Patents Assigned to Analog Devices, Inc.
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Patent number: 6531767Abstract: A novel array of optically and electrically interacting optical MEMS dies physically and electrically integrally attached upon an optically transmissive preferably (transparent) printed circuit substrate that is monolithically formed with one or more optical components, such as lenses, for providing fixed optical path alignment and interaction therebetween, and with provision for the integration also of active optical components such as lasers and photodiodes and the like.Type: GrantFiled: April 9, 2001Date of Patent: March 11, 2003Assignee: Analog Devices Inc.Inventor: Vernon Shrauger
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Patent number: 6531919Abstract: A phase inversion prevention circuit for an op amp input stage includes a detection circuit which detects when either of the input pairs' intrinsic diodes is near a forward-biased condition. When such a condition is detected, a switching network switches tail current from the primary input pair to a secondary input pair which takes over the input stage's amplifying duties. For a folded cascode input stage, the detection circuit preferably detects the onset of phase inversion by monitoring the cascode voltage which drives the cascode transistors. The outputs of the secondary input pair are connected to bypass the cascode transistors. Thus, when the onset of phase inversion is detected, the primary input pair is disabled, the second input pair is enabled, and with the cascode transistors bypassed the secondary input pair avoids phase inversion.Type: GrantFiled: August 15, 2002Date of Patent: March 11, 2003Assignee: Analog Devices, Inc.Inventor: Nathan R. Carter
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Publication number: 20030042886Abstract: An electronic meter includes a sensing circuit for sensing voltage and current values of a waveform, an analog-to-digital converter for converting the sensed voltage and current values to digital voltage and current values, a digital filter for delaying one or both of the digital voltage and current values to compensate for a phase shift error in the sensing circuit, and a computation circuit for computing one or more parameters of the waveform in response to the phase compensated voltage and current values. The electronic meter may be calibrated by applying to the meter a test waveform having a known phase shift, measuring the phase shift using the electronic meter, determining a phase shift error based on the difference between the known phase shift and the measured phase shift and determining digital filter coefficients to produce a digital filter delay that corresponds to the phase shift error.Type: ApplicationFiled: August 28, 2001Publication date: March 6, 2003Applicant: Analog Devices, Inc.Inventor: Guljeet S. Gandhi
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Patent number: 6528987Abstract: An operating circuit (1) for controlling the speed of a cooling fan motor (3) for computer cabinetry (7), and for determining an under-speed condition in the fan motor (3) comprises a control circuit (15) which controls a variable output signal generator circuit (18) for outputting a pulse width modulated signal corresponding to the desired fan speed for switching a switching circuit (8) in a power supply circuit of the fan motor (3) for pulse width modulating the power supply to the fan motor (3). A monitoring resistor (R1), a capacitor (C1) and a circuit (12) provides a tachometer signal to the operating circuit (1). A gate circuit (22) gates the second and fourth pulses of the tachometer signal to a counter (20) which counts clock pulses from a clock signal generating circuit (19) between the rising edges of the second and fourth pulses which are in turn stored in a register (23) for comparison with a reference count by a comparator (25).Type: GrantFiled: June 19, 2000Date of Patent: March 4, 2003Assignee: Analog Devices, Inc.Inventors: John Blake, David Hanrahan, Kohji Yoshida
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Patent number: 6529441Abstract: A data processor is provided which has integrated therein at least two of a bootstrap memory, a program memory and a data memory, wherein the at least two memories are of the same construction. In an exemplary embodiment, the memories are flash EEPROM memories. The data memory is provided with registers for temporarily storing the contents of an entire row of memory such that modifications can be easily made to a single bit within the row by storing the contents of the row, erasing the row, modifying the data and storing the data back in the row.Type: GrantFiled: July 31, 2001Date of Patent: March 4, 2003Assignee: Analog Devices, Inc.Inventors: Timothy J. Cummins, Dara Joseph Brannick
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Patent number: 6529078Abstract: Transimpedance amplifiers are provided that generate low-distortion output voltage signals with simple, inexpensive structures that are compatible with integrated-circuit fabrication processes. The amplifiers include a current processor and a complementary output stage. The processor provides in-phase upper and lower current signals in response to a differential input current signal and differentially alters respective first and second amplitudes of these signals in response to a common-mode input current signal. The complementary output stage has upper and lower transistors that provide the output voltage signal in respective response to the upper and lower current signals and with distortion that is reduced by the altered first and second amplitudes.Type: GrantFiled: August 22, 2001Date of Patent: March 4, 2003Assignee: Analog Devices, Inc.Inventors: Royal A. Gosser, Edward Perry Jordan
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Patent number: 6525606Abstract: A variable gain amplifier system for radio frequency signals is disclosed. The system provides a relatively constant gain change in decibels responsive to an incremental change in control voltage. The system includes two or more cascaded gain stage amplifiers. Each gain stage amplifier is adjustable between a first gain setting and a second gain setting.Type: GrantFiled: March 21, 2001Date of Patent: February 25, 2003Assignee: Analog Devices, Inc.Inventor: Simon Atkinson
