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8/7/2019 Fundametals of Analog Electronics_part II
1/17
Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
German-Jordanian University
School of Applied Natural Sciences -
Energy Engineering
Bipolar Junction Transistor
Configurations:
Common Base Configuration
Fig. 3.2 Types of transistors: (a) pnp; (b) npn.Fig. 3.6 Notation and symbols used with the
common-base configuration: npn transistor.
Fig. 3.8 Output or collector characteristics for a common-base transistor amplifier.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Common Emitter Configuration
Common Collector Configuration
Fig. 3.13 Notation and symbols used with the
common-emitter configuration: npn transistor
Fig. 3.14 Characteristics of a silicon transistor in the common-emitter configuration: (a) collector characteristics; (b)
base characteristics.
Fig. 3.20 Notation and symbols used with the common-collector
configuration: (a) pnp transistor; (b) npn transistor.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Operating Point
Fixed Bias Circuit
Fig. 4.1 Various operating points within the limits of operation of a transistor.
Fig. 4.2 Fixed-bias circuit.
Fig. 4.3 DC equivalent of Fig. 4.2.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Fig. 4.4 Baseemitter loop.Fig. 4.5 Collectoremitter loop.
Fig. 4.7 DC fixed-bias circuit for Example 4.1.
Fig. 4.9 Determining ICsat. Fig. 4.10 Determining ICsat for the fixed-bias configuration.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Emitter Bias
Fig. 4.17 BJT bias circuit with emitter resistor.Fig. 4.18 Baseemitter loop.
Fig. 4.19 Network derived from the result of Fig.4.18
Fig. 4.20 Reflected impedance level of RE.
Fig. 4.21 Collectoremitter loop.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Design Operation
Transistor Switching Network
Fig. 4.48 Example 4.19. Fig. 4.49 Example 4.20.
Fig. 4.53 Transistor inverter.
Saturation conditions and the
resulting terminal resistance.
Cutoff conditions and the
resulting terminal resistance.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Fig. 4.56 Inverter for Example 4.24.
Fig. 4.57 Defining the time intervals of a pulse waveform.
8/7/2019 Fundametals of Analog Electronics_part II
8/17
Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
German-Jordanian University
School of Applied Natural Sciences -Energy Engineering
Bipolar Junction Transistor
AC Analysis: A model is an equivalent circuit that represents the AC characteristics of the
transistor.
A model uses circuit elements that approximate the behavior of the transistor. There are two models commonly used in small signal AC analysis of a
transistor:
re model Hybrid equivalent model
The reTransistor Model:
BJTs are basically current-controlled devices, therefore the re model uses a diode and a
current source to duplicate the behavior of the transistor. One disadvantage to this model is its
sensitivity to the DC level. This model is designed for specific circuit conditions.
Common Base Configuration
Fig. 5.6 (a) Common-base BJT transistor; (b) re model for the configuration of (a).
Fi . 5.7 Common-base re e uivalent circuit.
Fig. 5.9 Defining Av = Vo/Vi for the common-base configuration.
8/7/2019 Fundametals of Analog Electronics_part II
9/17
Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Common Emitter Configuration
Common Collector Configuration
Use the common-emitter model for the common-collector configuration.
Fig. 5.11 (a) Common-emitter BJT transistor; (b) approximate model for the configuration of a).
Fig. 5.17 re model for the common-emitter transistorconfiguration.
Fig. 5.12 Determinin Zi usin the a roximate
Fig. 5.16 Determining the voltage and current gain for the
common-emitter transistor am lifier.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
The Hybrid Equivalent Model:
The following hybrid parameters are developed and used for modeling the transistor.
These parameters can be found in a specification sheet for a transistor:
hi = input resistance hr= reverse transfer voltage ratio (Vi/Vo) 0 hf= forward transfer current ratio (Io/Ii) ho = output conductance
Fig. 5.22 Complete hybrid equivalent circuit.
Fig. 5.23 Common-emitter configuration: (a) graphical symbol; (b) hybrid equivalent
Fig. 5.24 Common-base configuration: (a) graphical symbol; (b) hybrid equivalent
circuit.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Common-Emitter re vs. h-Parameter Model
Fig. 5.25 Effect of removing hre and hoe from the hybird equivalent circuit.
Fig. 5.26 Approximate hybrid equivalent model.
Fig. 5.27 Hybrid versus re model: (a) common-emitter configuration; (b) common-base configuration.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
German-Jordanian University
School of Applied Natural Sciences -
Energy Engineering
BJT Amplifier Circuits:
Common Emitter Configurations:
Common Emitter Fixed-bias The input is applied to the base The output is from the collector High input impedance Low output impedance High voltage and current gain Phase shift between input and output is 180
Fig. 5.34 Common-emitter fixed-bias configuration.
Fig. 5.35Network of Fig. 5.34 following the removalof the effects ofVCC, C1 and C2.
Fig. 5.36 Substituting the re model into the network of Fig.5.35.
Fig. 5.37DeterminingZo for the network of Fig. 5.36.
Co 10Rr
e
Cv
e
oC
i
ov
r
RA
r
)r||(R
V
VA
eBCo r10R,10Rri
eBCo
oB
i
oi
A
)r)(RR(r
rR
I
IA
C
ivi
R
ZAA
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Common Emitter Voltage-divider Bias
Fig. 5.39 Example 5.4.
Fig. 5.40 Voltage-divider bias configuration.
Fig. 5.41Substituting the re equivalent circuit into the ac equivalent network of Fig. 5.40.
eCo
Co
r10R,10Rr
i
oi
10Rr
ei
oi
eCo
o
i
oi
I
IA
rR
R
I
IA
)rR)(R(rrR
IIA
C
ivi
R
ZAA
Co 10Rr
e
C
i
ov
e
oC
i
ov
r
R
V
VA
r
r||R
V
VA
Fig. 5.38 Demonstrating the 180 phase shift between input and outputwaveforms.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Fig. 5.42 Example 5.5.
Common Emitter Bias
Fig. 5.43 CEemitter-bias configuration.Fig. 5.46 Example 5.6.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Common Base Configuration
The input is applied to the emitter. The output is taken from the collector. Low input impedance. High output impedance. Current gain less than unity. Very high voltage gain. No phase shift between input and output.
Fig. 5.44 Substituting the re equivalent circuit into the ac equivalent
network of Fig. 5.43.
Eb
Eeb
RZ
E
C
i
ov
)R(rZ
Ee
C
i
ov
b
C
i
ov
R
R
V
VA
Rr
R
V
VA
Z
R
V
VA
bB
B
i
oi
ZR
R
I
IA
C
ivi
R
ZAA
Fi . 5.46 Exam le 5.6.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud
Fig. 5.57 Common-base configuration.
Fig. 5.58 Substituting the re equivalent circuit into the ac equivalent network of Fig. 5.57.
e
C
e
C
i
ov
r
R
r
R
V
VA
1I
IAi
oi
Fig. 5.59 Example 5.11.
8/7/2019 Fundametals of Analog Electronics_part II
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Module: Fundamentals of Analog Electronics Module Number: ENRE213
Electronic Devices and Circuit Theory, 9th ed., Boylestad and Nashelsky
Lecturer: Dr. Omar Daoud