(1) Terminating resistor

　　It is better to connect a matching resistor at the end of a high-speed line or a digital signal line with higher frequency and longer routing.

　　(2) Connect the input signal line to a small capacitor in parallel

　　It is better to connect the signal line input from the interface to a small capacitor at the interface level near the interface. The size of the capacitor is determined by the strength and frequency of the signal, and cannot be too large, otherwise it will affect the integrity of the signal. For low-speed input signals, such as button inputs, a 330pF small capacitor can be selected, as shown in Figure 2.

　　Figure 2: PCB board design_ Connect the input signal line to a small capacitor

　　Figure 2: PCB board design_ Connect the input signal line to a small capacitor

　　(3) Driving ability

　　For example, a switch signal with a high driving current can be driven by a transistor; For buses with large fan outs, buffer drivers can be added.