Engineering Specification
ES-3U5T-1B257-AA
EMC Design Guide for Printed Circuit Boards
Frame 43 of 78
Rev. A
10/01/2002
Printed copies are uncontrolled
Where,
d is the distance between the center lines of the two conductors in inches
r is the wire radii in inches
Table 311 below, shows the impedance of various solid copper wire pairs versus
frequency. Each wire has a length of one (1) foot and wire separation of one (1) inch.
Note: wires with smaller diameters will have higher inductances.
Table 311. Impedance in Solid Copper Wires
Inductive Reactance
/foot
Frequency
4 AWG
16 AWG
22 AWG
100 Hz
172x10-6
277x10-6
329x10-6
1 kHz
1.72x10-3
2.77x10-3
3.29x10-3
10 kHz
17.2x10-3
27.7x10-3
32.9x10-3
100 kHz
172x10-3
277x10-3
329x10-3
1 MHz
1.72
2.77
3.29
100 MHz
172
276.9
329.3
500 MHz
860
1.38x10+3
1.65x10+3
1 GHz
1.72x10+3
2.77x10+3
3.29x10+3
Figure 319 shows a circular conductor of radius, r, located at height, h, over a ground
plane. The ground plane returns the current that flows through the circular conductor.
Figure 319. Inductance in Wires over Ground Plane
Equation 324 gives the self-inductance in micro henrys per foot for a circular wire over
a ground plane, with ground plane returning the current. Note that the inductance is about
one-half the inductance in Equation 323.
h
I
I
Ground plane
Summary :
Impedance in Solid Copper Wires Inductive Reactance /foot Frequency 4 AWG 16 AWG 22 AWG 100 Hz 172x10-6 277x10-6 329x10-6 1 kHz 1.72x10-3 2.77x10-3 3.29x10-3 10 kHz 17.2x10-3 27.7x10-3 32.9x10-3 100 kHz 172x10-3 277x10-3 329x10-3 1 MHz 1.72 2.77 3.29 100 MHz 172 276.9 329.3 500 MHz 860 1.38x10+3 1.65x10+3 1 GHz 1.72x10+3 2.77x10+3 3.29x10+3 Figure 319 shows a circular conductor of radius, r, located at height, h, over a ground plane.
Tags :
plane,ground,wire,329x103,277x103,172x103,inductance,circular,mhz,wires,awg,oer,foot