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Microelectronic Circuits Microelectronic Circuits Ch. 1 Introduction
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전자회로 전자회로 11Chapter 1: Chapter 1: Introduction to Introduction to ElectronicsElectronics
인하대학교정보통신공학부
2008 년 2학기
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Course AdministrationCourse Administration Professor: 정 덕진
Office: Hi-Tech 빌딩 510 호 TEL: (032) 860-7435 Email: djchung@inha.ac.kr http://vlsi.inha.ac.kr/
Class Web Site: Cyber-class in Inha Univ.
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Text and Reference booksText and Reference books
Text: Microelectronics Circuits (5th Edition), Sedra/Smith Class notes on the web site
– Cyber-class in Inha Univ.
Reference:
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Course ContentsCourse ContentsPart I. Devices and Basic Circuits
Ch.1. Introduction to Electronics • Definition about signal / Analog-digital / Continuous-Discrete 등
Ch 2. Operational Amplifiers (OP-AMP)• Ideal OP-AMP • Practical OP-AMP 및 연결방법
Ch. 3. Diodes • Ideal Diode • Practical Diode condition 및 회로 / 특수 Diode / Zener Diode
Ch. 4. MOS Field-Effect Transistors (MOSFETs)• 물리적인 특성 , MOSFET circuits, amplifiers
Ch. 5. Bipolar Junction Transistors (BJTs)• 물리적인 특성 , npn/ pnp Tr., BJT circuits, • small-signal operation and models, • BJT amplifiers
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Course ContentsCourse ContentsPart II, Analog and Digital Integrated Circuits
Ch. 6. Single-Stage Integrated-Circuit amplifiers
Ch. 7. Differential and Multistage Amplifiers
Ch. 8. Feedback
Ch. 9. Operational-Amplifier and Data-Converter Circuits
Ch. 10. Digital CMOS Logic Circuits
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Grading InformationGrading Information Grade determinants
Quiz/Homeworks ~ 10%– Will be scheduled later.
Exam-2 ~ 25%– Will be scheduled later
Final Exam ~ 25%– Will be scheduled later
Projects ~ 30%– Due at the beginning of class on the due date (No extensions).
출석 ~ 10%
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Chapter 1 Chapter 1 Introduction to ElectronicsIntroduction to Electronics
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Introduction Introduction Microelectronics: 작은 실리콘 ( 실리콘 칩 ) 에 수백만개의 회로를
만들수 있는 능력을 가진 Integrated Circuit (IC) technology 를 말한다 . Microelectronics circuit example: Microprocessor
– Intel Pentium, AMD Athlon, DRAM, CDMA modem chip, ASIC, FPGA etc.
Chapter 1 에서 배울점 . Basic concept 와 terminology 를 이해하며 , 주로
단일소자를 이용한 signal amplification ( 증폭 ) 에 중점을 둔다 .
Linear amplifier 에 대한 모델들을 이해하고 , 그 모델을 이용해서 실질적인 amplifier circuits ( 증폭회로 ) 들을 설계하고 분석한다 .
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The Transistor RevolutionThe Transistor Revolution
First transistorBell Labs, 1948
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The First Integrated Circuits The First Integrated Circuits
Bipolar logic1960’s
ECL 3-input GateMotorola 1966
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Intel 4004 Micro-ProcessorIntel 4004 Micro-Processor
• First microprocessor designed In 1971• 1000 transistors• 1 MHz operation
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Intel Pentium (IV) MicroprocessorIntel Pentium (IV) Microprocessor
• Released in 2000
• 42 million transistors
• 0.18 micron tech.
