1996
Universal Serial Bus (USB) is an interface to establish communication between devices and a host controller (usually personal computer). Nowdays USB has replaced a variety of earlier PC interfaces (such as RS-232 serial , parallel port , and even FireWire ). Due to the ability to supply power to the preipheral devices USB is often used as a power charger for portable devices .
An USB system architecture consists of a host controller, a USB ports, and multiple connected devices. Additional USB hubs may be included allowing branching into a tree structure with up to five tier levels. USB can connect computer peripherals such as mice, keyboards, digital cameras , PDA , mobile phones , printers, personal media players , Media Transfer Protocol (MTP) devices, flash drives, GPS , Network Adapters, and external hard drives . For many of those devices, USB has become the standard connection method.
USB interface aimed to remove the need for adding expansion cards into the computer's PCI or PCI-Express bus, and improve plug-and-play capabilities by allowing devices to be hot swapped or added to the system without rebooting the computer.
Pin | Name | Cable color | Description |
---|---|---|---|
1 | VCC | Red | +5 VDC |
2 | D- | White | Data - |
3 | D+ | Green | Data + |
4 | GND | Black | Ground |
There are several types of USB connectors. The connector mounted on the host or device is called the receptacle, and the connector attached to the cable is called the plug. The original USB specification detailed Standard-A and Standard-B plugs and receptacles. Nowdays there are 7 USB connectors known: Standard-A, Standard-B, Mini-A, Mini-B , Micro-A, Micro-AB, Micro-B , Type-C . Mini-USB pinout and Micro-USB pinout are slightly different: standard USB uses 4 pins while Mini-USB and Micro-USB uses 5 pins in connector. The additional pin is used as an attached device presence indicator.
USB is a serial bus. It uses 4 shielded wires: two for power (+5v & GND) and two for differential data signals (labelled as D+ and D- in pinout). NRZI (Non Return to Zero Invert) encoding scheme used to send data with a sync field to synchronise the host and receiver clocks. In USB data cable Data+ and Data- signals are transmitted on a twisted pair. No termination needed. Half-duplex differential signaling helps to combat the effects of electromagnetic noise on longer lines. Contrary to popular belief, D+ and D- operate together; they are not separate simplex connections. USB 2.0 provides for a maximum cable length of 5 meters for devices running at Hi Speed.
Univeral serial bus supports Control, Interrupt, Bulk and Isochronous transfer modes.
There are some major USB versions known nowdays:
USB 1.0 and USB 2.0 shares same connector pinout, USB 3.0 pinout and USB Type C features new connectors with their own pinouts.
An USB device must indicate its speed by pulling either the D+ or D- line high to 3.3 volts. These pull up resistors at the device end will also be used by the host or hub to detect the presence of a device connected to its port. Without a pull up resistor, USB assumes there is nothing connected to the bus.
In order to help user to identify maximum speed of device, a USB device often specifies its speed on its cover with one of the USB special marketing logos.
When the new device first plugs in, the host enumerates it and loads the device driver necessary to run it. The loading of the appropriate driver is done using a PID/VID (Product ID/Vendor ID) combination supplied by attached hardware. The USB host controllers has their own specifications: UHCI (Universal Host Controller Interface), OHCI (Open Host Controller Interface) with USB 1.1, EHCI (Enhanced Host Controller Interface) is used with USB 2.0.
The USB connector provides a single 5 volt wire from which connected USB devices may power themselves. A given segment of the bus is specified to deliver up to 500 mA. This is often enough to power several devices, although this budget must be shared among all devices downstream of an unpowered hub. A bus-powered device may use as much of that power as allowed by the port it is plugged into.
Bus-powered hubs can continue to distribute the bus provided power to connected devices but the USB specification only allows for a single level of bus-powered devices from a bus-powered hub. This disallows connection of a bus-powered hub to another bus-powered hub. Many hubs include external power supplies which will power devices connected through them without taking power from the bus. Devices that need more than 500 mA or higher than 5 volts must provide their own power.
