AnsweredAssumed Answered

Eliminating the cable capaciance

Question asked by baala on Feb 5, 2014
Latest reply on Feb 26, 2014 by seanbrown

Hi,

 

Iam using AD7745 to measure the capacitance value of a capacitive level sensor. The problem I am facing is with regard to the large cable capacitance of the cables connecting the sensor to the evaluation board. Without grounding the shield., the data I get is very noisy. I tried shielding the ground. The output then was very much less noisy but it was offsetted by a very high value. I assume that cable capacitance is affecting the input to the AD7745 IC Cin. Is there any way that I could eliminate this effect? Through some additional circuitry or by connecting the shield to some other points?

Outcomes