Q: What is Differential Signaling?
A: Differential signaling is a method used to reduce electromagnetic interference (EMI) from external sources such as other cables, devices and/or crosstalk between neighboring traces or wires. Coax, twisted pairs, twinax and circuit board traces often employ this technique. The receiving circuit responds to the electrical difference between the two signals rather than the difference between a single wire voltage and ground. The wave form instead of being single ended peaks and valleys (for example from zero volts to five volts and then back down again) will instead look like mirrored signals with an equal Positive and Negative charge opposite the ground plane (zero) reference. This enables circuits to use less voltage to create a signal which also enables higher frequencies and faster speed cables due to the reduced capacitance need.