We are developing the product which used ADM489A.
The A/B input impedance is described to be 12kohm in the data sheet.
however, It seems that there is no information more than them about the A/B input.
Please let me know an equivalent circuit which is in the data sheet of other suppliers.
*An attached file is the product of Texas Instruments.
As for it, description by a text is also useful for me.