Correctly adjust the output impedance and load impedance of the signal source, adjust the load power, modbus tcp gatewayand suppress signal reflection. Its purpose is to ensure that the signal or energy can be efficiently transferred from the signal source to the load.Second, the reason for impedance matchingResistor matching may not be used in low-speed PCBs, but complete, reliable, accurate, interference-free, and noise-free transmission signals must be provided when designing high-speed PCBs. Therefore, it is necessary to ensure that the characteristics of the PCB circuit are reflected in the transmission process, the signal is complete, the transmission loss is low, and it plays the role of matching impedance. If critical signals are not matched to resistors, it can cause signal reflections, bounces, loss, etc.3. Factors Affecting Impedance1. By changing the thickness of the medium, the impedance will also change. The thickness of the medium is proportional to the impedance; different prepregs have different glue content and thickness. The compression thickness depends on the press layout and platen program; for any material used, it is necessary to obtain the thickness of the insulating layer that can be produced for easy calculation, and engineering design, platen control, and material tolerance are the keys to adjusting the thickness of the medium.Figure 1 Medium thickness2. T-line width, increasing the line width can reduce the impedance, and reducing the line width can increase the impedance. In order to better meet the requirements of the impedance test line, a tolerance of ±10% is required to control the line width. The breakdown of the impedance test line affects the entire test waveform, and its single-point resistance is high, resulting in misalignment of the entire waveform. Impedance lines are not allowed, and the breakdown does not exceed 10%. Linewidth is mainly controlled by etch. In order to ensure the line width, the line width requirements should be met according to the etching, lithography error, graphic shear error and technical film compensation technology.3. The thicker the copper, the thinner the wire, the greater the impedance; the thicker the wire, the smaller the impedance. The Ebyte is a national high-tech enterprise specializing in the research and development of wireless modules and industrial IoT terminals. Independently developed and produced products include LoRa/WiFi Wireless Module/Bluetooth/ZigBee wireless modules, 4G networking equipment, Ethernet modules, NB-IoT data transmission terminals, industrial IoTthickness of the wires can be controlled by sample plating or by selecting a substrate with an appropriate thickness. serial rs232 to wifi converter Copper thickness should be controlled evenly. Add bypass blocks on thin wire and insulated wire boards to balance the current, avoid uneven copper thickness on the lines, affect impedance, and make uneven copper distribution on CS and SS surfaces. To achieve an even copper thickness on both sides, the board must be pulled across.
