AnsweredAssumed Answered

Resistor measurement error with AD5933

Question asked by Adnan.Kurt on May 28, 2012
Latest reply on Jul 16, 2012 by musach



I am using AD5933 to measure complex impedance of human skin at a constant frequency, under different conditions. In order to evaluate and compare measurements, I have purchased an EVAL-AD5933EBX rev.B. I have several questions, and these two are serious:


1. How could I get an exact schematic with part numbers for the circuit board I have? None of the documents I have downloaded or received with a CD have the correct component info. Page6 of Rev.PrC EvalAD5933EB tech note has the best fidelity, still lacks some parts.


2. Following many discussion threads on this forum, I have downloaded the analysis program ver1.3 (though it reads Beta version 1.0 on the window header). Anyway, I can not read resistors accurately. Say,

     Start Frequency 10kHz,

     Range 1Vpp or 2Vpp

     Calibrated with a 100k resistor

When I run sweep for an unknown resistor, 220k for example, it reads 102k.

     Multi-Point Frequency Calibration resulted AVG=2.202420251e-9


Would anyone advise?

Adnan Kurt

Teknofil & MakeLab