Table Of Content

Allen and Holberg - CMOS Analog Circuit Design Page I.0-1 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 Allen and Holberg - CMOS Analog Circuit Design Page I.0-2 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 Allen and Holberg - CMOS Analog Circuit Design Page I.2-1 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. Allen and Holberg - CMOS Analog Circuit Design Page I.2-1 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 ? Allen and Holberg - CMOS Analog Circuit Design Page I.2-2 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 Allen and Holberg - CMOS Analog Circuit Design Page I.2-3 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 Allen and Holberg - CMOS Analog Circuit Design Page I.2-4 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) Allen and Holberg - CMOS Analog Circuit Design Page I.3-1 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. Allen and Holberg - CMOS Analog Circuit Design Page I.3-2 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. Allen and Holberg - CMOS Analog Circuit Design Page I.3-3 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