I have one question which I encountered during usage of common mode choke.
Question : "If a common mode choke is used on the main power / ground input, ensure that no I/O circuits effectively bypass the ground side of the common mode choke. For example, the shield of screened cables or I/O signal grounds may present a better AC ground to the module than the main power ground. Common mode chokes may be needed on some I/O signals to prevent this."
Answer : "AC ground current may find an easier path to ground in the vehicle through IO circuits etc. rather than through the ground side of the common mode choke. If this occurs, the function of the common mode choke is effectively neutralised, potentially causing conducted emissions concerns. Normally signal grounds, cable shields would be connected to the "vehicle side" ground of the common mode choke, unless this causes a functional problem (e.g. accuracy of analog signals), in which case a common mode choke on analog / ground signals may also be needed."
I have the answer to the question also. But I am unable to understand it clearly. Can someone explain the question and answer in simple terms please. What the question is asking me to check and how will I check in my design?