Which of the following are the characteristics of a Junction Field Effect Transistor? 1. High input resistance 2. Good thermal stability 3. High current gain 4. Noisier than bipolar junction transistor

Which of the following are the characteristics of a Junction Field Effect Transistor? 1. High input resistance 2. Good thermal stability 3. High current gain 4. Noisier than bipolar junction transistor Correct Answer 1 and 2

JFET:

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Here, Gate is reversed biased, so current flow through the Gate is approximately zero. So, Input-impedance is very high in JFET Typically in megaohms.\

Now, when the temperature increases mobility decreases according to the equation μ α T^-m. So, the increase in current due to thermal generation is compensated by the decrement of mobility, Hence, FET has high thermal Stability.

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• JEFT stands for Junction Field Effect Transistor.
• A field-effect transistor is a voltage-controlled device i.e. the output characteristics of the device are controlled by the input voltage. There are two basic types of field-effect transistors:

  1. Junction field-effect transistor (JFET)

  2. Metal oxide semiconductor field-effect transistor (MOSFET)

• A JFET is a three-terminal semiconductor device in which current conduction is by one type of carrier i.e. electrons or holes.
• The current conduction is controlled by means of an electric field between the gate and the conducting channel of the device. To control the conduction of current from the source to the drain, the gate voltage must be more negative than the source voltage.
• JEFTs are further divided into two types that n-channel JEFT and p-channel JEFT. The three leads of a JEFT are labeled source, gate and drain.