Patents Assigned to Analog Devices, Inc.
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Patent number: 7619552Abstract: A system and method is provided for code independent switching in a digital-to-analog converter (DAC). A synchronous digital circuit is triggered by a synchronizing clocking signal and develops a digital data signal. A circuit arrangement provides the synchronizing clock a constant load at every clocking cycle, thereby assuring a data independent load. By providing a data independent load to the synchronizing clock at every clocking cycle, third harmonic distortion is advantageously reduced.Type: GrantFiled: April 24, 2008Date of Patent: November 17, 2009Assignee: Analog Devices, Inc.Inventor: William George John Schofield
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Patent number: 7617064Abstract: A high-definition multimedia interface circuit uses a high-definition multimedia interface encoder to produce a plurality of channels of data. An output circuit, connected to the high-definition multimedia interface encoder, produces a plurality of channels of high frequency data from the data produced by the high-definition multimedia interface encoder. A multiplexer selects a channel for sampling, and a capacitive coupler capacitively couples the multiplexer to a sampling circuit. The sampling circuit produces sampled data corresponding to the high frequency data having a clock rate less than a clock rate of the high frequency data. A test circuit compares the sampled data with the data produced by the high-definition multimedia interface encoder.Type: GrantFiled: April 12, 2006Date of Patent: November 10, 2009Assignee: Analog Devices, Inc.Inventors: Barry L. Stakely, Rodney D. Miller, Jingang Yi
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Patent number: 7616044Abstract: The intercept of a logarithmic amplifier is temperature stabilized by generating a signal having the form H log H where H is a function of temperature such as T/T0. The first H factor is cancelled, thereby generating a correction signal having the form Y log H. The cancellation may be implemented with a transconductance cell having a hyperbolic tangent function. The H log H function may be generated by a pair of junctions biased by one temperature-stable current and one temperature-dependent current. The pair of junctions and the transconductance cell may be coupled together in a translinear loop. A user-accessible terminal may allow adjustment of the correction signal for different operating frequencies.Type: GrantFiled: April 14, 2007Date of Patent: November 10, 2009Assignee: Analog Devices, Inc.Inventor: Vincenzo DiTommaso
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Patent number: 7612606Abstract: A bandgap reference circuit which is operable in low supply conditions is described. Such a circuit includes a second amplifier and a resistor at the output of a bandgap reference cell to create a constant current summing node at which PTAT and CTAT currents are summed. In modifications to the circuit it is possible to also provide a voltage reference node corresponding to the signal provided at the summing node. A further modification enables generation of a second voltage reference whose value is related to the base emitter voltage Vbe of a bipolar transistor. Further modifications provided for the generation of curvature correction within the circuit by biasing each of the first and second bipolar transistors Q1 and Q2 with currents of different forms.Type: GrantFiled: December 21, 2007Date of Patent: November 3, 2009Assignee: Analog Devices, Inc.Inventor: Stefan Marinca
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Patent number: 7612544Abstract: A linearized controller to operate a switching power converter which includes an inductor having its first terminal coupled to a first voltage (V1) and its second terminal switched so that it alternately connects to a second, higher voltage (V2) or to a common terminal. A sawtooth voltage generator produces a ramp voltage (Vramp) having a period T and an amplitude which varies in response to a control voltage Vx, and a voltage comparator which compares Vramp to a control voltage Vy. The comparator output controls the switching such that T is divided into intervals t1 and t2, during which the second terminal is connected to the common terminal or to V2, respectively. When Vy is maintained in a fixed proportion to V1, V2 is driven to be in the same proportion to Vx, independently of changes in V1, providing a boost converter. A buck converter is similarly realized.Type: GrantFiled: September 20, 2007Date of Patent: November 3, 2009Assignee: Analog Devices, Inc.Inventors: A. Paul Brokaw, Marc J. Kobayashi
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Patent number: 7612537Abstract: A galvanically isolated charge balance system for a multicell battery includes a balancing circuit associated with each cell; each balancing circuit including a flying capacitor; a variable conductance switch; and a biasing circuit for the variable conductance switch; and a galvanically isolating MEMS switching device for selectively connecting the flying capacitor to a voltage supply to charge it to a predetermined voltage and to the biasing circuit for setting the variable conductance switch to adjust the charge on its associated cell to a preselected level.Type: GrantFiled: January 25, 2007Date of Patent: November 3, 2009Assignee: Analog Devices, Inc.Inventors: John Wynne, Eamon Hynes
