Sum And Difference Amplifiers Patents (Class 330/69)
  • Publication number: 20130107933
    Abstract: An apparatus for equalizing channels is provided, which is generally transparent to link training. The apparatus generally includes equalization paths formed by an input circuit, a crossbar, and an output circuit and a controller. Each equalization path is coupled to at least one of the channels, and a controller has a VGA loop, a crossbar loop, and a driver loop. The AGC loop receives a first reference voltage and provides a gain control signal to the input circuit, and the gain control network comprises a replica of at least one of the equalization paths. The crossbar loop receives a second reference voltage and provides a crossbar control signal to the crossbar. The driver loop receives a third reference voltage and provides a driver control signal for the output circuit.
    Type: Application
    Filed: October 28, 2011
    Publication date: May 2, 2013
    Applicant: Texas Instruments Incorporated
    Inventors: Yaqi Hu, Yanli Fan, Huawen Jin, Ulrich Schacht, Karl Muth, Mark W. Morgan
  • Patent number: 8432222
    Abstract: Apparatus and methods for electronic amplification are provided. In one embodiment, an amplifier includes a first adaptive level shifter (ALS), a second ALS, a first transconductance amplification circuit, a second transconductance amplification circuit, and a transimpedance amplification circuit. The first ALS and the second ALS are electrically coupled to the first and second transconductance amplification circuits to improve the input voltage range and common-mode rejection ratio (CMRR) of the amplifier. The transimpedance amplification block is electrically coupled to the first and second transconductance amplification blocks and generates an output voltage of the amplifier. The first ALS receives a differential input voltage, and the second ALS is configured to receive a feedback signal configured to change in relation to the output voltage signal.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: April 30, 2013
    Assignee: Analog Devices, Inc.
    Inventor: Evgueni Ivanov
  • Publication number: 20130099858
    Abstract: This application reduces the power of series combined transformers and of parallel combined transformers while maintaining efficiency. In one embodiment, a series combined transformer is provided with a switch between a first primary inductor and a second primary inductor, in order to provide at least two modes. In a high power mode, the switch is open and the series combined transformer operates normally. In a low power mode, the switch is closed, one amplifier from a first differential amplifier pair is shut down, one amplifier from a second differential pair is shut down, and the series combined transformer operates efficiently in a low power mode.
    Type: Application
    Filed: October 22, 2012
    Publication date: April 25, 2013
    Applicant: RF MICRO DEVICES, INC.
    Inventor: RF MICRO DEVICES, INC.
  • Publication number: 20130099859
    Abstract: A multilevel class-D differential amplifier which can be operated in at least three modes includes a first power stage and a second power stage. In an idle mode, an output of the first power stage varies between a first voltage level and a second voltage level, wherein an output of the second power stage varies between the first voltage level and the second voltage level. In a PWM mode, the output of the first power stage varies between the first voltage level and the second voltage level, wherein the output of the second power stage varies between the first voltage level and the second voltage level. In a Multi-Level mode, the output of said first power stage varies between said second voltage level and a third voltage level, wherein said output of said second power stage is fixed at said first voltage level, and wherein said differential signal between said outputs of said power stages is pulse width modulated.
    Type: Application
    Filed: December 10, 2012
    Publication date: April 25, 2013
    Applicant: Maxim Integrated Products, Inc.
    Inventor: Maxim Integrated Products, Inc.
  • Publication number: 20130099857
    Abstract: A reconfigurable amplifier comprising a first operational amplifier having two inputs and an output. A second operational amplifier having two inputs and an output. A plurality of switches coupled to the two inputs and the output of the first operational amplifier and the two inputs and the output of the second operational amplifier, wherein a first configuration of the plurality of switches causes the first operational amplifier and the second operational amplifier to operate as an inverting differential input amplifier, and wherein a second configuration of the plurality of switches causes the first operational amplifier and the second operational amplifier to operate as a non-inverting differential input instrumentation amplifier.
    Type: Application
    Filed: October 24, 2011
    Publication date: April 25, 2013
    Inventors: Brian W. Friend, Christian Larsen
  • Patent number: 8427236
    Abstract: An operational amplifier includes an input differential stage having one external input receiving an external input voltage and two outputs; and two output stages. A switch section is provided between inputs of the two output stages and the two outputs of the input differential stage, and is configured to alternately connect the two outputs of the input differential stage and inputs of a positive-only output stage of the two output stages; and the two outputs of the input differential stage and inputs of a negative-only output stage of the two output stages.
