Stable Voltage Supply

Randy escreveu:

you just usa a power regulator like 7805, search in google for datasheet 7805, you will see that is very simple...

Getting a 5V regulator is just the tip of the iceberg.

You need to consider what it is that the power supply is doing for you: providing a stable supply (and reference, ie ground) over varying conditions of load, transients, frequencies, etc. A solid power supply (and return) for a digital system, such as your data acquisitions system, must be properly designed. This takes a lot of effort. One for a mixed signal system, including digital and analog is even more complex.

I would recommend that you do a fair amount of research and learning before you even attempt to implement the power supply. Not understanding what it is that you need to accomplish will only lead to confusion, frustration, and failure.

I personally, found Dr. Howard Johnson's books (and website

to be very informative in this regard, though there are other resources available. As far as a place to start, try searching for the concept of 'decoupling or bypass capacitors'.

You need to: 1) specify what "stable" and "precise" mean; 2) build a supply that meets those specs, and

3) make the voltage *at the acquisition board* "stable" and precise. The best supply in the world won't help if the supply is "corrupted" at the board and at the individual chips. (That's what happens.) My guess is that you won't have a problem using a simple supply at the supply end of things, but you'll need to pay a lot of attention at the board.

Ed

The simplest, and probably cheapest when the smoke clears, is a 5V wall wart, rated at the current you need, or more.

Good Luck! Rich