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ELECTRONIC DEVICES
CHAPTER 4
Lecturer: Dr. Đào Việt Hùng
Department of Electronics Technology and Biomedical Engineering
School of Electronics and Telecommunications
Hanoi University of Science and Technology
Email: hunget.bk@gmail.com
Field Effect Transistor
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What is Field Effect Transistor?
Field effect transistor (FET, transistor hiệu ứng
trường) is an unipolar transistor.
FET uses electric field to control the conductivity of
a conductive channel.
There are many types:
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FET vs. BJT
Criteria BJT FET
Charge carriers Both e and h(bipolar) Only e or h(unipolar)
Terminals C, B, E D, G, S
Main mechanism voltage-controlled: IBcontrols ICCurrent-controlled: UGS controls ID
Types NPN or PNP N-channel or P-channel
Advantages Linear, easy to use
High current, high voltage
Very high input impedance
Fast switching
Typical
applications
Analog amplifiers
Discrete analog circuits
Digital ICs
High current and high speed
switching elements
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Contents
1. Junction FET
2. Metal Oxide Semiconductor FET
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1 - Junction FET
Structure and basic operation
Characteristic curves of JFET
Shockley equation and transconductance
JFET biasing
Parameters and datasheets
