A transistor semiconductor device which can conduct as well as insulate electric current & voltage. Plenty of transistors are used with different designs and basic functionality. Some of the most used transistors with their symbols and features are listed here.
Transistor schematic symbols of electronic circuit - NPN, PNP, Darlington, JFET-N, JFET-P, NMOS, PMOS.
| Symbol | Name | Description |
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NPN Bipolar Transistor | Allows current flow when high potential at base (middle) |
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PNP Bipolar Transistor | Allows current flow when low potential at base (middle) |
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Darlington Transistor | Made from 2 bipolar transistors. Has total gain of the product of each gain. |
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JFET-N Transistor | N-channel field-effect transistor |
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JFET-P Transistor | P-channel field-effect transistor |
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NMOS Transistor | N-channel MOSFET transistor |
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PMOS Transistor | P-channel MOSFET transistor |
Bipolar transistors like NPN & PNP allow current according to potential conditions at the base i.e middle of the transistor. PNP allows current if the potential at the base is low while NPN is reciprocal of PNP and allows current if the base potential is high. Darlington transistor is a combo of 2 bipolar transistors and a product of gain as its total gain.
N transistor and P transistors are FET( Field Effect Transistor). These are three-terminal voltage-dependent transistors which depend on voltage input to control current. NMOS and PMOS transistors are Metal Oxide Semiconductor Field Effect Transistors( also short-named MOSFET). These are electric field transistors dependent on Metal oxides.
This table offers all these discussed transistors, the features of these transistors and their symbols.
The symbols used in the schematics to depict field effect transistors is identified by the letters "D", "G" and "S" corresponding to the terminals of Drain, Gate and Source respectively. The two major kinds that field effect transistors come in are Junction FET's, also known as JFETs or Insulated Gate FET's, or IGFETs.