dc / dc convertor....

[neduva]

hi,
can anyone give idea of choosing and knowing the dc/dc convertor in (www.ti.com/general/docs/lit/getliterature.tsp?...SLVS570&track.). which is needed to step down supply from 48v to 12 v .

 

[BradtheRad]

The link resulted in a 'not found' message.

A converter will have various specs to help you choose the right one.
Specs such as:

* Type of input: AC or DC
* Input voltage range
* Output voltage
* Current rating
* What connectors it uses

 

[neduva]

i have to design power supply module. in that case i took a power source from PoE concept. in order to do that i choose TPS2375-1 IC. my application require various range of supply, like 12v/500ma, and 3.3v/250ma. and i'm scared of dc/dc convertor. can i get this functionalists in one ic to regulate power.i found one reference design in that **broken link removed** .which is giving 3.3v/1.5a. how to get output form my need. please give some suggestion.

 

[BradtheRad]

A recent poster here wanted to convert power over ethernet to a lower volt level. He started with a schematic similar to the TI layout.

https://www.edaboard.com/threads/262192/

The protocol limits current to 350 mA. This makes about 15W max.

It became apparent that a single buck converter cannot give you more current than is available from the supply.

This means you can get 3.3V @ 250mA. But you can't get 12V @ 500mA.

A flyback converter emerged as a suitable solution. This contains a transformer.

It will take effort to obtain the right transformer. Several parameters need to be satisfied.

Then it will take more effort to construct the converter, and troubleshoot it.

Seems like there would be enough demand that there ought to be a commercially manufactured device that will convert PoE to a lower volt level.