    Type: Grant
    Filed: April 19, 2010
    Date of Patent: April 23, 2013
    Assignee: Renesas Electronics Corporation
    Inventor: Kouichi Nishimura
  • Publication number: 20130082770
    Abstract: An electronic circuit includes a band-gap reference circuit and a start-up circuit. The band-gap reference circuit includes an operational amplifier which has an output and first and second inputs. The band-gap reference circuit is configured to generate a predetermined reference voltage at the output of the operational amplifier after a start-up phase of the band-gap reference circuit. The start-up circuit includes at least one switch arranged to connect at least one current source to at least one of the inputs of the operational amplifier during the start-up phase, and to disconnect the at least one current source from the at least one of the inputs of the operational amplifier after the start-up phase.
    Type: Application
    Filed: September 30, 2011
    Publication date: April 4, 2013
    Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Chia-Fu LEE, Chih-Feng LI
  • Patent number: 8410847
    Abstract: A voltage level shifter for a direct coupling of an external voltage source to a common mode of a circuit may include an amplifier, a voltage-controlled current source, a first and second resistors. A first input of the amplifier may be connected to the common mode. A second input of the amplifier may, via the first and second resistors, receive a voltage indicative of the external voltage source. The output of the amplifier may indicate a voltage difference between the first and second inputs. The voltage-controlled current source may be controlled by the voltage difference to supply a current to a common node of the first and second resistors so that the voltage difference between the first and second inputs may be minimized.
    Type: Grant
    Filed: May 9, 2011
    Date of Patent: April 2, 2013
    Assignee: Analog Devices, Inc.
    Inventors: Robert Libert, Khiem Quang Nguyen
  • Publication number: 20130075608
    Abstract: According to example embodiments, an image sensor includes a charge sensing amplifier configured to amplify charges sensed by a sensing unit. The charge sensing amplifier includes an input terminal, an amplification terminal, an output terminal, a first capacitor connected between the input terminal and the amplification terminal, a first switch connected between the input terminal and the amplification terminal, a second capacitor connected between the amplification terminal and the output terminal, and a second switch connected between the output terminal and a reference voltage terminal.
    Type: Application
    Filed: August 29, 2012
    Publication date: March 28, 2013
    Applicants: KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY, SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Sang-wook HAN, Hyun-sik KIM, Gyu-Hyeong CHO, Chang-jung KIM, Jae-chul PARK, Young-hun SUNG, Young KIM, Jun-hyeok YANG
  • Patent number: 8405461
    Abstract: A trans-impedance amplifier (TIA) for a light-receiving circuit is disclosed where the TIA reduces the power consumption as suppressing the degradation of the signal quality in high frequency regions. The TIA comprises a primary core, a dummy core, and a differential amplifier that receives each output of two cores in the differential mode. Two cores have an arrangement substantially same to each other except that the power consumption thereof is smaller in the dummy core. Because the output impedance of two cores becomes substantially equal, the scattering parameter of the common mode to the differential mode at the output of the primary core becomes small enough.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: March 26, 2013
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Akihiro Moto, Keiji Tanaka
  • Publication number: 20130069718
    Abstract: Apparatus and methods for electronic amplification are provided. In one embodiment, an amplifier includes a first adaptive level shifter (ALS), a second ALS, a first transconductance amplification circuit, a second transconductance amplification circuit, and a transimpedance amplification circuit. The first ALS and the second ALS are electrically coupled to the first and second transconductance amplification circuits to improve the input voltage range and common-mode rejection ratio (CMRR) of the amplifier. The transimpedance amplification block is electrically coupled to the first and second transconductance amplification blocks and generates an output voltage of the amplifier. The first ALS receives a differential input voltage, and the second ALS is configured to receive a feedback signal configured to change in relation to the output voltage signal.
    Type: Application
    Filed: September 15, 2011
    Publication date: March 21, 2013
    Applicant: ANALOG DEVICES, INC.
    Inventor: Evgueni Ivanov
  • Patent number: 8400214
    Abstract: This disclosure describes at least one class AB amplifier output stage circuit arrangement that can operate at low supply voltages, with minimum current generated. Furthermore, at least one class AB amplifier stage circuit arrangement described herein reacts favorably to a supply voltage, that is, exhibits a good power supply rejection ratio. Moreover, this disclosure describes class AB amplifier output stage circuit arrangements that include a negative channel metal oxide semiconductor (NMOS) transistor current mirror arrangement and a positive channel metal oxide semiconductor (PMOS) transistor current mirror arrangement. In some implementations, a monitoring circuit may be coupled to a class AB amplifier output stage circuit arrangement to offset mismatch that may occur in the class AB amplifier output stage.
