Switched-capacitor circuits are periodically time-varying circuits and the noise at the output of these circuits is cyclostationary. This noise is therefore characterized by the average and harmonic spectral densities. In this paper, we extend the method proposed in a previous paper to compute the average and harmonic noise-spectral densities in periodically varying ciruits. We derive expressions for the average and harmonic spectral densities and use the mixed-frequency-time technique for the computation. The results for the average spectral density are compared with published results. The contribution of the harmonic spectral densities to the average noise-spectral density at the output of a cascaded block is estimated. © 2004 IEEE.

Vinita Vasudevan

Department of Electrical Engineering

M Ramakrishna

Department of Aerospace Engineering

Capacitors

Harmonic analysis

Spectrum Analysis

Spurious signal noise

Transfer functions

Analog circuits

CIRCUIT NOISE-SPECTRAL DENSITY

Switched Capacitor circuits

Time varying networks

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

Computation of the average and harmonic noise power-spectral density in switched-capacitor circuits

IEEE Transactions on Circuits and Systems I: Regular Papers

This paper presents a new time-domain technique for computing the noise-spectral density. The power-spectral density (PSD) is interpreted as the asymptotic value of the expected energy-spectral density per unit time. The methodology of stochastic differential equations is used to derive a set of ordinary differential equations for the expected energy-spectral density. This set of equations can then be integrated in time until the steady-state value of the PSD is obtained. The method can be used to find the noise spectrum in any circuit in which noise can be treated as a perturbation. The general nature of this algorithm has been illustrated in this paper by using it to get the noise-spectral density in switched-capacitor circuits, externally linear circuits and oscillators. The results match well with published experimental/analytical data. © 2004 IEEE.

A time-domain technique for computation of noise-spectral density in linear and nonlinear time-varying circuits

IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications

Numerical algorithm for noise analysis of switched-capacitor networks

Proceedings of the 40th conference on Design automation - DAC '03

Computation of noise spectral density in switched capacitor circuits using the mixed-frequency-time technique

Cyclostationary noise in radio-frequency communication systems

Adjoint network of periodically switched linear circuits with applications to noise analysis

Journal	IEEE Transactions on Circuits and Systems I: Regular Papers
Publisher	Institute of Electrical and Electronics Engineers Inc.
ISSN	10577122
Open Access	No