When USB devices (including hubs) are first connected they are interrogated by the host controller, which enquires of each their maximum power requirements. However, seems that any load connected to USB port may be treated by operating system as device. The host operating system typically keeps track of the power requirements of the USB network and may warn the computer's operator when a given segment requires more power than is available and may shut down devices in order to keep power consumption within the available resource.
Specification | Current | Voltage | Power (max) |
---|---|---|---|
Low-power device | 100 mA | 5 V | 0.50 W |
Low-power SuperSpeed (USB 3.0) device | 150 mA | 5 V | 0.75 W |
High-power device | 500 mA | 5 V | 2.5 W |
High-power SuperSpeed (USB 3.0) device | 900 mA | 5 V | 4.5 W |
Battery Charging (BC) 1.2 | 1.5 A | 5 V | 7.5 W |
Type-C | 1.5 A | 5 V | 7.5 W |
3 A | 5 V | 15 W | |
Power Delivery 2.0 Micro-USB | 3 A | 20 V | 60 W |
Power Delivery 2.0 Type-A/B/C | 5 A | 20 V | 100 W |
To recognize Battery Charging, a dedicated charging port places a resistance not exceeding 200 Ω across the D+ and D− terminals.
Dedicated charger mode:
A simple USB charger should incorporate 200 Ohm resistor between D+ and D- wires (sometimes shortcircuit D+ and D- together is enough). The device will then not attempt to transmit or receive data, but can draw up to 1.8A, if the supply can provide it.
Supplied voltage by a host or a powered hub ports is between 4.75 V and 5.25 V. Maximum voltage drop for bus-powered hubs is 0.35 V from its host or hub to the hubs output port. All hubs and functions must be able to send configuration data at 4.4 V, but only low-power functions need to be working at this voltage. Normal operational voltage for functions is minimum 4.75 V.
Shield should only be connected to Ground at the host. No device should connect Shield to Ground.
Shielded: Data: 28 AWG twisted Power: 28 AWG - 20 AWG non-twisted
Non-shielded: Data: 28 AWG non-twisted Power: 28 AWG - 20 AWG non-twisted
Power Gauge | Max length |
---|---|
28 | 0.81 m |
26 | 1.31 m |
24 | 2.08 m |
22 | 3.33 m |
20 | 5.00 m |
Usb pinout: the beginner’s guide.
Home » Blog » Components » USB Pinout: The Beginner’s Guide
Nowadays, the USB interface makes it easy to complete projects that involve creating a physical connection between a host controller and several other bus-powered devices.
USB stands for Universal Serial Bus and has since replaced its predecessors (FireWire, RS-232 serial, and even parallel) as the primary interface for connecting a host to a device.
Normally, a USB system’s architecture includes a host controller, USB ports, and a variety of devices.
Also, there are cases where you can add additional USB network hubs to create a tree connection structure.
However, that’s just the surface of it all.
In this article, we’ll explain everything about USB and give different USB examples for your circuits.
Let’s begin!
USB Flash drive
The USB has four shielded wires that work as pins. Two of these wires are for power supply, while the other two are for differential data signal pairs.
Check out the table below for the full USB pinout.
1 | VCC | Red | +5 VDC power supply pin |
2 | D- | White | Data- pin |
3 | D+ | Green | USB data cable Data+ |
4 | GND digital ground | Black | Ground pin |
Plugging a USB pen drive into a laptop
Like all connectors, all types of USB connectors have male and female types, making sure you connect your devices in the right direction.
It’s essential to make correct USB connections to allow the system to follow the required USB protocol. So, to establish a connection, USB remote devices feature what we call an upstream connection. These remote devices use this upstream connection to connect to a host.
Now, the hosts also have downstream connections that allow them to connect to the remote devices.
