Noise on PCB board circuit

For the noise on the PCB board, when it is found that electromagnetic interference occurs in the digital circuit, the main reason is that the obvious noise voltage can be observed on the power line and the ground line with an oscilloscope.

Termination of high-speed PCB board

In a high-speed PCB board? system, the impedance mismatch on the transmission line will cause signal reflection, and signal distortion such as overshoot, undershoot and ringing will occur.