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Patent number: 7612820Abstract: In one embodiment, a configurable timing generator outputs at least one timing signal. The configurable timing generator comprises a first timing generator configurable to output the at least one timing signal so that the at least one timing signal is adaptable to a plurality of applications. In one embodiment, a configurable parameter storage unit comprising a parameter storage area configurable so as to store a plurality of parameters at least partially defining a desired plurality of waveform hierarchy elements, where the desired plurality of waveform hierarchy elements enable the definition of a waveform. In one embodiment, a method of constructing a waveform for a configurable timing generator, the method comprising acts of constructing a first pattern waveform, where the first pattern waveform comprises a first basic pulse, and constructing a first sequence waveform, where the first sequence waveform comprises a plurality of repetitions of the first pattern waveform.Type: GrantFiled: April 26, 2005Date of Patent: November 3, 2009Assignee: Analog Devices, Inc.Inventors: Christopher Jacobs, Jianrong Chen
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Patent number: 7613016Abstract: A power converter provides power across an isolation barrier, such as through the use of coils. A coil driver has transistors connected in a positive feedback configuration and is coupled to a supply voltage in a controlled manner by measuring the output power and opening or closing a switch as needed between the power supply and the coil driver. An output circuit, such as a FET driver, can be used with or without isolation to provide power and a logic signal.Type: GrantFiled: November 6, 2006Date of Patent: November 3, 2009Assignee: Analog Devices, Inc.Inventors: Baoxing Chen, Ronn Kliger
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Patent number: 7608534Abstract: Bridge structures provide a surface on which to form interconnections to components through through-hole vias. The bridge structures at least partially, and preferably fully, span the gap between two wafers, and, more specifically, between a through-hole via in one wafer and a corresponding component on the other wafer. Bridge structure may be formed on the wafer having the through-hole via and/or the wafer having the component.Type: GrantFiled: January 26, 2005Date of Patent: October 27, 2009Assignee: Analog Devices, Inc.Inventors: Changhan Yun, Javier Villarreal, Maurice S. Karpman
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Patent number: 7609112Abstract: A circuit includes a pair of input transistors configured as a differential pair and having input terminals configured to receive an input voltage. The circuit also includes a first current source connected to and configured to provide a first tail current to the pair of input transistors, the first tail current being a class-A current having a non-zero quiescent value. The circuit also includes a second current source connected to and configured to provide a second tail current to the pair of input transistors, the second tail current being a class-B current having a zero quiescent value and a non-zero non-quiescent value. The second current source is configured to provide the second tail current as a function of the input voltage.Type: GrantFiled: April 17, 2008Date of Patent: October 27, 2009Assignee: Analog Devices, Inc.Inventors: Rikky Muller, David Hall Whitney
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Patent number: 7609144Abstract: A thin film composition is made from silicon, an insulator such as alumina or silicon dioxide, and at least one additional material such as chromium, nickel, boron and/or carbon. These materials are combined to provide a thin film having a ? of at least 0.02 ?-cm (typically 0.02-1.0 ?-cm), and a TCR of less than ±1000 ppm/° C. (typically less than ±300 ppm/° C.). A sheet resistance of at least 20 k?/? may also be obtained. The resulting thin film is preferably at least 200 thick, to reduce surface scattering conduction currents.Type: GrantFiled: December 8, 2006Date of Patent: October 27, 2009Assignee: Analog Devices, Inc.Inventors: Michael Lee, Steven Wright, Philip Judge, Craig Wilson, Gregory Cestra, Derek Bowers
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Publication number: 20090262841Abstract: Systems and methods for amplitude compressing a digital signal. An input signal is divided into frames having a first and second sets of samples. The samples in the second set are also in a subsequent frame. Peak values are determined for the first and second sets. One or more slopes are calculated based on the peak values. The slopes are used to define a scale factor which is applied to the first set to produce the output signal. For example, if the first peak value exceeds an amplitude threshold, first and last samples in the first set to exceed the amplitude threshold are found. Slopes are calculated for each of three regions of the first set demarcated by the first and last samples. In each region a slope is selected. These slopes along with an initial scale factor are used to calculate the scale factor.Type: ApplicationFiled: March 27, 2009Publication date: October 22, 2009Applicant: Analog Devices, Inc.Inventor: Mohammed Chalil
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Patent number: 7605578Abstract: A bandgap voltage reference circuit that can be implemented with low noise characteristics is described. To achieve such low noise, a bandgap reference circuit is provided that includes an amplifier coupled at its inputs to first and second transistors respectively, the transistors being arranged to generate a voltage representative of the base emitter voltage differences between each of the first and second transistors across a sensing resistor. The circuit additionally provides an additional current to the sensing resistor to reduce the noise contribution into the amplifier from the first transistor. Such a circuit may be corrected for second order temperature effects by inclusion of a temperature dependent current source.Type: GrantFiled: August 7, 2007Date of Patent: October 20, 2009Assignee: Analog Devices, Inc.Inventor: Stefan Marinca