• > 1GHz
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Silicon WaferSilicon Wafer
Single die
Wafer
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Transistor CountsTransistor Counts
1,000,000
100,000
10,000
1,000
10
100
11975 1980 1985 1990 1995 2000 2005 2010
8086
80286i386
i486Pentium®
Pentium® Pro
K1 1 Billion Billion
TransistorsTransistors
Source: IntelSource: Intel
ProjectedProjected
Pentium® IIPentium® III
Courtesy, Intel
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Design Abstraction LevelsDesign Abstraction Levels
n+n+S
GD
+
DEVICE
CIRCUIT
GATE
MODULE
SYSTEM
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Signals Signals
Signals: 정보를 포함한 신호 signal processing : 정보를 추출 , 가공 , 전송하는 과정
– Acoustic signal – Electrical signal – Optical signal
여기서는 주로 Electrical signal 을 취급한다 .
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1.1 Signals 1.1 Signals
In Fig.1.1(a), Signal is represented by a voltage Vs(t) having a source resistance Rs.
Figure 1.1 Two alternative representations of a signal source: (a) the Thévenin form, and (b) the Norton form.
0sR sR
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Figure 1.2 An arbitrary voltage signal vs(t).
Vs(t) = Rs is(t)
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1.2 Frequency Spectrum of Signals1.2 Frequency Spectrum of Signals
Figure 1.3 Sine-wave voltage signal of amplitude Va and frequency f = 1/T Hz. The angular frequency = 2f rad/s.
1) Signal 의 표시방법
1)-1. Time Domain
Va(t) = Va sin t
Figure 1.4 A symmetrical square-wave signal of amplitude V.
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1)-2. Frequency domain1)-2. Frequency domain
Figure 1.5 The frequency spectrum (also known as the line spectrum) of the periodic square wave of Fig. 1.4.
• Fourier series 와 Fourier transform에 의하여 frequency spectrum 이라는 신호표현이 얻어진다 .• 모든 signal 은 Fourier transform 에 의해서 주파수 영역으로 구분 가능
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2)-2. Frequency domain2)-2. Frequency domain
1
0 2sin2cos2 n
nn T
tnb
T
tna
a
Tn dt
T
nttf
Ta 0
2cos)(
2예 )
즉 . Fig. 1-4 의 파형은 ( )
: fundamental frequency : 3rd harmonic frequency
: 5th harmonic frequency
실효치 (Root-Mean-Square, rms) 로써 표시되기도 하며 sine wave 시 peak
치의 이다 audio band : 20 ㎐ ~ 20 ㎑ (20 ㎑ 이상은 사람의 귀에서 인식 불가능 )
Tw
20
)5sin5
13sin
3
1(sin
4)( twtwtw
vtv ooo
twosin two3sin3
1
two5sin5
1
2
1
Tn dt
T
nttf
Tb 0
2sin)(
2
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Figure 1.6 The frequency spectrum of an arbitrary waveform such as that in Fig. 1.2.
Unlike the case of periodic signals, where the spectrum consists of discrete frequencies (at 0 and its harmonics), the spectrum of nonperiodic signal contains in general all possible frequencies, that is continuous function of frequencies.
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1.3 1.3 Analog and Digital SignalsAnalog and Digital Signals 특성에 의한 분류
Analog signal : Fig. 1.2 Digital signal :
형태에 의한 분류 Continuous-time signal : Discrete-time signal :
Digital signal 의 장점 noise 에 의한 문제를 쉽게 치유가능 저전력으로 전송가능
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Figure 1.7 Sampling the continuous-time analog signal in (a) results in the discrete-time signal in (b).
Sampling: At each intervals along the time axis we have marked the time instants t0, t1, t2, and so on. At each of these time instants the magnitude of the signal is measured.
Continuous-time signal Discrete-time signal
Analog Signal
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Digital SignalDigital Signal After quantized, discretized, or digitized, the resulting digital signal is a
sequence of numbers that represent the magnitude of the successive signal samples.
Binary number system results in the simplest possible digital signals and circuits.
In binary system, each digit in the number takes on one of only two possible values, denoted 0 and 1.
Figure 1.8 Variation of a particular binary digital signal with time.
