Hi all ,
I have a question on LVDS transmitter design . I am using a common mode feedback circuit to stabilize the output common mode voltage and I want to do the stability analysis for this feedback loop.For that I need to get the pole at the output of the LVDS driver .Can anyone suggest what all the resistances and capacitances that come into play while calculating this pole !!!!!

Hi ,
I agree with u that CMFB pole should be the dominant one ...but i want to know at what frequency my output pole comes so that i can adjust the CMFB pole for the required phase margin .For that i need to know some rough estimation of  R and C of the output pole .Please suggest some simple way to model the transmisson line and the terminating resistor (100 ohm), so that i can get the R and C of the output pole from it .....

Hello,

Remember that to analyze the CM loop, you should only include the CM impedance ! It means any floating impedance between the two output nodes will be discarded in CM point of view and you just need to put the impedances connected from each output to ground or VDD.

SATurn