Are You Clear About FPC Circuit Board Impedance

1. Characteristic impedance

In electronic information products such as computers and wireless communications, the energy transmitted in the PCB circuit is a square wave signal (also called pulse pulse) composed of voltage and time, and the resistance it encounters is called characteristic impedance.

2. Differential impedance

Two identical signal waveforms with opposite polarities input at the driving end are respectively transmitted by two differential lines, and the two differential signals at the receiving end are subtracted. The differential impedance is the impedance Zdiff between the two wires.

3. Odd mode Impedance

The impedance of one of the two wires to the ground is Zoo, and the impedance of the two wires is the same.

4. Even mode impedance

The two input signal waveforms with the same polarity at the drive end, the impedance Zcom when the two wires are connected together.

5. Common mode impedance

The impedance of one of the two wires to ground is Zoe. The impedance of the two wires is the same, which is usually larger than the odd mode impedance.