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The sensitivity of a microphone is usually expressed as the sound field strength in decibels (dB) relative to 1 V/Pa (Pa = N/m 2) or as the transfer factor in millivolts per pascal (mV/Pa) into an open circuit or into a 1 kiloohm load. [citation needed] The sensitivity of a loudspeaker is usually expressed as dB / 2.83 V RMS at 1 metre.
A minimum detectable signal is a signal at the input of a system whose power allows it to be detected over the background electronic noise of the detector system. It can alternately be defined as a signal that produces a signal-to-noise ratio of a given value m at the output.
Paul Voigt patented a negative feedback amplifier in January 1924, though his theory lacked detail. [4] Harold Stephen Black independently invented the negative-feedback amplifier while he was a passenger on the Lackawanna Ferry (from Hoboken Terminal to Manhattan) on his way to work at Bell Laboratories (located in Manhattan instead of New Jersey in 1927) on August 2, 1927 [5] (US Patent ...
The decibel unloaded reference voltage, 0 dBu, is the AC voltage required to produce 1 mW of power across a 600 Ω impedance (approximately 0.7746 V RMS). [2] This awkward unit is a holdover from the early telephone standards, which used 600 Ω sources and loads, and measured dissipated power in decibel-milliwatts ( dBm ).
If a voltage outside the power supply rails is applied to the input, internal ESD protection diodes turn on, causing large currents to flow and damage these parts. Specialised current-sense amplifiers, by contrast are designed so that, when powered from a low-voltage power rail such as V CC = 5 V and V EE = 0 V, they can withstand pin voltages ...
Charge amplifier for piezoelectric sensors. Practical charge amplifiers usually include additional stages like voltage amplifiers, transducer sensitivity adjustment, high and low pass filters, integrators and level monitoring circuits. The charge signals at the input of a charge amplifier can be as low as some fC (FemtoCoulomb = 10 −15 C). A ...
Receiver sensitivity: 0.25 μV at 12 dB SINAD. This is stating that the receiver will produce intelligible speech with a signal at its input as low as 0.25 μV. Radio receiver designers will test the product in a laboratory using a procedure, which is typically as follows:
Fig. 2. Transimpedance amplifier with a reverse-biased photodiode. In the circuit shown in figure 1 the photodiode (shown as a current source) is connected between ground and the inverting input of the op-amp. The other input of the op-amp is also connected to ground.