USB data cable is one of the hardware devices that we must use for our daily use. Although the USB data cable is small, it is indispensable. The mobile phone that lacks the data cable will not work properly, which will bring a lot of trouble to consumers. The USB data cable has greatly increased the ease of use of the device, making the computer more easily and more public.
USB is the most common external bus standard on the PC field. It standardizes the connection and communication of the computer and external devices. The USB data cable supports the PnP (Plug in Plug) and hot-plug functions. With the rapid development of computer hardware, USB's application increases the speed of data transmission between external devices. The increased speed means that users can use more efficient external devices. For example, you can use a USB 2.0 scanner to scan a 4M picture within only 0.1 seconds.
Devices that support USB protocols according to different interfaces and data cables include mouse, keyboard, printer, scanner, camera, flash drive, MP3 machine, mobile phone, digital camera, mobile hard disk, external light software, USB network card, ADSL MODEM, Cable MODEM, and other electronic products.
USB (Universal Serial Bus) is an external bus structure for connecting the periphery of the applicable USB to the host. It is mainly used in medium-speed and low-speed peripherals. The USB data cable has four lines. Among them, two lines are responsible for transmitting 5V power supplies. They can directly power some peripherals. The additional two lines are the data line, and the data line is single work. The data rate throughout the system is predetermined, either high or low.
If you see a USB flag map on an interface or connection, you can determine that it is a USB device undoubtedly. And when the user connects the USB device to the computer while the machine is connected to the computer, the operating system immediately detects the USB device and automatically installs the corresponding driver.
Basic Framework for USB
A computer has several USB main controllers and root hubs, and the main controller is responsible for data processing, while the root gathering provides an interface and path between the main controller and the device. USB is a host-device structure system, and the picture below is the basic framework of USB.
Simply, that is, various devices can be connected to the host via the USB data cable, or to connect to the host via a USB Dock.
A USB interface is a common PC interface with only 4 lines. Red, white, green, and black is the standard wiring colors, corresponding to 1, 2, 3, 4 pins.
The definition of four lines is 1-power 2-data 3-data 4-power. And the general arrangement is: red, white, green and black from left to right.
USB interface definition
Definition:
Red -USB power -VCC, Power, 5V, 5VSB
White-OSB data channel (negative) -Data-, USBD-, PD-, USBDT +
Green-OSB data channel (positive) -data +, USBD +, PD +, USBDT +
Black - ground wire-Gnd, Ground
Note: don't reverse the positive and negative ends, otherwise you will burn the USB device or the computer's South Bridge chip.
The application of the USB data cable is very common in electronic devices such as smartphones, tablets, and cameras. Although many functions of different USB data cables are similar, their shape and size are different.
USB protocol overview
The USB-A data cable is extremely common. It can be found at one end of each USB data cable, which is used to connect various devices (such as smartphones, cameras, keyboards, etc.) to the computer. Of course, it has a charging function.
USB types
The USB Type-B data cable is not common like other USB connectors because the USB Type-B connector is mainly used to connect the printer and scanner to the computer. The USB TYPE-B data cable has a square shape with a tilted outer angle. Although they are still using them today, the USB B data cable is gradually eliminated.
The mini USB data cable is suitable for various equipment standards. However, it has been greatly eliminated and replaced by a micro USB data cable. Mini USB data lines are smaller than ordinary USB, but it is even bigger than the subsequent USB.
Mini USB data cables are very small. We often use them in thinner electronic devices. Almost all manufacturers worldwide, except Apple, have adopted mini USB.
USB types
The USB Type-C data cable is the latest USB port. It provides a faster data transfer rate than the previous USB version. The advantage of the USB TYPE-C data cable is that it is reversible. Unlike the previous product, it can be inserted up or down. The USB TYPE-C has become a new standard for mobile devices.
USB mouse, keyboard, camera, and other devices have different requirements for hosting. Therefore, USB's transmission mode can be four types:
1. Synchronously transfer. The bandwidth, determined interval time is determined. And fixed transfer rates are used in instant applications that require constant data transmission rates, such as the network telephone application that performs instant calls.
2. Interrupt transmission. The amount of data transmitted is small. But these data need to be handled in time to achieve real-time effects, mouse, and keyboards belong to this type.
3. Control transmission. This mode is usually smaller, transmitted between the computer and the USB peripheral endpoint,
4. Batch transmission. It is applied to a large number of transmission and receiving data. Its transmission speed is slow and the delay obvious, but it is transmitted correctly. Printers and scanners are these types.
On November 18, 2008, Intel, Microsoft, HP, Texas Instruments, NEC, ST-NXP, and other industry giants officially promoted USB3.0. USB 3.0 standards offer ten times the transfer speed and ten times the energy efficiency of USB 2.0, making them ideal for PC peripherals and consumer gadgets. The theoretical bandwidth of the USB3.0 interface is 5Gbps, and the theoretical bandwidth of USB2.0 is 480Mbps. All high-speed USB 2.0 devices will have a better performance to get USB3.0.
1. The data bandwidth of USB3.0 is ten times that of USB 2.0, which can reach 5Gb s (480MB/s). And its synchronous transmission bandwidth can reach 384MB/s, which is one of the main differences between USB3.0 and 2.0.
2. Low power consumption. The power consumption of USB3.0 is approximately 25% lower than USB2.0 when data transfer rates are 20MB/s.
3. USB3.0 is more energy-efficient than USB 2.0.
4. USB3.0 can provide greater power (2.5W to 4.5W) through the cable
5. USB3.0 is compatible. That's to say, it supports USB 2.0 devices, but USB2.0 cannot support USB3.0.
The USB cable constantly improves power means that people can use it to charge the laptop. Recently,
Intel and allies are developing USB Power Transmission (USB PD) technology. USB 2.0 can transmit 2.5-watt electric power, USB 3.0 is 4.5 watts, USB BC cable can transmit 7.5 watts of electricity, and USB PD can support 10 watts of mobile phone equipment, 18 watts of tablet equipment, and the vast majority of external, 36 Watt's thin client equipment, larger peripheral, 60 watts of notebooks, Docking Stations, and 100 watts of workstations.
The introduction of USB PD simplifies the charging of devices such as smartphones and tablets. As Intel Engineer Sanders and Dunstein said, "BBy supporting devices such as tablets, laptops, it makes the range of charging becomes wider.”