Power Supply Tip 26: Current Distribution of High Frequency Conductors - Theoretical Basis

Probe domestic high frequency needle JKT-50L high frequency needle with 3 probes

Shunluo high frequency inductor, parallel stack inductor, shun winding inductor, authorized agent

NT2S05-26-1.8V

description:

In this "Power Supply Tips", we will study the effective resistance of conductors in free space and wound structures. Figure 1 shows the first example. It is a cross section of a single wire in free space that carries high frequency current. If the current is DC, the current densities shown as different colors are all the same. However, as the frequency increases, the current moves toward the outside of the conductor, as indicated by red and orange. This crowding situation is called the skin effect. The penetration depth is defined as the distance from the outer surface to the point at which the current density drops to the outer surface current density 1/e. In the case of copper, the depth is: where f is megahertz and depth is in cm.