non logic level multiplexar

[Kevin Weddle]

What if I want a multiplexar that feeds through the input voltage. This way I could monitor a bunch of voltages by selecting one line and this goes to an A/D. In other words I want to use one A/D and monitor the voltages of many inputs. Does there exist a voltage follwer multiplexar?

 

[Ldanielrosa1]

For SPST analog switches, there are 4016 and 4066. There are also analog line selectors like 4051, 4052, 4053. Following one of these with a unity gain amplifier should fit the bill.

 

[audioguru2]

Hi Ldaniel,
Hey, aren't you near that volcano mountain in Usania that blew its head off? Did you see it happen? And you're surrounded by a few other beautiful dormant volcanos? Neat!
I don't think you need a unity gain amplifier to follow the multiplexer, since the input impedance of an A/D is high. Just feed the output of a 4051 8-to-1 analog multiplexer directly to the A/D.

 

[EnigmaOne]

I believe that the 74150 multiplexer is what you're looking for.
See:
http://www.qsl.net/yo5ofh/data_sheets/74150.htm
and
http://webpages.ull.es/users/fexposit/74150.pdf

Ok....forget that....I see that you're looking for an analog multiplexer now (darned old eyes!), so you'd actually be interested in something along the lines of:
http://www.intersil.com/products/deviceinfo.asp?pn=HI-518

or you could do an implementation of your own, using a series of JFETs or MOSFETs, digitally selected by something like a 74154 (1 of 16 selector), for 4-bit addressability.
Source: http://www.web-tronics.com/74154.html
Basic Data Sheet (non-pararmetric data): http://upgrade.cntc.ac.kr/data/ttl/74154.html
Mfr Data Sheet: http://www.sharpmz.org/download/74154.pdf