Furthermore, you can’t use upstream and downstream connections interchangeably. This helps you avoid misconnections and makes sure you connect the USB cable only in the right direction.
It also helps you avoid several issues like illegal loopback connections and connecting a downstream port to another downstream port.
First, a USB device will show its maximum speed by using pull-up resistors to draw the “D+” and “D-” terminals to 3.3V. Now, the host or hub will also use these pull-up resistors to detect when you connect a compound device to its port. Thus, without a pull-up resistor, the USB won’t detect your connected device or if you have a broken device or broken connector .
So, when you plug in an external device for the first time, the host device scans it and loads the correct driver version required to run the device. To do this, the host uses a product ID/vendor ID (PID/VID)—which the connected hardware or device supplies. Once the host completes the loading of necessary device drivers, the hardware/device will be ready for use.
Note: USB host controllers have their specifications. We have the Universal Host Controller Interface (UHCI), which works for all USB types; the Open Host Controller Interface (OHCI), which works with USB 1.1; and the Enhanced Host Controller Interface (EHCI), which works with USB 2.0.
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Originally, the USB cable could only be one of two types, and these two types included “Type A” and “Type B”. Afterward, we got the USB C type, which boasted a better data transfer speed with a more robust system.
Check out the table below for a full overview of the different USB types.
Type-A USB is the most popular type of USB connector. Plus, you can find them on host controllers, computers, flash drives, and several other items. Also, you can only make downstream connections with the Type-A USB, as its sole use is for controllers and hubs.
Flash Drive
Type-A USB connectors are bigger than other connectors and have flat and rectangular shapes. Plus, friction holds this connector in place, making it easy to connect and disconnect. However, using it in areas where your equipment might vibrate isn’t a great idea.
The Type-A USB has two versions: Male and female versions. The male version is the plug, while the female version is what we know as the socket or port.
Applications.
The older versions of the Type-A connector have four pins, while the newer versions have nine pins. Here’s a table showing all the pins of the Type-A connector.
Note: all generations of the Type-A USB connector have pins 1 to 4, while third-generation connectors have pins 5-9.
The USB-B is the second connector type that mostly works for connecting peripherals like printers and scanners. Plus, their pinouts have a different arrangement.
It has an almost square shape with a slight bevel at the top end corners of the connector. Also, it uses friction to remain in place when connected.
The Type-B USB port is an upstream connector that you can only find on peripheral devices. Thus, most Type-B USB applications require A to B USB cables.
Here’s an interesting fact:
Type-B USB canceled out the chances of creating a connection between two host computers. Thus helping to prevent damage.
This connector mainly works for peripherals like printers and scanners.
Like the Type-A USB, the older versions of Type-B have four pins, while the newer 3.0 versions have nine pins. Here’s a table showing all the pins:
Also, there is a second type of Type-B connector that has two extra pins:
10 | DPWR | N/A | Power to device |
11 | DGND | N/A | Ground DPWR return |
Source: Wikimedia Commons
The USB Type-C is the USB specification that’s slowly replacing the USB-B. It’s a tiny 24-pin reversible plug that works for USB cabling and devices.
Type-C USBs can serve as connectors for both hosts and devices. Plus, you can find Type-C USBs in most recent mobile devices.
The Type-C USB has 24 pins which you can connect reversibly. Here’s a table showing the full list of pins:
A smaller connector became necessary as the technology required smaller USB sizes for many items like modern mobile phones and audio devices. Thus, the USB Microcontroller was born.
The micro USB has both Type-A and Type-B USB versions available, like the 1.0 micro-USB and 2.0 micro-USB. However, these versions are smaller, and you can use them for much thinner lines of equipment.
Additionally, the micro USB is the USB standard and offers better transfer rates from an external source.
