Quantcast FORWARD BIAS - 14179_32

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
1-20 charged ions. The diffusion of electrons and holes across the junction will continue until the magnitude of the electrostatic field is increased to the point where the electrons and holes no longer have enough energy to overcome it, and are repelled by the negative and positive ions respectively. At this point equilibrium is established and, for all practical purposes, the movement of carriers across the junction ceases. For this reason, the electrostatic field created by the positive and negative ions in the depletion region is called a barrier. Figure 1-17.—The PN junction barrier formation. The action just described occurs almost instantly when the junction is formed. Only the carriers in the immediate vicinity of the junction are affected. The carriers throughout the remainder of the N and P material are relatively undisturbed and remain in a balanced condition. FORWARD BIAS.—An external voltage applied to a PN junction is call BIAS. If, for example, a battery is used to supply bias to a PN junction and is connected so that its voltage opposes the junction field, it will reduce the junction barrier and, therefore, aid current flow through the junction. This type of bias is known as forward bias, and it causes the junction to offer only minimum resistance to the flow of current. Forward bias is illustrated in figure 1-18. Notice the positive terminal of the bias battery is connected to the P-type material and the negative terminal of the battery is connected to the N-type material. The positive potential repels holes toward the junction where they neutralize some of the negative ions. At the same time the negative potential repels electrons toward the junction where they neutralize some of the positive ions. Since ions on both sides of the barrier are being neutralized, the width of the barrier decreases. Thus, the effect of the battery voltage in the forward-bias direction is to reduce the barrier potential across the junction and to allow majority carriers to cross the junction. Current flow in the forward-biased PN junction is relatively simple. An electron leaves the negative terminal of the battery and moves to the terminal of the N-type material. It enters the N material, where it is the majority carrier and moves to the edge of the junction barrier. Because of forward bias, the barrier offers less opposition to the electron and it will pass through the depletion region into the P-type material. The electron loses energy in overcoming the opposition of the junction barrier, and upon entering the P material, combines with a hole. The hole was produced when an electron was extracted from the P material by the positive potential of the battery. The created hole moves through the P material toward the junction where it combines with an electron.


Electrical News
Could India's Analog Wafer Fab be Moving South?
Cricket Semiconductor, a company set up with the purpose of...
eetimes.com
Apple Watch Tear Down Reveals European Chips
The Apple Watch, is the trailblazer of a wearables equipment...
eetimes.com
Ethernet Standards Ramp Up For Faster IT
The Ethernet Alliance and UNH-IOL hosted a plugfest to test...
eetimes.com
3-D Fingerprint Scanner Beats Apple's
The University of California at Davis, in cooperation with the...
eetimes.com
No Respect!
Every now and then, you see someone doing something, and...
eetimes.com
Friday Quiz: Name That 1994 Test Instrument
If you can remember back to 1994, then take a...
eetimes.com
It's a Bird. It's a Plane! It's a Drone!!
EE Times has gathered a panel of drone experts, including...
eetimes.com
Firework display as seen through the eyes of a drone
Have been thinking about purchasing a drone? If so, watching...
eetimes.com
FinFETs + FD-SOI Proposition: May Save Power
Ron Martino, vice president of application processors and advanced technology...
eetimes.com
Biodegradable Electronics Debut
Single crystal silicon transistors operating in the same microwave frequency...
eetimes.com
DesignCon 2016 Abstract Deadline Extended
You now have until Wednesday, July 8 so get your...
eetimes.com
IBM Makes Lake George World's Smartest Lake
Over 60 researchers, including ones from IBM and Rensselaer Polytechnic,...
eetimes.com
Developing Safety Certified Code for Industrial Systems
The right design framework and RTOS can help simplify and...
eetimes.com
Intel President, Execs Step Down
Intel President Renee James is among several top executives who...
eetimes.com
High-Speed Converters Aid Record Terabit Field Trial
Ultra high-speed digital-to-analog and analog-to-digital converters from Socionext Inc. (Yokohama,...
eetimes.com
Speech Recognizer / Synthesizer Shield for Arduino & Other MCUs
A Kickstarter project the just launched promises a rather interesting...
eetimes.com
Want a Free GPAK4 Mixed-Signal FPGA Development Kit From Silego?
25 GPAK4 mixed-signal FPGA development kits will be given by...
eetimes.com
IMB-GlobalFoundaries Deal Finalized
Following final approval by U.S. regulators, IBM closed the sale...
eetimes.com
20% Discount for ESC Silicon Valley 2015 Using Secret Code
Max's top-secret-squirrel code for the forthcoming ESC Silicon Valley 2015...
eetimes.com
UWAS: Playing Hide and Seek with Drones
The Paris Air Show (June 15-21) was rich in drone...
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 +