IEEE Transactions on Circuits and Systems

The program ZSIM (nonlinear Z-domain simulator) is used to explore the benefits and limitations of a table-based approach to the simulation of delta-sigma modulators with switched-capacitor integrators. Simulations demonstrating the effects of clock feedthrough and incomplete settling are presented, as are simulations demonstrating the importance of using an accurate and charge-conservati... View full abstract»

An algorithmic analog-to-digital converter (ADC) that combines current mode and dynamic techniques is presented. The converter does not rely on high-gain amplifiers or well-matched components to achieve high resolution and is inherently insensitive to the amplifier's offset voltage. An analysis of the converter's limitations indicates that the resolution of practical circuits will be limited by th... View full abstract»

A criterion for the absolute stability of discrete-time feedback systems utilizing the saturation nonlinearity is presented. The criterion is based on the passivity properties associated with the saturation nonlinearity. The present approach is essentially a generalization of an earlier one due to D. Mitra (ibid., vol.CAS-26, no.6, p.365-71, 1978) View full abstract»

Oversampling interpolative coding has been demonstrated to be an effective technique for high-resolution analog-to-digital (A/D) conversion that is tolerant of process imperfections. A novel topology for constructing stable interpolative modulators of arbitrary order is described. Analysis of this topology shows that with proper design of the modulator coefficients, stability is not a limitation t... View full abstract»

A general scheme is presented for the construction of device models for circuit simulators. Two general n-dimensional C 1 table models have been constructed under this scheme. Each table model can automatically reconstruct the exact DC current behavior of two basic physical device models, namely, the Ebers-Moll bipolar transistor model and the GLASMOST MOSFET model. Th... View full abstract»

A recursive model is obtained for two-dimensional shift-variant bilinear systems whose double impulse response is representable by a kth order degenerate sequence. The bilinear system may be quarter-plane or weakly causal. This formulation makes use of the structure of the matrix input-output characterization of the system to arrive at a recursive model. The model is based on a three-poin... View full abstract»

An extension of the well-known canonical representation for continuous piecewise-linear functions is introduced. This form is capable of describing all piecewise-linear functions in two dimensions, being no longer subject to any restrictions. Moreover, it is shown that just one nesting of absolute-value functions is sufficient to cover the whole class View full abstract»

A number of class-E, half-wave and full-wave, zero-voltage-switching (low dv/dt), zero-current-switching (low di/dt), and mixed-mode rectifiers are introduced and verified experimentally. The rectifiers are derived from conventional rectifiers by adding reactive components. New conventional rectifiers are also introduced and presented in a systematic manner. The... View full abstract»

A method is proposed for realizing two-dimensional transfer functions (TDTF). Using this method, realizations can be directly obtained from the coefficients of the TDTF, without performing canonical decomposition of the state equations and solving nonlinear equations. The possibility of reducing the realization dimensional and determining the conditions to be imposed on the TDTF for the reduction ... View full abstract»

The design considerations for fast-settling operational amplifiers (op amps) are significantly different between sampled-data switched-capacitor (SC) and conventional continuous-time applications. In SC circuits, the shape of the output voltage waveform of an op amp is of no consequence provided that the output settles to within a specified tolerance of its steady-state value prior to the next sam... View full abstract»

A novel adaptive nonlinear filter with the least-mean-square (LMS) error criterion is presented. It is based on the so-called canonical piecewise-linear structure. As an alternative to approaches based on the Wiener-Volterra series which have so far been widely employed for adaptive nonlinear filtering, the proposed approach can exhibit adaptive performance, especially in strongly nonlinear cases,... View full abstract»

The analysis of switched networks encounters a major difficulty due to the discontinuity of network variables and the presence of impulsive voltages and currents at the switching instants. The problem of obtaining consistent initial conditions for linear networks with ideal switched is addressed. The method used is based on numerical Laplace transform theory and is applicable to any circuit config... View full abstract»

A systematic approach is presented for the design of analog neural nonlinear programming solvers using switched-capacitor (SC) integrated circuit techniques. The method is based on formulating a dynamic gradient system whose state evolves in time toward the solution point of the corresponding programming problem. A neuron cell for the linear and the quadratic problem suitable for monolithic implem... View full abstract»

The feasibility of using computers to perform the generation of alternative circuits (that have different topologies), the evaluation of these alternatives, and the selection of the best solution according to a given set of criteria is demonstrated. Based on this idea, an expert system VMD (voltage multiplier designer) has been developed for the design of voltage multiplier circuits. Some unconven... View full abstract»

An approach toward higher dimensional autonomous chaotic circuits is discussed. Special consideration is given to a particular class of circuits which includes only one nonlinear element, namely, a three-segment piecewise-linear resistor, and one small inductor, L 0, serially connected with it. A simple four-dimensional example that realizes hyperchaos is given. For the case in... View full abstract»

On the basis of voltage level, an electric power system can be viewed as consisting of a generation system, a transmission system, and a distribution system. The steady-state operation of a power system requires that the power supply, transmission losses, and load demand be balanced, as described by the load flow equations. The configuration of a transmission network is that of a loop while the co... View full abstract»

A gradient-type-least-squares (LS) algorithm for adaptive implementation of Pisarenko's method is presented. The algorithm, which uses the Lagrange multiplier technique for parameter updating, has faster convergence and improved tracking capability when compared to a least-mean-squares-type algorithm. Moreover, since the gradient-type LS algorithm does not use an approximation for deriving the upd... View full abstract»

Physical timing models for small-geometry CMOS inverters with interconnection lines have been developed. Large-signal equivalent circuits of CMOS inverters and 10-section RC ladder networks for interconnection lines are considered assuming nonstep input waveforms and initial delay times. Due to more realistic and complete considerations, the model accuracy is expected to be higher than th... View full abstract»