<h1> Accessories </h1> <p> Supplementary items used with other devices in this category. </p> <p>

<h1> Adapter Cards </h1> <h2> 1. What are Adapter Cards? </h2> <p> Adapter Cards are function expansion cards in computer hardware. They are inserted into expansion slots on the motherboard (such as PCI and PCIe interfaces) to connect the system to peripheral devices or add specific functions. Its core function is to establish a standardized interface between the computer bus and external devices to complete signal conversion, protocol adaptation, and data transmission. </p> <p>   </p> <h2> 2. What are the Main Types of Adapter Cards? </h2> <p> Adapter cards can be divided into the following categories according to their functions: </p> <p> Network Adapter Card (NIC) </p> <p> Used to connect computers to wired/wireless networks, supporting Ethernet protocol and data encapsulation transmission. </p> <p>   </p> <p> <strong>Sound Card (Audio Card)</strong> </p> <p> Processes the input/output of audio signals, supporting high-fidelity sound effects and multi-channel output. </p> <p>   </p> <p> <strong>Storage Interface Card</strong> </p> <p> Such as the SCSI adapter card, used to connect high-speed storage devices (such as hard disk arrays). </p> <p> <strong>Specialized Function Expansion Card</strong> </p> <p> Including video capture cards, industrial control cards, etc., providing customized functions for specific scenarios. </p> <p>   </p> <h2> 3. Hardware Composition and Related Components of Adapter Cards </h2> <h3> 1) ‌Core Components‌ </h3> <p> <strong>‌Interface Circuit‌</strong>: Realize electrical signal matching between bus and device‌. </p> <p> <strong>‌Control Chip‌</strong>: Manage data transmission protocols (such as TCP/IP, SCSI)‌. </p> <p> <strong>‌Connectors‌</strong>: Such as gold fingers (motherboard slot contacts), which must meet high plug-in life and stable contact resistance‌. </p> <p>   </p> <h3> 2) ‌Supporting Components‌ </h3> <p> <strong>‌Power Adapter Module‌</strong>: Provides regulated DC power (such as DC 12V/1A) for the card-mounted chip‌. </p> <p> <strong>‌Capacitor/Resistor‌</strong>: Used for signal filtering and circuit protection‌. </p> <p>   </p> <h2> 4. What are Adapter Cards Used for? </h2> <p> Adapter cards are widely used in computer expansion, industrial control, network communication, and other fields, supporting modular design and equipment function upgrades‌. For example, security cameras access the network through adapter cards, and routers rely on network cards to achieve data transmission‌. </p> <p>

