Synopses & Reviews
SigmaDelta A/D Conversion for Signal Conditioning addresses the application of continuous-time SigmaDelta A/D converters in receivers for a.o. wireless communication. In particular, it focuses on their assets for digitizing such channels. The book gives an overview of the state-of-the-art in SigmaDelta design and of the challenges for future realizations. It provides an understanding of the fundamental power efficiency of SigmaDelta converters. In addition, it presents an analysis of the power consumption in the decimation filter. Understanding these power/performance trade-offs, it becomes clear that straight-forward digitization of a conditioning channel, i.e. exchanging analog for digital conditioning, comes at a major power penalty. This book proposes an alternative vision on digitization: because of its inherent immunity to interferers, part of the signal conditioning can be integrated into the continuous-time SigmaDelta A/D converter. This approach results in a major improvement of the power/performance balance of the entire channel. The various aspects of the interferer immunity of the converter are analyzed in much detail and improved SigmaDelta topologies with even higher immunity are presented. Design examples for highly digitized AM/FM and Bluetooth radios serve as an illustration. The examples include detailed circuit diagrams, simulation and test results, as well as an evaluation of the SigmaDelta-based conditioning channel as compared to more conventional solutions. The book is essential reading for mixed-signal and RF designers who want to familiarize with the basics of SigmaDelta design. For the experienced designer and for the system architect, the book provides an in-depth understanding of the major assets of SigmaDelta converters in digitized receivers.
Synopsis
1.1 Background Moore s Law predicts a decrease by a factor of two in the feature size of CMOS te- nology every three years and has been valid for years. It implies a doubling of the - eration speed and a four times higher transistor count per unit of area, every three years. The combination leads to an eight times higher processing capability per unit of area. This on-going miniaturization allows the integration of complex electronic systems with millions of transistors (Very-Large-Scale-Integration) and enables the integration of el- tronic systems. An electronic system A generic picture of an integrated electronic system is shown in ?g. 1.1. The heart of the system is the signal processing core. This core supports a wide variety of functions, such as customization and programmability of multiple applications, channel coding, the de?nition of the user interface, etc. These functions are enabled by DSP, a controller CPU and various blocks of memory. In advanced ICs these blocks provide (almost) all signal processing and usually dominate in the overall power and area consumption of integrated systems. The huge data rates involved, require high-speed busses for communication between these blocks. A power-management unit fuels the system by providing the - propriate supply voltages and currents."
Synopsis
The book gives an overview of the state-of-the-art in SigmaDelta design and of the challenges for future realizations. It provides an understanding of the fundamental power efficiency of SigmaDelta converters. In addition, it presents an analysis of the power consumption in the decimation filter. Understanding these power/performance trade-offs, it becomes clear that straight-forward digitization of a conditioning channel, i.e. exchanging analog for digital conditioning, comes at a major power penalty.
About the Author
Kathleen Philips was born in 1972, in Aalst, Belgium. In 1992 and in 1995, respectively, she obtained the B. Sc. and the M. Sc. degree in Electrical Engineering from the "Katholieke Universiteit Leuven" in Belgium. The graduation project was on the design of monolithic microwave ICs based on HEMT-transistors. In the summer of 1993, she did a traineeship at the IMEC, Belgium, on methodologies to evaluate contamination in IC technology steps. In September 1995, she started working in the Mixed-signal Circuits and Systems group of the Philips Research Laboratories in Eindhoven, the Netherlands, where she is now a senior research scientist. She respectively worked on the design of D/A converters and class-D amplifiers for audio, sigma delta A/D conversion for FM and AMradio, variable-gain amplifiers, sigma delta design for UMTS and for Bluetooth receivers. Her research interests also include the system-level design of transceivers for wireless communication. In the fall of 1997, she was seconded to Philips Semiconductors, France, on the topic of PLL design. Another secondment in 2000, to the Philips Research Laboratories in the United Kingdom, involved the study of third-generation mobile receivers and the derivation of circuit specifications. The author was a lecturer in the Educational Sessions of the IEEE Custom Integrated Circuits Conference in 2003 and 2004. From 2005 on, she also serves in the technical program committee of this conference.
