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Data converters are circuits used to interface between the digital signal processing (DSP) core of a system and the analog world. The processing of signals is predominantly performed in the digital world rather than in the analog world. This is because digital circuits can achieve tremendous degrees of integration, complexity, and programmability and can also provide very repeatable results from wafer to wafer. Digital circuits are also much easier to synthesize than their analog counterparts, lending themselves to automation without any performance degradation. A system, which among other things can be a car radio, an MP3 player, a GPS unit, or a computer, receives inputs from the analog world that are converted to digital signals by an Analog-to-Digital Converter (ADC) and fed to the system's DSP core for processing. Then the DSP core generates outputs that it sends to a Digital-to-Analog Converter (DAC), after which some filtering and amplification may take place. For example, when ...
Data converters are circuits used to interface between the digital signal processing (DSP) core of a system and the analog world. The processing of signals is predominantly performed in the digital world rather than in the analog world. This is because digital circuits can achieve tremendous degrees of integration, complexity, and programmability and can also provide very repeatable results from wafer to wafer. Digital circuits are also much easier to synthesize than their analog counterparts, lending themselves to automation without any performance degradation. A system, which among other things can be a car radio, an MP3 player, a GPS unit, or a computer, receives inputs from the analog world that are converted to digital signals by an Analog-to-Digital Converter (ADC) and fed to the system's DSP core for processing. Then the DSP core generates outputs that it sends to a Digital-to-Analog Converter (DAC), after which some filtering and amplification may take place. For example, when we talk using a cell phone, our voices are digitized by an ADC and processed by the DSP core, then they are converted back to analog signals by a DAC, amplified, and sent out as radio waves.nnThe speed and capabilities of DSP circuits increase every year, which in turn requires ever faster and accurate interfaces to the analog world. As a result, a lot of research effort has been put into optimizing the performance of ADCs and DACs.
References
[1] R. Schreier and G. Temes, Understanding Delta-Sigma Data Converters, John Wiley & Sons, Hoboken, New Jersey, 2005, pp 1-2.'
Online Articles
Continuous-time delta-sigma modulators thesis: Presents the implementation of a sigma-delta modulator using continuous-time techniques MIDAS example #1: Berkeley example of using MIDAS
MIDAS example #2: Berkeley example of using MIDAS
Berkeley ADC/DAC course lectures - Fall 2007: Berkeley's data converters' course lectures
Berkeley opamp class project: Fully Differential OTA for 13-bit pipelined ADC
UC-Berkeley ADC/DAC lectures: From EECS290Y, "A/D Interfaces in VLSI Technology"
Analog Electronics class notes at Georgia Tech: Lecture notes and problems from analog electronics course at Georgia Tech
Maxim ADC/DAC application notes: Over 100 application notes and some Excel spreadsheets from Maxim
Texas Instruments' "Understanding Data Converters": Application note discusses how data sheets' specifications affect performance
Texas Instruments' application notes: Hundreds of application notes by topic
National's Current Feedback application note: Discusses the performance of current feedback op-amps in closed-loop topologies
National's op-amp circuit collection: Op-amp topologies for signal generation and processing
National's 1974 IC Op-amp tutorial: Thorough analysis of an integrated two-stage bipolar op-amp
DAC class project: 8-bit R-2R DAC class project at the University of Utah
8-bit 200 MHz DAC presentation from Sam Blackman at Berkeley: Discusses topology and design trade-offs given a set of specifications Citeseer: Search over 1 million articles Berkeley collection of papers on ADC and switched-capacitor circuit design: Many papers and projects by Andrew Abo of Berkeley, plus his thesis
Berkeley thesis on sigma-delta modulators: Arnold Feldman's thesis discusses architectural and circuit techniques for sigma-delta modulators
Berkeley thesis on decimation filters: Carol Barrett's thesis presents a decimation filter for GSM/DECT applications
Linear Technologies data converter application notes: Two dozen data converter application notes, including a data acquisition circuit collection
MIT's OpenCourseWare microelectronics course: Microelectronics' course covers physics' effects in semiconductor devices and basic circuit analysis - Fall 2005
Berkeley's ADC/DAC course webcast - Fall 2007: Berkeley's data converters' course webcast (requires RealPlayer)
ADC papers from UC-Berkeley: From mid- to late 90's ADC thesis: Sigma-Delta modulator for transceivers Digitally-calibrated ADCs in deep-submicron CMOS PhD thesis: Presents adaptive digital technique to calibrate pipelined ADCs, demonstrated in 0.13-um CMOS Oversampling ADCs in CMOS paper from U. of Toronto: Tutotial of oversampling sigma-delta converters for high frequency applications discusses topologies and issues Oversampling, continuous-time sigma-delta ADC paper: Oversampling of 20-MHz-bandwidth signals by combining time-interleaving and continuous-time techniques Third-Order Sigma-Delta ADC for audio paper from Professor Moon at Oregon State: Combines double-sampling switched-capacitor switched-RC techniques to implement a 0.13-um delta-sigma ADC that works from 0.9-V 500-MS/s, 5-bit ADC in 65-nm CMOS paper from MIT: 6-channel, time-interleaved, SAR ADC for UWB application 500-MS/s, 5-bit ADC in 65-nm CMOS presentation from MIT: Time-interleaved SAR ADC for UWB application
100-kS/s 12-bit ADC for Wireless Sensor Networks applications: paper from MIT: 12-bit ADC implemented in 0.25-um CMOS draws 25 uA from 1-V supply 100-kS/s, 12-bit ADC for Wireless Sensor Networks: presentation from MIT: 12-bit ADC draws 25-uA from 1-V supply Power-saving techniques for CMOS ADCs: Techniques demonstrated on a 65-nm CMOS time-interleaved ADC Low-voltage design for ultra-low-power applications presentation: Presents techniques to meet challenges of ultra-low-power applications such as WSNs. Prototypes 0.3-V SoC and sub-1V ADCs in 65-nm CMOS ADCs for UWB thesis from the MIT: Analysis of UWB ADCs requirements and demonstration of a 4-bit, 4-GS/s ADC in 0.18-um CMOS ADC performance metrics presentation from India Institute of Technology: Comprehensive presentation shows performance metrics of ADCs and typical requirements of various applications Power-optimized pipelined CMOS ADCs thesis from Georgia Tech: Analysis og high-speed, medium-resolution pipelined ADCs, techniques to reduce power dissipation, 10-bit, 100-MS/s pipelined ADC implemented in 0.18-um CMOS ADCs for SoC sensor applications thesis from Georgia Tech: Includes frequency and time domain modeling of ADCs and a design framework for ADCs. Sigma-Delta modulator in 90-nm CMOS thesis from Georgia Tech: Multi-rate, multi-bit sigma delta ADCS for wireless applications, techniques to reduce power consumption of sigma-delta ADCs. Mixed-signal IC Design course notes and video from Boise State, 2006: 27 lectures and videos from Professor Jacob Baker, very good.
