Download DEPARTMENT OF COMPUTER SCIENCE ENGINEERING II B.Tech

DEPARTMENT OF COMPUTER SCIENCE ENGINEERING
II B.Tech CSE I-SEM
UNIT I
Syllabus:
PN JUNCTION DIODE:
Qualitative theory of pn junction diode, PN junction as a diode,diode equation, VI characteristics,
temperature dependence of VI characteristics, Ideal vs practical resistance level(static and dynamic),
Transition and diffusion capacitance, Diode equivalent circuits,load line analysis, Break down mechanisms
in diode, Zener diode characteristics.
OBJECTIVES:
1. A Junction is formed between a simple of p-type and one of n-type semiconductor, this combination
possesses the properties of a rectifier.
2. The volt ampere characteristics of such a junction are derived.
3. Electron and hole currents as a function of distance are studied in detail.
Lecture plan:
NO OF
CLASSES
UNIT
CONTENTS
1
PN JUNCTION DIODE
1.1
Qualitative theory of p-n junction diode
3
1.2
PN junction as a diode, diode equation
1
1.3
VI characteristics, temperature dependence of VI characteristics
2
1.4
Ideal vs practical resistance level(static and dynamic)
1
1.5
Transition and diffusion capacitance
2
1.6
Diode equivalent circuits, load line analysis
1
1.7
Break down mechanisms in diode
1
1.8
Zener diode characteristics
1
Assignments:
1. What do you understand by depletion region at p-n junction? What is the
effect of forward and reverse biasing of p-n junction on the depletion region?
Explain with necessary diagrams.
2. (a) What are the various applications of p-n junction diode? Explain.
(b) Draw the symbol and explain the V-I characteristics of the p-n junction diode.
3. (a) Compare the characteristics of a p-n junction diode, zener diode and tunnel
diode.
(b) How do you determine whether a given semiconductor is p-type or n-type?
Explain the principle with necessary equations.
4. (a) Give the relation between voltage and current for a p-n junction diode.
(b) If two similar germanium diodes are connected back to back and the voltage
V is impressed upon. Calculate the voltage across each diode and current
through each diode. Assume similar value of Io = 1μa for both the diodes
and η=1.
(c) Explain about diffusion capacitance of p-n junction diode.
UNIT II
Syllabus:
RECTIFIERS AND FILTERS:
Pn junction as a rectifier, Half wave rectifier, Fullwave rectifier,bridge rectifier, Harmonic components in a
rectifier, Inductor , capacitor filters, l-section and π-section filters, Comparison of filters,voltage regulation
using zener diode.
OBJECTIVES:
1. Almost all electronic circuits require a dc source of power. For portable low power systems batteries may
be used.
2. Electronic equipment is energized by a power supply, a piece of equipment which converts the alternating
waveform from the power lines in to an essentially direct voltage.
Lecture plan:
NO OF
CLASSES
UNIT
CONTENTS
2
RECTIFIERS AND FILTERS
2.1
Pn junction as a rectifier
1
2.2
Half wave rectifier
1
2.3
Full wave rectifier, bridge rectifier
2
2.4
Harmonic components in a rectifier
1
2.5
Inductor , capacitor filters
2
2.6
L-section and π-section filters
1
2.7
Comparison of filters, voltage regulation using zener diode
1
Assignments:
1. (a) Explain about diffusion capacitance in detail.
(b) Derive an expression for diffusion capacitance.
2. Draw the circuit diagram of a FWR:
(a) With centre tap connection and
(b) Bridge connection and explain its operation.
3. Derive all the necessary parameters of HWR.
4. (a) Write a short notes on multiple L- Section and multiple _ - Section Filter.
(b) Compare all the filter circuits from the point of view of ripple factor.
5. (a) Derive the expression for ripple factor for FWR with L-Section filter. Explain
the necessity of a bleeder resistor.
(b) A 3K resistive load is to be supplied with a d.c.voltage of 300V from a.c.voltage
of adequate magnitude and 50Hz frequency by wave rectification. The LC filter is used along the
rectifier. Design the bleeder resistance, turns ratio of transformer, VA rating of transformer PIV rating of
diodes.
UNIT III
Syllabus:
BIPOLAR JUNCTION TRANSISTOR:
Junction transistors, Transistor current components, Transistor as an amplifier, Transistor construction, BJT
operation, symbol, CE,CB configuration, CC configuration, limits of operation, BJT specifications.
