I am looking at the TIDA-01063 reference design (document TIDUBV4A) as a starting block for developing an over current sensor in the DC leg of a half bridge high frequency inverter. I will need a PCB Rogowski coil and an integrator circuit. I was trying to follow the formulas in document TIDUBV4A. I see the physical dimensions of the Rogowski coil in Table 1 (Page 2) (coil inner and outer radius, number of turns, etc.). Then on page 8, equation 9, I see the formula for mutual inductance. According to Table 2, page 14, that inductance is .048 uh. The dimension for h (dist between upper and lower trace of the PCB) is not listed in Table 1 so I am having a hard time reconciling the formula to give .048 uh. If I assume an h = 1.255 mm I can get 48 uh but that is far off and very high inductance. Can someone please help me out with this? The formula I'm using is M=(N x (uh)/(2pi))xln(Dext/Dint). Maybe I don't have it right.
Thank you - John