AD7714-AR5 from Analog Devices..

[PeterClaassen]

I am attempting to use AD7714, have got it communicating with 8051, but channels AN1 to AN6 all give the same reading with the signal connected to AN1. Anyone out there that has used this chip before?
Thanx

 

[don01]

Peter,
I had a similiar problem with an A/D in a small commercial plugin unit which connected straight to the parrellel port of the computer. TheA/D chip had been given the Black pen on its ID.

I solved it by shorting all unused inputs to the input amps (home made TC amps) thus forcing all unused inputs low.

I never did sort out the true cause. I suspect input impedance mismatch and a common 0 volt rails in the a/d.

Isolation amps may have helped but never tried

Regards Don

 

[jbartos]

Suggestion: Check
1. Cut and paste this http into the "open page" in the browser

http://www.p8s.com/ic/detail2.asp?id=6412&name=AD7714

2.

http://nwd2

http://www1.analog.com/techsupt/eb/lin_eb/ad7714/ad7714-5.html