Differentialeingang

Differentialeingang is a circuit configuration used in electronics to measure or process an electrical signal by comparing the voltage difference between two input points. This method is particularly useful for rejecting common-mode noise, which is unwanted electrical interference that affects both input signals equally. By subtracting one input voltage from the other, the common-mode noise is effectively canceled out, leaving only the desired differential signal.

A typical differential input circuit consists of two identical input terminals, often connected to an operational amplifier or a dedicated differential amplifier. The signal of interest is applied to one input, and the other input may be connected to a reference voltage, ground, or another signal source. The output of the differential amplifier is proportional to the difference between the two input voltages.

This technique finds widespread application in various fields. In audio systems, it helps to reduce hum and interference picked up by cables. In instrumentation and measurement, differential inputs are crucial for accurately measuring small signals in the presence of larger common-mode voltages, such as in sensors or communication systems. The balanced nature of differential signaling also allows for longer cable runs without significant signal degradation.