Abstract: A bandgap voltage reference circuit for 0.35-.mu.m, 3-volt CMOS technology operates in an essentially temperature independent manner and having low supply voltages. The bandgap voltage reference circuit incorporates two operational amplifiers. One operational amplifier biases bipolar devices of the circuit and generates a PTAT voltage across a resistor, and the other operational amplifier buffers a voltage related to the PTAT voltage and a voltage across one bipolar device to generate the bandgap voltage reference. In one embodiment, the circuit includes a start-up circuit to ensure a stable and desired start-up state. A current bias may also be provided. The bandgap voltage reference of the second operational amplifier may also provide a regulated supply for the first stage of the circuit. The second operational amplifier also provides a buffered output to a resistor divider circuit to supply a voltage divider to generate voltages below the 1.24-volt bandgap voltage.

Abstract: A preamplifier system for receiving information from at least one magnetoresistive head cell and for supplying a signal to circuitry external to the preamplifier system is disclosed. The preamplifier system includes a bias current generator, a first preamplifier gain stage, and a second preamplifier gain stage. The bias current generator is connected between a first potential and the magnetoresistive head cell for providing a bias current to the magnetoresistive head cell. The first and second preamplifier gain stages include multiple transistors, resistors, capacitors, and current sources. The combination of first and second preamplifier gain stages provide the proper amplification of a signal received from the head cell while eliminating an unwanted DC offset signal.

Abstract: A speech recognition system learns characteristics of speech by a user during a learning phase to improve its performance. Adaptation data derived from the user's speech and its recognized result is collected during the learning phase. Parameters characterizing hidden Markov Models (HMMs) used in the system for speech recognition are modified based on the adaptation data. To that end, a hierarchical structure is defined in an HMM parameter space. This structure may assume the form of a tree structure having multiple layers, each of which includes one or more nodes. Each node on each layer is connected to at least one node on another layer. The nodes on the lowest layer of the tree structure are referred to as "leaf nodes." Each node in the tree structure represents a subset of the HMM parameters, and is associated with a probability measure which is derived from the adaptation data.

Abstract: A device in which one or more thin film transistors are monolithically integrated with a light emitting diode is disclosed. The thin film transistor has an organic semiconductor layer. The light emitting layer of the light emitting diode is also an organic material. The device is fabricated economically by integrating the fabrication of the thin film transistor and the light emitting diode on the substrate and by employing low cost fabrication techniques.

Abstract: A method is provided for synchronizing video data buffers in a system including: an encoder for encoding input data into a compressed data bitstream; an encoder buffer for storing the compressed data bitstream; a decoder buffer for receiving the compressed data bitstream, with a sum of an encoder buffer delay and a decoder buffer delay is constant; a variable rate transmission channel operatively connecting the encoder buffer and the decoder buffer; and a decoder for receiving and decoding the compressed data bitstream. The instantaneous encoder buffer delay is used to generate a control signal; the control signal is inserted into the compressed data bitstream following the encoder buffer. In an exemplary embodiment, each of the encoder and decoder performs encoding and decoding operations, respectively, in the Motion Picture Experts Group (MPEG) standard, using the VBV.sub.-- DLY parameter of the MPEG standard as the control signal.

Abstract: An optical fiber cable splice closure has a base member and a cover mated therewith. The cover is extended to accommodate stacking large numbers of splice trays or splice holders so that the coverall capacity of the closure is increased over prior art structures. The extended cover has a plurality of longitudinal and transverse strengthening ribs molded integrally with the top and side walls of the cover. For increased resistance to outside forces, the top wall is bowed and strengthened and supported by the ribs both above and below the wall. In a second embodiment, the side walls are also bowed, as are the strengthening ribs.

Abstract: Information can be communicated back from a receiver to a transmitter over a serial link designed for communication to be essentially only in one direction without requiring a separate feedback path with an extra wire. This is achieved by changing at least one characteristic of the receiver input. For example, the receiver input impedance, the receiver input voltage, or both, may be altered. The change in a characteristic of the receiver input can be detected by an appropriately designed transmitter, and such detection can be used to trigger a change in the behavior of the transmitter. Advantageously, only simple alterations are required in conventional serial link circuits to provide a low bandwidth reverse communication path over the same wires. Such a change in a receiver input characteristic can also be employed to inform a transmitter of the existence of a receiver that is on a card that is hot-plugged into system.

Abstract: A facility is provided in which an ATM switch may operate as a switch in the provision of connection oriented services and operates as a router in the provision of connectionless services. In the router mode, the ATM switch may determine "on the fly" a route which may be used to forward received data cells to an intended destination and then forwards each of the data cells in sequence over the determined route. In the switch mode, the ATM switch operates conventionally and forwards a received data cell over a previously defined switched virtual path. In certain cases, the ATM switch may operate as a router only.

Abstract: A digital filter receives signals from each stage of a MASH delta-sigma modulator and filters noise components from the signals prior to combination as a single sequence of values decimation. Each stage of the MASH delta-sigma modulator provides an output sequence of one-bit, binary values, which are then filtered to remove high-order, out of band quantization noise. After filtering, the output sequences are then combined through a cascade-combiner, which may be similar to the pre-processing stage of a MASH delta-sigma modulator architecture. The digital filter processes signals of each stage separately. Consequently, the digital filter does not perform multiplication of two, multi-bit values. Multiplication of two values, the first of which is a one-bit, binary value, may be implemented with a multiplexer selecting either the second value or a zero value based on the first one-bit, binary value (i.e., logic 1 or 0, respectively).