    Type: Grant
    Filed: July 21, 2011
    Date of Patent: March 19, 2013
    Assignee: Infineon Technologies AG
    Inventor: Dieter Draxelmayr
  • Patent number: 8400229
    Abstract: An vector modulator using a time delay and a phase shifter is disclosed, the vector modulator including a time delay (110) varying a phase of an input signal by time-delaying the input signal; a first coupler (120) converting the signal outputted in changed phase through the time delay to an I channel signal and a Q channel signal each having a 90° phase difference and outputting the I/Q channel signals; a first phase shifter (130) varying the phase of the I channel signal outputted from the first coupler within a predetermined phase range and outputting the phase-variable I channel signal; a second phase shifter (140) varying the Q channel signal outputted from the first coupler within a predetermined phase range and outputting the phase-variable Q channel signal; and a second coupler (150) coupling phase-variable I/Q channel signals and outputting the coupled signals.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: March 19, 2013
    Assignee: LS Industrial Systems Co., Ltd.
    Inventors: Heon soo Choi, Chang su Choi, Hyung jun Jeon, Yeong chan Kim, Jae hwan Im, Jin Kuk Hong
  • Publication number: 20130063207
    Abstract: A capacitive sensor system and method resistant to electromagnetic interference is disclosed. The system includes a capacitive core, differential amplifier with inverting and non-inverting inputs, capacitive paths, and chopping system. Core can include inputs and outputs coupled to variable capacitors, and common nodes coupling variable capacitors. Capacitive paths couple core outputs to amplifier inputs. When chopping system is high, one polarity voltage is applied to core inputs, a first core output is coupled to the inverting input and a second core output is coupled to the non-inverting input. When the chopping system is low, opposite polarity voltage is applied to core inputs, and core output to amplifier input couplings are flipped. Capacitive paths can include bond wires. Chopping system can be varied between high and low at frequencies that smear noise away from a frequency band of interest, or that smear noise substantially evenly across a wide frequency range.
    Type: Application
    Filed: July 25, 2012
    Publication date: March 14, 2013
    Applicant: Robert Bosch GmbH
    Inventors: Ganesh Balachandran, Vladimir Petkov
  • Patent number: 8390374
    Abstract: Apparatus and methods reduce the likelihood of amplifier saturation due to propagated DC offsets, and reduce the recover from saturated stated when such saturation occurs. Advantageously, these attributes are beneficial for monitoring of bioelectric signals. A circuit uses an instrumentation amplifier connected as a high pass filter to attenuate large DC offsets and amplify small signals. The circuit can include an instrumentation amplifier electrically coupled with a first feedback circuit including at least one resistor and a second feedback circuit including an op-amp. The feedback circuit can also include a low-pass filter. The op-amp in the second feedback circuit can be configured as a non-inverting amplifier, an inverting amplifier, and/or an integrator circuit. Alternatively, the circuit can include an instrumentation amplifier with one feedback circuit including at least one resistor, and a coupling capacitor electrically coupled with a reference voltage.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: March 5, 2013
    Assignee: Analog Devices, Inc.
    Inventors: Alasdair Gordon Alexander, David James Plourde, Matthew Nathan Duff
  • Patent number: 8390496
    Abstract: System and method for common mode translation in continuous-time sigma-delta analog-to-digital converters. An embodiment includes a loop filter having an RC network coupled to a differential signal input, a Gm-C/Quantizer/DAC circuit (GQD) coupled to the loop filter, a common-mode level adjust circuit coupled to signal inputs of the GQD, and a tuning circuit coupled to the GQD and the common-mode level adjust circuit. The GQD evaluates an input signal provided by the RC network. computes a difference between a filtered input signal and the feedback quantization signal to generate an error signal, measures the error signal, and compensates for the error signal with sigma-delta noise-shaping. The common-mode level adjust circuit alters a common-mode level of a differential input signal to be substantially equal to a desired common-mode level and the tuning circuit provides a compensation voltage to the common-mode level adjust circuit based on a difference between the common-mode levels.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: March 5, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Ayman A. Fayed, Russell Byrd, Baher Haroun
  • Publication number: 20130049857
    Abstract: This invention discloses circuit and methods of a NAND-based 2T-string NOR flash cell structure as a building block for a fast random-read NOR flash memory. The key concept of this new set of bias conditions in cell array improves over the critical concern of punch-through issue when cell is migrating to the more advanced technology node of next generation. The invention adopts a novel preferable symmetrical 2T-string NOR flash cell. Each NAND or NAND like cell of this 2T-string NOR cell is to store 2 bits and is preferable to be made of N-channel device. The cell is preferable to use Fowler-Nordheim Tunneling scheme for both erase and program operations- The invention is to provide a novel 2T-string NOR flash cell structure made of N-channel device offering most flexible erase sizes in unit of byte, page, sector, block and chip with the least program and erase disturbances.
