USB to USB Cables

USB or Universal Serial Bus standard was designed in the mid 1990 to replace old standards like serial or parallel ports.  In our days the USB connector can be found in keyboards, printers, digital cameras, flash drives, external hard drives and almost all peripheral digital equipment.

Until now three USB standards were released:
  • USB 1 released in 1996 with speeds of 1.5 Mbps for Low-Bandwidth and 12 Mbps for High-Bandwidth;
  • USB 2.0 release in 2000 is the most used usb port at the moment at supports a maximum speed of 480 Mbps;
  • USB 3.0 released in 2008 in the latest standard who can support speed up to 5Gbps.
There are 7 USB connector types: type A, type B, Mini-A, Mini-B, Micro-A,Micro-B and Micro-AB. Type A and B has 4 pins, Mini and Micro A and B has 5 pin usb pinout.

 Pinout description for main usb connectors:

usb to usb

Micro usb pinout has the same configuration as mini usb. Both will be discussed in particular in other articles on this website.

USB voltage can vary from 4.75V to 5.25V and the amperage is 100 mA for USB 2.0 and 150 mA for USB 3.0. If you want to charge a device or a home build circuit then you must know that for a UBS 2.0 you can draw a maximum of 500 mA or 900 mA for usb 3.0. By using a voltage convertor you can even charge your cell phone or other device who doesn’t require a high power supply source.

USB standard is compatible with almost all other standards. You can buy a rj45 to usb adapter with only a few dollars or you can make one. When building your one usb adapter you have to be very careful with the other standard pinouts like Ethernet pinout or rs232 pinout because you can connect the 5 volt output to the data- or + of  your motherboard usb pinout and do short circuit.

Frequent questions about usb pinout:
  • USB 3.0 have the same pinout of USB 2.0 ?
No, USB pinout for 3.0 standard is different,  it has 9 pins from which two are used as a super speed receivers another two as super speed transmitters and one for GND drain. We will cover the USB 3.0 pinout in other article.
  • What is the iPod pinout ?
Ipods are not equipped with a usb port, they have a 30 pin port and latest models came with an adapter compatible with usb, dvi, hdmi and other standards. Usually Apple devices are equipped with a firewire port or 30 pin port. You can buy an adapter or make it yourself but be careful at the firewire pinout.
  • What is the usb pinout color code?
For USB 2.0: 
Pin 1 – Red-VCC
Pin 2  - White – D-
Pin 3 – Green – D+
Pin 4 – GND – black.
  • USB port not working!
If your USB port is not working you first have to check to see if the device that you are trying to connect works properly and if it does then one of these three problems has occurred: usb card is not connected to the motherboard (to see if this is true you can check the voltage between pin 4 and 1); your usb device needs a software to run (in my computer – device manager check for uninstalled hard drives, usually signaled with a question mark) and the last one you usb port is broken (if you have a desktop pc then you can change the old usb card with a new one and if you have a laptop I recommend a specialist to do that job).