Standard older micro USB connectors have five pins, while the less common 3.0 version has ten pins. Here’s a table showing the pins of the micro USB connector:
The fourth pin mode is what we call the USB on-the-go (OTG). It allows you to switch between the peripheral and host roles on your devices. It’s also what enables devices to decide which will act as a power source once connected. For instance, plugging an Android phone into a laptop. The laptop will charge the phone if you have a charge-only cable, not the phone charging the laptop.
It’s worth mentioning that sometimes, it’s possible to use USB A to USB A cables to establish connections between a computer or USB device to another USB device with an A-style female port. So you can transfer data between both systems.
However, you shouldn’t use the type A to A cable connection to create connections between two computers or a USB hub and two computers.
Well, creating such a connection would mean the cable would receive equal amounts of voltage (5V) from both computers.
Thus connecting both power supplies and causing irreparable damage and other issues. Sometimes, it may even cause a fire hazard.
Well, that wraps up this article.
Feel free to reach us if you have any questions, and we’ll be happy to help.
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Introduction to usb pinout.
USB connects computers, smartphones, printers, cameras, and more. It has become a common data transport and charging interface since 1996. USB's pinout, which controls how the connector's pins transport data and power, is crucial.
USB pinout connects and transfers data. Its pins transfer data, provide power and determine device orientation. Several USB connectors have different pin configurations. Type-A, Type-B, Mini-USB, and Micro-USB connectors are the most popular.
The most prevalent USB connector on computers and chargers is Type-A. It has two power and two data pins (D+ and D-) (VCC and GND). Printers, scanners, and other power-hungry equipment employ Type-B connectors. It contains five pins: two data, two power, and one ground.
Cameras, smartphones, and tablets employ Mini-USB and Micro-USB ports. They have a ground pin, two data pins, and two power pins. These connectors are more compact than Type-A and Type-B connectors.
USB pinout is crucial for data transfer, charging, and device performance. The pinout limits data transfer speed, power, and data type. So, understanding USB pinout is essential for troubleshooting and device communication.
Data transport and charging depend on USB pinout. Knowing USB connector types and pinouts helps troubleshoot and ensure device communication. To maintain device connectivity, keep up with USB pinout changes as technology evolves.
USB pinout is the connector's pin configuration and how it transfers data and power. Each USB connector has a unique pinout and function. Depending on the connector, USB has four or five pins. Type-A, Type-B, Mini-USB, and Micro-USB connectors are the most popular.
The most popular USB connector, the Type-A, contains four pins: two data pins (D+ and D-) and two power pins (VCC and GND). Power pins power devices, whereas data pins convey data.
Printers, scanners, and other power-hungry equipment employ Type-B connectors. It contains five pins: two data, two power, and one ground. The Type-B connector contains a ground pin and data and power pins like the Type-A connector.
Cameras, mobile devices, and tablets frequently use Mini-USB or Micro-USB charging and data transfer connections. Two power pins, two data pins, and a ground pin make up the standard configuration for these ports. Mini-USB and Micro-USB connectors have fewer data and power pins than Type-A and Type-B connectors.
USB connector data pins transfer digital signals. D+ and D- pins encode and decode data when transmitting. DC voltage powers linked devices through power pins.
USB pinout defines the connector's pin layout and how they transfer data and power. Troubleshooting and device connectivity require knowledge of USB connector types and pinouts.
USB data transmission is the process of exchanging information between two USB-enabled devices. Information stored digitally can take many forms, from static images to moving ones. The USB protocol defines the rules for data transfer between devices connected via USB.
The USB protocol's multi-layered architecture comprises the physical layer, data link layer, and application layer. Together, these layers provide error-free information exchange between gadgets. The USB cable and connector are part of the physical layer, which also specifies the signal's electrical characteristics. While the application layer specifies the nature of the data being exchanged, the data connection layer controls how that data moves between devices.
Bulk transmission, interrupt transfer, isochronous transfer, and control transfer are the many types of data transfer available over USB. While interrupt transfer is used for inputs from the keyboard and mouse, bulk transfer is utilized for larger data transfers like file transfers. Real-time data transfers, such as audio and video streams, employ isochronous transfer whereas device configuration and status updates use control transfer.