<h1> Adapters, Converters </h1> <h2> 1. What are Adapters, Converters?‌ </h2> <h3> 1) ‌Adapters‌: </h3> <p> Mainly used for power conversion, such as converting alternating current (AC) to direct current (DC), or adjusting the voltage level to meet the needs of different devices. Common power adapters (Power Adapter) belong to this category and are widely used in scenarios such as mobile phone chargers and laptop power supplies. </p> <p>   </p> <h3> 2) ‌Converters‌: </h3> <p> <strong>Covering a wider range of voltage/current form conversion functions, including</strong>: </p> <p> <strong>‌DC-DC Converter‌</strong>: Adjusting the DC voltage level (such as boost or buck). </p> <p> <strong>‌AC-DC Rectifier‌</strong>: Converts AC to DC. </p> <p> <strong>‌DC-AC Inverter‌</strong>: Converts DC to AC (such as home inverter power). </p> <p> <strong>‌AC-AC Converter‌</strong>: Adjusts the amplitude or frequency of AC (such as inverter). </p> <p>   </p> <h2> 2. What are the ‌Core Functions and Features of Adapters, Converters?‌ </h2> <h3> 1) ‌Adapter‌: </h3> <p> Take the power adapter as an example. Its core function is to convert the mains power (such as 220V AC) into the low-voltage direct current (such as 5V DC) required by the device, and it has functions such as voltage regulation and overload protection. </p> <p>   </p> <h3> 2) ‌Converter‌: </h3> <p> <strong>‌Efficiency‌</strong>: Due to the high-frequency switching characteristics, the efficiency of switching converters (such as DC-DC) can reach more than 90%. </p> <p> <strong>‌Isolation and Non-isolation‌</strong>: The isolated converter uses a transformer to isolate the input/output circuit to improve safety. </p> <p> <strong>‌Control Mode‌</strong>: Including PWM (pulse width modulation) and PFM (pulse frequency modulation), etc. </p> <p>   </p> <h2> 3. What are Adapters, Converters Used for?‌ </h2> <p> <strong>‌Adapter‌</strong>: </p> <p> Mobile device charging (mobile phones, tablets). </p> <p> Industrial equipment power supply adaptation (such as sensor, controller power supply). </p> <p>   </p> <p> <strong>‌Converter‌</strong>: </p> <p> <strong>‌DC-DC‌</strong>: New energy vehicle power management, photovoltaic power generation system. </p> <p> <strong>‌AC-DC‌</strong>: Household appliance power module, industrial rectifier equipment. </p> <p> <strong>‌DC-AC‌</strong>: Solar inverter, UPS uninterruptible power supply‌. </p> <p> ‌<strong>AC-AC‌</strong>: Motor speed regulation (such as elevator, fan variable frequency control)‌. </p> <p>   </p> <h2> 4. ‌Technology Development Trends of Adapters, Converters‌ </h2> <p> <strong>‌High Integration‌</strong>: Chip-level packaging (such as SIP) improves power density and reduces volume‌. </p> <p> <strong>‌Intelligence‌</strong>: Digital control technology (such as DSP) optimizes dynamic response and energy efficiency‌. </p> <p> <strong>‌Wide Input Range‌</strong>: Supports a wider voltage input range and enhances device compatibility‌. </p> <p>   </p> <h2> 5. Adapters, Converters FAQs </h2> <h3> ‌1) What is the difference between Adapters and Converters? ‌ </h3> <p> <strong>‌Adapters‌</strong>: Mainly used to solve compatibility issues of physical interfaces. For example: </p> <p> Converting the shape of power plugs in different countries during travel (such as US standard to European standard); </p> <p> In software development, it is used to adapt data models and views (such as ViewModel in MVVM mode adapts data to UI)‌. </p> <p>   </p> <p> <strong>‌Converters‌</strong>: Solve the conversion problem of function or format. For example: </p> <p> Voltage conversion (such as converting 220V to 110V to protect the device); </p> <p> Data format conversion (such as converting SQL query results to DataFrame, type conversion in data binding). </p> <p>   </p> <h3> ‌2) Do you need to carry both an Adapter and a Converter when traveling? ‌ </h3> <p> <strong>‌Adapter only</strong>: If the device supports dual voltage (such as mobile phones and laptop chargers marked 100-240V), you only need to use an Adapter to adapt the plug shape. ‌<strong>Converter required</strong>: If the device only supports single voltage (such as some hair dryers and electric kettles), you need to use a Converter to convert the voltage to avoid damaging the device. ‌ </p> <p>   </p> <h3> ‌3) How to choose a suitable travel adapter? ‌ </h3> <p> <strong>‌Choose by destination</strong>: Different countries have different plug standards (such as US Type A, European Type C); </p> <p> <strong>‌Versatility</strong>: It is recommended to use a universal adapter that supports multiple countries' plugs (such as versions with USB-C interfaces); </p> <p> <strong>‌Safety</strong>: Give priority to brands with built-in overload protection or fireproof materials. ‌ </p> <p>   </p> <h3> 4) What should be noted when using Converters? ‌ </h3> <p> <strong>‌Voltage matching‌</strong>: Avoid using ordinary Converters with high-power devices (>1600W), which may cause overheating‌; </p> <p> <strong>‌Data conversion‌</strong>: Type safety needs to be handled during development (such as adding exception handling when converting Float to String)‌; </p> <p> <strong>‌Obfuscation compatibility‌</strong>: If the code is obfuscated (such as ProGuard), Converter-related classes/methods need to be retained (through the -keep rule)‌. </p> <p>

