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PCB Trace Length-How To Know?

When dealing with high-speed signals, sound signals, high currents, and voltage, you need to be keen about your PCB traces. For example, when dealing with high-speed random access memory data bus signals and not using a buffer, you need to ensure that the timing is just right. This can be achieved by seeing that the traces are not too long and preferable of the same length. When the PCB traces are carrying a high AC, you may want to be concerned with the width more than the length. In other cases, the PCB trace length and shape is an important consideration. In short, you know you have the wrong PCB trace length if your signal is compromised.

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1.Rule of PCB Trace Length

When making a PCB, aim to make your PCB as small as possible. Short but wide PCB traces are more preferred. You want signal propagation time to be as fast as possible and minimize any power loss. For timing-constrained applications, always use the design software to ensure that the PCB traces in question are of the same length. Most PCB software programs assume that the PCB trace is 1oz per 0.035mm of copper for all the PCB traces. If a sensor is connected to the microcontroller in a PCB, especially an analog sensor, the PCB trace should join the two using the shortest route possible.

For electromagnetic applications, it is recommended that the PCB traces should be straight and far apart from each other. Your PCB trace length should not be comparable with one-tenth of the shortest frequency of your signal. For high-speed signal designs, you want to ensure that the signal that leaves an output is correctly received at the input. This is achieved by controlling the impedances and matching the PCB trace lengths and width.

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Hi, I am Hommer, the founder of WellPCB. So far we have more than 4,000 customers worldwide. Any questions you can feel free to contact me. Thanks in advance.