USBインターフェースはなぜそれほど大きいのですか?

 そのような質問をする友人がしばしばいます、そして、コンピューターまたは電子装置の小型化の傾向はますます明白になっています。設計時には、コンピュータは標準のUSBインタフェースと同じくらい薄くなるように設計できること、そして巨大で肥大化したUSBインタフェースが依然として存在し続けるという価値と意味を持ち続けることができるかどうかがよくわかります。今日は、USB開発の歴史を簡単に概説し、この問題を説明して説明します。

  明確にするための最初のことは、携帯電話で最も一般的に使用されているマイクロUSBインターフェースと主流のUSB Type-Cのサイズが比較的小さいということです。 Thunderboltや他の専用インターフェースと比べて、小型化されたUSBインターフェースはすでにかなり優れています。それからUSBインターフェースは比較的大きいと思います、それは最も早いタイプAコネクタに集中するべきです。後のタイプBのため、インタフェースはすでにケーブルよりはるかに太いです。

  USB Type A誕生於1996年,當時並行接口和串行接口是主流。作為一個新事物,USB接口是劃時代的。首先,將並行接口的25針,36針大型連接器放在一邊,比較A型和9針串行接口的實際參數。它是標準的USB母頭連接器,即使橫截面積為14.4 * 7.1 mm,小尺寸為13.4 * 7.1 mm,它甚至可以做到一點點。串行接口DB 9的母連接器尺寸為16.9 * 9.2 mm,比A型大得多。串口對連接穩定性有嚴格要求,通常有兩個固定螺孔。兩個固定螺釘孔之間的距離為25 mm,因此一個串行接口的尺寸實際為30.8 * 9.2 mm。寬度是USB接口的兩倍,高度超過它。使用與VGA顯示器相同的9孔串行接口,讓我們想一想作者的初始鼠標。

  然後,經過多年的發展,每個人都會問這個界面是否會變得越來越小。作者認為,另一個問題是傳輸速度顯著增加,並且線路的EMI掩模要求越來越高。在USB 2.0時代,傳輸速度已達到480 Mbps。由高頻信號引起的高頻脈衝干擾需要厚掩模層來解決EMI問題。所以現在USB接口並沒有變小,原因就在這裡。

  但總的來說,考慮到這個問題不能落後於時代。當時的設計師並不認為隨後的發展如此之快。

DisplayPort connector standard interface technology

DisplayPort technology, which emerged as the successor to DVI technology, adds support for HD audio signal transmission while transmitting video signals while supporting higher resolution and refresh rates. The DisplayPort connector is designed to support both external display connections and built-in display connections. VESA hopes notebook manufacturers not only use DisplayPort to connect independent displays, but also can use it to directly connect the LCD screen and the motherboard for notebook upgrades. To this end, DisplayPort interface is also designed to be very compact, not only for the convenience of the notebook, but also allows the graphics card to configure multiple interfaces.

Now DisplayPort interface technology, support for single-channel, one-way. Si County Road connection, efficient data transfer rate enough to send uncompressed video and related audio, but it also supports two-way secondary channel for device control purposes. Not long after the Video Standards Electronics Association (VESA) developed the DisplayPort connector, the Special Interest Group (SIG) proposed UDI, which is compatible with both HDMI and DVI, which is what DisplayPort lacked but which does not support audio Signal transmission, so DIisplayOirt supporters have many well-known notebook manufacturers brands, Dell, Hewlett-Packard, Lenovo and so on. DisplayPort micro-packet transmission architecture, but the high bandwidth is absolutely not in the transmission process, "drop package" phenomenon; micro-packet architecture and another big feature is the flexibility so that DisplayPort can easily split-screen display (Up to six 1080i or three 1080p video streams on a single DisplayPort cable), DisplayPort can transmit multiple groups of video within the same Lane / Link, and this is what the micro-packet architecture has given power. The use of switching transmission DVI, HDMI and other video can only be transmitted within a group of Link video. In addition, DisplayPort also has an external channel for bi-directional communication with a transfer rate of more than 1Mbps, which can be directly used as a transmission channel for low-bandwidth data such as voice and video, and can also be used for game devices without delay.

