Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

How can a microcontroller be used to drive smps power mosfets?

Status
Not open for further replies.

israel7732

Member level 3
Joined
May 2, 2010
Messages
66
Helped
6
Reputation
12
Reaction score
5
Trophy points
1,288
Location
Nigeria
Activity points
1,668
please how can a microcontroller be used to drive smps power mosfets.
i tried to drive the mosfets with the mcu but the out put voltage drops significantly to about
40 from the expected 250volts
 

Re: microcontroller smps

You can not turn a POWER MOSFET fully on by directly driving using a microcontroller. You need a MOSFET driver. Take a look at TC427 and L6385:
http://www.datasheetcatalog.org/datasheet/microchip/21415b.pdf - TC427
http://www.datasheetcatalog.org/datasheet/stmicroelectronics/5652.pdf - L6385

To fully turn on a POWER MOSFET you need to drive its gate using at least 8v. The microcontroller can not output 8v from its port pins. So the MOSFET is not fully turned on. The current from the microcontroller is also limited. Using a MOSFET driver allows you to drive the MOSFET driver using 5v and the MOSFET driver drives the MOSFET using a higher voltage (8 volt plus, supplied to it through Vcc) while driving the MOSFETs quickly, keeping pretty low rise/fall times.

Hope this helps.
Tahmid.
 
Re: microcontroller smps

The choice of Mosfet driver is strongly dependent of SMPS circuit topology.
Give us more details if want a more accurate help.

+++
 
Re: microcontroller smps

The choice of Mosfet driver is strongly dependent of SMPS circuit topology.
Give us more details if want a more accurate help.

+++

Yes, that is very important.

The circuit topology would determine if you need high-side or low-side gate drive and which driver would be suitable. If you used half-bridge or full-bridge, you will need a high-side driver. For push-pull, flyback, forward, you need a low side driver. For double transistor forward, I think you need to use a gate drive transformer.

Hope this helps.
Tahmid.
 

Re: microcontroller smps

I tiered this but I can't archive expected success, drive transformer helps some extend
better way use L6385 as said tahmid
 

Re: microcontroller smps

thanks tihmid. i'll get back to you.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top