USB speeds vary by version. And USB 2.0 has 480 Mbps data transfer, while USB 1.1 has 12 Mbps.
USB 3.2 allows 20 Gbps data transferring speed. USB data transfer speed and reliability depend on USB cable quality. Several lengths and types of Type-A, Type-B, Mini-USB, Micro-USB, and USB-C cables are available.
USB Power Delivery (USB-PD) lets devices charge faster through USB cables. USB-PD uses USB Type-C connectors and cables and extends the USB standard. The USB-PD protocol allows the host and device to negotiate power, delivering up to 100W across the USB cable. This is a big boost over USB 1.0 and 2.0's 2.5W and USB 3.0's 7.5W.
The USB-PD charges several devices simultaneously, laptops, and other high-powered devices faster. USB-PD lets devices negotiate power for optimal charging.
USB-PD supports USB Type-C connectors, a major benefit. Reversible USB Type-C connectors are easier to use. They can charge laptops and other high-powered gadgets due to their increased data transmission speeds and 100W power output.
USB Power Delivery also powers screens and connects peripherals. USB-PD powers screens without a power cord. USB-PD powers and connects docking stations and external hard drives.
USB Power Delivery lets devices charge faster using USB cables. USB Power Delivery uses USB Type-C connectors and cables and extends the USB standard. USB-PD charges several devices simultaneously, laptops, and other high-powered devices faster. USB-PD may also power screens and connect devices.
A USB cable's wiring and connections can be visualized with the help of a pinout diagram. Type-A, Type-B, Mini-USB, Micro-USB, and USB-C are just a few of the varieties of USB connectors available. Pinout diagrams, which display the configuration and functionality of connectors, are specific to each variety.
The most used USB connector is the USB Type-A connector, which is used to link peripherals to a computer. The USB Type-A pinout consists of four pins labelled VBUS (power), D+ (data), D- (data), and GND (ground). The data transmission occurs between the device and the computer via the D+ and D- connections, while the VBUS pin provides power to the device. Electrical ground is provided through the GND pin. If you're having problems with your USB connections, data transfer, or power delivery, studying the USB Type-A pinout diagram should assist.
The USB Type-B connector is commonly utilized on devices like printers and scanners that are linked to a computer. The pinout diagram for USB Type-B comprises five pins, including VBUS (power), D+ (data), D- (data), GND (ground), and ID (identification).
The Mini-USB connector is a more compact version of the USB Type-B connector. This connector is frequently found in mobile phones and other portable electronic devices. VBUS (power), D+ (data), D- (data), GND (ground), and ID are the five pins that are included in the pinout schematic for Mini-USB (identification).
USB connector is a smaller variant of the USB connector and is often utilized on small devices such as smartphones. It has five pins in its pinout diagram, which are VBUS (power), D+ (data), D- (data), GND (ground), and ID (identification).
Newer devices have USB-C connectors. It provides speedier data transfer and charging and may be plugged in either direction. USB-C has 24 power, data, and miscellaneous pins.
In conclusion, USB pinout diagrams provide a visual representation of a USB cable's wiring and connectors. There are numerous varieties of USB connectors, and each has its own pinout diagram. Understanding these diagrams might be useful for debugging USB connection problems or developing and constructing USB devices.
Connection, data transfer, and charging issues are just some of the issues that might arise from a faulty USB pinout. To fix USB pinout problems, use these troubleshooting steps:
Make sure the USB cable you're using isn't broken and is in good working order. Worsening connection and data transfer challenges are bent or broken pins or cables. If the issue remains after trying a different USB cable, it may be time to call IT.
Checking the USB port you're connecting to is the next step when resolving USB pinout difficulties. Verify that the USB port is undamaged and working properly; a broken USB port might disrupt connections and prevent data from being transferred. Swap out the USB port on your computer or gadget to see if that helps.