    Type: Application
    Filed: September 2, 2011
    Publication date: February 28, 2013
    Inventor: Andrew Myles
  • Patent number: 8384473
    Abstract: A voltage output device capable of preventing an increase in circuit scale includes an offset compensation function and is suitably applicable to a drive circuit for display devices. The voltage output device includes an operational amplifier having an inverting input terminal and a non-inverting input terminal. Resistance values of a load resistor on the inverting input side and a load resistor on the non-inverting input side are maintained when the output voltage of the amplifier has changed while sequentially varying either one or both of the resistance values of the load resistor on the inverting input side and the load resistor on the non-inverting input side in a state that the inverting input terminal and the non-inverting input terminal are connected. The voltage output device is configured to output the output voltage of the amplifier with the inverting input terminal not connected to the non-inverting input terminal.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: February 26, 2013
    Assignee: Lapis Semiconductor Co., Ltd.
    Inventor: Hiroyoshi Ichikura
  • Publication number: 20130043942
    Abstract: A sensing device is provided. The sensing device successively operates in a plurality of operation periods and includes a plurality of first electrodes, a plurality of differential amplifiers, and a plurality of sensing circuits. The first electrodes are disposed successively. The differential amplifiers at least comprise a first differential amplifier and a second differential amplifier. Each of the differential amplifiers comprises a first input terminal and a second input terminal. Each of the sensing circuits has an input terminal and an output terminal. The sensing circuits at least comprise first, second, and third sensing circuits. The input terminals of the sensing circuits are coupled to the first electrodes. The output terminals of sensing circuits are coupled to the differential amplifiers. The output terminal of at least one of the sensing circuits is coupled to both of the first differential amplifier and the second differential amplifier.
    Type: Application
    Filed: August 15, 2011
    Publication date: February 21, 2013
    Inventors: Shinji KONOSHITA, Yoshikazu Matsui, Kazuyuki Hashimoto
  • Publication number: 20130038388
    Abstract: An auto-zero amplifier is disclosed, having an amplifying circuit, a switch, and a difference signal generating circuit. The amplifying circuit receives a first input signal for generating a first output signal, and receives a second input signal for generating a second output signal. The switch is coupled between the amplifying circuit and a capacitor. The switch is conducted for charging or discharging the capacitor to a voltage with the first output signal, and the switch is not conducted for keeping the capacitor at the voltage. The difference signal generating circuit is coupled with the amplifying circuit and the capacitor for generating a difference signal of the first output signal and the second output signal, a multiple of the difference signal, a part of the difference signal, and/or a digital output value for the difference signal.
    Type: Application
    Filed: August 10, 2012
    Publication date: February 14, 2013
    Inventors: Shiueshr JIANG, An-Tung Chen, Jo-Yu Wang, Jen-Hung Chi
  • Publication number: 20130035679
    Abstract: A radio-frequency (RF) amplifier having a direct response to an arbitrary signal source to output one or more electrosurgical waveforms within an energy activation request, is disclosed. The RF amplifier includes a phase compensator coupled to an RF arbitrary source, the phase compensator configured to generate a reference signal as a function of an arbitrary RF signal from the RF arbitrary source and a phase control signal; at least one error correction amplifier coupled to the phase compensator, the at least one error correction amplifier configured to output a control signal at least as a function of the reference signal; and at least one power component coupled to the at least one error correction amplifier and to a high voltage power source configured to supply high voltage direct current thereto, the at least one power component configured to operate in response to the control signal to generate at least one component of the at least one electrosurgical waveform.
    Type: Application
    Filed: August 1, 2011
    Publication date: February 7, 2013
    Applicant: TYCO Healthare Group LP
    Inventor: James H. Orszulak
  • Publication number: 20130033313
    Abstract: Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.
    Type: Application
    Filed: July 30, 2012
    Publication date: February 7, 2013
    Applicant: Parker Vision, Inc.
    Inventors: David F. SORRELLS, Gregory S. Rawlins, Michael W. Rawlins
  • Publication number: 20130033312
    Abstract: A circuit for single ended to differential conversion is disclosed. The circuit comprises a source for providing a single ended signal; and a transformer for receiving the single ended signal. The transformer includes first and second inductors. The first and second inductors are mutually coupled. When the operating frequency changes, a phase difference of currents flowing through the inductors changes, and therefore a phase difference between effective impedance of the first and second inductors changes to maintain a substantially 180 degree phase difference due to the mutual coupling.
