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 Pinout and color code
Mini USB pinout
|4||Can be GND, N/C or presence indicator||ID|
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.