# Help in Common Mode voltage

#### rahul_electronics

Joined Dec 15, 2015
2
Can anyone please explain the answers for belo or provide me reference to books that I could refer for explanations?
Thanks a lot!!!
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#### WBahn

Joined Mar 31, 2012
26,398
What is it about their explanation that is causing confusion? In other words, how far can you get through their explanation before you hit a stumbling point?

#### rahul_electronics

Joined Dec 15, 2015
2
What is it about their explanation that is causing confusion? In other words, how far can you get through their explanation before you hit a stumbling point?
I am not sure how the amplitude and average length of the trapezoid is calculated.
Could you pl let me know how it is arrived? Thanks in advance

#### WBahn

Joined Mar 31, 2012
26,398
Recall that the definition of the common mode voltage is the average value of the two signals. If one of the signals is 0V, then that means that the average of the two is one-half of the other.

Does that help?

You can derive the waveform by simply using the definition. Add the two waveforms together and then divide by two to get the average.