Wednesday, October 23, 2019

USB Type-A Connector Pinout, Features, Connections & Datasheet

USB Type-A Connector Pinout, Features, Connections & Datasheet

USB Type-A (Female) Connector

Pin Configuration

Pin No:

Pin Name:




This pin should be provided with +5V, through which the device is powered



Differential pair D-, must be connected to D- of the host for data transfer



Differential pair D+, must be connected to D+ of the host fo data transfer



Connected to the ground pin of the host.


  • Type-A USB 2.0 Plug (Female)
  • Universal and secure USB protocol
  • Its plug and play (Hot pluggable)
  • Can be used to interface mouse and keyboards to uP/uC
  • USB power supply: 100 to 500 mA
  • Protocol supports robust error detection

Alternative USB plugs

micro-USB, USB Type-B, USB Type-C

Where to Use USB-A Jack

The term USB stands for Universal Serial Bus, as the name implies it is universal form of communication which is even now supported by all hardware and software that has USB host. This works through Asynchronous Serial Protocol, meaning there is no clock shared between the sender and receiver. Every device that we connect to USB port works though this protocol. If a Microcontroller or Microprocessor supports USB host then we can connect any USB device like Keyboard, mouse, camera, printer, MP3 player etc to exchange information between this device and the host (uP or uC). It can also be used to transfer data between two Microcontrollers and Microprocessor, if you project requires you to do so. Few popular microcontrollers that support USB host are Arduino USB host, UMFT120DC, Arm Cortex M4 etc..

So if your project requires you to establish an USB connection, then this jack can be connected to the device and wired to your uP or uC.

How to use USB-A Jack

The USB Jack has only three pins and hence is relatively simple to use. Out of the four pin two pins (pin 1 and Pin 4) are used to provide the Vcc and Ground. The supply voltage of Vcc is +5V and is usually provided from the Microcontroller itself. The ground pin is connected to the ground of microcontroller.

The remaining two pins are the D+ and the D-. These pins should be connected to the D+ and D- pins of the host respectively. They also require a pull-down resistor of value 15K each for the data to transfer. A sample connection set-up is shown below.

USB-A Jack Circuit Connections

Based on the microcontroller you are using there are a tons of library that are available to work with USB protocol, use one of them and you should be all set to use USB peripherals with your project.


  • Interface Keyboard or mouse with MCU
  • Serial Bus connections
  • Portable and pluggable devices
  • Small distance, high speed communication

2D Model of USB-A Jack

USB-A Jack Dimensions

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Difference Between USB 1.0 and USB 2.0 Difference Between | Difference Between

Difference Between USB 1.0 and USB 2.0 Difference Between | Difference Between

Difference Between USB 1.0 And USB 2.0

usbUSB 1.0 vs 2.0

The Universal Serial Bus or USB has become the most used port in computers today. It currently exists in two versions. 1.0 which was the original standard of USB, and 2.0 which is the improved version for newer devices. To the end user, the difference between these two devices is purely in its speed. USB 1.0 devices can only achieve a maximum speed of 12Mbps while 2.0 devices can theoretically achieve up to 40 times that at 480Mbps. The real world speeds are lower for both standards since there are other factors that can affect its total throughput.

Originally intended for much slower devices, the initial USB implementation did not provide any option for high speed data transmission. Devices like mice, keyboards, game controllers, and a few others, which were the devices that USB was for, usually transmitted only a very small amount of data to function properly. But as USB became more popular, more devices also began to switch to USB because of the growing popularity of the USB port and the relative ease of plugging in devices. High speed devices like thumb drives proliferated quickly, and digital cameras and camcorders began to sport a USB cable for connecting to computers, but the hindrance of very slow connection speeds became quite apparent rather quickly.

The 12Mbps speed of 1.0 devices is already an upgrade to the very first standard which only allowed 1.5Mbps connections. USB 1.0 devices can either be a low speed device which runs at 1.5mbps or a full speed device at 12Mbps. A connecting device must identify whether it's a low or full speed device at its initialization. USB 2.0 adds the high speed connection to the previous two, and it is in high speed that you can get the 480Mbps theoretical throughput.

Because USB 1.0 can only recognize low speed and full speed devices, USB 2.0 must create a workaround in order to retain backwards compatibility with the older standard. A 2.0 device identifies itself as a full speed device at first then negotiates with the controller via a series of chirps. Once the controller identifies the device as a high speed device, the connection is then reset to and high speed signalling is used.

1.USB 2.0 is the upgrade of 1.0
2.USB 2.0 is much faster compared to 1.0
3.USB 1.0 has two modes of operation while 2.0 adds another one
4.USB 2.0 devices needs to connect as a 1.0 device and negotiate for a 2.0 connection

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Difference Between USB 1.0 and USB 2.0 Difference Between | Difference Between

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