    Type: Application
    Filed: August 3, 2011
    Publication date: February 7, 2013
    Applicant: Ralink Technology Corporation
    Inventor: Eric Chiyuan LU
  • Patent number: 8369534
    Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A switched attenuator circuit is also provided that has first and second states. In the first state, the attenuator circuit couples a sense point of the reference contact to the cold input, while in the second state the cold input is isolated from the reference sense point. Other embodiments are also described and claimed.
    Type: Grant
    Filed: March 28, 2012
    Date of Patent: February 5, 2013
    Assignee: Apple Inc.
    Inventors: Timothy M. Johnson, Lawrence F. Heyl, Wendell B. Sander, Douglas M. Farrar
  • Patent number: 8368464
    Abstract: The balanced output signal generator uses four interconnected plus-type second-generation current conveyors, a couple of load resistors and a single input resistor that can provide both current- and voltage-mode outputs. No matching conditions are required.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: February 5, 2013
    Assignee: King Fahd University of Petroleum and Minerals
    Inventor: Muhammad Taher Abuelma'atti
  • Publication number: 20130021097
    Abstract: Described is an inductive compensating network coupled between the differential inputs of an operational amplifier circuit. The inductive compensating network includes at least one inductive element having an inductance value selected so as to provide proper compensation of the operational amplifier circuit. Also described is a feedback compensation scheme which adjusts loop characteristics by introducing zeros into a system with the addition of inductive or capacitive elements in a feedback path.
    Type: Application
    Filed: July 22, 2011
    Publication date: January 24, 2013
    Applicant: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    Inventors: Douglas Jay Kozak Adams, Rahul Sarpeshkar
  • Patent number: 8358788
    Abstract: An audio host device has a connector having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a first cold input, a second cold input, and hot input. The first cold input is coupled to an output of the speaker amplifier, while the second cold input is coupled a sense point for the reference contact. The hot input is coupled to the microphone contact. Other embodiments are also described and claimed.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: January 22, 2013
    Assignee: Apple Inc.
    Inventors: Lawrence F. Heyl, Timothy M. Johnson
  • Publication number: 20130015916
    Abstract: An auto-zero amplifier includes a main amplifier for amplifying an input signal; the main amplifier receives an offset-correction signal for cancelling an offset at a first common-mode level of the input signal. At the first common-mode level, the offset-correction signal is based on a first value stored using a first offset-storage element. When a change is detected in the input common-mode from the first level to a second level, the first offset-storage element is switched out and a second offset-storage element, having a second value based on the second common-mode level, is switched in.
    Type: Application
    Filed: December 14, 2011
    Publication date: January 17, 2013
    Applicant: Analog Devices, Inc.
    Inventors: Quan Wan, Alasdair Alexander
  • Patent number: 8344802
    Abstract: An operational amplifier device includes an operational amplifier, a first transmission gate, and a first switch module. The operational amplifier includes an output stage, which has a first signal input terminal and a signal output terminal, and outputs an output voltage at the signal output terminal. The first transmission gate is coupled between the signal output terminal and a transmission output terminal, having a first transmission control terminal. The first switch module is utilized for controlling electrical connection between the first signal input terminal and the first transmission control terminal. During a first transmission period, the first switch module controls the first transmission control terminal to be coupled to the first signal input terminal, thereby conducting the first transmission gate to not only transmit the output voltage but also act as a Miller capacitor.
    Type: Grant
    Filed: April 20, 2011
    Date of Patent: January 1, 2013
    Assignee: NOVATEK Microelectronics Corp.
    Inventors: Ju-Lin Huang, Peng-Yu Chen
  • Publication number: 20120326785
    Abstract: An amplifier arrangement constituted of: a first input lead; a second input lead; a difference amplifier; a first buffer, the input of the first buffer coupled to the first input lead, the output of the first buffer coupled to a first input of the difference amplifier; a second buffer, the input of the second buffer coupled to the second input lead, the output of the second buffer coupled to a second input of the difference amplifier; and a transconductance amplifier, the non-inverting input and the non-inverted output of the transconductance amplifier coupled to the first input of the difference amplifier, the inverting input and the inverted output of the transconductance amplifier coupled to the second input of the difference amplifier. The input signals are thus buffered and the offset of the buffers are compensated for.
