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This paper presents a complete set of blocks implemented in the popular MATLAB SIMULINK environment, which allows designers to perform time-domain behavioral simulations of switched-capacitor (SC) sigma--delta ([SIGMA][DELTA]) modulators. The proposed set of blocks takes into account most of the SC [SIGMA][DELTA] modulator nonidealities, such as sampling jitter, kT/C noise, and operational amplifier parameters (white noise, finite dc gain, finite bandwidth, slew rate and saturation voltages). For each block, a description of the considered effect as well as all of the implementative details are provided. The proposed simulation environment is validated by comparing the simulated behavior with the experimental results obtained from two actual circuits, namely a second-order low-pass and a sixth-order bandpass SC [SIGMA][DELTA] modulator. Index Terms--Analog--digital conversion, discrete-time systems, sigma--delta ([SIGMA][DELTA]) modulation.

In this paper, we discuss theoretical and practical issues concerning low-voltage and low-power data converters. By looking at a series of constraints affecting the design of basic elements and building blocks, the paper analyzes different architectures for Nyquist rate data converters and discusses important aspects of low-voltage and low-power operation. Following this, the minimization of power consumption in the very popular sigma-delta technique is considered. A number of hints and indications are provided throughout the paper.

In this paper, we present a switched-capacitor sigma--delta (Σ--Δ) modulator for high resolution applications. In particular, this Σ--Δ modulator is well suited for distributed sensor networks. The circuit, implemented in a double-poly, double-metal 0.6 μm CMOS technology, is based on a fourth-order single-loop architecture with a sampling frequency of 256 kHz. The chip consumes 50 mW from a single 5-V supply and achieves a signal-to-noise ratio of 104.9 dB over a bandwidth of 400 Hz, corresponding to a resolution of 17.1 bits. [ABSTRACT FROM AUTHOR]