I am trying to use ADA4938 as a differential driver for transferring signal from board to board (DC coupling through SMA cable). I am wondering what is the output impedance of ADA4938 when it's configured as a DC coupled differential driver? And how should I terminate the output of ADA4938 to drive signal through a SMA cable (50 ohm)?
The following figure is one example I found from the ADA4938 data sheet. Are the two 50 ohm resistors at the output used for matching the output impedance with 50 ohm cable?
The actual output impedance of the ADA4938 is not directly stated in its datasheet. However, also like an op amp, the ADA4938 has a low output impedance.
For the proper termination of the output of the ADA4938 to drive a signal through a SMA cable, kindly take a look at the Figure 3 of the user guide of ADA4938 evaluation board. Here is the link: http://www.analog.com/static/imported-files/user_guides/UG-132.pdf
Anyway, can I ask what is your application?