The differential signal is used widely in high-speed circuit designing and most of the critical signal in the circuit is designed by differential layout. Compared to the differential signal and single-ended signal traces, there are a lot of advantages with differential PCB layout, such as strong anti-interference, effective suppression to EMI, and accurate timing positioning. The popular low voltage differential signaling is one of the examples of the differential signal technology with small amplitude. The most important rule of the differential layout in the PCB design is to match the line length. The others can be adjusted according to the design requirements and practical application.