Need help with A/D converter

Thread Starter

bsj8377

Joined Dec 31, 2006
2
Hello all, I'm new to the forum and was wondering if anyone here may be able to help me with a question I have...I've been searching the internet for days now without any luck finding what I'm looking for...I need a stand alone A/D converter with a 3 or 4 bit output...also, it needs to accept up to 15 v on the input.

Everything I've seen has been at least 8 bits, but that makes my logic circuit huge...and I don't need 8 bit resolution...

Can anyone help me??? Thanks in advance!
Brian
 

beenthere

Joined Apr 20, 2004
15,819
Hi,

I don't think there are any conmmercial A to D's with less than 8 bits resolution. Just use one and ignore the lower 4 or 5 bits. If the 15 volts is a problem, use a voltage divider to put it in a range the A to D can handle.
 

Thread Starter

bsj8377

Joined Dec 31, 2006
2
Hi,

I don't think there are any conmmercial A to D's with less than 8 bits resolution. Just use one and ignore the lower 4 or 5 bits. If the 15 volts is a problem, use a voltage divider to put it in a range the A to D can handle.
I guess I could try that...just trying to keep it as simple as possible...and if they aren't offered commecially then that would explain why I couldn't find one online anywhere...thanks for the input, I think I'll try that and see what I can come up with...
 

Distort10n

Joined Dec 25, 2006
429
I have not seen a 3 or 4 bit ADC or DAC from any manufacturer. You will have to use an 8 bit converter and ignore the last 4 bits.
When it comes to the 15V input you will also have difficulty as the industry is pushing toward single supply for portable/low power applications.
A voltage divider on the input will be easy enough for a single ended, bipolar signal since it sounds like you do not need the greatest precision in the world. Otherwise, use an op-amp attenuator.
 
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