Make sure the gadget you're trying to connect is configured to work with the proper USB settings by checking its settings. USB connections and data exchanges might be affected by the various configurations available on various devices. Verify the right configuration of the equipment by consulting the handbook or the settings.
It's crucial to verify the device's power supply when addressing USB pinout difficulties. Verify the power supply if the USB device is not charging or is not getting enough juice. Verify that the gadget is set up to accept power through USB and that the power source is providing sufficient power. Problems with charging or powering may occur if the USB device's power needs exceed those of the present power supply. These problems may be fixed by checking the power supply and making any necessary modifications.
If you're having problems with the USB port, one good step is to see if there are any updated drivers available. Verify that you have the most recent USB drivers installed on your PC or another device. Problems with connectivity and data transfer can be caused by using outdated drivers. Check the manufacturer's website for updated drivers, and apply them if they're available. If your computer or device isn't fully compatible with the USB device you're trying to connect, this should help fix the problem and allow the devices to communicate.
Testing the USB device on a different computer or device is a helpful troubleshooting step when dealing with USB pinout difficulties. Seeing if the issue persists after connecting the USB device to another device is one possible solution. If the USB device is functional with another computer or device, the issue may lie with the drivers or settings on your computer or device. This can help you zero in on the precise nature of the problem and get to its origin so you can address it effectively.
USB pinout difficulties can be frustrating, but there are various ways to fix them. Examining the USB cable, port, device USB settings, power source, and driver updates, and testing the USB device on another computer or device will help you find and fix the problem. These actions will ensure your USB devices work properly and prevent further troubles. To avoid future troubles, update your computer's USB drivers and utilize high-quality cables and devices.
The USB pinout is a crucial component of USB technology, facilitating accurate data transfer and power delivery among devices that use the USB standard. Familiarity with USB pinout diagrams and troubleshooting USB pinout issues can help you diagnose and resolve problems with USB connections, data transfer, and power delivery. Understanding the USB pinout is essential for maximizing the potential of USB technology, whether you are developing and constructing USB devices or utilizing USB technology to connect and charge your devices.
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Discover How a USB Works (A, 2.0, 3.0), Connector Pinout, Wiring Diagrams, Schematics, and Common Applications. Visit To Learn More.
USB type A and B ( Male and Female) pinout. Both these USB types differ in purpose and shape, but their pin connections are the same. Pin 1 is dedicated to the supply and pin 4 is for ground connection. Even pin 2 and 3 take the data input in both these types.
The USB 2.0 pinout diagram illustrates the arrangement of pins within the connector, which includes four pins for power and ground, two data pins, and additional pins for USB differential signal and shield connections.
USB Pinout for USB 2.0 Type A, Type B Mini-A, Mini-B, Micro-A, Micro-B, USB 3.0, USB Type C. Different USB Ports and connectors with pinouts.
USB 1 and 2 pinout for connectors type A and B. Signals and wire colors for connectors.
USB 2.0/1.1 Header pins and signals. The standard USB 2.0 Header is a 10 pin .1 pitch header using the standard IDC pin numbering. The header has a key slot on the pin 1-9 side if enclosed.
Find the complete USB pinouts diagram for different USB connectors and cables. Learn about the pin assignments and functionality of each pin.
USB 1.0 and USB 2.0 shares same connector pinout, USB 3.0 pinout and USB Type C features new connectors with their own pinouts. An USB device must indicate its speed by pulling either the D+ or D- line high to 3.3 volts.
The USB has four shielded wires that work as pins. Two of these wires are for power supply, while the other two are for differential data signal pairs. Check out the table below for the full USB pinout. How Does a USB Work? Plugging a USB pen drive into a laptop.
USB pinout is the physical layout of the pins on a USB connector. This article provides a comprehensive guide to USB pinout, including an overview, understanding, data transfer, power delivery, pinout diagram, and troubleshooting.