I used the formula below to calculate the differential impedance with
trace width (w) = 1.2953
trace separation (d) = .2
trace thickness (t) = .035
dielectric thickness (h) = 1.6
relative dielectric constant (er) = 4.5
Zd = [174/(sqrt(er+1.41))] * ln[5.98h/(.8w+t)] * [1- 0.48exp(-.96d/h)]
With those values, I get the differential impedance to be exactly 90ohms.
However, the width is either 1.2953mm (too big) or 1.2953mil (too small)
I'm designing a PCB... what should I do?
Thank You
trace width (w) = 1.2953
trace separation (d) = .2
trace thickness (t) = .035
dielectric thickness (h) = 1.6
relative dielectric constant (er) = 4.5
Zd = [174/(sqrt(er+1.41))] * ln[5.98h/(.8w+t)] * [1- 0.48exp(-.96d/h)]
With those values, I get the differential impedance to be exactly 90ohms.
However, the width is either 1.2953mm (too big) or 1.2953mil (too small)
I'm designing a PCB... what should I do?
Thank You