<h1> Brackets </h1> <p> Brackets usually refer to a mechanical structure used to fix or support electronic components/modules. </p> <p>   </p> <h2> What are the ‌Functional Characteristics of Brackets?‌ </h2> <p> Mainly used for mechanical fixation of components on circuit boards (PCBs), such as the installation of heat sinks, power modules, or special devices‌; </p> <p> Some models have auxiliary heat dissipation functions, and improve thermal conductivity through metal material design‌; </p> <p> In packaging applications, it is used in conjunction with surface mounting technologies such as SOP (Small Outline Package) to ensure device welding stability‌. </p> <p>   </p> <h2> What are the Types of Brackets? ‌ </h2> <p> <strong>Plastic Brackets</strong>: commonly used in lightweight scenarios, with insulation properties‌; </p> <p> <strong>Metal Brackets</strong>: mainly aluminum alloy/copper alloy, with both structural strength and heat dissipation requirements‌; </p> <p> <strong>Composite Materials</strong>: Improve high-temperature resistance through processes such as glass fiber reinforcement‌. </p> <p>   </p> <h2> What are Brackets Used for?‌ </h2> <p> Fixed installation of power semiconductor devices (such as thyristors and MOS tubes)‌; </p> <p> Auxiliary support structure of BGA packaged chips;‌ </p> <p> Electromagnetic shielding frame components of RF modules‌. </p> <p>

<h1> Cameras, Projectors </h1> <p> Devices designed for transmitting visual signals. </p> <p>

<h1> Computer Mouse, Trackballs </h1> <p> Products in this category are user interface devices, most commonly used for 2-dimensional directional input in context of navigating a graphical user interface of the type common in desktop computing environments. Both finished goods products suitable for consumer use and modular products designed to be assembled as a component of a larger system are included. </p> <p>

<h1> Desktop Joysticks, Simulation Products </h1> <p> Products in the desktop joystick and simulation product family are finished goods, user interface products designed to emulate control mechanisms commonly found in aircraft, vehicles, or other similar equipment, for use in computer simulation or other similar applications. Interface to a PC or similar device is typically achieved through a standard USB interface. </p> <p>

<h1> Keyboards </h1> <p> Products in the keyboard family are finished goods user interface devices commonly encountered in general purpose computing applications, and equipped with one or more of the interconnect modalities (USB, PS/2) common thereto. Primarily used for text input, some devices include a mouse-type function used for providing two-dimensional directional input, which is commonly employed as a means of navigating graphical user interfaces. </p> <p>

<h1> KVM Switches (Keyboard Video Mouse) </h1> <p> KVM (Keyboard Video Mouse) Switches are designed to control multiple computers in a rack from one or more KVM switches. The types of switches are network KVM, PS/2, standard KVM, and USB KVM with the number of ports being 1 to 32 and the peripherals are display port monitor, USB keyboard, USB mouse, audio, DVI monitor, keyboard, mouse, DVI/VGA monitor, VGA monitor, PS/2 keyboard, and PS/2 mouse. </p> <p>

<h1> KVM Switches (Keyboard Video Mouse) - Cables </h1> <p> KVM (keyboard-video-mouse) adaptor cables are designed for use with KVM switches, which allow for selecting between peripherals and protocols and account for differences in connector types. Common adaptations include D-Sub 15 position connectors to USB, mini DIN, DVI-D dual link, RJ45, 3.5 mm, and HDMI. Cables are selected by length and compatible KVM switch used. </p> <p>

