IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications
1558-1268
Cơ quản chủ quản: N/A
Các bài báo tiêu biểu
Variable gain amplifiers based on a new approximation method to realize the exponential function
Tập 49 Số 9 - Trang 1348-1354 - 2002
A new current mode variable-gain amplifier (VGA) is developed. The new circuit
is based on a novel approximation function that is very close to the ideal
exponential relation over a very wide range. Pspice simulations are provided
based on Mietec 0.5-/spl mu/m CMOS technology. The simulations show that the
dynamic range achieved is over 50 dB in a single stage. The proposed circuit
consumes averag...
#Approximation methods #Dynamic range #CMOS technology #Circuit simulation #Difference equations #Voltage #Gain control #Auditory system #Communication system control #Bipolar transistors
Synchronizability of distributed clock oscillators
Tập 49 Số 9 - Trang 1271-1278 - 2002
We analyze the synchronizability of synchronous distributed oscillators (SDOs),
a novel clocking scheme for microprocessors. A computer-aided perturbation
analysis is developed for such systems, where analytically tractable equations
of the clock phases are reduced from experimental data reflecting all circuit
details. Using this reduction, a theory is constructed to explain the underlying
mechani...
#Clocks #Frequency synchronization #Circuits #Equations #Voltage-controlled oscillators #Jitter #Delay #Distributed computing #Large scale integration #Threshold voltage
The effects of generation redispatch on Hopf bifurcations in electric power systems
Tập 49 Số 8 - Trang 1180-1186 - 2002
In this paper, we examine how varying the generation redispatch can improve the
system stability margins with respect to Hopf bifurcations, as well as
robustness to uncertainties in load modeling and distribution. It is seen that
an optimal selection of load following units plays a key role in accomplishing
these objectives. An optimal redispatch strategy is proposed, and is verified
through a var...
#Power generation #Bifurcation #Power system modeling #Voltage #Load modeling #Eigenvalues and eigenfunctions #Robust stability #Power system stability #Differential equations #Power system dynamics
Optimal digital redesign of hybrid cascaded input-delay systems under state and control constraints
Tập 49 Số 9 - Trang 1382-1392 - 2002
This paper presents a new multi-objective evolutionary programming (MOEP)-based
digital redesign scheme to find an optimal low-gain digital tracking controller
for hybrid control of multi-input, multi-output (MIMO) cascaded analog systems
with input time delays, having the constraints on the states and inputs. The
proposed global optimization searching technique enables one to find a high-gain
opt...
#Optimal control #Control systems #Digital control #MIMO #Delay effects #Pulse modulation #Genetic programming #Constraint optimization #Sampling methods #Amplitude modulation
A minimal integral nonlinearity criterion to optimize the design of a new tanh/sinh-type bipolar transconductor
Tập 49 Số 8 - Trang 1062-1070 - 2002
We report on the use of a simple design optimization criterion for obtaining
maximum static transfer function linearity. It is based on an analytic function
that corresponds to the integral nonlinearity of the circuit. The criterion may
be useful, either as an analytic tool to gain insight into the circuit's
behavior, or as an efficient computational alternative to calculating total
harmonic disto...
#Design optimization #Transconductors #Linearity #Transfer functions #Harmonic analysis #Circuit analysis computing #Total harmonic distortion #Circuit simulation #Transconductance #Voltage
Noise analysis of phase-locked loops
Tập 49 Số 9 - Trang 1309-1316 - 2002
This work addresses the problem of noise analysis of phase-locked loops (PLLs).
The problem is formulated as a stochastic differential equation and is solved in
the presence of circuit white noise sources yielding the spectrum of the PLL
output. Specifically, the effect of loop filter characteristics, phase-frequency
detector, and phase noise of the open-loop voltage-controlled oscillator (VCO)
on...
#Phase noise #Phase locked loops #Voltage-controlled oscillators #Filters #Phase detection #Shape measurement #Circuit noise #Phase frequency detector #Phase measurement #Stochastic resonance
A loop-breaking method for the analysis and simulation of feedback amplifiers
Tập 49 Số 8 - Trang 1045-1061 - 2002
Two-circuit models for feedback subcircuits are developed from a modification to
the two-port method of feedback amplifier analysis and are applied in a method
to break the feedback loop. These models are terminally equivalent to linear and
nonlinear subcircuits, have physically-disconnected topologies, and employ
dependent sources to control lateral signal transfer with a switch-like on or
off ma...
#Analytical models #Feedback amplifiers #Feedback loop #Operational amplifiers #SPICE #Integrated circuit interconnections #Circuit simulation #Voltage #Circuit topology #Equivalent circuits
On the jitter requirements of the sampling clock for analog-to-digital converters
Tập 49 Số 9 - Trang 1354-1360 - 2002
In this work, the effect of sampling clock jitter on the SNR of an
analog-to-digital (AD) conversion is investigated from a practical perspective.
Aperture jitter analyses have been dealing up to now with white spectrum jitter.
This assumption does not hold for the output of phase-locked loops (PLL)-like
frequency synthesizers, where the spectrum is shaped by the loop transfer
function. Based on a...
#Jitter #Sampling methods #Clocks #Analog-digital conversion #Frequency synthesizers #Apertures #Phase locked loops #Transfer functions #Linear approximation #Autocorrelation
A PWL circuit approach to the definition of a /spl epsiv/-approximation model of scalar static hysteresis
Tập 49 Số 9 - Trang 1290-1308 - 2002
A piecewise-linear (PWL) circuit model of hysteresis phenomena is presented. The
proposed model involves the use of parallel-connected simple PWL circuits. The
PWL characteristic of the model allows a direct determination of the condition
on a rate-independent hysteresis behavior. The basic features of the model are
discussed through proper demonstrations. In particular, it is shown that the
param...
#Hysteresis #Biological system modeling #Piecewise linear techniques #Nonlinear circuits #Mathematical model #Robustness #Arithmetic #Ferroelectric materials #Biological systems
Unified analysis of synchronous commutations in switching converters
Tập 49 Số 8 - Trang 1150-1166 - 2002
The analysis of synchronous commutations in switching converters is discussed in
this paper. The Compensation Theorem (CT) is applied in order to define two
matrices, called respectively zero-order and first-order master-slave connection
matrix (Z-MSCM, F-MSCM), which allow a unified analysis of both hard and soft
synchronous commutations in switching converters. The Z-MSCM and F-MSCM provide
the ...
#Switching converters #Switches #Diodes #Buck converters #Matrix converters #Zero voltage switching #Master-slave #Feedback circuits #Numerical simulation #Clocks