1,034 research outputs found
Current-Mode Techniques for the Implementation of Continuous- and Discrete-Time Cellular Neural Networks
This paper presents a unified, comprehensive approach
to the design of continuous-time (CT) and discrete-time
(DT) cellular neural networks (CNN) using CMOS current-mode
analog techniques. The net input signals are currents instead
of voltages as presented in previous approaches, thus avoiding
the need for current-to-voltage dedicated interfaces in image
processing tasks with photosensor devices. Outputs may be either
currents or voltages. Cell design relies on exploitation of current
mirror properties for the efficient implementation of both linear
and nonlinear analog operators. These cells are simpler and
easier to design than those found in previously reported CT
and DT-CNN devices. Basic design issues are covered, together
with discussions on the influence of nonidealities and advanced
circuit design issues as well as design for manufacturability
considerations associated with statistical analysis. Three prototypes
have been designed for l.6-pm n-well CMOS technologies.
One is discrete-time and can be reconfigured via local logic for
noise removal, feature extraction (borders and edges), shadow
detection, hole filling, and connected component detection (CCD)
on a rectangular grid with unity neighborhood radius. The other
two prototypes are continuous-time and fixed template: one for
CCD and other for noise removal. Experimental results are given
illustrating performance of these prototypes
A modular CMOS analog fuzzy controller
The low/medium precision required for many fuzzy applications makes analog circuits natural candidates to design fuzzy chips with optimum speed/power figures. This paper presents a sixteen rules-two inputs analog fuzzy controller in a CMOS 1 /spl mu/m single-poly technology based on building blocks implementations previously proposed by the authors (1995). However, such building blocks are rearranged here to get a highly modular architecture organized from two high level blocks: the label block and the rule block. In addition, sharing of membership function circuits allows a compact design with low area and power consumption and its highly modular architecture will permit to increase the number of inputs and rules in future chips with hardly design effort. The paper includes measurements from a silicon prototype of the controller
A low-offset low-voltage CMOS Op Amp with rail-to-rail input and output ranges
A low voltage CMOS op amp is presented. The circuit uses complementary input pairs to achieve a rail-to-rail common mode input voltage range. Special attention has been given to the reduction of the op amp's systematic offset voltage. Gain boost amplifiers are connected in a special way to provide not only an increase of the low-frequency open-loop gain but also a significant reduction of the systematic offset voltag
CMOS design of chaotic oscillators using state variables: a monolithic Chua's circuit
This paper presents design considerations for monolithic implementation of piecewise-linear (PWL) dynamic systems in CMOS technology. Starting from a review of available CMOS circuit primitives and their respective merits and drawbacks, the paper proposes a synthesis approach for PWL dynamic systems, based on state-variable methods, and identifies the associated analog operators. The GmC approach, combining quasi-linear VCCS's, PWL VCCS's, and capacitors is then explored regarding the implementation of these operators. CMOS basic building blocks for the realization of the quasi-linear VCCS's and PWL VCCS's are presented and applied to design a Chua's circuit IC. The influence of GmC parasitics on the performance of dynamic PWL systems is illustrated through this example. Measured chaotic attractors from a Chua's circuit prototype are given. The prototype has been fabricated in a 2.4- mu m double-poly n-well CMOS technology, and occupies 0.35 mm/sup 2/, with a power consumption of 1.6 mW for a +or-2.5-V symmetric supply. Measurements show bifurcation toward a double-scroll Chua's attractor by changing a bias current
Development of a Low-Noise High Common-Mode-Rejection Instrumentation Amplifier
Several previously used instrumentation amplifier circuits were examined to find limitations and possibilities for improvement. One general configuration is analyzed in detail, and methods for improvement are enumerated. An improved amplifier circuit is described and analyzed with respect to common mode rejection and noise. Experimental data are presented showing good agreement between calculated and measured common mode rejection ratio and equivalent noise resistance. The amplifier is shown to be capable of common mode rejection in excess of 140 db for a trimmed circuit at frequencies below 100 Hz and equivalent white noise below 3.0 nv/square root of Hz above 1000 Hz
Smart-Pixel Cellular Neural Networks in Analog Current-Mode CMOS Technology
This paper presents a systematic approach to design CMOS chips with concurrent picture acquisition and processing capabilities. These chips consist of regular arrangements of elementary units, called smart pixels. Light detection is made with vertical CMOS-BJT’s connected in a Darlington structure. Pixel smartness is achieved by exploiting the Cellular Neural Network paradigm [1], [2], incorporating at each pixel location an analog computing cell which interacts with those of nearby pixels. We propose a current-mode implementation technique and give measurements from two 16 x 16 prototypes in a single-poly double-metal CMOS n-well 1.6-µm technology. In addition to the sensory and processing circuitry, both chips incorporate light-adaptation circuitry for automatic contrast adjustment. They obtain smart-pixel densities up to 89 units/mm2, with a power consumption down to 105 µW/unit and image processing times below 2 µs
An Energy-Efficient, Dynamic Voltage Scaling Neural Stimulator for a Proprioceptive Prosthesis
Accepted versio
Offset-compensated comparator with full-input range in 150nm FDSOI CMOS-3d technology
This paper addresses an offset-compensated comparator
with full-input range in the 150nm FDSOI CMOS-
3D technology from MIT- Lincoln Laboratory. The comparator
discussed here makes part of a vision system. Its architecture is
that of a self-biased inverter with dynamic offset correction. At
simulation level, the comparator can reach a resolution of 0.1mV
in an area of approximately 220μm2 with a time response of less
than 40ns and a static power dissipation of 1.125μW
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