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Analog-to-Digital (A/D) ConverterAnalog-to-Digital (A/D) Converter
A/D converter accepts at its input the samples of an analog signal and provides for each input sample the corresponding N-bit digital representation at its N output terminals.
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1.4 Amplifiers1.4 Amplifiers Signal Amplification
Signal 을 증폭할 때 선형성이 유지되어야 하며 , 선형성이 유지되지 않으면 Nonlinear Distortion 이 발생 .
A : Amplifier gain, 만약 A=const. 이면 linear Amplifier 라고 부른다 .
Voltage gain (Av) ≡ , current gain (Ai) ≡ , power gain (Ap) ≡
∴ Ap = Av Ai
i
o
v
v
i
o
i
i
ii
oo
i
L
iv
iv
P
P
)()( tAvtv io
Transfer characteristic of a linear amplifier
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Expressing Gain in Decibels Voltage gain in decibels = 20 log |Av| dB Current gain in decibels = 20 log |Ai| dB Power gain in decibels = 10 log |Ap| dB
A negative gain Av means that there is a 180º phase difference between input and output signals.
Amplifier Power Supplies
|100 0
2211
iPdc
L
dissipatedLidc
dc
P
P
PPPP
IVIVP
V+ = 10V, V- = -10VVo = Vpeak, RL=1K
DC power
: amplifier efficiency
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Example 1.1
V+ = 10V, V- = -10V Vo = Vpeak, RL=1K,
mAII 5.921 mAIi 1.0 peaki VV 1
i
ov V
vA 9log20 10vA
k
V
R
vI peak
L
oo 1
990
1.0
9
i
oi
I
IA dBAi 1.3990log20
mWIVP ormsormsL 5.402
9
2
9 mWIVP irmsirmsI 05.0
2
1.0
2
1
WWP
PA
I
LP /810
05.0
5.40 dBAP 1.2980log10
%3.21100
1495.4005.0190
1905.9105.910
dc
L
LIdcdissipated
dc
P
P
mWPPPP
mWP
91
9
peak
peak
V
VdB1.19
peakmA9
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Amplifier Saturation
Figure 1.13 An amplifier transfer characteristic that is linear except for output saturation.
The output voltage cannot exceed a specified positive limit and cannot decrease below a specified negative limit. L+ : Positive saturation level L-: Negative saturation level
Note that the peaks of the larger waveform have been clipped off because of amplifier saturation.
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Nonlinear Transfer Characteristic and BiasingNonlinear Transfer Characteristic and Biasing
• In practical amplifiers the transfer characteristic may exhibit nonlinearities of various magnitude.
• The transfer characteristic is nonlinear and, because of the single-supply operation, is not centered around origin.
• Biasing: signal 의 전부분이 증폭될 수 있도록 DC voltage 를 부가하여 중심점을 옮기는 것 .
• See page.19.
Figure 1.14 (a) An amplifier transfer characteristic that shows considerable nonlinearity. (b) To obtain linear operation the amplifier is biased as shown, and the signal amplitude is kept small. Observe that this amplifier is operated from a single power supply, VDD.
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Figure 1.15 A sketch of the transfer characteristic of the amplifier of Example 1.2. Note that this amplifier is inverting (i.e., with a gain that is negative).