OBJECTIVE:
1. To study the introduction of a transistor.
2. To analyze various configurations of BJT.
Lecture plan:
NO OF
CLASSES
UNIT
CONTENTS
3
BIPOLAR JUNCTION TRANSISTOR
3.1
junction transistors
1
3.2
Transistor current components
1
3.3
Transistor as an amplifier
2
3.4
Transistor construction
1
3.5
BJT operation, symbol
1
3.6
CE,CB configuration
2
3.7
CC configuration, limits of operation, BJT specifications
1
Assignments:
1. With necessary diagram explain the input & output characteristics of Common
Emitter configuration.
2. (a) With neat diagram explain the various current components in an pnp transistor.
(b) Explain the input and output characteristics of a transistor in CB configuration.
3. (a) Obtain the expression for the collector current of a transistor in CE configuration.
(b) Define αdc and βdc of a transistor, for a transistor the base current in 100μA
and collector current in 2.9μA. Find αdc and βdc.
4. (a) Draw a circuit to obtain the characteristics of a NPN Transistor in CC configuration,
and prove that it is also called as emitter follower.
(b) Draw the input and output characteristics of a Common Collector Transistor
and discuss the method of obtaining the device characteristics.
(c) What are the parameters that can be calculated from the characteristics?
5. (a) With the help of input & output characteristics, explain the operation of a BJT in Common Emitter
Configuration.
(b) For an NPN transistor with α = 0.98, J = 2μA and I = 1.6μA connected in Common Emitter
N
CO
EO
Configuration, calculate the minimum base current for which the transistor enters into saturation
region. V and load resistance are given as 12 V and 4.0 KΩ respectively.
CC
UNIT IV
Syllabus:
TRANSISTOR BIASING STABILIZATION:
Operating point, the dc &ac load lines, need of biasing, fixed bias, collector feedback bias, collector emitter
feedback bias, voltage divider bias, bias stability, Stabilization against variations in vbe, beta, bias
compensation using diodes, Transistors, thermal runaway, thermal stability
OBJECTIVES:
1. We establish a certain current & voltage conditions for the transistor .When
we are considering the biasing, this conditions are known as operating point.
2. Biasing circuits provide stability of operating point in case of variations in the transistor parameters.
3. Compensation techniques use temperature sensitive devices to maintain
Operating pt constant.
Lecture plan:
UNIT
4
4.1
CONTENT
Transistor Biasing and Stabilization
Operating pt, the dc & ac load lines, need of biasing
NO OF CLASSES
2
4.2
Fixed bias, collector feed back bias, collector emitter feedback bias,
voltage divider bias
2
4.3
Bias stability, stabilization factors
2
4.4
Stabilization against variations in vbe& beta.
2
4.5
Bias compensation using diodes &transistors
1
4.6
Thermal run away, thermal stability
1
Assignments:
1. (a) What is the importance of dc load line?
(b) The figure 5b shows that D.C bias circuit of a common Emitter transistor
amplifier. Find the percentage changer in collector current, if the transistor
with HFE = 50 is replaced by another transistor with HFE = 150. It is given
that the base emitter drop VBE = 0.6V.
2. (a) Explain thermal instability. What are the factors affecting the stability factor.
(b) For the CE amplifier circuit shown below, find the percentage change in collector current if the transistor with hfe=50 is replaced by another transistor
with hfe=150. Assume VBE=0.6V
3. (a) For the transistor switching circuit shown in figure 4(a)iii, determine the following:
i. What is VCE when Vin=OV?
ii. What minimum value of IB in required to saturate the transistor?
iii. Calculate the maximum value of RB to keep the transistor under saturation when Vin=5V.
(b) How should the gate-source junction of a JFET be biased? Explain how the
potential applied to this junction controls the drain current.
4.a) Explain how self biasing can be done in a BJT with relevant sketches and waveforms.
b) Design a self bias circuit for the following specifications:
V = 12 V; V = 2V; I = 4mA; h = 80. Assume any other design parameters required. Draw the
CC
CE
designed circuit.
C
fe
UNIT V
Syllabus:
SMALL SIGNAL LF BJT MODELS
BJT hybrid model, determination of H parameters from transistor characteristics, analysis of transistor
amplifier circuit using H parameters, comparisons of CB, CE & CC amplifier configurations.
Objectives:
1. Determination of h-parameters from transistor characteristics.
2. Comparisons of CB, CE,CC amplifier configurations.
Lecture plan:
S.No
5
5.1
Topic
Small Signal LF BJT Models
BJT Hybrid model, Determination of H-parameters
No. of lectures
02
5.2
Analysis of amplifier using h-parameters
03
5.3
Comparison of CE,CC,CE amplifier configurations.