<h1> Magnetic Strip, Smart Card Readers </h1> <h2> 1. ‌Magnetic Strip‌ </h2> <p> <strong>1) ‌Technical Principle‌</strong>: Magnetic stripe cards record information through magnetic oxide particles arranged on the surface, and need physical contact with the magnetic head for reading and writing, which is a passive recording medium. </p> <p> <strong>2) ‌Features‌</strong>: </p> <p> Low storage capacity (usually only a few dozen bytes), only supports one-way data reading. </p> <p> Weak security, susceptible to magnetic field interference or copying. </p> <p> <strong>3) ‌Typical Applications‌</strong>: traditional bank cards, hotel door cards, membership cards, etc. </p> <p> <strong>4) ‌Development Trend‌</strong>: Due to insufficient security, it is gradually being replaced by chip card technology. </p> <p>   </p> <h2> 2. ‌Smart Card Readers‌ </h2> <p> <strong>1) ‌Technical Principle‌</strong>: Based on radio frequency identification (RFID) or chip contact technology, it communicates with the embedded chip in the smart card through radio frequency signals, supporting two-way data interaction and encryption processing. </p> <p> <strong>2) ‌Core Components‌</strong>: </p> <p> <strong>‌Smart Card Chip‌</strong>: integrated with CPU, RAM, ROM, and other modules, can process data independently and filter erroneous instructions. </p> <p> <strong>‌Card Reader Interface‌</strong>: including physical contact (such as SIM card slot) or contactless (such as NFC). </p> <p> <strong>3) ‌Features‌</strong>: </p> <p> <strong>High Security</strong>: supports encryption algorithms to prevent data tampering. </p> <p> <strong>Versatility</strong>: can be used for identity authentication, payment, access control and other scenarios at the same time. </p> <p> <strong>4) ‌Typical Applications‌</strong>: </p> <p> <strong>‌Financial Field‌</strong>: payment verification for POS and ATM machines. </p> <p> <strong>‌Enterprise Scenarios‌</strong>: access control system, attendance management. </p> <p> <strong>‌Internet of Things‌</strong>: transportation card, smart device identity binding. </p> <p>   </p> <h2> 3. ‌Technology Comparison between ‌Magnetic Strip and ‌Smart Card Readers‌‌ </h2> <table> <tbody> <tr class="firstRow"> <td width="130" valign="top" style="padding: 0px 7px; border-width: 1px; border-color: windowtext; background: rgb(215, 215, 215);"> <p> ‌Dimensions </p> </td> <td width="204" valign="top" style="padding: 0px 7px; border-width: 1px; border-color: windowtext; background: rgb(215, 215, 215);"> <p> ‌Magnetic Strip </p> </td> <td width="234" valign="top" style="padding: 0px 7px; border-width: 1px; border-color: windowtext; background: rgb(215, 215, 215);"> <p> ‌Smart Card Readers </p> </td> </tr> <tr> <td width="130" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> ‌Data Interaction </p> </td> <td width="204" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p>  One-way reading </p> </td> <td width="234" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p>  Two-way reading and writing (including encryption) </p> </td> </tr> <tr> <td width="130" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> ‌Storage Capacity </p> </td> <td width="204" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> Low (<1KB) </p> </td> <td width="234" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> High (up to hundreds of KB) </p> </td> </tr> <tr> <td width="130" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> ‌Security </p> </td> <td width="204" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> Easy to copy, no encryption </p> </td> <td width="234" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> Support hardware-level encryption </p> </td> </tr> <tr> <td width="130" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> ‌Applicable Scenarios </p> </td> <td width="204" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p>  Gradually phased out traditional scenarios </p> </td> <td width="234" valign="top" style="padding: 0px 7px; border-left-width: 1px; border-left-color: windowtext; border-right-width: 1px; border-right-color: windowtext; border-top: none; border-bottom-width: 1px; border-bottom-color: windowtext;"> <p> High-security, multi-functional modern scenarios </p> </td> </tr> </tbody> </table> <p>   </p> <p> <strong>‌Integration Trend‌</strong>: Some devices are compatible with dual-mode reading of magnetic stripes and smart cards to meet the needs of the transition period. </p> <p>   </p> <h2> 4. ‌Industry Challenges and Development Directions‌ </h2> <p> <strong>‌Magnetic Strip‌</strong>: Gradually withdraw from the mainstream market and only retain in low-cost, low-risk scenarios. </p> <p> <strong>‌Smart Card Readers‌</strong>: Evolve towards miniaturization, low power consumption, and multi-protocol compatibility (such as NFC+Bluetooth), and expand to the Internet of Things, military electronics, and other fields. </p> <p>   </p> <p>

