Wire diameter
HPN
dW = 0.127602 – 7.507e-3 (x) + 1.546e-4 (x2 )– 1.107e-6 (x3)
TPN
dW = 0.1557005 – 9.699e-3 (x) + 2.1299e-4 (x2 )– 1.632e-6 (x3)
QPN
dW = 0.1622482 – 1.007e-2 (x) + 2.2073e-4 (x2 )– 1.69e-6 (x3 )
Surface area of wire
Aw = [dw (π ) lwire ] / 2
Where winding length = lWIRE = NP * L/T
Wire Inductance per inch
Wire Length per Turn on a Toroid
L/T = (OD – ID) + 2H
Inductance of Winding Wire = Leakage Inductance
Lw = (L/T) Np (LWIRE) = Ll
Total Turns per Layer
Cover Effect on Leakage Inductance
Secondary Leakage Inductance
(cover less than 360 degrees)
(cover greater than 360 degrees)RiseTime
Coupling Capacitance
Distributed Capacitance
Cp = [ 0.224 * K * Aw * ( N – 1 ) ] / l ave
Where:
Aw = [ ( OD – ID ) + 2H ] *dw * ( π / 2 )
lAVE = average distance between turns
Insertion Loss – Low Frequency
Insertion Loss – High Frequency
Where:
Low frequency rolloff
fo = Re / ( 2*π*LP )
where
High 3db Rolloff Frequency
HzWire Resistance of AWG
Return Loss – Low Frequency
Where: LP is in MH
Return Loss – High Frequency
Due to Leakage Inductance:
where
Due to Distributed Capacitance:
where
Coil Size estimator:
Coil OD:
OD coil = (OD core)*[1+0.35 EXP(-0.12*(H core/dW))]+ 2* dW
Where: dW = wire or cable diameter
Coil H:
H coil = (H core) * [1+(1.4)*(0.35 EXP(-0.12*(H core/dW))]+ 2* dW
Where: dW = wire or cable diameter
Coil ID:
ID coil = (ID core) * [1 – (0.35 EXP(-0.12*(H core/dW))] – 2* dW
Where: dW = wire or cable diameter
Near End Crosstalk
Capacitance formulas:
C1 = 0.224 ( K ) ( * ODXFMR ) (( 1 + 0.44 ( tXFMR ))2 ) ( 0.012 / tXFMR )
C2 = 0.224 ( K ) ( * ODCMI ) (( 1 + 0.44 ( tCMI ))2 ) ( 0.012 / tCMI )
CT = C1 + C2
Where K = 1, the dielectric of air.
Near End Crosstalk formula:
where: K = buffer dielectric at each frequency of interest