This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

OPA189: OPA189 impedance value issue

Part Number: OPA189
Other Parts Discussed in Thread: OPA192, OPA191, OPA196

Dear sir,

Good day,

Please find the attached Circuit diagram.

Actually we are using opa189.

we choosing the input  resistor value for 10M ohm and given the know input voltage  from Fluke source meter  1v and we  measure the output voltage  of opam 6 th pin we getting 1.005 to 0.995 fluctuation.

If  we measuring the resistance value  of IN7+ and IN7-  we getting 17.2 to 21.2 M ohm ( using the 10M ohm 1% tolerance value resistor)


Same case we change the Resistor as 10Kohm  the value fluctuation between 0.9999 to 1.001 (2mv only).

Actually our requirement acceptable fluctuation is below 4mv  at the same time input impedance is 10M ohm.

Please do the needful and image for your reference.