<h1> Memory Card Readers </h1> <h2> 1. What are Memory Card Readers? </h2> <p> ‌Memory Card Readers‌ are electronic devices used to read or write data from memory cards (such as SD cards, microSD cards, etc.). Its core functions include: </p> <p> <strong>‌Data Interaction‌</strong>: Connect memory cards to computers, mobile phones, and other devices through physical interfaces (such as USB, Type-C) to achieve data backup, transmission, or sharing; </p> <p> <strong>‌Compatibility Expansion‌</strong>: Support multiple memory card formats (such as SDXC, SDHC) and different sizes of adaptation (such as microSD to SD card slot); </p> <p> <strong>‌Plug and Play‌</strong>: Most card readers do not require driver installation and are directly identified as removable storage devices by the operating system. </p> <p>   </p> <h2> 2. What are the Types of Memory Card Readers? </h2> <h3> 1) ‌By Interface Type‌: </h3> <p> <strong>‌USB Card Reader‌</strong>: compatible with USB 2.0/3.0 protocols, supports high-speed data transmission; </p> <p> <strong>‌Type-C Card Reader‌</strong>: suitable for modern mobile devices, supports forward and reverse plugging; </p> <p> <strong>‌Wireless Card Reader‌</strong>: wireless data transmission via Wi-Fi or Bluetooth (needs to be combined with specific memory cards). </p> <p>   </p> <h3> 2) ‌By Card Slot Type‌: </h3> <p> <strong>‌Single Card Slot Reader‌</strong>: supports only a single type of memory card (such as a dedicated SD card reader); </p> <p> <strong>‌All-in-one Card Reader‌</strong>: integrates multiple card slots and is compatible with multiple formats such as SD, microSD, and CF cards. </p> <p>   </p> <h2> 3. What are the Technical Features of Memory Card Readers? </h2> <p> <strong>‌Transfer Rate‌</strong>: depends on the memory card standard (such as UHS-I, UHS-II) and the card reader interface protocol, up to 300MB/s; </p> <p> <strong>‌Compatibility‌</strong>: needs to match the physical size and communication protocol of the memory card (such as SD 3.0/4.0 specifications); </p> <p> <strong>‌Stability‌</strong>: the built-in controller optimizes the data reading and writing process and reduces the transmission error rate. </p> <p>   </p> <h2> 4. What are Memory Card Readers Used for? </h2> <p> <strong>‌Photography and Videography‌</strong>: quickly export high-definition materials shot by cameras, drones, and other devices; </p> <p> <strong>‌Mobile Device Expansion‌</strong>: provide additional storage space for mobile phones and tablets (such as through OTG function); </p> <p> <strong>‌Industrial and Embedded Systems‌</strong>: used for firmware updates or data collection (need to meet specific environmental protection levels). </p> <p>   </p> <h2> 5. Selection Recommendations for Memory Card Readers </h2> <p> <strong>‌Interface Matching‌</strong>: Give priority to card readers that are compatible with the device interface (such as USB-C interface adapting to Type-C devices); </p> <p> <strong>‌Multi-format Support‌</strong>: If you need to frequently switch between different memory cards, it is recommended to use an all-in-one card reader to reduce the number of devices; </p> <p> <strong>‌Speed Requirement‌</strong>: For high-resolution video editing scenes, it is recommended to choose a card reader that supports UHS-II and above standards. </p> <p>   </p> <h2> 6. Memory Card Readers FAQs </h2> <h3> ‌1) Is the card reader compatible with all types of memory cards? ‌ </h3> <p> The compatibility of the card reader depends on the memory card formats it is designed to support (such as SD, microSD, CF cards, etc.). Some all-in-one card readers can adapt to multiple types, but it is necessary to pay attention to the interface and protocol differences of different devices (such as USB 3.0 and USB-C). </p> <h3> ‌2) How to improve the data transmission speed of the card reader? ‌ </h3> <p> Use a card reader that supports high-speed protocols (such as USB 3.2 or UHS-II standards); </p> <p> Make sure the read and write speed of the memory card itself matches the card reader. </p> <h3> 3) What to do if the card reader cannot recognize the memory card? ‌ </h3> <p> Check whether the memory card is correctly inserted into the card reader; </p> <p> Try to change the card reader or computer port; </p> <p> If the memory card is damaged, you can use professional data recovery tools (such as EaseUS Partition Master) to try to repair or recover data. </p> <h3> 4) How to choose a suitable card reader? ‌ </h3> <p> Choose a card reader with the corresponding slot according to the common memory card type; </p> <p> Give priority to brand products (such as SanDisk and Western Digital) to ensure compatibility and stability; </p> <p> Pay attention to additional features (such as waterproof and multi-device compatibility) and warranty services. </p> <h3> 5) What are the precautions for memory card data management? ‌ </h3> <p> Regularly back up important data to other devices or the cloud; </p> <p> Avoid unplugging the memory card or card reader during data transfer; </p> <p> Format the memory card before use (be sure to choose a file system that matches the device). </p> <p>

<h1> Monitors </h1> <p> Monitor products are user interface components used to display text, images, video, or other visual information. Integration of touchscreen inputs allows these devices to also function as user input devices to a system by inference of user intent in context of the information being displayed at the screen location and point in time where the user makes contact. </p> <p>

