Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 6: Problem 9

In general, comment on the polarity of the various voltages and direction of the currents for an \(n\) -channel JFET versus a \(p\) -channel JFET.

Short Answer

Expert verified
The polarity of voltages in an n-channel JFET is negative for the gate and positive for the drain. The current flows from drain to source. On the other hand, for a p-channel JFET, the gate voltage is positive and the drain voltage is negative. The current flows from source to drain.

Step by step solution

01

Understanding N-Channel JFET

An n-channel JFET is a type of transistor where the majority charge carrier is an electron. This means that current conduction is by electrons. The voltage polarity for the n-channel JFET is such that the gate voltage (\(V_{GS}\)) is usually negative, the source voltage \(V_S\) is conventionally grounded (0V), and the drain voltage (\(V_{DS}\)) is positive. This facilitates a flow of current from the drain to the source.
02

Understanding P-Channel JFET

A p-channel JFET on the other hand conducts by means of holes. Therefore, the polarity of voltages for a p-channel JFET is opposite that for an n-channel JFET. The gate voltage (\(V_{GS}\)) is positive, the drain voltage (\(V_{DS}\)) is negative, while the source voltage \(V_S\) remains at ground potential. In this case, the current flows from source to drain.
03

Comparing N-Channel and P-Channel JFET

In conclusion, both n-channel and p-channel JFETs are similar in function, but their operation is dictated by the type of semiconductor material used, which in turn determines the polarity of their voltages and the direction of currents. N-channel JFETs have a negative \(V_{GS}\), positive \(V_{DS}\), and the current flows from drain to source. P-channel JFET have a positive \(V_{GS}\), negative \(V_{DS}\), and the current flows from source to drain.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Using an average value of \(2.9 \mathrm{~mA}\) for the \(I_{D S S}\) of the 2N3797 MOSFET of Fig. 31 , determine the level of \(V_{G S}\) that will result in a maximum drain current of \(20 \mathrm{~mA}\) if \(V_{P}=-5 \mathrm{~V}\).

Does the current of an enhancement-type MOSFET increase at about the same rate as a depletiontype MOSFET for the conduction region? Carefully review the general format of the equations, and if your mathematics background includes differential calculus, calculate \(d I_{D} / d V_{G S}\) and compare its magnitude.

a. Describe in your own words why \(I_{G}\) is effectively \(0 \mathrm{~A}\) for a JFET transistor. b. Why is the input impedance to a JFET so high? c. Why is the terminology field effect appropriate for this important three- terminal device?

a. Sketch the transfer and drain characteristics of an \(n\) -channel enhancement-type MOSFET if \(V_{T}=3.5 \mathrm{~V}\) and \(k=0.4 \times 10^{-3} \mathrm{~A} / \mathrm{V}^{2}\) b. Repeat part (a) for the transfer characteristics if \(V_{T}\) is maintained at \(3.5 \mathrm{~V}\) but \(k\) is increased by \(100 \%\) to \(0.8 \times 10^{-3} \mathrm{~A} / \mathrm{V}^{2}\).

a. Describe in your own words why the VMOS FET can withstand a higher current and power rating than devices constructed with standard techniques. b. Why do VMOS FETs have reduced channel resistance levels? c. Why is a positive temperature coefficient desirable?
See all solutions

Recommended explanations on Physics Textbooks

Magnetism

Read Explanation

Fields in Physics

Read Explanation

Rotational Dynamics

Read Explanation

Waves Physics

Read Explanation

Fundamentals of Physics

Read Explanation

Physics of Motion

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free