Abstract: An LED with improved current spreading structures that provide enhanced current injection into the LED's active layer, improving its power and luminous flux. The current spreading structures can be used in LEDs larger than conventional LEDs while maintaining the enhanced current injection. The invention is particularly applicable to LEDs having insulating substrates but can also reduce the series resistance of LEDs having conductive substrates. The improved structures comprise conductive fingers that form cooperating conductive paths that ensure that current spreads from the p-type and n-type contacts into the fingers and uniformly spreads though the oppositely doped layers. The current then spreads to the active layer to uniformly inject electrons and holes throughout the active layer, which recombine to emit light.

Abstract: A multiple-stage digitally-switched impedance has one “type B” stage and at least two “type A” stages. The type A stages are cascaded between high and low reference nodes and the type B stage. Each stage comprises a string of series-connected impedances and a switch network. A decoder responds to an digital input signal by controlling the switch networks to switch selectable portions of the strings in the type A stages into a series connection with the type B stage's string, and to control the type B stage's switch network to tap its string at a location to provide a impedance corresponding to the n-bit digital input signal between the final output node and at least one of the high and low reference nodes. Each stage provides a portion of the impedance's n-bit resolution, and the sum of the bits of resolution provided by each stage equals the total n-bit resolution.

Abstract: A mass flow meter employs discrete chip-type temperature sensors to sense a fluid flow rate. The sensor can be a semiconductor chip such as SiC or silicon, or thin film tungsten on an AlN substrate. The sensors can be distributed symmetrically with respect to the conduit through which the fluid flows, and can be connected in a four-sensor bridge circuit for accurate flow rate monitoring. An output from the mass flow meter can be used to control the fluid flow.

Abstract: An inductor current emulation circuit for a switched-mode power supply (SMPS) which is arranged such that its inductor current (IL) goes to zero at least once per switching cycle. The emulation circuit includes an RC integrator connected in parallel across the inductor, and a zero reset switch (ZRS) connected in parallel across the integrator's capacitor. A control circuit operates the ZRS such that it is opened when IL is non-zero, and is closed for a least a portion of the time during each switching cycle when IL is zero such that the capacitor is substantially discharged. In this way, the ZRS essentially recalibrates the emulation circuit when IL is zero. When so arranged, the voltage (VC) across the capacitor emulates IL. The invention may be implemented with either a discontinuous-inductor-current SMPS, or a continuous-bipolar-inductor-current SMPS.

Abstract: User interface systems gain access to media data stored in a database for a predetermined amount of time. Access is gained through a server that presents to the interface a selection menu for selecting media data. Upon selection of media data the server accesses the data from the database and transmits it to the user interface. The server also presents to the user interface a content history menu by which ancillary data associated with the content played by the system during the predetermined time is presented. The ancillary data may include the title of the content, the artist of the content, the availability of the content for purchase and its price, the title of one or more compilations, e.g., CDs, on which the content is contained and the availability of the compilations/CD for purchase and the price.

Abstract: There is disclosed a core structure with a very low profile, high power density and lower losses. Higher core surface area and improved core utilization in terms of flux density are other desirable feature in the disclosed design. The disclosed design also allowed for a larger core area where the DC fluxes are added, thereby reducing the air-gap requirements in the cores derived from low saturation density materials such as ferrites. The cellular nature of the design can also be effectively employed in vertically packaged power converters and modules.

Abstract: A low temperature chemical route to efficiently produce nanomaterials is described. The nanomaterials are synthesized by intercalating ions into layered compounds, exfoliating to create individual layers and then sonicating to produce nanotubes, nanorods, nanoscrolls and/or nanosheets. It is applicable to various different layered inorganic compounds (for example, bismuth selenides/tellurides, graphite, and other metal complexes, particularly transition metal dichalcogenides compounds including oxygen, sulfur, tellurium or selenium).

Abstract: A bipolar junction transistor (BJT) requires the fabrication of a BJT structure and of a support post which is adjacent to, but physically and electrically isolated from, the BJT structure. The BJT structure includes a semi-insulating substrate, a subcollector, a collector, a base, and an emitter. Metal contacts are formed on the subcollector and emitter to provide collector and emitter terminals. Contact to the structure's base is accomplished with a metal contact which extends from the top of the support post to the edge of the base nearest the support post. The contact bridges the physical and electrical separation between the support post and the base and provides a base terminal for the device. The base contact need extend over the edge of the base by no more than the transfer length associated with the fabrication process. This results in the smaller base contact area over the collector than would otherwise be necessary, and a consequent reduction in base-collector capacitance.

Abstract: Methods and structures are provided that reduce conversion errors in pipelined analog-to-digital converters which are induced in one converter cycle by component memory of signals in one or more preceding converter cycles. The methods and structures include the use of digital filters that provide a digital representation of the residue of a preceding converter cycle, multiply this representation by an appropriate memory parameter, and sum the product with the digital representation of the residue of a current converter cycle to thereby reduce the memory effect. The methods and structures also form capacitors of switched-capacitor converter structures with sub-capacitors that are reconfigured (e.g., reversed or alternated between differential sides of differential amplifiers) in different converter cycles.

