

 

[Tahmid]

uc3843 boost

An IR2117 can be used for high side drive.

 

[jayce3390]

uc3843 boost converter

As FvM mentionned, you need a level shifting circuit between this driver and your MOSFET.
You can do it using a transformer, this will help you to get a floating node voltage to the MOSFET gate.
A transformer 1:1 turns ratio is usually sufficient.

 

[hortelanus]

Re: Buck converter using the UC3843 driving a N-Chanel Mosfe

Hi , you can probe an Sepic version of same circuit .