    Type: Application
    Filed: May 3, 2012
    Publication date: December 27, 2012
    Applicant: MICROSEMI CORPORATION
    Inventors: Kai KWAN, Peter KIM
  • Publication number: 20120326778
    Abstract: This disclosure relates to radio frequency (RF) amplification devices and methods for amplifying an RF input signal. To set the quiescent operating level of the RF output signal, a bias signal to be applied to the RF input signal is received prior to amplifying the RF input signal. The bias signal is amplified to generate the RF output signal at the quiescent operating level and a feedback signal is received that is indicative of the quiescent operating level of the RF output signal. Prior to amplifying the RF input signal, the bias signal level of the bias signal is adjusted such that the quiescent operating level is set to a reference signal level based on the feedback signal level. This allows for adjustments to be made to the quiescent operating level and maintain the quiescent operating level at a desired value.
    Type: Application
    Filed: June 21, 2012
    Publication date: December 27, 2012
    Applicant: RF MICRO DEVICES, INC.
    Inventors: Praveen Varma Nadimpalli, Mike Landherr, Michael B. Thomas, Wonseok Oh
  • Patent number: 8340312
    Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A variable attenuator circuit is also provided having an input coupled to receive a signal from a sense point for the reference contact, and an output coupled to the cold input of the difference amplifier. A controller has an output coupled to control the variable attenuator. Other embodiments are also described and claimed.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: December 25, 2012
    Assignee: Apple Inc.
    Inventors: Timothy M. Johnson, Lawrence F. Heyl
  • Publication number: 20120319769
    Abstract: Multiple-Input-Single-Output (MISO) amplification and associated VPA control algorithms are provided herein. According to embodiments of the present invention, MISO amplifiers driven by VPA control algorithms outperform conventional outphasing amplifiers, including cascades of separate branch amplifiers using conventional power combiner technologies. MISO amplifiers can be operated at enhanced efficiencies over the entire output power dynamic range by blending the control of the power source, source impedances, bias levels, outphasing, and branch amplitudes. These blending constituents are combined to provide an optimized transfer characteristic function.
    Type: Application
    Filed: September 1, 2011
    Publication date: December 20, 2012
    Applicant: ParkerVision, Inc.
    Inventors: Gregory S. Rawlins, David F. Sorrells
  • Patent number: 8330537
    Abstract: A rail-to-rail buffer receiving a differential input signal and generating a differential output signal includes first and second amplifier circuits configured in a pseudo differential buffer structure and first and second comparators coupled to compare the respective part of the differential input signal and a first voltage and to generate select signals. Each of the first and second amplifier circuits includes first and second complementary differential input stages and the first and second comparators generate respective select signals to turn on only one of the first or the second differential input stage in each amplifier circuit depending on a value of the respective part of the differential input signal. In operation, the first and second complementary differential input stages of each amplifier circuit not being turned on at the same time.
    Type: Grant
    Filed: March 18, 2011
    Date of Patent: December 11, 2012
    Assignee: National Semiconductor Corporation
    Inventors: Gururaj Ghorpade, Theertham Srinivas, D V J Ravi Kumar, Mehmet Aslan, K. Krishna Mahesh
  • Publication number: 20120302179
    Abstract: An analog envelope shaper within an envelope tracking power amplifier system detects an envelope voltage of a transmission signal and generates a shaped envelope amplifier control signal based upon a programmable threshold, below which the output does not fall, and a plurality of different voltages centered around a corresponding threshold input voltage, a selectable spacing of which controls the shape of the transition between negative clipping and linear regions of the envelope detector output function. The programmable features and the resulting piecewise linear shaping allow for tailoring of the envelope response to balance linearity and efficiency, without negating the efficiency benefits of envelope tracking power amplification. Since the analog envelope shaper employs no high speed data converter functions, the resulting power dissipation will be substantially less than digital designs.
    Type: Application
    Filed: May 17, 2012
    Publication date: November 29, 2012
    Applicant: Samsung Electronics Co., Ltd.
    Inventor: Michael Brobston
  • Patent number: 8319550
    Abstract: A programmable-gain amplifier has a first input node coupled to receive a first input signal and a control input coupled to receive a gain select signal. The programmable-gain amplifier includes a differential amplifier having a first input and a first output and a plurality of capacitors. A first terminal of each of the plurality of capacitors is coupled to the first input of the differential amplifier, and a second terminal of each of the plurality of capacitors is coupled to the first input node during a sampling phase of the programmable-gain amplifier and selectively coupled to the first output of the differential amplifier, based on the gain select signal, during a gain phase of the programmable-gain amplifier.
