Why “50-Ohm”
In design, we often encounter a special impedance value – 50 Ohm. Why is the standard impedance value 50 Ohm and not some other value? Many people may have this doubt. In fact, the most commonly used standard impedance is 75 Ohm in addition to 50 Ohm.
The Army
Part of the reason comes from the military, and most of the technology is preferred for military use.
During World War II, the choice of impedance completely depended on the needs of use, and there was no standard value. With the advancement of technology, the American organization finally chose 50 ohms after comprehensive consideration, which was transformed into a standard for various cables.
The European standard at that time was 60 ohms. Under the influence of enterprises, Europe also accepted the 50 ohm standard, so 50 ohms eventually became a standard in the industry.
PCB Manufacturer
Considering the PCB design, generally lower impedance is better, and crosstalk will be reduced accordingly.
There is also a key factor, in the 20th century, most chips could not drive transmission lines with impedance less than 50 ohms, and higher impedance transmission lines were inconvenient to implement, so 50 ohms was chosen as the default value for conventional controlled impedance.
Application
In the end 50 Ohm won out, 50 Ohm is neither the best nor the worst impedance, it’s just an acceptable compromise.
If you think this article is helpful to you, please leave your comments at the bottom, and we will improve it in time. If you need preferential components and PCBs, you can also leave your contact information or click the homepage to send us an Product model or BOM.
Related Articles
Wonderful PCB, share the method of correcting the bottom plate of the PCB.
What to Look for in a Good PCB Manufacturing
Wonderful PCB You can send us your requirements first, we will reply you as soon as possible. Click here to contact us.
You can click on our component store. Click here to contact us.
English