USB Cables
USB Cables (Universal Serial Bus Cables) are core components used to connect electronic devices and realize data transmission and power supply.
1. USB Cables Overview
USB Cables follow the USB standard, use serial communication technology, transmit data bit by bit through a single wire, and integrate power supply functions. Its core functions include:
Bidirectional Communication: support data interaction between device and host;
Power Transmission: provide 5V basic voltage, which can be expanded to 20V, and the power supply power reaches 100W;
Plug and Play: support hot plugging, and the connection can be recognized without restarting the device.
2. What are the Physical Structure of USB Cables?
The standard USB 2.0 cable contains four independent cores (USB 3.0 and above versions add additional data channels):
VCC (Red): provides a 5V power supply, the current limit varies depending on the version (such as 500mA for USB 2.0);
GND (Black): forms a power loop to ensure current stability;
D+ (Green) and D- (White): responsible for differential signal transmission to ensure data accuracy.
3. What are the Interface Types of USB Cables?
The interface form of USB Cables has undergone many iterations:
Type-A: rectangular design, commonly seen on the host side (such as computer USB port);
Type-B: square or trapezoidal, mostly used for peripherals such as printers and mobile hard drives;
Type-C: oval symmetrical design, supports positive and negative blind insertion, integrates high-speed transmission (USB4 up to 40Gbps) and high-power power supply capability, and has now become a mainstream interface.
4. What are USB Cables Used for?
Device Interconnection: connecting computers and peripherals (such as keyboards, and mobile hard drives);
Cross-device Transmission: data transmission between two devices is realized through a bridge cable (USB-to-USB);
Fast Charging: The Type-C interface cooperates with the PD protocol to power high-power devices such as laptops and mobile phones.
5. Technology Evolution Trend of USB Cables
From USB 1.0 (1.5Mbps) in 1996 to USB4 (40Gbps) in 2019, the transmission rate has increased by more than 2,600 times, and compatibility has continued to increase, supporting video output and multiprotocol expansion (such as Thunderbolt 3). The popularity of the Type-C interface marks the development of USB technology towards multi-functional integration.