The relevant knowledge points of usb connector
What is a usb connector
USB connector can easily add equipment to the computer without occupying the computer's parallel port and serial port. Just plug in the device and it can be used, but it is sometimes difficult to use.
Characteristics of usb connector
1, with multiple types of interface designs such as A Type/B Type/C Type/micro type/Mini USB male and female sockets
2. There are DIP/SMT/clamping type/welding type for installation
3. The contact part of the terminal adopts elastic design to ensure good contact performance and long life requirements
4. Meet the temperature resistance requirements of various welding equipment parameters.
The relevant knowledge points of usb connector
USB connector configuration function
USB defines the following four transmission types.
● Control transmission: Send short commands and queries to the device, or receive status responses from the device.
● Interrupt transmission: Transmit with very small data packets to ensure fast response, such as mouse or keyboard.
● Block transmission: large data transmission with error detection, such as printers or hard disks.
● Synchronous transmission: Real-time streaming data transmission without error detection, such as speakers.
The internal driver of the device sets the device type of each downstream device. According to different device types, the operating system can load standard drivers. The human-machine interface device class (HID) and mass storage device class (MSD) have drivers that come with the operating system. Other types include audio, printer, video, and test and measurement. In addition, USB also provides a vendor class to allow customers to customize.
Usb connector use
is suitable for information or power interface in electronic devices such as computers and mobile phones.
The relevant knowledge points of usb connector
How to use the usb connector
There are many factors that need to be considered when selecting a usb connector, among which environmental parameters are one of the important factors, including temperature, humidity, air pressure, etc. Under different environmental conditions, the use of usb connectors is also different. Here are some tips for use in extreme environments.
1. High temperature environment
The metal material and insulating material of the usb connector determine the working environment temperature of the connector. High temperature will destroy the edge material, causing the insulation resistance and pressure resistance to decrease; for metals, high temperature can make the contact pair lose its elasticity, accelerate oxidation and cause coating deterioration. The usual ambient temperature is -40~80℃, which may be even higher in special occasions.
2, humid environment
The relative humidity is greater than 80%, which is the main cause of electrical breakdown. Humid environment causes the absorption and diffusion of water vapor on the surface of the insulator, which easily reduces the insulation resistance below MΩ. Long-term exposure to high humidity will cause physical deformation, decomposition, and escape of products, resulting in respiratory effects, electrolysis, and corrosion And cracks. Especially for the USB connector outside the device, environmental conditions such as humidity, water seepage and pollution are often considered. In this case, a sealed connector should be selected.
3, sudden temperature change environment
Humidity sudden change test is to simulate the actual use of using a USB connector in a cold environment to a warm environment, or to simulate a sudden change in the ambient temperature of a spacecraft or probe. Sudden changes in temperature may crack or delamination of insulating materials.
4. Thin air environment
At high altitudes where the air is thin, the plastic emits gas to contaminate the contact pair, and the corona tends to increase, the pressure resistance decreases, and the circuit produces a short circuit failure. When the altitude reaches a certain value, the performance of the plastic deteriorates. Therefore, when unsealed connectors are used at high altitude, they must be derated.
5. Corrosive environment
According to the use of the usb connector in different corrosive environments, the corresponding metal, plastic, and plating structure connectors are selected. Like the connectors used in the salt spray environment, if there is no anti-corrosion metal surface, the performance will deteriorate rapidly. In an environment with a considerable concentration of SO2, it is not advisable to use silver-plated connectors. In hot flash areas, mold is also an important issue.
Netizen asks: Is it necessary to use high-quality usb connectors when designing electronic products?
Expert answer: The problem mentioned by this netizen is often encountered by many usb system designers, and it is also a misunderstanding, because the importance of connectors is often underestimated when designing and cheap and poor quality connectors are used. . Although this seems to save costs, the subsequent maintenance costs are considerable. Low-quality connectors can cause usb systems to fail to operate normally, product recalls, product liability cases, circuit board damage, rework and repairs, which will lead to loss of users. I believe this is not what companies want to see. Therefore, don't underestimate the importance of connectors when designing usb products, you should choose a high-quality and suitable usb connector.
