Your Electronics Open Source

The USB specification was introduced in November 1995. USB was promoted by Intel, Microsoft, Philips and US Robotics. Originally USB was intended to replace the multitude of connectors at the back of PCs, as well as to simplify software configuration of communication devices. A USB system has an asymmetric design, consisting of a host, a multitude of downstream USB ports, and multiple peripheral devices connected in a tiered-star topology.[Wikipedia, USB]
Universal Serial Bus (USB) connects more than computers and peripherals. It has the power to connect with a whole new world of PC experiences. A major advantage when using USB is Power (Vbus) is bus powered devices, so called bus powered devices can draw their power from the usb bus without using any external power supplies or sockets. Careful considerations must be made according to the following criteria. The three classes of USB functions are:
* Low power bus powered functions
* High power bus powered functions
* Self power functions
But behind all these, it is an entire world about USB. Discover it in our 100% USB Book!