Abstract: Line drivers are provided that are suitable for driving communication cables (e.g., in Data Over Cable Service Interface Specification (DOCSIS) certified systems) without the need for output drivers and their size, power-consumption, noise and signal-distortion penalities. These line drivers directly couple switched current mirrors to a transformer's input winding to simultaneously provide currents in response to a differential input signal and a digital command signal and drive the load impedance to thereby realize a corresponding signal gain.

Abstract: The present invention is a circuit comprising two series-coupled field effect transistor (FET) devices with a resistor network coupled in parallel forming a composite device (that can be substituted directly for a single FET device). In applications such as active loads or current sources, the composite device exhibits a greater breakdown voltage and superior high-frequency characteristics. The resistor network provides optimum direct current (DC) bias for depletion mode devices and superior high-frequency loading. Bandwidth and stability are both increased. Furthermore, this circuit is compatible with depletion mode FET processes having a single fixed threshold voltage.

Abstract: A focal plane array has a plurality of detectors for each pixel of the array. The detector having the best operability for each pixel is determined and a custom microlens array is fabricated, with each lens having a focal point directed to the best detector on each pixel. A Multiplexer (MUX) similarly transmits signals from the selected detectors while blocking transmission from the non-selected detectors.

Abstract: This invention describes new LEDs having light extraction structures on or within the LED to increase its efficiency. The new light extraction structures provide surfaces for reflecting, refracting or scattering light into directions that are more favorable for the light to escape into the package. The structures can be arrays of light extraction elements or disperser layers. The light extraction elements can have many different shapes and are placed in many locations to increase the efficiency of the LED over conventional LEDs. The disperser layers provide scattering centers for light and can be placed in many locations as well. The new LEDs with arrays of light extraction elements are fabricated with standard processing techniques making them highly manufacturable at costs similar to standard LEDs. The new LEDs with disperser layers are manufactured using new methods and are also highly manufacturable.

Abstract: Space vector modulation methods and structures are provided that reduce feedback errors which degrade motor control performance. In particular, the rotation of a reference voltage vector Vref is modified as it rotates with respect to voltage vectors that each represent a respective one of converter switch states in an electric-motor control system. One embodiment modifies the reference voltage vector Vref as it approaches various voltage vectors and another modifies the reference voltage vector Vref when its magnitude is less than a predetermined magnitude.

Abstract: A poly fuse trim cell includes a poly fuse and a transistor connected together at a first node; the transistor conducts a current necessary to blow the fuse in response to a control signal. The cell also includes a switching transistor, connected between the first node and a current source circuit. A logic gate is connected to the first node at one input, and to a reset signal at a second input. The output of the logic gate provides the trim cell's output, and controls the switching transistor. When the fuse is intact, the logic gate output is “low” such that the switching transistor is off and the cell's quiescent current is zero. When the fuse is blown, the logic gate output goes “high” upon the occurrence of a reset signal, which turns on the switching transistor and allows the current source circuit to pull down the first node.

Abstract: Differential sampler structures are provided that reduce signal distortion and current demand. The structures include first and second buffers that drive first and second capacitors and first and second switches. First and second current pumps are capacitively coupled and also cross coupled to the first and second capacitors relative to the coupling of the first and second buffers to these capacitors. As a result, signal distortion and current demand are both reduced.

Abstract: A high temperature hybrid-circuit structure includes a temperature sensitive device which comprises SiC, AlN and/or AlxGa1−xN(x>0.69) connected by electrodes to an electrically conductive mounting layer that is physically bonded to an AlN die. The die, temperature sensitive device and mounting layer (which can be W, WC or W2C) have temperature coefficients of expansion within 1.06 of each other. The mounting layer can consist entirely of a W, WC or W2C adhesive layer, or an adhesive layer with an overlay metallization having a thermal coefficient of expansion not greater than about 3.5 times that of the adhesive layer. The device can be encapsulated with a reacted borosilicate mixture, with or without an upper die which helps to hold on lead wires and increases structural integrity. Applications include temperature sensors, pressure sensors, chemical sensors, and high temperature and high power electronic circuits.

Abstract: A bipolar transistor breakdown voltage enhancement circuit extends the voltage swing which can be tolerated at an output terminal driven by an emitter follower-connected bipolar output transistor operating in a high impedance state. The enhancement circuit connects the base of the output transistor to a voltage which extends the allowable high impedance output voltage swing: an NPN output transistor's base is tied to a voltage that is the lower of the output voltage or ground, and a PNP output transistor's base is tied to a voltage which is the higher of the output voltage or VDD.

Abstract: A micro-bore catheter for use with an infusion pump wherein the micro-bore lumen of the catheter acts as an adjustable flow restricting element. The flow rate through the catheter can be increased proportionally by trimming the length of the catheter. One end of the catheter is attached to a needle for insertion of the catheter into the elastomeric septum of a drug infusion pump.

Abstract: Unwanted voltage drops associated with the bit switches of a DAC are compensated with an output amplifier circuit for the DAC that includes a feedback circuit with a switch compensation resistance element that is connected in a combined series/parallel circuit with a feedback resistance circuit, so as to reduce both the size and associated capacitance of the resistance element.