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Patent number: 6526562Abstract: A method for developing an integrated circuit chip design includes the steps of developing an architecture specification defining the functions of the chip, developing a microarchitecture specification based on the architecture specification, developing a functional and structural model of the chip based on the microarchitecture specification, designing software tools for use with the chip based on the architecture specification, and designing chip verification tools based on the microarchitecture specification. The activities associated with chip development are divided into phases which may be performed concurrently. The result of the development is an RTL model of the chip which can be utilized in implementation of products without comprising proprietary circuit, layout and fabrication process information of the entity that is implementing the products.Type: GrantFiled: May 10, 2000Date of Patent: February 25, 2003Assignee: Analog Devices, Inc.Inventors: Elie Haddad, James Monaco, Thomas Tomazin, William C. Anderson
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Patent number: 6525601Abstract: An input system for a variable gain amplifier using a continuously interpolated attenuator includes a plurality of gm stages in which the collector current from one transistor in each gm stage is diverted to AC ground, thereby eliminating a feedforward path and providing flat frequency response at very high frequencies. An additional feedforward path through the parasitic emitter capacitances in each gm stage is eliminated by a filter capacitor coupled the common emitter node of each gm stage. A compensation transistor included in each gm stage provides a differential output signal which can be used to cancel common mode feedforward signals which are coupled to the output through the collector-junction capacitances of the gm stages. The effects of parasitic capacitances are further reduced by reverse biasing the gm stages that are off.Type: GrantFiled: June 11, 2002Date of Patent: February 25, 2003Assignee: Analog Devices, Inc.Inventor: Barrie Gilbert
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Patent number: 6525566Abstract: A logic isolation circuit has a transmitter circuit for receiving a logic input signal and providing a periodic signal to an isolation barrier, and a receiving circuit for receiving the periodic signal from the isolation barrier and for providing an output signal that indicates the transitions in the logical input signal.Type: GrantFiled: June 1, 2001Date of Patent: February 25, 2003Assignee: Analog Devices, Inc.Inventors: Geoffrey T. Haigh, Baoxing Chen
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Patent number: 6522206Abstract: 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. This is determined by successively comparing a feedback frequency of the feedback signal to a destination frequency of the reference signal over a comparison window of time. The invention also provides a feedback control system that practices the invention's methods.Type: GrantFiled: October 9, 2001Date of Patent: February 18, 2003Assignee: Analog Devices, Inc.Inventors: John J. Kornblum, David T. Crook
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Publication number: 20030030478Abstract: An RMS-DC converter generates a series of progressively amplified signal pairs which are then multiplied and weighted in such a way as to cancel uncorrelated noise while still providing true square-law response. The converter includes two series of gain stages for generating the amplified signal pairs, and a series of four-quadrant multipliers for multiplying and weighting the amplified signal pairs in response to a series of weighting signals. The outputs from the multipliers are summed and averaged, and a final output signal is generated by integrating the difference between the averaged signal and a reference signal. To preserve the square-law response over a wide range of input voltages, the system is servoed by feeding the final output signal back to an interpolator which generates the weighting signals as a series of continuously interpolated, overlapping, Gaussian-shaped current pulses having a centroid that moves along the length of the interpolator as the final output signal varies.Type: ApplicationFiled: July 9, 2002Publication date: February 13, 2003Applicant: Analog Devices, Inc.Inventor: Barrie Gilbert
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Patent number: 6516651Abstract: A method for testing a Coriolis transducer having a mass adapted vibrate along a vibratory direction in a resonant structure and undergo a displacement along a sensitive axis, perpendicular to the vibration, in response to an angular rate about a mutually perpendicular rate sensing axis. In the absence of an angular rate about the rate sensing axis, forces, FTEST VIBRATORY and FTEST SENSITIVE are applied on the mass along the direction of vibration and along the sensitive axis, respectively, in a predetermined ratio, N. The output VOUT TEST of the transducer is measured in response to the forces, FTEST VIBRATORY and FTEST SENSITIVE.Type: GrantFiled: July 22, 1999Date of Patent: February 11, 2003Assignee: Analog Devices, Inc.Inventor: John Albert Geen
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Patent number: 6518842Abstract: A bipolar rail-to-rail input stage includes complementary differential input pairs, and a switching circuit which makes one or the other of the input pairs active depending on the relationship between a transition threshold voltage Vth and the common mode input voltage Vcm. A transition threshold voltage selection circuit provides a selectable one of at least two different Vth voltages to the switching circuit in response to a select signal. In one embodiment, the select signal has logic “high”, logic “low”, and “floating” states. The transition threshold voltage selection circuit provides a first Vth voltage when the select signal is in a first state, a second Vth voltage when the select signal is in a second state, and disables the input stage when the select signal is in a third state.Type: GrantFiled: June 7, 2002Date of Patent: February 11, 2003Assignee: Analog Devices, Inc.Inventors: Nathan Carter, JoAnn P. Close
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Patent number: 6515542Abstract: An amplifier circuit includes a first operational amplifier having an inverting input and a non-inverting input. The non-inverting input receives an input signal, and the inverting input is connected to a noise generating system. The amplifier circuit further includes a second operational amplifier having an inverting input and a non-inverting input. The non-inverting input of the second operational amplifier receives an input signal, and the inverting input is connected to a noise generating system. A differential in/out operational amplifier, in the amplifier circuit, has an inverting input connected to an output of the second operational amplifier and a non-inverting input connected to an output of the first operational amplifier. The noise generating system injects a narrow band noise into a differential amplifier with no insertion loss and mismatching along the signal path. The narrow band noise is obtained by amplifying thermal noise of an amplifier. The amplified thermal noise is bandwidth limited.Type: GrantFiled: May 16, 2001Date of Patent: February 4, 2003Assignee: Analog Devices, Inc.Inventors: Yi Wang, James Hand
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Patent number: 6510745Abstract: A method for testing a Coriolis transducer having a mass adapted vibrate along a vibratory direction in a resonant structure and undergo a displacement along a sensitive axis, perpendicular to the vibration, in response to an angular rate about a mutually perpendicular rate sensing axis. In the absence of an angular rate about the rate sensing axis, forces, FTEST VIBRATORY and FTEST SENSITIVE, are applied on the mass along the direction of vibration and along the sensitive axis, respectively, in a predetermined ratio, N. The output VOUT TEST of the transducer is measured in response to the forces, FTEST VIBRATORY and FTEST SENSITIVE.Type: GrantFiled: December 28, 2001Date of Patent: January 28, 2003Assignee: Analog Devices, Inc.Inventor: John Albert Geen
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Patent number: 6512546Abstract: In one embodiment, an image sensor includes an area pixel array, column readout lines, and array readout lines, wherein the area pixel array includes columns of pixels, each including pixels of a first type, each column readout line is selectively coupled to outputs of the pixels of the first type that are included in a respective column of pixels, and each array readout line is selectively coupled to at least one of the first column readout lines. In another embodiment, an image sensor includes a pixel array, column readout lines, and array readout lines, wherein the pixel array includes a row of pixels which includes pixels of a first type, each column readout line is selectively coupled to an output of a respective pixel of the first type that is included in the row of pixels, and each array readout line is selectively coupled to at least one of the column readout lines.Type: GrantFiled: July 17, 1998Date of Patent: January 28, 2003Assignee: Analog Devices, Inc.Inventors: Steven Decker, Stuart Boyd, Laurier St. Onge
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Patent number: 6513125Abstract: A multi-phase, multi-access pipeline memory system includes a number, n, of processors; a pipeline memory including a latch; and a bus for interconnecting the processors and pipeline memory; a clock circuit responsive to a system clock signal divides the system clock signal into n phases for providing multiple clock signals corresponding to the n phases of the system clock signal for application to each processor to allow data and address to be transferred only during its assigned phase thereby enabling the memory and each processor to operate at the system clock rate while allowing n accesses to the memory during each system clock signal period, one access for each processor.Type: GrantFiled: January 6, 1997Date of Patent: January 28, 2003Assignee: Analog Devices, Inc.Inventor: Douglas Garde
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Patent number: 6510510Abstract: A computation block for use in a digital signal processor includes a register file for storage of operands and results and one or more computation units for executing digital signal computations. A first digital signal computation is performed with one of the computation units, and an intermediate result is produced. The intermediate result is transferred from a result output of the computation unit to an intermediate result input of one or more of the computation units without first transferring the intermediate result to the register file. A second digital signal computation is performed using the intermediate result to produce a final result or a second intermediate result.Type: GrantFiled: December 22, 1998Date of Patent: January 21, 2003Assignee: Analog Devices, Inc.Inventor: Douglas Garde
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Patent number: 6508561Abstract: Optical mirror coatings are used for high-temperature diffusion barriers and mirror shaping. Certain materials for use as high-temperature diffusion barriers under optical mirror coatings include metals that have high melting and/or boiling points and amorphous and partially recrystallized inorganic amorphous materials that have high glass transition temperatures (Tg). Candidate metals are selected based upon the boiling point or a combination of melting point and boiling point. Candidate amorphous and partially recrystallized inorganic amorphous materials are selected based upon the glass transition temperature. Optical mirrors having such high-temperature diffusion barriers maintain reflectivity when exposed to elevated temperatures, and are particularly useful in optical Micro Electro-Mechanical Systems (MEMS) that are exposed to high-temperature manufacturing processes. Optical mirrors are shaped using tensile and/or compressive films.Type: GrantFiled: October 17, 2001Date of Patent: January 21, 2003Assignee: Analog Devices, Inc.Inventors: Susan A. Alie, Allyson Hartzell, Maurice Karpman, John R. Martin, Kieran Nunan