    Type: Grant
    Filed: January 18, 2011
    Date of Patent: November 27, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Ammisetti V. Prasad, James R. Feddeler
  • Publication number: 20120295556
    Abstract: A signal transceiver includes a first power amplifier coupled to a chip output port of a chip; an impedance transforming circuit; a switching circuit arranged to selectively couple the chip output port to a first port of the impedance transforming circuit; and a receiving amplifier coupled to a second port of the impedance transforming circuit.
    Type: Application
    Filed: May 16, 2012
    Publication date: November 22, 2012
    Inventors: George Chien, Chia-Hsin Wu, Tsung-Ming Chen, Yi-An Li
  • Publication number: 20120286859
    Abstract: A voltage level shifter for a direct coupling of an external voltage source to a common mode of a circuit may include an amplifier, a voltage-controlled current source, a first and second resistors. A first input of the amplifier may be connected to the common mode. A second input of the amplifier may, via the first and second resistors, receive a voltage indicative of the external voltage source. The output of the amplifier may indicate a voltage difference between the first and second inputs. The voltage-controlled current source may be controlled by the voltage difference to supply a current to a common node of the first and second resistors so that the voltage difference between the first and second inputs may be minimized.
    Type: Application
    Filed: May 9, 2011
    Publication date: November 15, 2012
    Applicant: ANALOG DEVICES, INC.
    Inventors: Robert LIBERT, Khiem Quang NGUYEN
  • Patent number: 8310278
    Abstract: A voltage detection circuit includes operational amplifiers, a battery, and a voltage circuit. The voltage circuit offsets the inverting input terminals and non-inverting input terminals of the operational amplifiers to the positive side with reference to a ground GND.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: November 13, 2012
    Assignees: Denso Corporation, Toyota Jidosha Kabushika Kaisha
    Inventors: Yusuke Shindo, Tsuneo Maebara, Keisuke Hata
  • Publication number: 20120268202
    Abstract: A circuit for a charge amplifier for converting piezoelectric measurement signals continuously sets the output signal of the amplifier to a value close to zero, such that a reset switch becomes unnecessary. The amplifier includes a pulse generator that provides the output signal of the amplifier in the form of pulses, which are easy to transmit with low interference. The pulse frequency is proportional to the rate of change of charge. The pulses, which are added in a counter, represent a value proportional to the change in the charge since the last counter reset, which is proportional to the present measured value at the measurement element.
    Type: Application
    Filed: November 18, 2010
    Publication date: October 25, 2012
    Applicant: Kistler Holding AG
    Inventors: Leo Amstutz, Kurt Neff
  • Publication number: 20120268086
    Abstract: A power supply device includes a power supply unit and a feedback control unit. The power supply unit is configured for generating an electric potential to be provided to a load. The feedback control unit detects the electric potential and adjusts relevant parameters of the electrical potential to achieve predetermined values. The feedback control unit includes a first feedback circuit and a second feedback circuit electrically connected in series.
    Type: Application
    Filed: December 30, 2011
    Publication date: October 25, 2012
    Applicant: HON HAI PRECISION INDUSTRY CO., LTD.
    Inventors: WEI-CHIEH CHOU, DUEN-YI HO, CHUN-JEN CHEN, TSUNG-SHENG HUANG
  • Publication number: 20120262320
    Abstract: Two T filters, one of which includes two resistive elements and one capacitive element and the other of which includes two capacitive elements and one resistive element, are inserted in a negative-feedback section of an operational amplifier, and a resistive element and a capacitive element are connected between each of intermediate nodes and a signal input terminal. A resistive element and a capacitive element which are connected to each other in parallel are connected between the signal input terminal and an inverting input terminal of the operational amplifier. With this configuration, overall admittances where elements connected to the corresponding intermediate nodes are in parallel connection are equal to each other.
    Type: Application
    Filed: June 27, 2012
    Publication date: October 18, 2012
    Applicant: Panasonic Corporation
    Inventors: Yosuke Mitani, Kazuo Matsukawa, Masao Takayama, Koji Obata, Shiro Dosho
  • Publication number: 20120262231
    Abstract: Contactless differential coupling structures can be used to communicate signals between circuits located on separate chips or from one chip to a probing device. The contactless coupling structures avoid problems (breaks, erosion, corrosion) that can degrade the performance of ohmic-type contact pads. The contactless coupling structures comprise pairs of conductive pads placed in close proximity. Differential signals are applied across a first pair of differential pads, and the signals are coupled wirelessly to a mating pair of conductive pads. Circuitry for generating and receiving differential signals is described.