Example 1.2 Find the limits L- and L+ and the corresponding Find the VI that results in VO = 5V and the voltage gain at the corresponding
operating point
1) L- = 0.3V, = 0.3V in Eq. (1.10)
= 0.690V
2) L+ =
3) VI = 0.673V by substituting = 5V
in Eq. (1.10)
4) Av = -200 V/V by evaluating the
derivative at = 0.673V
)3.00(1010 4011
0VvandVvforev
OI
vI
Iv
Ov
Iv
V101010 11
Ov
IOdvdv /
Iv
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Symbol ConventionSymbol Convention IA: Direct-current (dc) current VC: Direct-current (dc) Voltage iA(t): Instantaneous current (Total current) iC(t): Incremental current signal VDD: Power-supply (dc) voltage IDD: dc current drawn from the power supply
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Circuit Models for AmplifiersCircuit Models for Amplifiers Circuit Model 의 4 가지 유형
Vi R i
R o
AvoViR i R oA isii
ii
R i R oG mVi
io
ViR i R m ii
ii
Vo
R o
Voltage Amplifier (Avo : unitless) Current Amplifier (Ai : unitless)
Transconductance Amplifier (Gm : conductance)
Resistance Amplifier (Rm : Resistance)
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1.5.1 Voltage Amplifiers1.5.1 Voltage Amplifiers
Figure 1.17 (a) Circuit model for the voltage amplifier. (b) The voltage amplifier with input signal source and load.
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Vi R i
R o
AvoVi R i R oA isii
ii
R i R oG mVi
io
ViR i R m ii
ii
Vo
R o
Voltage Amplifier (Avo : unitless) Current Amplifier (Ai : unitless)
Transconductance Amplifier (Gm : conductance)
Resistance Amplifier (Rm : Resistance)
The Four Amplifier TypesThe Four Amplifier Types
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Frequency Response of AmplifiersFrequency Response of Amplifiers Amplifier frequency response: 다른 주파수들을 가지고 있는 Input
sinusoids 에 대한 응답에 관한 특성 . Measuring the Amplifier Frequency Response
Figure 1.20 Measuring the frequency response of a linear amplifier. At the test frequency v, the amplifier gain is characterized by its magnitude (Vo/Vi) and phase .
Fig. 1.20 depicts a linear amplifier fed at its input with a sine-wave signal of amplitude Vi and frequency
Whenever a sine-wave signal is applied to a linear circuit, the resulting output is sinusoidal with the same frequency as the input.
Linear Amplifier 에서는 gain 이 일정하나 일반적인 Amplifier 에서는 frequency 에 따라 증폭율이 달라진다 .
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Measuring the Amplifier Frequency ResponseMeasuring the Amplifier Frequency Response
Figure 1.20 Measuring the frequency response of a linear amplifier. At the test frequency , the amplifier gain is characterized by its magnitude (Vo/Vi) and phase .
Magnitude of the amplifier gain (or transmission), or transfer function |T()| = Vo/Vi
Phase of the amplifier transmission: T() = Amplifier 의 Frequency response 는 amplitude response 와 phase response
를 구성한다 Amplitude response: gain magnitude |T()| versus frequency Phase response: phase angle T() versus frequency
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1.6.2 Amplifier Bandwidth1.6.2 Amplifier Bandwidth
Express the magnitude of transmission in decibels The gain is almost constant over a wide frequency range, roughly
between 1 and 2. Amplifier bandwidth: The band of frequencies over which the gain of
the amplifier is almost constant.
Figure 1.21 Typical magnitude response of an amplifier. |T()| is the magnitude of the amplifier transfer function—that is, the ratio of the output Vo() to the input Vi().
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1.6.3 Evaluating the Frequency Response of 1.6.3 Evaluating the Frequency Response of AmplifiersAmplifiers
In frequency-domain analysis
Vi
Vo
C c
C E
C bc
C be
C S
the Amplifier transfer function T (w) = Vo()/Vi()
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1.6.4 Single-Time-Constant Networks1.6.4 Single-Time-Constant Networks Two examples of STC networks are
Low-pass network High-pass network
Figure 1.22 Two examples of STC networks: (a) a low-pass network and (b) a high-pass network.
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Low-pass networkLow-pass network
Vi Vo
R
C
jw 대신에 complex frequency variable s
1
11
1
)(
jwCR
jwCR
jwCV
VwT
i
o
1
1
oww
j
12
2
|
1
1log20
oww
ww
oo w
w
w
w|tan 1
)(
)()(
sV
sVsT
i
o
dB32
1log20
The transmission of low-pass network will decrease with frequency and approach zero as approach .
