differensialsignal

A differential signal is a type of signaling where two complementary signals are transmitted over two conductors. These conductors are typically twisted together to minimize electromagnetic interference. The information is carried by the difference between the voltages of these two signals, rather than the absolute voltage of a single signal. This technique is known as differential signaling or balanced signaling.

The primary advantage of differential signaling is its robustness against noise. Common-mode noise, which affects both conductors equally, is effectively canceled out because it is the *difference* between the signals that is detected. This makes differential signaling ideal for applications where data integrity over long distances or in electrically noisy environments is critical. Examples include high-speed data transmission like USB, Ethernet, and HDMI, as well as audio and video transmission.

The two complementary signals are often referred to as the non-inverting and inverting signals. When the non-inverting signal increases, the inverting signal decreases, and vice versa. The receiver measures the voltage difference between these two lines. If noise is introduced, it tends to add the same amount to both lines. Consequently, the difference between the lines remains largely unchanged, preserving the integrity of the transmitted data. This common-mode rejection is a key feature that distinguishes differential signaling from single-ended signaling, where a signal is referenced to a common ground.