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Patent number: 7605741Abstract: An analog to digital converter having improved differential non-linearity is provided. The converter has a memory which is used to look up the actual weight or a weight error corresponding to the bits that have been kept as part of the SAR process to form an output correction value A part of this, for example a residue (the part following the decimal point in a decimal representation) is used to drive a correction DAC which causes a correction to be applied to the trial value presented to a comparator used by the ADC.Type: GrantFiled: December 5, 2006Date of Patent: October 20, 2009Assignee: Analog Devices, Inc.Inventor: Christopher Peter Hurrell
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Patent number: 7606092Abstract: A method of testing a memory cell includes generating a logic low signal, generating a logic high signal, reducing the logic high signal to a level corresponding to the logic low signal plus an offset to produce a reduced logic high signal, providing the logic low signal and the reduced logic high signal to a memory cell, allowing the memory cell to achieve a memory state, and testing the memory cell to determine if the memory state is an expected memory state. A memory array has an array of memory blocks, a write select circuit to provide write data to the array of memory blocks, and a data retention test circuit to reduce write data having a level corresponding to a logic high to a level corresponding to a logic low plus an offset.Type: GrantFiled: February 1, 2007Date of Patent: October 20, 2009Assignee: Analog Devices, Inc.Inventors: Michael D. Eby, Gregory P. Mikol, James E. DeMaris
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Publication number: 20090256531Abstract: Disclosed is a method and circuit for dissipating injected parasitic charge including a circuit stage, a pulse generating circuit and a switch. The circuit stage having an input node and an output node that injects a parasitic charge when switched OFF to the output node. The pulse generating circuit can generate a pulsed signal having an input for receiving a control signal. The control signal indicates the circuit stage is switching OFF, and has an output for outputting a pulsed signal in response to the control signal at the input. The pulsed signal can have a predetermined duration. The switch can be configured to be actuated by the pulsed signal output by the pulse generating circuit, and having a terminal connected to the output node of the circuit stage and a terminal connected to circuit to substantially dissipate the injected parasitic charge.Type: ApplicationFiled: April 9, 2008Publication date: October 15, 2009Applicant: Analog Devices, Inc.Inventors: Padraig Liam FITZGERALD, Nigel James HAYES
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Patent number: 7602169Abstract: A system and method are provided for isolating an input without adding significant distortion and without significantly adversely affecting the bandwidth of input circuits. In one embodiment, a single ended signal is substantially cancelled by an arrangement including an input resistance path in parallel with a negative resistance path wherein both paths substantially match in resistance. In another embodiment, a differential signal is substantially cancelled by a pseudo differential arrangement including two independent input resistance paths each in parallel with a corresponding negative resistance path, wherein the resistance paths substantially match the input resistance paths.Type: GrantFiled: April 24, 2008Date of Patent: October 13, 2009Assignee: Analog Devices, Inc.Inventors: William George John Schofield, Lawrence A. Singer
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Publication number: 20090251347Abstract: In one aspect, an apparatus for data conversion is provided.Type: ApplicationFiled: April 3, 2008Publication date: October 8, 2009Applicant: Analog Devices, Inc.Inventor: Wenhua Yang
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Patent number: 7598841Abstract: A thin film resistor (5) of an integrated circuit comprises an elongate resistive film (7) extending between electrical contact pads (10,11). A low impedance element (20) overlays and is electrically coupled to a portion of the resistive film (7) in an intermediate portion (22) thereof adjacent a second side edge (17) of the resistive film (7) for conducting current in parallel with the intermediate portion (22), and for reducing current density in the intermediate portion (22). First and second transverse edges (28,29) formed by spaced apart first and second slots (26,27) which extend from a first side edge (16) into the resistive film (7) define with a first side edge (16) of the resistive film (7) and the low impedance element (20) first and second trimmable areas (30,31) in the intermediate portion (22).Type: GrantFiled: September 20, 2005Date of Patent: October 6, 2009Assignee: Analog Devices, Inc.Inventors: Patrick M. McGuinness, Bernard P. Stenson
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Patent number: 7598799Abstract: A bandgap voltage reference circuit with an inherent curvature correction which comprises an amplifier having an inverting terminal, a non-inverting terminal and an output terminal is described. A first and second bipolar transistor operable at different current densities are provided each of the transistors being coupled to a corresponding one of the inverting and non-inverting terminals of the amplifier such that a ?Vbe is reflected across a first load element. A current biasing circuit is provided which includes a semiconductor device coupled to each of the first and second bipolar transistors and is configured for applying a non-linear bias current to the first and second bipolar transistors for biasing thereof.Type: GrantFiled: December 21, 2007Date of Patent: October 6, 2009Assignee: Analog Devices, Inc.Inventor: Stefan Marinca