Quantcast Figure 3-45.JFET structure

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
3-39 The elements of one type of FET, the junction type (JFET), are compared with the bipolar transistor and the vacuum tube in figure 3-44. As the figure shows, the JFET is a three-element device comparable to the other two. The "gate" element of the JFET corresponds very closely in operation to the base of the transistor and the grid of the vacuum tube. The "source" and "drain" elements of the JFET correspond to the emitter and collector of the transistor and to the cathode and plate of the vacuum tube. Figure 3-44.—Comparison of JFET, transistor, and vacuum tube symbols. The construction of a JFET is shown in figure 3-45. A solid bar, made either of N-type or P-type material, forms the main body of the device. Diffused into each side of this bar are two deposits of material of the opposite type from the bar material, which form the "gate." The portion of the bar between the deposits of gate material is of a smaller cross section than the rest of the bar and forms a "channel" connecting the source and the drain. Figure 3-45 shows a bar of N-type material and a gate of P-type material. Because the material in the channel is N-type, the device is called an N-channel JFET. Figure 3-45.—JFET structure. In a P-channel JFET, the channel is made of P-type material and the gate of N-type material. In figure 3-46, schematic symbols for the two types of JFET are compared with those of the NPN and PNP bipolar transistors. Like the bipolar transistor types, the two types of JFET differ only in the configuration of bias voltages required and in the direction of the arrow within the symbol. Just as it does in transistor symbols, the arrow in a JFET symbol always points towards the N-type material. Thus the symbol of the N-channel JFET shows the arrow pointing toward the drain/source channel, whereas the P-channel symbol shows the arrow pointing away from the drain/source channel toward the gate.


Electrical News
Intel, Altera, Moore...and Drinks
The on-again, off-again Intel/Altera acquisition was the talk of a...
eetimes.com
Huawei's Everything-Connected Game Plan
As Chinese Internet companies like Tencent, Alibaba and Xiaomi bulldoze...
eetimes.com
Samsung Ramps 10nm in 2016
Samsung said its 10nm FinFET process node will be in...
eetimes.com
Friday Quiz: Losses in Power Devices
Power devices such as MOSFETs and IGBTs can waste power...
eetimes.com
HP Strikes China Deal, Sales Slump
The same day it reported declining quarterly results, Hewlett-Packard announced...
eetimes.com
Quarter-Sized, Magnetically Stackable Modules for Students and Makers
mCookies are small, powerful, Arduino-compatible modules for makers, designers, engineers,...
eetimes.com
Apple Watch Lacks Pulse, Says Startup
Bloom Technologies aims to pave the way toward medical-grade wearables...
eetimes.com
Mao Zedong & Little Red Internet
Linking Internet leaders like Jack Ma with Chairman Mao...
eetimes.com
Self-Driving Cars Without Passengers
Forschungszentrum Informatik (FZI) is aiming for self-driving cars that you...
eetimes.com
Apple Watch, Android Wear Updates Begin
The first update for the Apple Watch makes performance improvements...
eetimes.com
Crowdfunding Gives IoT a Boost
Wearable startups are getting more attention these days -- from...
eetimes.com
Software Secure? Good! But What About the Hardware (FPGAs & SoCs)?
The Prospect Hardware Security Design and Analysis Toolkit from Tortuga...
eetimes.com
DesignCon 2016 Welcomes Abstracts
DesignCon fans, the time has come! If your work concerns...
eetimes.com
Moore's Law: What Broke the Model
In a sense Moore's Law, or at least many of...
eetimes.com
ITU Targets 5G Wireline Standards
I have lost count of the number of standards efforts,...
eetimes.com
Raspberry Pi 2: 10 Unusual & Interesting Projects
Raspberry Pi Foundation's newest board the RPi 2 is gaining...
eetimes.com
EEVblog #746 – Sharp X68000 Retro Computer Teardown
What’s inside the a 1987 vintage Sharp X68000 personal computer...
eevblog.com
Huawei launches 10KB LiteOS to power the internet of things | The Verge
Chinese telecoms giant Huawei is preparing to launch an operating...
wsnblog.com
CAP-XX Launches 0.6mm Thinline Supercapacitors for Designing Wearable, Ultra-Portable and Connected IoT Devices
CAP-XX, developer of flat supercapacitors for burst and back-up power...
wsnblog.com
Security Takes a MIPS Twist
Imagination Technologies announced OmniShield, a framework for hardware-backed security covering...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +