Results 11 
16 of
16
Dynamic computation in a recurrent network of heterogeneous silicon neurons
 in Proc. IEEE Int. Symp. Circuits Syst
, 2006
"... Abstract — We describe a neuromorphic chip with a twolayer excitatoryinhibitory recurrent network of spiking neurons that exhibits localized clusters of neural activity. Unlike other recurrent networks, the clusters in our network are pinned to certain locations due to transistor mismatch introduce ..."
Abstract

Cited by 3 (1 self)
 Add to MetaCart
Abstract — We describe a neuromorphic chip with a twolayer excitatoryinhibitory recurrent network of spiking neurons that exhibits localized clusters of neural activity. Unlike other recurrent networks, the clusters in our network are pinned to certain locations due to transistor mismatch introduced in fabrication. As described in previous work, our pinned clusters respond selectively to oriented stimuli and the neurons ’ preferred orientations are distributed similar to the visual cortex. Here we show that orientation computation is rapid when activity alternates between layers (staccatolike), dislodging pinned clusters, which promotes fast cluster diffusion. I. PATTERNFORMING RECURRENT NETWORKS A 2D recurrent network of spiking neurons with Mexican hat connectivity (local excitation and distal inhibition) can exhibit clusters of activity when the feedback is sufficiently
Floating Gate Current Mirror For Gain Correction In Cmos Translinear Circuits
 in Proc. IEEE Int. Symp. Circuits Syst
, 1999
"... The exponential behavior of MOSFETs in subthreshold operation has recently been exploited to build CMOS translinear circuits such as multipliers and logdomain filters. A major obstacle in developing a practical CMOS implementation is the variation in threshold voltage between devices. In translinea ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
The exponential behavior of MOSFETs in subthreshold operation has recently been exploited to build CMOS translinear circuits such as multipliers and logdomain filters. A major obstacle in developing a practical CMOS implementation is the variation in threshold voltage between devices. In translinear circuits, these voltage offsets manifest themselves as gain errors in the currentmode outputs. We have designed a floatinggate CMOS current mirror that can adapt its gain to compensate for these errors. The adaptation process uses only hotelectron injection, so the high voltages typically associated with tunneling are not needed. A small array of these circuits were fabricated in a standard 1.2 ¯m doublepoly CMOS process. We demonstrate gain adaptation and discuss the nonlinearity introduced by the adaptive mirror. 1. INTRODUCTION Translinear circuits use devices whose transconductance is linear with current (i.e., the current through the device is an exponential function of the input...
A OneDimensional Analog VLSI Implementation for Nonlinear RealTime Signal Preprocessing
, 2001
"... this paper (see Theory section) can be restated in the CNN framework [25] as well. The model has to be altered to the hardwarefriendly fullrange model [26] using nonlinear feedback templates. Nevertheless the CNN framework is defined on a discrete grid and therefore limited in its applications. Va ..."
Abstract

Cited by 2 (1 self)
 Add to MetaCart
this paper (see Theory section) can be restated in the CNN framework [25] as well. The model has to be altered to the hardwarefriendly fullrange model [26] using nonlinear feedback templates. Nevertheless the CNN framework is defined on a discrete grid and therefore limited in its applications. Various CMOS VLSI implementations of CNNs have been reported [27]. They can be discriminated by fixed [28] or variable [29, 30] templates, current [26] or voltage mode [31], full [32] or limited [33] CNNmodel, onchip [34] or o#chip sensors. They are referenced here in detail as a starting point for further investigations in the field of analog VLSI systems for signal processing.
A Silicon Cochlea With Active Coupling
"... chip that emulates nonlinear active cochlear signal processing. Modeling the cochlea’s micromechanics, including outer hair cell (OHC) electromotility, this silicon (Si) cochlea features active coupling between neighboring basilar membrane (BM) segments—a first. Neighboring BM segments, each impleme ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
chip that emulates nonlinear active cochlear signal processing. Modeling the cochlea’s micromechanics, including outer hair cell (OHC) electromotility, this silicon (Si) cochlea features active coupling between neighboring basilar membrane (BM) segments—a first. Neighboring BM segments, each implemented as a class AB logdomain secondorder section, exchange currents representing OHC forces. This novel activecoupling architecture overcomes the major shortcomings of existing cascade and parallel filterbank architectures, while achieving the highest number of digital outputs in an Si cochlea to date. An activecoupling architecture Si cochlea with 360 frequency channels and 2160 pulsestream outputs occupies 10.9 mm2 in a fivemetal 1poly 0.25 m CMOS process. The chip’s responses resemble that of a living cochlea’s: Frequency responses become larger and more sharply tuned when active coupling is turned on. For instance, gain increases by 18 dB and 10 increases from 0.45 to 1.14. This enhancement decreases with increasing input intensity, realizing frequencyselective automatic gain control. Further work is required to improve performance by reducing large variations from tap to tap. Index Terms—Class AB, cochlear amplifier, logdomain, neuromorphic, silicon (Si) cochlea.
The MultipleInput Translinear Element: A Versatile Circuit Element
 Proceedings of the 1998 IEEE ISCAS
, 1998
"... We define the multipleinput translinear element (MITE), a versatile circuit primitive from which we can construct lowvoltage translinear circuits and logdomain filters. A Kinput MITE produces an output current that is exponential in a weighted sum of its K input voltages. We briefly discuss s ..."
Abstract
 Add to MetaCart
We define the multipleinput translinear element (MITE), a versatile circuit primitive from which we can construct lowvoltage translinear circuits and logdomain filters. A Kinput MITE produces an output current that is exponential in a weighted sum of its K input voltages. We briefly discuss six MITE implementations and show experimental data from two of these six that we have fabricated in a 2m doublepoly CMOS process available through MOSIS. 1. TRANSLINEAR CIRCUIT ELEMENTS In 1975, Barrie Gilbert [1] coined the word translinear to describe a class of nonlinear circuits whose operation is based on the exponential currentvoltage relationship of the bipolar transistor. The word translinear derives from a contraction of one way of expressing the exponential currentvoltage relationship of the bipolarthat is, the bipolar's transconduc tance is linear in the current flowing into its collector terminal. The subthreshold MOS transistor also has an exponential currentvo...
unknown title
, 2005
"... Modelling mismatch effects in CMOS translinear loops and current mode multipliers ..."
Abstract
 Add to MetaCart
Modelling mismatch effects in CMOS translinear loops and current mode multipliers