USB Connector Pinouts - HobbyTronics USB Connector Pinouts. USB is a serial bus. It uses 4 shielded wires: two for power (+5v & GND) and two for differential data signals (labelled as D+ and D- in pinout). In a USB data cable Data+ and Data- signals are transmitted on a twisted pair with no termination needed. USB pinout, wiring and how it works! - Electroschematics USB A, B 2.0 and 3.0 Cable Pinout. The USB cable provides four pathways- two power conductors and two twisted signal conductors. The USB device that uses full speed bandwidth devices must have a twisted pair D+ and D- conductors. The data is transferred through the D+ and D- connectors while Vbus and Gnd connectors provide power to the USB device.