Transcript OPTICAL FIBER communication

ACTIVE LEARING ASSIGNMENT
ELECTRONIC &COMMUNICATION
SEM-3
YEAR-2014/15
ELECTRONIC DEVICES AND CIRCUITS
(2131006)
PREPARED BY :Pooja Patel (130810111007)
Varsha Shukla (130810111010)
Akshay Parekh (130810111005)
Rohit sutariya (140813111014)
Brinda Gandhi (140813111001)
GUIDED BY :- PROF. KRUPA PATEL
VENUS INTERNATIONAL COLLAGE OF
TECHNOLOGY
Presentation Outlines
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Introduction
types
working
Application
Advantages
Disadvantages
bibliography
 INTRODUCTION OF TRANSISTOR
 It is a three terminal semiconductor device having two
junctions.
 It is bipolar junction transistor having two type N-P-N
& P-N-P.
 Three terminal are (1) emitter (2) base (3) collector.
 To operate transistor as an amplifier connected in
active region, The emitter-base junction is forward
bias & collector-base junction is reverse bias.
 INTRODUCTION
INTRODUCTION
 A transistor is a semiconductor device commonly
used to amplify or switch electronic signals.
 A transistor is made of a solid piece of a
semiconductor material, with at least three
terminals for connection to an external circuit.
 A voltage or current applied to one pair of the
transistor's terminals changes the current flowing
through another pair of terminals.
 Types of TRANSISTOR
 Heterojunction bipolar transistor
 Alloy junction transistor
 Unijunction transistors
 Pentode transistor
 Darlington transistors
 Photo transistor
 Inverted-t field effect transistor
 Avalanche transistor
 Thin film transistor
HOW A TRANSISTOR WORKS
 A transistor can control its output in proportion to the
input signal; this is called an "amplifier". Or, the
transistor can be used to turn current on or off in a
circuit like an electrically controlled "switch", where
the amount of current is determined by other circuit
elements.
TRANSISTOR HAS A SWITCH
 The basic component used in implementing any
digital logic circuit is a switch.modern digital ic’s use a
high speed transistor switches used in implementing
digital ics bjt and mosfet.
 The primary function of a transister switch in a digital
logic circuit is to alternately connect and disconnect a
load to and from circuit power supply.in doing this the
transistor switch produces two distinct voltage levels
across the load which represents the binary o and
binary 1
TRANSISTOR HAS A SWITCH
 In 1 state the transistor is non-conducting or cut-off
and acts as essentially an open circuit.in the other state
i.e.on 0 state the transistor is conducting heavily and
acts as a very low resistance approaching to a short
circuit. The two state logic input signal is applied to
the transistor to produce this on-off operation.
 Now there are two types of ics;
 -saturated ic
 -non-saturated ic
TRANSISTOR HAS A SWITCH
 The cut-off and linear regions are found in the non-
saturated bipolar circuits whereas cut-off satyration
modes are found in saturated bipolar circuits.
 In non-saturating digital circuits the transistor
switches between cut-off and linear region.they are
also used in many application where high speed
opration is desirable.
 In case of the saturated bipolar transistor too,cut-off
and saturation states are found.most digital circuitry
in use today use saturated bipolar switching transistor
for data representation.
APPLICATION
 The transistor as an amplifier.
 The transistor as switch.
 Integrated Circuits .
ADVANTEGES
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Transistors are small.
require very little power.
run cool.
much more reliable.
Because of the transistors the 2nd generation
computers were small, faster and reliable.
DISADVANTEGES
 Costly.
 had less memory than ICs.
 Require much space than ICs.
Bibliography
1. www.whereisdoc.com
2. www.slideshare.net
3. www.eforu.com
4. Microsoft power point