We propose a technique that enables a designer to study the effect of weak loop filter nonlinearities in a class of continuous-time delta-sigma modulators. Thanks to this technique, the utility of the Schreier Delta-Sigma Toolbox can be extended to include weakly nonlinear effects, enabling the architectural exploration of alternate loop filter and opamp topologies. The results from the use of our technique are compared to those obtained using a circuit simulator, and good agreement is seen. ©2010 IEEE.

Shanthi Pavan Y

Department of Electrical Engineering

Circuit simulators

Continuous time

DELTA SIGMA MODULATOR

DELTA-SIGMA

LOOP FILTER

Non-Linearity

Nonlinear effect

Circuit simulation

Continuous time systems

Fabrics

Nonlinear optics

MODULATORS

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Understanding weak loop filter nonlinearities in continuous time ΔΣ converters

ISCAS 2010 - 2010 IEEE International Symposium on Circuits and Systems: Nano-Bio Circuit Fabrics and Systems

We propose a technique that enables the study of weak loop filter nonlinearities in a class of continuous-time delta-sigma modulators. The technique can easily be implemented in a tool intended to simulate discrete-time modulators with linear loop filters, thereby significantly reducing the simulation time. Thanks to this technique, the utility of the Schreier Delta-Sigma toolbox can be extended to include weakly nonlinear effects in the loop filter, thus enabling the architectural exploration of alternate loop filter and operational amplifier (opamp) topologies. The results from the use of our technique are compared to those obtained using a circuit simulator, and good agreement is seen. © 2006 IEEE.

IEEE Transactions on Circuits and Systems I: Regular Papers

Efficient simulation of weak nonlinearities in continuous-time oversampling converters

We present design considerations for low-power continuous-time ΔΣ modulators. Circuit design details and measurement results for a 15 bit audio modulator are given. The converter, designed in a 0.18 μm CMOS technology, achieves a dynamic range of 93.5 dB in a 24 kHz bandwidth and dissipates 90 μW from a 1.8 V supply. It features a third-order active-RC loop filter, a very low-power 4-bit flash quantizer, and an efficient excess-delay compensation scheme to reduce power dissipation. © 2008 IEEE.

IEEE Journal of Solid-State Circuits

A power optimized continuous-time ΔΣ ADC for audio applications

We analyze the effect of nonlinearity in the first integrator of a single-loop multibit continuous-time delta-sigma modulator, when the loop filter is of the cascade of integrators with feedforward kind. When a multibit quantizer is used in the loop, we show that integrator nonlinearity results in an increased in-band noise (IBN) floor. We develop analytical relations for the IBN spectral density for several opamp topologies, assuming that the shaped quantization noise is approximately Gaussian. Our results agree well with macromodel and transistor level simulations. © 2007 IEEE.

IEEE Transactions on Circuits and Systems II: Express Briefs

Analysis of integrator nonlinearity in a class of continuous-time delta-sigma modulators

A 20-mW 640-MHz CMOS Continuous-Time $SigmaDelta$ ADC With 20-MHz Signal Bandwidth, 80-dB Dynamic Range and 12-bit ENOB

IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems

Analyzing continuous-time /spl Delta//spl Sigma/ Modulators with generic behavioral models

Journal	Data powered by TypesetISCAS 2010 - 2010 IEEE International Symposium on Circuits and Systems: Nano-Bio Circuit Fabrics and Systems
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers Inc.
Open Access	No