02
Assignments:
1. Draw the low frequency hybrid equivalent. Circuit for CE & CB amplifier.
2. Give the approximate h-parameter conversion formulae for CB and CC configuration in terms of CE.
3. Give the advantages of h-parameter analysis.
4. Give the procedure to form the approximate h - model from exact h – model of amplifier.
5 (a). Write down the hybrid equations of a transistor and determine the h parameters.
(b) What are the advantages of h parameters?
UNIT VI
Syllabus:
FIELD EFFECT TRANSISTOR
JFET (Construction, Principle of operation, symbol), Pinch –Off voltage , V-I characteristics, JFET small
signal model, MOSFET (construction, Principle of operation, symbol),MOSFET characteristics in
Enhancement & Depletion modes.
Objectives:
1. To study the constructional, operational details of JFET,MOSFET
2. To understand the concept of Pinch –Off voltage & V-I characteristics of JFET
3. To study the MOSFET characteristics in Enhancement & Depletion modes.
Lecture plan:
S.No
6
6.1
Topic
Field Effect Transistor
JFET constructional, operational details, with symbol
No. of lectures
01
6.2
Pinch –Off voltage & V-I characteristics of JFET
01
6.3
JFET small signal model
01
6.4
MOSFET (construction, Principle of operation, symbol)
01
6.5
MOSFET characteristics in Enhancement & Depletion modes.
02
Assignments:
1. Sketch the drain characteristic of MOSFET for diff values of VGS &mark different region of operation.
2. Draw the structure of an n-channel JFET &explain its principle of operation.why the name field effect
used for the device? show the circuit symbol of JFET.
3. (a) For a small signal JFET iD = f(VGS, VDS). Obtain expressions for iD and
hence define gm, rd and μ.
(b) From the definition of gm and rd obtain expression for μ.
(c) For an n-channel silicon FET with a = 3×10−4cm and ND = 1015 electrons/cm3.
4. Find the pinch off voltage.
a) Explain the significance of threshold voltage of a MOSFET. Discuss the methods to reduce threshold
voltage, V .
T
b) A FET follows the relation ID= IDSS [1-VGS/VP ] [1-VGS/VP ]What are the values of I and g for
D
V = -1.5 V if I
GS
DSS
and V are given as 8.4 mA and -3V respectively.
P
m
UNIT VII
SYLLABUS
FET AMPLIFIERS
CS,CD Amplifiers, Generalized FET amplifier, Biasing FET, FET as VVR, Comparison of FET and
BJT, UJT.
OBJECTIVE
1. To study the importance of FET amplifiers.
2. To compare FET with BJT.
3. To analyze UJT.
Lecture plan:
UNIT
7
Topic
FET Amplifier
No. of lectures
7.1
CS,CD Amplifiers
02
7.2
Generalized FET amplifier
01
7.3
Biasing FET
02
7.4
FET as VVR
01
7.5
Comparison of FET and BJT, UJT
01
Assignment
1)
2)
3)
4)
5)
Derive the expression for voltage gain in the case of a common source FET amplifier.
Derive the expression for voltage gain in the case of a common drain FET amplifier.
Explain how FET acts as VVR?
With a neat circuit diagram explain the operation of UJT.
If an input signal Vi is impressed between gate and ground, find the amplification Av = V0/Vi.
Apply miller’s theorem to the 50k resistor. The FET parameters are µ=30 and rd= 5k. Neglect
capacitances.
UNIT VIII
SYLLABUS
SPECIAL PURPOSE ELECTRONIC DEVICES
Operation and characteristics of Tunnel diode (with the help of energy band diagram), Operation and
characteristics of Varactor diode, Operation of Schottky Barrier diode, SCR and semi-conductor
photo diode.
OBJECTIVE:
1. To familiarize the Special purpose diodes
2. To understand the operation of SCR
Lecture plan:
UNIT
8
8.1
Topic
No. of lectures
Special Purpose Electronic Devices
01
8.2
Operation and characteristics of Tunnel diode(with the help of energy band
diagram)
Operation and characteristics of Varactor diode
8.3
Operation of Schottky Barrier diode
01
8.4
SCR and semi-conductor photo diode
02
ASSIGNMENT
1)
2)
3)
4)
With a neat circuit, explain the operation of tunnel diode.
With a neat circuit, explain the operation of varactor diode.
With a neat circuit, explain the operation of Schottky barrier diode.
With a neat circuit, explain the operation of SCR.
5) With a neat circuit, explain the operation of semiconductor photo diode.
01