    Type: Application
    Filed: May 24, 2012
    Publication date: October 18, 2012
    Applicant: STMicroelectronics S.r.l
    Inventors: Mauro SCANDIUZZO, Luca Perilli, Roberto CANEGALLO
  • Patent number: 8289257
    Abstract: A circuit for reducing and offsetting the voltage swing of a differential pre-drive circuit. The circuit includes a first H-bridge of transistors receiving a differential pair of input signals. A swing resister is coupled to the H-bridge for reducing a voltage swing of the differential pair of input signals. The reduced swing is generated as a differential pair of output signals. Also, the differential pre-drive circuit includes an offset resistor that is coupled to the H-bridge. The offset resistor acts to offset the differential pair of output signals. As such, the differential pair of output signals having reduced swing and offset as applied to gates of output transistors in an output stage allow the output transistors to remain in the saturation operating state.
    Type: Grant
    Filed: May 30, 2006
    Date of Patent: October 16, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Daniel L. Simon
  • Publication number: 20120257339
    Abstract: Techniques for amplifying a plurality of input voltages to generate a corresponding plurality of output voltages. In an exemplary embodiment, each of the plurality of input voltages is referenced to a common voltage comprising the average of the plurality of input voltages, without the need to reference an independently provided common voltage. In an alternative exemplary embodiment, techniques are provided for automatically measuring the input impedance between any two nodes corresponding to the plurality of input voltages. Further techniques are provided for coupling input nodes of the amplifier modules to a common reference voltage, and to the housing of the apparatus.
    Type: Application
    Filed: April 6, 2012
    Publication date: October 11, 2012
    Inventors: Kent W. Leyde, Tyler R. Hart, Khaled M. Boulos, Jason A. Higgins
  • Publication number: 20120256684
    Abstract: Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals is individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.
    Type: Application
    Filed: April 11, 2012
    Publication date: October 11, 2012
    Applicant: ParkerVision, Inc.
    Inventors: David F. Sorrells, Gregory S. Rawlins, Michael W. Rawlins
  • Publication number: 20120242404
    Abstract: Embodiments of the present invention provide a sample and hold amplifier that provides a preamplifier with a multi-stage zeroing architecture. The multi-stage architecture reduces effects of parasitic capacitance exponentially over prior attempts, which yields increased accuracy.
    Type: Application
    Filed: July 20, 2011
    Publication date: September 27, 2012
    Applicant: Analog Devices, Inc.
    Inventor: Sanjay RAJASEKHAR
  • Patent number: 8270630
    Abstract: An audio host device has a headset electrical interface in which a reference contact is shared by a microphone and a speaker. A variable or programmable gain amplifier, PGA, has a signal input coupled to a sense point for the reference contact. A first difference amplifier has its inputs coupled to a microphone contact and the PGA through a first gain stage; a second difference amplifier has its inputs coupled to the microphone contact and to the output of the PGA, through a second gain stage having a different gain than the first gain stage; a third difference amplifier has its inputs coupled to the microphone contact and the output of the PGA through a third gain stage having a gain in between that of the first and second gain stages. A controller monitors outputs of the first and second difference amplifiers and changes a gain setting of the PGA. Other embodiments are also described and claimed.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: September 18, 2012
    Assignee: Apple Inc.
    Inventor: Timothy M. Johnson
  • Publication number: 20120229215
    Abstract: An amplifier assembly includes an input signal determiner that determines a first input signal and a second input signal based on an initial signal having an amplitude and an initial frequency. Amplifiers amplify the first and second input signal to form first and second output signals having a phase offset with respect to one another. The first and second amplified output signals are fed to a common coupling element that forms a useful signal and a loss signal, such that a total power of the useful signal and loss signal is independent of the phase offset, the power of the useful signal has a maximum corresponding to a predetermined value of the phase offset, and the partial power of the useful signal decreases with a deviation of the phase offset from the predetermined value.
    Type: Application
    Filed: October 18, 2010
    Publication date: September 13, 2012
    Inventor: Oliver Heid
  • Publication number: 20120229204
    Abstract: According to the present invention, a switched capacitor circuit comprises: an inverting amplifier for removing the offset by using a chopper stabilization circuit; a sampling unit which is connected between an input terminal and the inverting amplifier; and a feedback unit which is connected to the inverting amplifier in parallel.
    Type: Application
    Filed: July 12, 2010
    Publication date: September 13, 2012
    Applicant: Industry-Academic Cooperation Foundation, Yonsei University
    Inventors: Gunhee Han, Youngcheol Chae, Inhee Lee, Dongmyung Lee, Seunghyun Lim, Ji Min Cheon