CICC 2002 Ed Sessions: Session 1

Advanced Data Converter Design and Test Techniques

Organizer: Doug Garrity, Motorola
Co-organizer: David Allee, Arizona State University

E2-1
Introduction to Delta-Sigma Data Converters
Bob Adams, Analog Devices
8:00-9:50

Noise-shaping converters have by now completely displaced data-acquisition converters in applications where spectral performance is the key performance metric. This talk will start with the basics of noise-shaping converter theory and progress to more advanced and recent topics such as mismatch-shaping schemes that are used in modern multi-bit noise-shapers. Practical aspects of noise-shaping converter design will also be covered.

E2-2
Multi-bit Mismatch-Shaping DACs for High- Performance Delta-Sigma Data Conversion
Ian Galton, UC San Diego
10:10-12:00

Mismatch-shaping DACs have become widely used in high-performance delta-sigma data converters. By suppressing the signal-band portion of the error introduced by inevitable component mismatches, mismatch-shaping DACs have made the use of multi-bit quantization in delta-sigma modulators practical. Relative to single-bit quantization, which was the norm prior to the availability of mismatch-shaping DACs, multi-bit quantization significantly relaxes the performance required of the analog circuitry thereby increasing the data conversion performance that can be achieved for a given power consumption and circuit area. This tutorial will present a detailed explanation of mismatch-shaping DACs and their application to high-performance delta-sigma data converters at both the signal processing and circuit levels. After a brief review of delta-sigma modulation, the tutorial will provide a practical explanation of the signal processing principle underlying the ability of mismatch-shaping DACs to shape mismatch error without knowledge of the mismatches, a survey of alternative mismatch-shaping DAC topologies, a detailed circuit-level description of highly efficient first-order and second-order mismatch-shaping DACs, and the system and analog circuit level delta-sigma modulator design implications of mismatch-shaping DACs. Examples of state-of-the-art delta- sigma data converters will be presented as case studies.

E2-3
Practical Aspects of Nyquist-Rate Switched- Capacitor ADC's
David Nairn, Analog Devices
1:00-2:50

System- and circuit-level issues for switched-capacitor (SC), Nyquist rate analog-to-digital converters (ADCs) will be discussed. After a brief review of the common SC ADC architectures, flash, successive approximation, cyclic and pipelined, the trade-offs between the architectures will be considered. Then, system-level issues such as noise and accuracy in conjunction with their effects on partitioning and scaling will be considered for the ADCs. Following this, the discussion will focus on specific circuit and design issues related to subcomponents such as switches, capacitors, op amps and comparators. Where appropriate, example circuits will be analyzed and good layout practices will be considered.

E2-4
State of the Art Lab Characterization Methods for High-Speed ADCs and DACs
Steve Reine, Analog Devices
3:10-5:00

High Speed ADCs and DACs are making the distance, often spoken of as bits to the antenna, shorter in each new generation of converters. Cutting-edge digital communications systems require novel and unique characterization methods for ADCs and DACs. Converter characteristics are now defined in terms of radio and broadband communications technology. Spectral characteristics become key, while time-domain effects take on new meaning. Generation of high-speed analog and digital test signals requires that generators be capable of synthesizing high dynamic range multi-carrier and wideband signals.