Switch Mode Power Supply for Propeller Project

Coley

I'm looking for a bit of advice on switch mode power supplies which I know very little about.
I have a design that needs to run off a source voltage of 13.6V DC and the drop from this to 5V and 3V3 means quite a bit of heat will be dissipated so I am looking for something much more efficient that an linear regulator.
My idea is to use the switchmode psu to take the voltage down to 5V and then use an LDO to drop it further to 3V3.
I'll need up to 300mA at 3V3 and I can do thru hole or smt.

Any help will be gratefully received.

Regards,

Coley

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
PropGFX - The home of the Hybrid Development System and PropGFX Lite

khd00

I did this one. It uses the TI TPS54233. But I also used it to go directly to 3.3 also. Handles VIN from 7.2 - 24V (ignore my 25V caps - this one is for testing and not at 24V). Was more of a learning exercise in design, pcb layout and smt soldering. Supposed to be 85% ++ efficient at .5 - 1A and is rated at 2A for both voltages.

Regards,
Kevin

Post Edited (khd00) : 5/9/2010 2:15:32 PM GMT

Coley

Thanks Kevin, I will take a good look at this.

Regards,

Coley

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
PropGFX - The home of the Hybrid Development System and PropGFX Lite

HollyMinkowski

Low cost switchers from a Thailand seller.
I have used these before.
This one has a 5v and an adjustable output, but costs 14.97
www.ereshop.com/index.php?main_page=product_info&cPath=75&products_id=189

This one is a 5v switcher for just 3.78. I would use this one with a 3.3 low drop out linear...not much heat going from 5 to 3.3 even with a linear.
I think this is just what you need, buy several, you will use them.
Shop around, there is a lot of great stuff at ere and you will find other stuff you can use.
www.ereshop.com/index.php?main_page=product_info&cPath=75&products_id=188

Both can take up to 40v in and source 1 amp without a heatsink.

Coley

Thanks Holly that is a nice site, might just order a few of those regulators for my toolbox anyway.....

Regards,

Coley

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
PropGFX - The home of the Hybrid Development System and PropGFX Lite

BradC

HollyMinkowski said...
Both can take up to 40v in and source 1 amp without a heatsink.

Can't even buy the parts for that price! Gold!

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"Are you suggesting coconuts migrate?"

max72

I use the LM2594M series.
Low parts count, it works rather well.

www.national.com/mpf/LM/LM2594.html#Overview

Massimo