I want to use AD5933 for measure 200pF between 400pF capacitance. I tried some measurements with EVAL-AD5933EBZ but results didnt satisfy me. I calibrated board with 30kHz with 20k RFB and RCAL, 2Vp_p. I measured 380pF capacitor to 364pF. I want to ask that this capacitance range so large? Must i use multiplexer etc. for change the RFB and RCAL or did i something wrong??