CMOS Analog Circuit Design

477 Pages·2002·2.108 MB·English

by  Allen P.E., Holberg D.R.

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I . INT R ODUCTION
Contents
I.1 Introduction
I.2 Analog Integrated Circuit Design
I.3 Technology Overview
I.4 Notation
I.5 Analog Circuit Analysis Techniques
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Organization
Chapter 10
Chapter 11
D/A and A/D
Analog Systems
Converters
SYSTEMS
Chapter 7 Chapter 8 Chapter 9
CMOS Simple CMOS High Performance
Comparators Opamps Opamps
COMPLEX
CIRCUITS
Chapter 5 Chapter 6
CMOS CMOS
Subcircuits Amplifiers
SIMPLE
Chapter 2 Chapter 3 Chapter 4
CMOS CMOS Device Device
Technology Modeling Characterization
DEVICES
Introduction
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I.1 - INTRODUCTION
G LOBAL O BJECTIVES
• Teach the analysis, modeling, simulation, and design of analog circuits
implemented in CMOS technology.
• Emphasis will be on the design methodology and a hierarchical
approach to the subject.
S PECIFIC O BJECTIVES
1. Present an overall, uniform viewpoint of CMOS analog circuit design.
2. Achieve an understanding of analog circuit design.
• Hand calculations using simple models
• Emphasis on insight
• Simulation to provide second-order design resolution
3. Present a hierarchical approach.
fi fi fi
• Sub-blocks Blocks Circuits Systems
4. Examples to illustrate the concepts.
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I.2 ANALOG INTEGRATED CIRCUIT DESIGN
ANALOG DESIGN TECHNIQUES VERSUS TIME
FILTERS AMPLIFICATION
Passive RLC circuits Open-loop amplifiers
1935-1950
Active-RC Filters Feedback Amplifiers
Requires precise definition
Requires precise definition
of time constants (RC
of passive components
products)
1978
Switched Capacitor Switched Capacitor
Filters Amplifiers
Requires precise C Requires precise C
ratios and clock ratios
1983
Continuous Time Continuous Time
Filters Amplifiers
Time constants are Component ratios
adjustable are adjustable
1992
? Digitally assisted analog circuits ?
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DISCRETE VS. INTEGRATED ANALOG CIRCUIT DESIGN
Activity/Item Discrete Integrated
Component Accuracy Well known Poor absolute accuracies
Breadboarding? Yes No (kit parts)
Fabrication Independent Very Dependent
Physical PC layout Layout, verification, and
Implementation extraction
Parasitics Not Important Must be included in the
design
Simulation Model parameters well Model parameters vary
known widely
Testing Generally complete Must be considered
testing is possible before the design
CAD Schematic capture, Schematic capture,
simulation, PC board simulation, extraction,
layout LVS, layout and routing
Components All possible Active devices,
capacitors, and resistors
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THE ANALOG IC DESIGN PROCESS
Conception of the idea
Definition of the design
Comparison Comparison
with design Implementation with design
specifications specifications
Simulation
Physical Definition
Physical Verification
Parasitic Extraction
Fabrication
Testing and Verification
Product
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COMPARISON OF ANALOG AND DIGITAL CIRCUITS
Analog Circuits Digital Circuits
Signals are continuous in amplitude Signal are discontinuous in
and can be continuous or discrete in amplitude and time - binary signals
time have two amplitude states
Designed at the circuit level Designed at the systems level
Components must have a continuum Component have fixed values
of values
Customized Standard
CAD tools are difficult to apply CAD tools have been extremely
successful
Requires precision modeling Timing models only
Performance optimized Programmable by software
Irregular block Regular blocks
Difficult to route automatically Easy to route automatically
Dynamic range limited by power Dynamic range unlimited
supplies and noise (and linearity)
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I.3 TECHNOLOGY OVERVIEW
BANDWIDTHS OF SIGNALS USED IN SIGNAL PROCESSING
APPLICATIONS
Video
Acoustic
Seismic imaging
Sonar Radar
Audio AM-FM radio, TV
Telecommunications Microwave
1 10 100 1k 10k 100k 1M 10M 100M 1G 10G 100G
Signal Frequency (Hz)
Signal frequency used in signal processing applications.
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BANDWIDTHS THAT CAN BE PROCESSED BY PRESENT-
DAY TECHNOLOGIES
BiCMOS
Bipolar analog
Bipolar digital logic
MOS digital logic
MOS analog
Optical
GaAs
1 10 100 1k 10k 100k 1M 10M 100M 1G 10G 100G
Signal Frequency (Hz)
Frequencies that can be processed by present-day technologies.
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CLASSIFICATION OF SILICON TECHNOLOGY
Silicon IC Technologies
Bipolar Bipolar/MOS MOS
Junction Dielectric PMOS
Isolated Isolated CMOS (Aluminum NMOS
Gate)
Aluminum Silicon Aluminum Silicon
gate gate gate gate