fala
Full Member level 5
Hi, I have bought 10 AD625 instrument amplifier. In its datasheet it has been noted that differential resistance is about 1G Ohm and also common mode resistance has the same value. when I put one AD625 according to datasheet in a circuit for fixed gain configuration(page 9 of datasheet) I found out that input draws considerable current about 2.5 mA. supply voltage was +/-12V and input voltages were 0V and -3.5V gain is 50. I checked voltage of all pins for many times and all were according to datasheet. I replaced the opamp but result did not change. I measured resistance between +input and - input via a multimeter when they were not connected to any circuit or voltage and it was 700Kohm(it was about the same for all AD625s). Can someone please help me?
This is a link to data sheet
https://www.analog.com/UploadedFiles/Data_Sheets/AD625.pdf
This is a link to data sheet
https://www.analog.com/UploadedFiles/Data_Sheets/AD625.pdf