AnsweredAssumed Answered

Issue with AD698 used with 3 wire LVDT in Single Supply mode

Question asked by Vinutha on May 11, 2017
Latest reply on Jun 19, 2017 by jcolao



Based on the AD698 datasheets, we have rigged up below circuit for 3 wire LVDT in a single supply (24Volts) mode.


Component values used for fsubsystem  =400Hz, fexcitation =4KHz & Spool Stoke = +/- 5mm

R1 =10K ohm

C1 = 10nF

R2 = 33K ohm

C2 = C3= C4 = 0.2microFarad

C5 = 0.1microFarad

R3 = R4 = Open

R5 = 50K ohm

R6 = 6.8K ohm

We are getting sine wave at -BIN/-AIN pins, +BIN/+AIN also wave form is seen but the amplitude is in the order of millivolts, but no waveform at BFILT pins.  With Spool position change, phase change observed at AIN pin but no significant change in Sig Out.  Not sure what is wrong.  Could any one help me in debugging this. Thanks.