Sensitivity (electronics)

The sensitivity of an electronic device, such as a communications system receiver, or detection device, such as a PIN diode, is the minimum magnitude of input signal required to produce a specified output signal having a specified signal-to-noise ratio, or other specified criteria. In general, it is the signal level required for a particular quality of received information. In signal processing, sensitivity also relates to bandwidth and noise floor as is explained in more detail below. In the field of electronics different definitions are used for sensitivity. The IEEE dictionary states: "Definitions of sensitivity fall into two contrasting categories." It also provides multiple definitions relevant to sensors among which 1: "(measuring devices) The ratio of the magnitude of its response to the magnitude of the quantity measured.” and 2: "(radio receiver or similar device) Taken as the minimum input signal required to produce a specified output signal having a specified signal-to-noise ratio.”. The first of these definitions is similar to the definition of responsivity and as a consequence sensitivity is sometimes considered to be improperly used as a synonym for responsivity, and it is argued that the second definition, which is closely related to the detection limit, is a better indicator of the performance of a measuring system. To summarize, two contrasting definitions of sensitivity are used in the field of electronics Sensitivity first definition: the ratio between output and input signal, or the slope of the output versus input response curve of a transducer, microphone or sensor. An example is given in the section below on electroacoustics. Sensitivity second definition: the minimum magnitude of input signal required to produce an output signal with a specified signal-to-noise ratio of an instrument or sensor. Examples of the use of this definition are given in the sections below on receivers and electronic...