Low-pass filter passes low-frequency sine-wave inputs with little or no attenuation (at =0, the transmission is unity)
RCw
10
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Bode plots of Low-pass networkBode plots of Low-pass network
Magnitude response
Phase response
3-dB frequency (0)
= corner frequency
= break frequency
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High-pass networkHigh-pass network
Its transmission is unity at = and decrease as is reduced.
Vi VoR
C
예 ) C = 1 ㎋ , R = 1 ㏀ sol)
Transfer function :
RCjw
jw
jwCR
R
V
VwT
i
o
11)(
)/(1
1
wwj o
RCw
10
KHzw
frequencydBf
RCw
oo
o
1592
3
1010
1
1010
11 6693
610)(
s
ssT )
10(tan
)/10(1
1 61
26 ww
w
w
wwo
o
1
2tan
)/(1
1
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Bode plots of High-pass networkBode plots of High-pass network
Magnitude response
Phase response
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Example 1.5Example 1.5
a) Amplifier voltage gain V0 / VS , dc gain and the 3-dB frequency ?
b) RS = 20kΩ, Ri = 100kΩ, Ci = 60pF, = 144V/VkΩ , Ro = 200Ω , RL = 1kΩ, Calculate dc gain, 3-dB frequency, unit gain frequency ?
c) V0 = ?
i) Vi = 0.1 sin102t V ii) Vi = 0.1 sin105t V iii) Vi = 0.1 sin106t V iv) Vi = 0.1 sin108t V
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Example 1.5: Solution (see pp. 36)Example 1.5: Solution (see pp. 36)a
)
Time constant
s
i
oL
Lio
sii
ss
i
ii
s
sis
ssi
isi
V
V
RR
RVV
RsCRRV
V
sCR
RV
YRV
RZ
ZVV
)1(
1
)1
(1
1
1
1
oioi w
RRC1
)||(
oL
o
o
ss
o
ww
jRR
RRV
V
1
1
1
1
1
1
isi
i
s RRsCRR ||1
1
1
1
isi
L
o
i
s RRsCRR
RR ||1
1
1
1
1
1
oww
j
K
1
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Example 1.5: Solution (see pp. 36)Example 1.5: Solution (see pp. 36)
b) dc gain
VVK /100
1000200
1
1
10020
1
1144
3 dB frequency
kHzf
srKKpF
wo
2.1592
10
/10)100||20(60
1
6
0
6
unit gain frequency =
sr /108
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Example 1.5: Solution (see pp. 36)Example 1.5: Solution (see pp. 36)c
) 610/1
100)()(
jwjw
v
vjwT
s
o
010
10tantan) 6
211
ow
wi
)(tvo
7.510
10tantan) 6
511
ow
wii
)(
95.91
1002
610
510
tv
gain
o
4510
10tantan) 6
611
ow
wiii
)(
7.701
1002
610
610
tv
gain
o
4.8910
10tantan) 6
811
ow
wiv
)(
4.891
1002
610
810
tv
gain
o
Gain =
t2sin10 Vt )7.510sin(95.9 5
Vt )4510sin(7.70 6 Vt )4.8910sin(1.0 8
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1.6.5 Classification of Amplifier Based on 1.6.5 Classification of Amplifier Based on Frequency ResponseFrequency Response
Figure 1.26 Frequency response for (a) a capacitively coupled amplifier, (b) a direct-coupled amplifier (Low-pass filter), and (c) a tuned or bandpass amplifier (bandpass filter).
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1.7 Digital Logic Inverters1.7 Digital Logic Inverters1.7.1 Function of the Inverter1.7.1 Function of the Inverter
Figure 1.28 A logic inverter operating from a dc supply VDD.