<h1> Printers, Label Makers </h1> <p> Printers and label makers are equipment used to transfer images or text onto a flat surface (typically paper). Types include dot matrix, plotter, thermal, or UV printers. Models include desktop, embedded, or handheld. Styles include barcodes, labels, receipts, markers, tapes, sleeves, and plastic tags. </p> <p>

<h1> Privacy Filters, Screen Protectors </h1> <p> Privacy filters or screen protectors are used to enhance or restrict visibility of a monitor or screen. Types include anti-glare, film, privacy, and widescreen privacy. These are often purchased by type and by either diagonal screen size or viewing area, while others are manufactured for specific monitor types. </p> <p>

<h1> Server Acceleration Cards </h1> <p> Server Acceleration Cards, also known as system memory accelerators, target the continually evolving requirements of modern data centers. By providing higher performance than traditional CPUs, programmable accelerator cards speed up any workload without having to change existing hardware. Server accelerator cards provide advanced performance in machine learning artificial intelligence, video transcoding, financial (crypto) trading, and database search and analytics applications. </p> <p>

<h1> USB Hubs </h1> <h2> 1. What are the ‌Functions and Features of USB Hubs?‌ </h2> <p> USB Hubs are electronic components used to expand the host USB interface, which can expand a single USB interface into multiple independently working downstream ports. Core functions include: </p> <p> <strong>‌Interface Expansion‌</strong>: Connect multiple devices (such as USB flash drives, mice, keyboards, etc.) through a star topology to solve the problem of insufficient host interfaces. </p> <p> <strong>‌Power Management‌</strong>: Support bus-powered or self-powered modes, distribute power to downstream devices (voltage range is usually 4.4V-5.25V), and have built-in overcurrent/short-circuit protection mechanisms. </p> <p> <strong>‌Data Transmission‌</strong>: Support USB protocols of different speeds (such as USB 2.0/3.0), and achieve rate matching between high-speed and low-speed devices through transaction translators. </p> <p>   </p> <h2> 2. How does USB Hubs Work?‌ </h2> <p> <strong>‌Data Transmission Process‌</strong>: When a device is inserted into the Hub, the Hub detects the level change and reports it to the host. The host allocates power and transmission rate through initialization commands and then starts data transmission. </p> <p> <strong>‌Topology‌</strong>: Adopting hierarchical star topology, Hub acts as a relay node, responsible for signal enhancement, power distribution, and data forwarding (bidirectional transmission: host ↔ device). </p> <p> <strong>‌Internal Modules‌</strong>: </p> <p> <strong>‌Hub Repeater‌</strong>: Bidirectional data forwarding (uplink ↔ downlink). </p> <p> <strong>‌Hub Controller‌</strong>: Communicates with the host and implements Hub control. </p> <p> <strong>‌Transaction Translator‌</strong>: Converts high-speed/full-speed/low-speed transmission transactions. </p> <p>   </p> <h2> 3. ‌Hardware Design and Protocol Support of USB Hubs‌ </h2> <p> <strong>‌Chip Solution‌</strong>: For example, high-performance chips such as CH334/CH335 support MTT (multi-transaction translator) mode, and each port has an independent bandwidth of 12Mbps (USB 2.0). </p> <p> <strong>‌Power Circuit‌</strong>: Cooperate with the current limiting switch chip to realize current detection (GANG mode or independent mode), and integrate ESD protection (anti-electrostatic discharge). </p> <p> <strong>‌Protocol Compatibility‌</strong>: </p> <p> <strong>USB 2.0 Hub</strong>: Theoretical bandwidth 480Mbps, compatible with USB 1.1 devices. </p> <p> USB 3.0/3.1 Hub: bandwidth increased to 5Gbps/10Gbps, backward compatible with old protocols. </p> <p>   </p> <h2> 4. ‌Application Scenarios and Precautions for USB Hubs‌ </h2> <p> <strong>‌Scenarios‌</strong>: home/office equipment expansion, industrial computer interface expansion, embedded systems, etc. </p> <p> <strong>‌Bandwidth Allocation‌</strong>: downstream ports share upstream bandwidth, and the actual rate is affected by Hub loss (such as USB 3.0 Hub total bandwidth ≤5Gbps). </p> <p> ‌<strong>Selection Suggestions‌</strong>: Comprehensive selection based on the number of devices, power supply requirements (self-powered devices are preferred over high-power devices), and transmission rate (MTT chips are preferred). </p> <p>