Sensitivity (electronics)

The sensitivity of an <a href="/facts/Electronic_device/E4JhgISq">electronic device</a>, such as a <a href="/facts/Communications_system/5t3Ys2DI">communications system</a> receiver, or detection device, such as a <a href="/facts/PIN_diode/H4hdX9Un">PIN diode</a>, is the minimum <a href="/facts/Magnitude_(mathematics)/KCn9PoF0">magnitude</a> of input <a href="/facts/Signal/41YqUJ8c">signal</a> required to produce a specified output signal having a specified <a href="/facts/Signal-to-noise_ratio/qohClhyG">signal-to-noise ratio</a>, or other specified criteria. In general, it is the signal level required for a particular quality of received information.
In <a href="/facts/Signal_processing/Npaja6zb">signal processing</a>, sensitivity also relates to <a href="/facts/Bandwidth_(signal_processing)/7eMDzfJI">bandwidth</a> and <a href="/facts/Noise_floor/upf5bAvq">noise floor</a> 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 <a href="/facts/Responsivity/8ks9YC5D">responsivity</a> and as a consequence sensitivity is sometimes considered to be improperly used as a synonym for <a href="/facts/Responsivity/8ks9YC5D">responsivity</a>, and it is argued that the second definition, which is closely related to the <a href="/facts/Detection_limit/Qd2cAguT">detection limit</a>, 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

<ul><li>Sensitivity first definition: the ratio between output and input signal, or the slope of the output versus input response curve of a <a href="/facts/Transducer/YS7zfv9d">transducer</a>, <a href="/facts/Microphone/7YWGlXCl">microphone</a> or <a href="/facts/Sensor/RN8SXbjs">sensor</a>. An example is given in the section below on electroacoustics.</li>
<li>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 <a href="/facts/Sensor/RN8SXbjs">sensor</a>. Examples of the use of this definition are given in the sections below on receivers and electronic sensors.</li></ul>

Sensitivity (electronics) open-in-new

Sensitivity (electronics)