Sigma delta modulation is a popular technique for high-resolution analog-to-digital conversion and digital-to-analog conversion. We investigate chaotic phenomena in multibit first-order sigma-delta modulators. Particular attention is placed on the occurrence of periodic orbits or limit cycles. These may result in idle tones audible to the listener when sigma-delta modulation is used for audio s...

In this paper, a new approach to optimize a sigma-delta modulator has been presented. This last became the most popular tools in analog-to-digital conversion application. Sigma delta modulator will be the most suitable choice for multistandard system reception. We proposed to add dither before the quantizer of sigma-delta modulator in order to eliminate any distortions introduced by the quantiz...

A new application of sigma-delta modulation has emerged in soft switching three phase power electronic converters. For this application, a conventional sigma-delta modulator with scalar signals and binary quantizer is generalized to a sigma-delta modulator with vector signals and a truncated hexagonal lattice quantizer. This vector sigma-delta modulator has an interesting output spectrum which ...

Over-sampling sigma-delta analog-to-digital converters (ADCs) are one of the key building blocks of state of the art wireless transceivers, especially with the voice communication system. This paper addresses a brief review for designing a Sigma-Delta modulator. A Genetic Algorithm (GA) based 2 order Sigma-Delta modulator design is proposed.

There is two main parts of Sigma-delta ADC: analog modulator and digital filter, the performance of modulator determines the performance of sigma-delta ADC, so the design of modulator is very important. This paper introduces the principle of sigma-delta ADC modulator with high accuracy and the applied over sampling technique, noise shaping technique and multi-bit quantize technique. This paper ...

A new sigma-delta modulator architecture for wide bandwidth application called cascaded feedforward sigma-delta modulator is proposed in this paper. This sigma-delta modulator is similar to the conventional feedforward summation sigma-delta modulator. The conventional feedforward summation sigma-delta modulator uses multi-bit feedback and therefore a multi-bit digital-to-analog converter (DAC) ...

A third-order single-bit delta-sigma modulator is presented in this paper. An op-amp dynamic current biasing technique is used to improve the power-efficiency of the modulator. The voltage reference block is integrated with the delta-sigma modulator core to avoid the use of large off-chip bypass capacitors and to minimize pin numbers. It achieves 89.2 dB dynamic range over 10 kHz signal bandwid...

This paper discusses the design of picowatt power Sigma-delta modulator with genetic algorithm (GA) based oversampling technology. This Sigma-delta modulator design is paid special attention to its low power application of portable electronic system in digitizing biomedical signals such as Electro-cardiogram (ECG), Electroencephalogram (EEG) etc. [1]. A high performance, low power second order ...

A Low power discrete time sigma delta ADC consisting of a second order sigma delta modulator and third order Cascaded Integrated Comb (CIC) filter is proposed. The second order modulator is designed to work at a signal band of 20K Hz at an oversampling ratio of 64 with a sampling frequency of 2.56 MHz. It achieves a signal to noise ratio of 85.2dB and a resolution of 14 bits. The CIC digital fi...

This paper presents a complete set of SIMULINK ® models, which allow exhaustive behavioral simulations of any sigma-delta modulator to be performed. The proposed set of models takes into account most of the sigma-delta modulator non-idealities, such as sampling jitter, kT/C noise and operational amplifier parameters (noise, finite gain, finite bandwidth, slew-rate and saturation voltages). For ...