AnsweredAssumed Answered

ADA4961 input RLC model

Question asked by gavint on Oct 31, 2016
Latest reply on Nov 2, 2016 by bsam



I am looking to do a simulation of the ADA4961 input driver circuitry using a SPICE simulation tool.

I am only able to find the S parameters for the ADA4961 on the ADI website.

I unfortunately do not have access to any software packages that can convert the S parameters to a SPICE model (RLC equivalent circuit).


1) If possible, please can you an RLC equivalent of the ADA4961 input stage that could provide a good approximation of the frequency response?


The  reason I want to simulate the ADA4961 input stage is that I am using the same input stage as the ADA4961 evaluation board. This input stage consists of a TCM2-43X+ RF transformer to convert 50R single ended to 100R differential. I am concerned that this 100R impedance combines with the input capacitance of the ADA4961 (1.3pF single ended) and any parasitic capacitance of the board to create an RC low pass filter. This will cause roll-off of the signal before the 3GHz bandwidth.


2) Do you have a plot of the frequency response of the ADA4961 evaluation board from 350MHz to 3GHz?