Our customer has found a divergence between ADE7880 EVB user guide (UG-356) Page.4 and AN-639 Page.3 about the formula of CT burden resistance calculation description as below:
and [AN-639 P.3] :
UG-356 description is R1 = R2 = Ra = Rb = 1/2 x 0.5 / root(2) x N / IFS = y/x, where y = 1/2 x 0.5 / root(2), x = 1/(IFS/N),
so, Ra = Rb = y/x
but AN-639 description is 2Rb = y/x;
Then, which one description is correct?