Abstract: The invention provides a device containing a low .kappa., hydrogen-free a-C:F layer with good adhesion and thermal stability. It was found that the combination of desirable properties was attainable by a relatively easy process, as compared to processes that utilize gaseous sources, such as CVD. Specifically, the a-C:F layer is formed by sputter deposition, using only solid sources for the fluorine and carbon, and in the absence of any intentionally-added hydrogen-containing source. The sputtering is performed such that the layer contains 20 to 60 at. % fluorine, and also, advantageously, such that the a-C:F exhibits a bandgap of about 2.0 eV or greater. The a-C:F layer formed by the process of the invention exhibits a dielectric constant, at 1 MHz and room temperature, of 3.0 or less, advantageously 2.5 or less, along with being thermally stable up to at least 350.degree. C., advantageously 450.degree. C., and exhibiting a stress of about 100 MPa or less, in absolute value.

Abstract: A buildout system generally comprising a buildout base and a buildout cap. The base includes lateral sides that extend beyond the top and bottom sides of the base to form side flanges, and upper and lower panel flanges that extend upwardly and downwardly from the side flanges. In addition, the base includes a plurality of gussets that extend forwardly from the lateral sides of the base. The cap includes upper and lower latch tabs that extend outwardly from the top and bottom sides of the cap and a plurality of recesses that are adapted to receive the gussets of the base. In one aspect of the invention, the base further includes vertical flanges and the cap includes vertical recesses adapted to receive the vertical flanges of the base when the cap is releasably connected to the base.

Abstract: A network interface device is attachable to an intermediate field of a building entrance protector unit. The network interface device includes a jack section having a jack which is designed to receive the plug of a standard telephone. The jack includes wire leads which may be connected to any of the terminals on the intermediate field. The jack section is mountable into a base module which is in turn attachable to the intermediate field by wedging a portion of the base module between adjacent terminals on the intermediate field. A plug section is pivotally connected to the jack section by a living hinge. The plug section includes a plug having a pair of conductive blades therein. The network interface device performs a connecting function when the plug is pivoted to a position within the jack, and the conductive blades establish an electrical connection between the wire leads connected to the telephone company network and the wire leads connected to the customer equipment.

Abstract: There is disclosed a transconductance amplifier receives a voltage input and provides a current output. The transconductance amplifier includes a current mirror having a lowpass filter between transistors implementing the current mirror.

Abstract: The present invention is directed to a method for providing oligonucleotides or oligonucleotide analogs having known subunit sequences in which the desired oligomers are released from selected storage sites in one, two, or three dimensions, on a substrate by locally denaturing double-stranded complexes at the storage sites containing the desired oligomers. The released oligomers are useful in schemes for determining solutions to mathematical problems, in methods wherein hybridizing oligomers are used to encrypt and transmit data, in diagnostic and screening assay methodologies, and as primers or building blocks for synthesizing larger polynucleotides.

Abstract: A new encoder is provided which operates on a database of n-dimensional signal vectors where such signal vectors are restricted to being non-negative. In the establishment of a codebook for this encoder, p signal vectors (of dimension n) are placed in an n.times.p matrix X, and an approximate factorization: X.apprxeq.WV is constructed, where W and V are matrices whose entries are non-negative. Each column of the n.times.r matrix W is characterized as a "feature", such features having been "learned" from the database of n-dimensional signal vectors.

Abstract: An on-chip processor is used as a controller for burn-in and endurance testing of embedded non-volatile memory. An automated test machine downloads a test program into the non-volatile memory. The downloaded program contains a test program to be run on the non-volatile memory. When the burn-in or endurance test equipment activates the processor, the processor executes the program and performs a test on the non-volatile memory. The same method can be utilized to perform either the burn-in or endurance tests. Only the clock and reset lines are required to operate the test. Since the clock and reset lines are part of the processor's standard inputs, the method performs burn-in and endurance testing of an embedded non-volatile memory without bringing out the memory's address, data and control lines to the package pins of the integrated circuit.

Abstract: Distributed precomputation techniques for determining primary and/or restoration paths in an optical or electrical network. The invention provides a number of partially and fully asynchronous distributed precomputation algorithms which may be implemented, for example, by the nodes of an all-optical network, in which network links are constrained in terms of optical signal wavelength and failure isolation. A given distributed precomputation algorithm may include a first phase in which paths are allocated for capacity demands to the extent possible without resolving contentions, and a second phase in which contentions between demands for the same capacity are resolved.

Abstract: A path-oriented approach is provided to determine surviving paths in a decoder. The paths that are retained as the surviving paths are some number, M, of the paths which have the smallest path metrics, even if two or more of those paths come into a given state. This approach provides significantly improved performance in at least those applications in which branch metrics are a function of the surviving path from which the branch emanates.

Abstract: A device for changing the power levels of signals transmitted by an optical fiber, along with signal modulation and wavelength routing, comprises a length of optical fiber in which for a predetermined section of the length of the fiber, the fiber core is surrounded by a cladding having one or more variable refractive index (VRI) regions disposed therein in close proximity to the core. The VRI regions are fabricated with a material having an index of refraction higher than that of the cladding and may comprise a variable attenuator.

Abstract: Fabrication of devices of micron and submicron minimum feature size is accomplished by lithographic processing involving a back focal plane filter. A particularly important fabrication approach depends upon mask patterns which produce images based on discrimination as between scattered and unscattered radiation by accelerated electrons.