AVR-Chat

I didn't give enough information.   The particular application does not need
the full 10 bits of resolution.   9 bits or even 8 bits would be ok.   I'm
trying to keep the board to minimal size so I'd prefer not to have to cram
in an opamp.   In addition, the application will allow things to be
calibrated, so a correction could be applied in software.  Anyone have a gut
feeling given all that?  That's all I'm looking for.   Steve

 

From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of David VanHorn
Sent: Friday, February 05, 2010 12:22 PM
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] ADC source impedance

 

  

On Fri, Feb 5, 2010 at 12:37 PM, Steve Hodge <steve@terrafirma.us
<mailto:steve%40terrafirma.us> > wrote:
> The Atmel data sheets, at least the ones I'm dealing with, say the "ADC is
> optimized for analog signals with an output impedance of approximately 10
K
> or less".   Does anyone have any experience about how much you can exceed
> this 10 K?

Depends on how much precision you want to loose, and there are no hard
answers.
A buffer amp will let you have >1Gohm, and there are some flea-powered
opamps out there.





__________ Information from ESET Smart Security, version of virus signature
database 4839 (20100205) __________

The message was checked by ESET Smart Security.

http://www.eset.com



[Non-text portions of this message have been removed]