Why Op AD829 only offer differential input impedance?

[alphi]

AD829 op datasheet only offer differential input impedance,how can I to know the input+ impedance and input- impedance?
I want use ad829 for gain +2 noninverting circuit,and source impedance is 50K,how can i do it?
AD829 datasheet link:
https://www.analog.com/UploadedFiles/Data_Sheets/AD829.pdf

 

[10kangstroms]

See the attached schematic.

 

[alphi]

thanks
but which type op offer differencial input impedance? and which other type op offer common mode input impedance?

 

[10kangstroms]

thanks
but which type op offer differencial input impedance? and which other type op offer common mode input impedance?

MOSFET and JFET input op amps have virtually infinite differential and common mode input resistance (capacitance should be specified in datasheet). Bipolar input op amps should at least spec differential input resistance, but apparently not all do.
Common mode rejection should be spec'ed in all op amps, but I don't know if it is.