The DisplayPort interface will be the primary interface standard for future display devices and will completely replace today's DVI and VGA, and even HDMI. Compared to the most advanced HDMI interface, DisplayPort connector has more advantages and greater transmission bandwidth, and scalability and peripheral compatibility is much stronger than the HDMI interface; cost, DisplayPort Not only can drive the panel directly, save a lot of circuit costs and space, and the standard is completely open, do not need to pay for the copyright costs involved in the HDMI interface.

Phone connector category and performance

With the renewal of mobile phone technology, the design and manufacturing technology of mobile phone components are continuously upgraded. Among them, the connector is one of the most important electronic components. The quality of the mobile phone directly affects the quality of the mobile phone and the reliability when used.

  The main types of mobile phone connector:
  Connector generally refers to the connection of two active devices, transmission current or signal. According to the application environment, objects, power, frequency, a wide range of connectors, the main applications are FPC connector, I / O connector, card connector, battery connector and antenna connector five.

  FPC connector: Used to connect LCD display screen and drive circuit (PCB).
  I / O connector: contains two parts of the signal and power connections, is the most important mobile phone access.
  Card connector: Mainly used to connect the SIM card and T-flash card, is an integral part of the phone.
  Battery connector: can be divided into knife blade and shrapnel, the main application for the shrapnel.
  Antenna Connector: It is responsible for connecting the antenna and the mobile phone driver circuit (PCB), and the shape of the antenna affects the high frequency performance of the antenna.

  Mobile phone connector's main performance:
  1, mechanical properties
  As the use of mobile phones in the relatively high number of connectors, should have a good insertion and removal force, that is, insertion force and pull-out force must meet the requirements of the industry standards. In general, the insertion force standard mainly limits the maximum insertion force, while the standard of the pullout force mainly stipulates the minimum pullout force because the resistance when inserted is too large and the pullout resistance is too small, which is unfavorable to the normal use of the handset.
In addition, another important mechanical performance of the connector is its mechanical life, that is, the durability of the phone connector. The manufacturer must conduct this test before the product is sold to determine the mechanical life of the part for the cooperator and customer to know about the quality of the product.


  2, electrical performance
  Contact resistance: Low and stable contact resistance is one of the prerequisites for high quality connectors.
  Insulation resistance: can determine the connector between the connector and the shell, the contact between the contacts and the insulation is qualified.
  Dielectric strength: also known as withstand voltage, dielectric withstand voltage, used to determine the connector between the connector and the shell, the contact between the contacts and the rated voltage withstand capability.
  Other electrical properties: Depending on the type of connector varies.


  3, environmental performance
  Temperature: The general rating of the operating temperature range of -65 ℃ ~ 200 ℃ (except for special categories, such as high temperature special connector), due to the working principle of the connector will have heat, it is generally recognized that the working temperature is the ambient temperature and contact temperature rise Sum.
  Moisture resistance: the insulation of the connector will be affected by water vapor intrusion, and moisture may cause corrosion of the metal parts, so the connector will be made constant moist heat test before leaving the factory, the test time varies according to the product category .
  Resistance to salt spray: When the working environment of the connector contains salt and moisture, galvanic corrosion may occur on the surface of the contact piece and the metal structural parts, which may affect the normal use of the physical and electrical connectors.
  Vibration and Shock: These two items are one of the important properties of a connector and are important criteria for judging the electrical contact reliability of a connector and the robustness of the mechanical structure.
  Other environmental performance: Depending on the use of the connector requirements, there are low pressure, sealing (liquid pressure, air leaks), liquid impregnation (for specific liquid resistance to abuse ability) and other properties.