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What is Field Effect Transistor

Warm hints: The word in this article is about 587 and  reading time is about 5 minutes. 
Guidance: Field effect transistor (FET) is abbreviated as field effect transistor. Generally, transistors are conductive by two kinds of polar carriers, i.e. most carriers and a few negative carriers. Therefore, they are called bipolar transistors, while FET is conductive only by most carriers. It is opposite to bipolar transistors, it is also called unipolar transistors.

Field Effect Transistor(FET)

Field effect transistors are referred to as FET. Generally, transistors are conductive by two kinds of polar carriers, i.e. most carriers and a few negative carriers. Therefore, they are called bipolar transistors, while FET is conductive only by most carriers. It is opposite to bipolar transistors, it is also called unipolar transistors. It belongs to voltage-controlled semiconductor devices. It has the advantages of high input resistance (108-109_), low noise, low power consumption, large dynamic range, easy integration, no secondary breakdown, wide safe working area, etc. It has become a strong competitor of bipolar transistors and power transistors.

Different from ordinary three-stage transistors, FET belongs to voltage control device. Its tube current is controlled by gate voltage, which is similar to the characteristics of electronic transistors.

Types of Field Effect Transistor

According to the difference of channel semiconductor materials, the junction type and insulating gate type are divided into two kinds: channel and P channel. According to the conductive mode, FETs can be divided into depletion type and enhancement type. The junction FETs are both depletion type. The insulated gate FETs have both depletion type and enhancement type. Field effect transistors can be divided into junction field effect transistors and MOS field effect transistors. MOSFETs can be divided into four types: N-channel depletion type and enhanced type, P-channel depletion type and enhanced type.

Type Naming Method

There are two current naming methods. The first naming method is the same as bipolar triode. The third letter J stands for junction field effect transistor, and the third letter O stands for insulated gate field effect transistor. The second letter represents the material, D is P-type silicon, the inversion layer is N-channel, and C is N-type silicon P-channel. For example, 3DJ6D is a junction N-channel field effect transistor and 3DO6C is an insulated gate N-channel field effect transistor. The second naming method is CS *, CS stands for field effect transistors, * numbers for models, and letters for different specifications in the same model. For example, CS14A, CS45G, etc.

Parameters of FET

There are many parameters of FETs, including DC parameters, AC parameters and limit parameters, but in general, the following main parameters are concerned in use:

  1. IDSS-saturated leakage current. It refers to the leakage current when the grid voltage UGS = 0 in the junction or depletion insulated gate FET.
  2. The triode of UP working in switching state can be called switching transistor. Triode has PNP, NPN, single junction transistor, etc.

Images of FET

image of FET
image of FET
What is a Field Effect Transistor
What is a Field Effect Transistor
Field Effect Transistor
Field Effect Transistor

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10 thoughts on “What is Field Effect Transistor

  1. Good post!

  2. sir, I’m writing an electronics circuit simulator and I need a very simple and straightforward model for a field-effect transistor (as simple as the Ebers-Moll model for a BJT). I can use resistors, voltage sources, current sources, diodes, (I can also use a resistor with a very large resistance to measure the gate-source voltage).
    What model would you suggest?
    Tks first.

  3. Good post,
    And I want to know what are the benefits of utilizing a hetero-intersection in Tunneling Field Effect Transistors (TFETs)?

  4. Ok, I just met some question about FET when I do an electronic project –How might I do little flag investigation of the circuit to discover yield obstruction? Do I simply set Vgs equivalent to Vds ? and I found this website. It is really avaible. I will follow you and hope the author can provide more interesting and useful knowledge about electronics.

    1. Tks, I will try my best to provide more useful for my readers.

  5. sir, thank you for offering pages about FET, but I have a request could you post some about JFET? I have some trouble about it!!!
    In terms of drain and source current P-channel JFET is similar to which BJT ? npn or pnp?

    1. Hi~ thank you for your trust, jacob
      I will put some article about JFET, and about your confuse:
      The JFEt Transistor is fundamentally the same as an ordinary transistor to the extent connecting it goes. Regular Emitter = Common Source Configuration. The Main distinction in activity Of a JFET to a transistor, The transistor depends on current to work the base while the JFET entryway is constrained by voltage. As somebody above expressed it is fundamentally the same as a cylinder speaker however with substantially less voltage on the Drain. What is it useful for, inputs that have next to no current however have voltage. I have utilized it for timing circuits, charging a capacitor and resistor mix, since the door does not draw much current, the entryway won’t seep down the voltage on the capacitor as it charges. 555 Use FETs It has may even now to utilized in Tuner RF arranges as it won’t over-burden with an enormous sign as a transistor would, going about as a diode identifier and let the sign from a solid station abrogate a progressively inaccessible station. On the off chance that you need to plan something I would utilize a MOSFET rather, VN2222 is a low level N channel. All the more usually utilized today.

  6. What is the advance of OFET’s (Organic Field effect transistors) over the traditional CMOS Transistors?

    1. The upsides of OFET’s over customary CMOS transistors all get from how OFET’s can be made. Customary transistors are produced utilizing vacuum statement procedures. These are moderate, tedious, bunch forms, henceforth the greater expense for electronic parts created by such strategies.
      I will write an pages about it, just follow me. Thanks.

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