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Bio-FETs couple a transistor device with a bio-sensitive layer that can specifically detect bio-molecules such as nucleic acids and proteins. A Bio-FET system consists of a semiconducting field-effect transistor that acts as a transducer separated by an insulator layer (e.g. SiO 2) from the biological recognition element (e.g. receptors or probe molecules) which are selective to the target ...
A FET amplifier is an amplifier that uses one or more field-effect transistors (FETs). The most common type of FET amplifier is the MOSFET amplifier , which uses metal–oxide–semiconductor FETs (MOSFETs).
The first discrete-transistor audio amplifiers barely supplied a few hundred milliwatts, but power and audio fidelity gradually increased as better transistors became available and amplifier architecture evolved. [94] Modern transistor audio amplifiers of up to a few hundred watts are common and relatively inexpensive.
The input signal is applied across the ground and the base circuit of the transistor. The output signal appears across ground and the collector of the transistor. Since the emitter is connected to the ground, it is common to signals, input and output. The common-emitter circuit is the most widely used of junction transistor amplifiers.
The only terminal remaining is the source. This is a common-source FET circuit. The analogous bipolar junction transistor circuit may be viewed as a transconductance amplifier or as a voltage amplifier. (See classification of amplifiers). As a transconductance amplifier, the input voltage is seen as modulating the current going to the load.
For R S values in the vicinity of r E the amplifier is transitional between voltage amplifier and current buffer. For R S ≫ r E the driver representation as a Thévenin source should be replaced by representation with a Norton source. The common base circuit stops behaving like a voltage amplifier and behaves like a current follower, as ...
Although many electrodes still connect to an amplifier using wires, some amplifiers are small enough to mount directly on the electrode. Some minimal specifications for a modern EMG amplifier includes: [1] Low internal noise (<0.5 mV) High input impedance (>100 MΩ) Flat bandwidth and sharp high and low frequency cutoffs (>18 dB/octave).
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude (magnitude of the voltage or current) of a signal applied to its input ...