A logical variable is associated with a nominal voltage level for each logic state 1 VOH and 0 VOL
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1.7.2 The Voltage Transfer Characteristic (VTC) 1.7.2 The Voltage Transfer Characteristic (VTC)
The regions of acceptable high and low voltages are delimited by VIH and VIL that represent the points where the gain of VTC curve = -1.
VIL ~ VIH: transition region
VIL VIH Vin
Slope = -1
Slope = -1
VOL
VOH
Vout
“ 0” VOL
VIL
VIH
VOH
UndefinedRegion
“ 1”
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1.7.3 Noise Margins 1.7.3 Noise Margins
Noise margin high
Noise margin low
VIH
VIL
UndefinedRegion
"1"
"0"
VOH
VOL
NMH
NML
Gate OutputStage M
Gate InputStage M+1
For a gate to be robust and insensitive to noise disturbance, “0” and “1” intervals (noise margins) should be as large as possible.
* Noise Margin High NMH = VOH - VIH * Noise Margin Low
NML = VIL - VOL
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1.7.4 Ideal VTC1.7.4 Ideal VTC
Ri = Ro = 0Fanout = NMH = NML = VDD/2
g =
The ideal gate should have infinite gain in the transition region a gate threshold located in the middle of the logic swing high and low noise margins equal to half the swing input and output impedances of infinity and zero, respectively.
Ideal voltage-transfer characteristic of anIdeal inverter
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1.7.5 Inverter Implementation1.7.5 Inverter Implementation
CMOS Inverter CMOS Inverter
Polysilicon
In Out
VDD
GND
PMOS 2
Metal 1
NMOS
OutIn
VDD
PMOS
NMOS
Contacts
N Well
Its Layout
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Figure 1.31 (a) The simplest implementation of a logic inverter using a voltage-controlled switch; (b) equivalent circuit when vI is low; and (c) equivalent circuit when vI is high. Note that the switch is assumed to close when vI is high.
OutIn
VDD
PMOS
NMOS
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OutIn
VDD
PMOS
NMOS
Figure 1.32 A more elaborate implementation of the logic inverter utilizing two complementary switches. This is the basis of the CMOS inverter studied in Section 4.10.
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1.7.6 Power Dissipation1.7.6 Power Dissipation
Power dissipation: how much energy is consumed per operation and how much heat the circuit dissipates
Two important power consumption: Dynamic and static power dissipation P (watts) = CLVdd²f01+ tscVddIpeakf01+VddIleakage
f01 = P01 fclock
Dynamic power dissipation = CLVdd²f01
Static power dissipation = tscVddIpeakf01+VddIleakage
– CL: load capacitance Capacitance between the output node and ground
– Vdd: power-supply voltage
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1.7.7 Propagation Delay1.7.7 Propagation Delay Propagation delay: time delay between switching of v1
(from low to high or vice versa) and the corresponding change appearing at the output. Propagation arises for two reasons:
– The transistors that implement the switches exhibit finite (nonzero) switching times
– The capacitance that is inevitably present between the inverter output node and ground needs to charge (or discharge) before the output reaches its required level of VOH or VOL
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Important model – matches delay of inverter
Modeling Propagation DelayModeling Propagation Delay
vout
vin C
R
Model circuit as first-order RC network
where RC (time constant)
Time to reach 50% point is
tp = ln (2) = 0.69
Time to reach 90% point is
tp = ln (9) = 2.2
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Figure 1.34 Example 1.6: (a) The inverter circuit after the switch opens (i.e., for t 0). (b) Waveforms of vI and vO. Observe that the switch is assumed to operate instantaneously. vO rises exponentially, starting at VOL and heading toward VOH .
Example 1.6
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Solution)
on
on
offsetDD
offsetOLR
RR
VVVV
V55.01.01.1
1.051.0
/)55.05(5)( t
Oetv
)(2
1)(
OLOHPLHOVVtv
)55.05(2
1
ns
RC
tPLH
9.6
101069.0
69.0
69.0
113
ii) by substituting in Eq. (1.33)
i) iii)
iv) The result is