Is it a "C"?

The history of connection ports goes long back to the bulky and heavy ports that used to have low data transfer rates… until the USB(Universal Serial Bus) came into existence in 1996. It changed how we designed the physical transmission devices. From the first USB 1 to the latest USB 4 V2(2022), the concept has gained a lot of useful characteristics.

The USBs are categorized on the basis of the type of port and the technology they use for data transfer.

What is absolutely interesting about Type C USB is its ability to connect either side. This makes it helpful and convenient for daily use purposes, which is a reason why nowadays each and every port is being replaced by USB Type-C. But how does the Type-C port achieve this?

Well, I stumbled upon the same question, and in order to know that, we must first know how our system really detects USBs.

The USBs rely on a very basic fundamental circuit in electronics called the voltage divider circuit(potential divider). This circuit provides a lower voltage at the junction of two resistors, as compared to the Vin, following Ohm’s Law.

$$Vout = (Vin * R2)/(R1+R2)$$

This formula tells us the Vout. The drawbacks of this circuit in general is that we cannot connect a heavy load to the Vout as it might disrupt the total resistance and make the calculations different. The main purpose of this circuit is to provide a different voltage than the standard Vin voltage that our device detects and understands that a USB device is connected.

To achieve this function, just as shown in the figure, the USB port and the plug have resistors attached. These are pull-up and pull-down resistors. Usually, the port contains the pull-down resistor(R2 in the figure), and the plug contains the pull-up resistor(R1 in the figure)

The pull-down resistor in the USB plug is connected to the CC pin. This pin helps to detect the orientation of the USB-C and also provides a connection to the voltage divider circuit. The USB-C has two of these CC pins located at the extreme end of the plug (CC1 and CC2 in the figure), and thus the USB-C is bidirectional instead of unidirectional like the previous types.

As soon as we connect the plug to the port, the divider circuit gets completed, and the device is notified that a USB is connected.

USB-C, with the help of USB 3.2 and USB reaches a great speed of data transfer. It is reimaginging how we look and connect with the system of devices and advancements in the field are of great use to us as a species.

#USB #Electronic #DailyElectronics