ADC lecture notes from Phillip Allen: Lecture 10 has >100 pages, including topologies and performance metrics Sigma-delta presentation from Instituto de Microelectronica de Sevilla: Nice presentation targeting ADSL applications, delta-sigma implemented in 0.35-micron CMOS Lowpass and bandpass delta-sigma modulators presentation from ADI's Richard Schrier (hosted by MIT): Very good guest lecture as part of an MIT OCW course, stars from the basics and buils from that
Books
CMOS Mixed-Signal Circuit Design by Jacob Baker: Highly regarded Oversampling Delta-Sigma Data Converters: Theory, Design, and Simulation by J. Candy and G. Temes: 1991 compilation of selected delta-sigma papers Continuous Time Sigma Delta Modulation for A/d Conversion in Radio Receivers by L. Breems and J. Huijsing: From description: "...main focus is on dynamic range, linearity and power efficiency aspects of sigma-delta modulators..." Continuous-Time Delta-Sigma Modulators for High-Speed A/D Conversion by J. Sherry W. Snelgrove: Delta-sigma modulators that use a continuous-time loop filter, MATLAB routines, simulated and measured results for a 1-GHz ADC presented. A tad bit expensive. Design of Multi-Bit Delta-Sigma A/D Converters by Y. Geerts, M. Steyaert, and W. Sansen: High-resolution, high-speed ADC's targeting ADSL and other high-speed applications Systematic Design for Optimisation of Pipelined ADCs by J. Goes, J Vital, and J. Franca: General considerations, self-calibration technique to extend linearity of pipelined ADC's, design examples with layout considerations, simulated, and measured results CMOS Data Converters for Communications by M. Gustavsson, J. Wikner, and N. Tan: How to derive data converter requirements for a given communications system, architectures and building blocks. Seems like there are a few copies moderately priced so that's good. Integrated Converters: D to A and A to D Architectures, Analysis and Simulation by P. Jespers: Includes MATLAB routines and examples Modular Low-Power, High-Speed CMOS Analog-To-Digital Converter for Embedded Systems by K. Lin and A. Kemna: 8-12 bit folding and interpolated ADC's with an eye on low power applications Top-Down Design of High-Performance Sigma-Delta Modulators by F. Medeiro, B. Perez-Verdu: Presents CAD methodology to design delta-sigma mod's using in-house tools (SDOPT, FRIDGE, ASIDES). Three design examples using the proposed methodology are discussed.
High Speed A/D Converters - Understanding Data Converters Through SPICE by A. Moscovici: Learning Nyquist converters using SPICE and Mathcad Delta-Sigma Data Converters: Theory, Design, and Simulation by S. Norsworthy, R. Schreier, and G. Temes: from the back cover: "...offers a detailed treatment of the analysis, design, simulation, and testing of the full range of today's leading delta-sigma data converters..." The Design of Low-Voltage, Low-Power Sigma-Delta Modulators by S. Rabii and B. Wooley: from description: "...an analysis of power dissipation in sigma-delta modulators is presented, and a low-voltage implementation of a digital-audio performance A/D converter based on the results of this analysis is described..." Principles of Data Conversion System Design by Razavi: from description: "...Topics covered include: sampling circuits and architectures, D/A and A/D architectures; comparator and op amp design; calibration techniques; testing and characterization..." Data Converters for Wireless Standards by C. Shi and I. Mostafa: Prototype data converter designs for various wireless standards. Very inexpensive used copies available High Speed Analog-to-Digital Converters by W. Sansen and J. Huijsing: Paper compilation of DAC's and PLL's for various applications Circuit Techniques for Low-Voltage and High-Speed A/D Converters by M. Waltari and K. Halonen: Low-voltage circuit blocks and techniques for pipelined ADC's Design of Analog-Digital VLSI Circuits for Telecommunications and Signal Processing by J. Franca and Y. Tsividis: 1993 article compilation Besser Associates' High-Speed BiCMOS Design for Mixed-Signal Circuits: Data converter and other circuit types in SiGe, GaAs, InP technologies Delta-Sigma Modulators: Modeling, Design and Applications by George Bourdopoulos: from description: "...provides an overview of the architectures, the quantizer models, the design techniques and the implementation issues encountered in the study of the delta–sigma modulators..."
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