Table of Contents
List of symbols and abbreviations 1 Introduction 1.1 Background 1.1.1 Anelectronicsystem 1.1.2 Digital signalprocessing 1.1.3 Digitizationof signal conditioning 1.1.4 Digitization of inter-die interfaces 1.2 Aim of this thesis 1.3 Scope 1.3.1 BasebandA/Dconditioning channels 1.3.2 Continuous-time single-bit sigma-delta conversion 1.3.3 CMOS technology 1.3.4 Power consumptionas cost parameter 1.3.5 Performance parameters 1.4 Outline 2 The signal conditioning channel 2.1 Generic communication channel 2.2 Performance parameters 2.3 Conventional conditioning channels 2.4 Evolution 2.4.1 Technology advances 2.4.2 Systemdemands 2.4.3 Advances in digital signal processing and analog circuit design 2.4.4 Digitizationof the architecture 2.5 Nomenclature 2.6 Conclusions 3 Sigma delta A/D conversion 3.1 Historical overview 3.2 State-of-the-art in sigma delta A/D conversion 3.2.1 Architectural considerations 3.2.2 Implementation aspects 3.2.3 Performance metrics for sigma delta ADCs 3.3 sigma delta ADCs infuture conditioning channels 3.3.1 The Shannon theorem and sigma delta based signal conditioning 3.3.2 Comparison of Nyquist and sigma delta based signal conditioning 3.3.3 Survey of published power/performance values 3.4 Limitations of sigma delta A/D conversion 3.4.1 Linear limitations 3.4.2 Non-linear limitations 3.5 Conclusions 4 Power consumption in channel building blocks 4.1 Literature on power/performance analysis 4.2 Figures-of-merit 4.2.1 FOM related to thermal noise 4.2.2 FOMincluding distortion 4.2.3 FOM related to signal resolution 4.3 Power consumption in analog conditioning circuits 4.3.1 Power/performance relations 4.3.2 Discussion 4.4 Power consumption in a sigma delta ADC 4.4.1 Power/performance relations 4.4.2 Discussion 4.5 Power consumption in digital conditioning circuits 4.5.1 Filter functions 4.5.2 Power/performancerelations 4.5.3 Discussion 4.6 Comparison 4.7 Conclusions 5 Full-analog and full-digital conditioning channels 5.1 Full-analog conditioning channel 5.1.1 The conditioning channel 5.2 Full-digital conditioning channel 5.2.1 The conditioning channel 5.2.2 Power/performance analysis 5.3 Conclusions 6 Conditioning sigma delta ADCs 6.1 Generic conditioning sigma delta ADC 6.1.1 Conceptofoperation 6.1.2 Universal model of a sigma delta modulator 6.1.3 Interferer immunity 6.1.4 Power/performance analysis 6.2 Signal conditioning in the decimation filter 6.2.1 Interferer immunity 6.2.2 The conditioning channel 6.2.3 Power/performance analysis 6.3 Signal conditioning with a restricted filtering STF 6.3.1 Interferer immunity 6.3.2 The conditioning channel 6.3.3 Power/performance analysis 6.3.4 Conditioning hybrid sigma delta ADC 6.4 Signal conditioningbyunrestrictedSTFdesign 6.4.1 Interferer immunity 6.4.2 The conditioningchannel 6.4.3 Power/performanceanalysis 6.5 Comparisonof conditioningADCs 6.5.1 Comparison of topologies 6.5.2 Flexibility 6.5.3 Power consumption 6.5.4 Guidelines 6.6 Conclusions 7 Digitization of the inter-die interface 7.1 Considerations 7.2 Power inthe interface 7.2.1 Analoginterface 7.2.2 Digital interface after decimation 7.2.3 Digital interface before decimation 7.2.4 Comparison 7.3 Application to the conditioning channels 7.4 Conclusions 8 Highly analog and highly digital channels for FM/AM radio 8.1 System 8.1.1 Conventional radio with analog demodulation 8.1.2 Radio with digital demodulation 8.2 VGAdesign 8.2.1 HighlylinearVGAdesign 8.2.2 Evaluation 8.3 ADCdesign 8.3.1 Conventionalsolutions 8.3.2 sigma delta ADC with integrated passive mixer 8.3.3 Evaluation 8.4 Evaluationof the channel 8.4.1 Discussion 8.4.2 Benchmark 8.5 Conclusions 9 Conditioning sigma delta ADCs for Bluetooth 9.1 System 9.1.1 Conventional radio with analog demodulation 9.1.2 Radio with digital demodulation and analog signal-conditioning 9.1.3 Radio with digital demodulation, without analog signal conditioning 9.2 Feed forward sigma delta ADC 9.2.1 Design 9.2.2 Evaluation 9.3 Conditioning feedback sigma deltaADC 9.3.1 Design 9.3.2 Evaluation 9.4 FFB-ADC 9.4.1 Design 9.4.2 Evaluation 9.5 Evaluationof the channels 9.5.1 Benchmark with published ADCs 9.5.2 Comparison of the presented ADCs 9.5.3 Benchmark with published Bluetooth conditioning channels 9.6 Conclusions 10 General conclusions A Overview of published sigma delta ADCs B Power/performance relation of analog circuits B.1 Simple differential pair B.2 Differentialpair in aglobal feed-back configuration B.3 Degenerated differential pair C Power/performance relation of digital filters C.1 Analysis of the filter topology C.2 Calculation of filter parameters C.3 Calculation of powerc onsumption C.4 Extensionto other implementations D Third-order distortion in analog circuits and sigma delta ADCs E Power consumption in a data interface. E.1 Analogdata interface. E.2 Digital data interface References Original contributions List of publications Summary Samenvatting Dankwoord Biography