Abstract: In an improved system for receiving digital voice signals from a data network, a jitter buffer manager monitors packet arrival times, determines a time varying transit delay variation parameter and adaptively controls jitter buffer size in response to the variation parameter. A speed control module responds to a control signal from the jitter buffer manager by modifying the rate of data consumption from the jitter buffer, to compensate for changes in buffer size, preferably in a manner which maintains audio output with acceptable, natural human speech characteristics. Preferably, the manager also calculates average packet delay and controls the speed control module to adaptively align the jitter buffer's center with the average packet delay time.

Abstract: A dynamic magnet system, particularly useful for electrical generation, employs multiple magnets in polar opposition to each other for individual movement relative to a support structure. The magnets have a critical angle of displacement from a horizontal static position of less than 1 degree, with at least some of the magnets having mutually different properties. With different magnetic strengths, a greater movement is produced for both magnets in response to movements of the support structure, for particular ranges of magnetic strength ratios, than would be the case with equal magnets. The magnet movement can be translated into an electrical signal to power an operating system. Ultra low friction ferrofluid bearings can be used to establish static coefficients of friction between the magnets and support structure less than 0.02, enabling useful power generation from only slight movements of the support structure.

Abstract: Signal coupling systems are provided which enhance signal isolation and dynamic range with structures that increase bias voltages in upstream signal amplifiers to guard against transistor saturation that would otherwise increase current drain, reduce response time and possibly cause lock-up of an associated gain-control system. Dynamic range is thus enhanced because these systems can operate over an extended range of source signals. The increased bias voltages also decrease parasitic junction capacitances which increases input impedances and thereby enhances signal isolation and reduces signal distortion.

Abstract: A BJT device configuration includes an emitter finger and via arrangement which reduces emitter finger width, and is particularly suitable for use with compound semiconductor-based devices. Each emitter finger includes a cross-shaped metal contact which provides an emitter contact; each contact comprises two perpendicular arms which intersect at a central area. A via through an interlevel dielectric layer provides access to the emitter contact; the via is square-shaped, centered over the center point of the central area, and oriented at a 45° angle to the arms. This allows the via size to be equal to or greater than the minimum process dimension, while allowing the width of the emitter finger to be as narrow as possible with the alignment tolerances still being met.

Abstract: A robust output buffer component capable of providing high quality output signals comprising a cascode module for receiving a differential signal from a differential pair module and transmitting that differential signal as two output waveforms. Using a bipolar implementation example, the emitter end of a common base cascode pair is coupled to the collector end of a common emitter differential pair with an optional resistive module inserted between the cascode pair and the differential pair. Engineering the cascode bias, the resistance at the collector nodes of the differential pair and/or the resistance at the base nodes of the differential pair effects: the degree of non-linearity of the base-collector capacitance as a function of the base-collector voltage, the voltage swing of the collector nodes, and the degree of symmetry of the input voltages. These three parameters may be used to optimize the symmetry of the output waveforms.

Abstract: Switched-capacitor structures are provided that reduce distortion and noise in their processed signals because they increase isolation between structural elements and ensure that selected elements are securely turned off in one mode and quickly turned on in another mode.

Abstract: A method and apparatus for detecting electrical arcs in an electrical system having a periodic power supply is disclosed. A method according to the invention compares instantaneous values of a monitored waveform both with (a) their past values at corresponding phases of the AC supply waveform, and (b) their future values at corresponding phases of the AC supply waveform. The monitored waveform is delayed or stored to allow such comparisons in near real time, to produce an output which is only slightly delayed behind the monitored waveform. An apparatus according to the present invention discloses a sampling circuit that samples electrical signals indicative of transient load conditions to produce a sampling circuit output. A storage device receives the sampling circuit's output and stores a time history of that output over an interval.

Abstract: A system and method for portable computer battery management using host processing relocates analog and digital components needed to implement the SBDS standard from the battery pack to the computer, which processes the acquired battery data using the host processor. The battery pack requires only battery temperature and voltage sensing circuits, and an interface circuit for conveying the sensed data out of the battery pack. The portable computer includes a circuit which senses current provided to or drawn from the battery. Battery temperature, voltage and current data is provided to the computer's host system, which executes a battery management application program to determine battery status in accordance with the SBDS standard.

Abstract: A wireless IC interconnect system and method facilitates interconnections between first and second IC locations via a wireless transmission medium; the IC locations may be on the same chip or on separate chips. A signal to be conveyed is modulated, and the modulated signal is capacitively coupled to the wireless transmission medium—preferably a properly terminated microstrip transmission line (MTL) or a coplanar waveguide (CPW). The modulated signal is capacitively coupled from the wireless medium to a receiver which demodulates the modulated signal and provides the demodulated signal to the second IC location. In a preferred embodiment, the wireless transmission system conveys numerous signals simultaneously, with the signals modulated and demodulated with multiple access algorithms such as code-division (CDMA) and/or frequency-division (FDMA) multiple access algorithms.