**NOT RECOMMENDED FOR NEW DESIGNS*** The MIC2550 is a single-chip transceiver that complies with the physical layer specifications for Universal Serial Bus (USB). The MIC2550 supports full-speed (12Mbps) dual supply voltage operation (patent pending) and low-speed (1.5Mbps) operation. A unique dual supply voltage operation allows the MIC2550 to reference the system I/F I/O signals to a supply voltage down to 2.5V while independently powered by the USB VBUS. This allows the system interface to operate at its core voltage without addition of buffering logic and also reduce system operating current.