Abstract: A multi layered high impedance structure presents a high impedance to multiple frequency signals, with a different frequency for each layer. Each layer comprises a dielectric substrate, and an array of radiating elements such as parallel conductive strips or conductive patches on the substrate's top surface with a conductive layer on the bottom surface of the bottommost layer. The radiating elements of succeeding layers are vertically aligned with conductive vias extending through the substrates to connect the radiating elements to the ground plane. Each layer presents as a series of parallel resonant L-C circuits to an E field at a particular signal frequency, resulting in a high impedance surface at that frequency. The new structure can be used as the substrate for a microstrip patch antenna to provide an optimal electrical distance between the resonator and backplane at multiple frequencies.

Abstract: A method for protecting the surface of a semiconductor material from damage and dopant passivation is described. A barrier layer of dense or reactive material is deposited on the semiconductor material shortly after growth in a growth reactor such as a MOCVD reactor, using the MOCVD source gasses. The barrier layer blocks the diffusion of hydrogen into the material. The reactor can then be cooled in a reactive or non-reactive gas ambience. The semiconductor material can then be removed from the reactor with little or no passivation of the dopant species. The barrier layer can be removed using a variety of etching processes, including wet chemical etching or can be left at the semiconductor material for surface protection. The barrier layer can also be a gettering layer that chemically binds hydrogen trapped in the semiconductor material and/or blocks hydrogen diffusion into the material.

Abstract: In order to generate a carrier frequency Fc, a digital modulator must operate (to satisfy the Nyquist criteria) at a system sample rate Rs which is at least twice the carrier frequency Fc. However, digital modulator structures are provided herein that facilitate the use of M quadrature modulators which modulate, at a reduced modulation rate Rs/M, respective ones of M polyphase cosine elements and M polyphase sine elements with respective ones of interpolated I elements and interpolated Q elements to thereby form M polyphase modulated elements. The modulated elements are then sequentially selected in a multiplexer to form a modulated digital signal. The reduced modulation rate simplifies modulator design and lowers fabrication costs.

Abstract: Feedback methods and systems are provided to achieve rapid switching of oscillator frequencies without compromising operational feedback loop bandwidths that filter out spurious tones and phase noise to thereby enhance loop spectral and noise performance. The methods respond to frequency changes in a reference signal by providing an open-loop drive current to drive a feedback signal towards the reference signal. The drive current is terminated and the feedback control loop closed when the feedback signal is within a predetermined acquisition range of the reference signal. Preferably, the closed loop is initially configured with a first feedback bandwidth and is subsequently reconfigured with a second steady-state feedback bandwidth that is less than the first feedback bandwidth.

Abstract: A system and method for reducing reaction forces induced in a machine frame by an oscillating tool employs a counterforce assembly which is driven to move along linear slides mounted to the machine frame. The counterforce assembly is driven with a drive signal derived from two signals: a first signal which is proportional to the acceleration of the tool, and a second signal which is directly proportional to the velocity of the oscillating tool. By properly-adjusting the acceleration and velocity components of the drive signal, the magnitude of the reaction forces induced in the machine frame by the oscillating tool can be substantially reduced. The counterforce assembly preferably includes a centering means which prevents it from moving to either end of the slide. An accelerometer is preferably mounted to the machine frame to sense its vibration, with the accelerometer output used to adjust the counterforce assembly's drive electronics to reduce vibration to a minimum.

Abstract: An asynchronous timing oscillator re-synchronizer enables a clocked system which uses a high frequency clock to measure time intervals to re-synchronize to the clock after it has been temporarily disabled, using a low frequency, low accuracy, low power clock to determine the number of high frequency clock cycles that would have occurred during such intervals. Both high frequency and low frequency clocks are provided to the re-synchronizer, and the ratio between their respective frequencies is periodically determined and stored. A command sent to the re-synchronizer disables the high frequency clock for a specified number of cycles of the low frequency clock. When the disablement period has expired, the high frequency clock is re-enabled.

Abstract: The present invention is connected across a sense resistor which carries a current of interest. A first pair of cross-coupled switches are connected between the sense resistor and respective input capacitors, and a second pair of cross-coupled switches are connected between the input capacitors and the inputs of an amplifier having differential inputs and outputs. Feedback capacitors are connected between each of the amplifier's outputs and inputs. A control circuit operates the cross-coupled switches in accordance with a switching cycle, during which the connections between the sense resistor and the input capacitors are interchanged, after which the connections between the input capacitors and the differential amplifier are interchanged. When so arranged, the sensed voltage is sampled on the input capacitors and transferred to the feedback capacitors to produce a differential output voltage Vout from the differential amplifier which is proportional to the current of interest.

Abstract: An auto-ranging current integration circuit includes an operational amplifier which receives an input current to be integrated, and an array of integration capacitors which are switchably connected in parallel between the op amp's output and inverting input. A control circuit initially connects a first capacitor across the op amp, and then connects additional capacitors in parallel with the first whenever the op amp's output exceeds a predetermined voltage, but before the output becomes saturated. In this way, a smaller integration capacitance is automatically employed for a small input current, and larger capacitance values are automatically switched in for larger input currents, which lowers the integration gain, prevents the output from saturating, and keeps the current integration circuit's signal-to-noise ratio high.

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.