DC-DC converter for analog application

Hello to all..!!!

I'm looking for a single output , 5V @ 1A, DC-DC step down converter for an analog application. Does anyone know where can I find one module like this ?

Thanks,

Hideo.

Reply to
kikuzo
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I'll just rattle off some ideas... Ebay Numerous electronics distributors Thrift Store..maybe for $5.00 Phihong Omron Xantrex Computer power supply...about $50.00CAD...from numerous computer shops...old or new.. Don't use your own computer supply.. You might not be able to post more interesting posts. :)

But if you need very clean output...then that I don't know.. D from BC

Reply to
D from BC

Without knowing more about how you would use this power supply,

I can only suggest google.

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Reply to
Donald

What input? What load? Not just analog; a really quiet requirement might have a switcher feeding a low noise linear device, but for general use a straight switcher will probably be fine.

So be specific about the application and we might be able to help.

Cheers

PeteS

Reply to
PeteS

Recom R7805-1.0

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Regards,

Adrian Jansen           adrianjansen at internode dot on dot net
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Reply to
Adrian Jansen

Check Digikey. For really noise-critical apps I can only tell you from experience that I always rolled my own. And beware of "vaporware" PWM controllers that look almost too good to be true on the datasheet and then turn out to be non-stock everywhere.

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Regards, Joerg

http://www.analogconsultants.com
Reply to
Joerg

Also, check out Mouser. They have several. Price range will be about $7 to $25 ea. I am guesssing your input is around 12V.

Tam

Reply to
Tam/WB2TT

Without knowing your application, you might look at the National Semiconductor LM2575T. It's a switching regulator, but very efficient. We use them in our audio products here and we don't have problems with noise. (Though admittedly, our products are not specifically intended to satisfy the discriminating audiophile...)

Also, (from memory), I think these are good for 1.5A. (?) I recall National has another line (very similar numbering) that's qualified to 3A.

The '2575 requires a few extra parts (inductor, shottky diode, in & out caps), as compared to your standard 7805. It also has a shutdown pin, if that's useful in your application. Digikey has them. DIP, TO-220 and surface mt. They keep changing the part number, but my bin says : "LM2575T-5.0-ND" for the 5-pin TO-220 variety.

-mpm

Reply to
mpm

I was not very specific... sorry !!

The application is for measuring several accelerometer and magnetometers using low noise instrumentaion amplifiers. The input voltage range is from 9Vdc to 24Vdc. The circuit input current is about 0.5A and the most important, the output ripple should be something about 20UVrms (micro volts).

I'm trying to find a DC-DC switching converter instead of a linear regulator for efficiency and lower power disipation. I used a LT1763, with excellent low noise output, but it was disipating too much heat.

Thank you all for your comments.

Hideo.

Reply to
kikuzo

You can always do a DC-Dc and follow it with a LDO. [Drop most of the voltage with the DC-DC, then do the last volt with the LDO. ] You probably want the DC-DC in a separate box since the switcher noise radiates. Put the LDO near the analog circuits. Critical designs have LDOs per section to increase the isolation, though beware if there is an issue with the LDOs being slightly different in output voltage.

Reply to
miso

The 24V may be a problem as far as cheap modules go. Somebody suggested a National buck regulator chip; that might be the best way to go. Also, check out TI. They used to make regulators that looked like large DIPs that included the inductor. For audio, you will want the switching frequency to be above 100 KHz.

Tam

Reply to
Tam/WB2TT

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