• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

PC DC-to-DC Power Supply

Status
Not open for further replies.

Delivereath

New Member
Hello,

I'm looking to build a kind of power supply for a low consumption computer. The voltage source will be a 15V DC supply. Total power output would be 60 or 80W with 4 voltage outputs (+12V, +5V, +3.3V and -12V). I've been looking for step-down converters but I don't know which ones I should try.

Has anyone any advice about which kind of step-down converter I should buy ? The main goal is to create a complete ATX 2.2 power supply.

Thanks in advance.
 

crutschow

Well-Known Member
Most Helpful Member
For good efficiency you need switching power converters.

Do you want to build your own or buy modules?
 

Delivereath

New Member
I want to build my own supply. I've already checked existing DC power supply for Mini-ITX computers but I'm more interested in the project of doing it myself.

I've seen some step-down converters that could be used (like MAX8548). However these components have a single output. This means that I would 4 different step-down converters. Do you know any way to use only one switching component and 4 MOSFET/coils stages ? Or do I really need 4 integrated step-down converters ?
 

crutschow

Well-Known Member
Most Helpful Member
For proper voltage regulation, each output needs it's own control circuit, so typically you do use 4 separate step-down converters. The -12V unit needs to invert the input polarity also, of course.
 

Delivereath

New Member
Thanks for your reply.

I've found an IC that should match what I'm looking for :

QuickView - MAX8576, MAX8577, MAX8578, MAX8579 3V to 28V Input, Low-Cost, Hysteretic Synchronous Step-Down Controllers

Vin from 3 to 28V, Vout from 0.6 to 25V and max output current of 15A.

I will use one of those for each positive output (12V, 5V and 3.3V).

However I'm still missing the way to create the -12V output. I've found some switching inverters but I only need a small current on this line (less than 0.5 amps).

Is there an easier solution ?

Thanks in advance
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top