Having Particular Biasing Arrangement Patents (Class 330/261)
  • Patent number: 8593221
    Abstract: Examples of circuits and methods are provided for common mode stability and bandwidth broadening. A current generator circuit may include a first and a second transistor. Each of the first and second transistors includes a first, second, and third terminal. The first and second transistors provide a first and a second output current at their corresponding third terminals. A first branch including a first resistor and a first capacitor coupled in series is coupled between the third terminal of the first transistor and the first terminal of the second transistor. A second branch including a second resistor and a second capacitor coupled in series is coupled between the third terminal of the second transistor and the first terminal of the first transistor. The first and the second branches are configured to enable the current generator circuit to provide the first and second currents with improved common mode stability.
    Type: Grant
    Filed: November 18, 2011
    Date of Patent: November 26, 2013
    Assignee: Semtech Corporation
    Inventors: Liping Zhang, Thomas W. Krawczyk, Andrew J. Bonthron, David A. Rowe
  • Publication number: 20130307623
    Abstract: Various embodiments of an amplifier circuit are provided. In one embodiment, the amplifier circuit includes an input differential circuitry configured to convert a pair of input differential voltage signals to a pair of differential current signals. The amplifier circuit includes a cascode circuitry operable to mirror the pair of differential current signals received from the first output terminal and the second output terminal to an output terminal of the first cascode transistor and an output terminal of the second cascode transistor. The amplifier circuit includes a current control circuit operable to divert an amount of bias current to reduce a current through the cascode circuitry, to thereby reduce a load of the amplifier circuit, the reduction in the load of the amplifier circuit allowing a reduction in current through the input differential circuitry for maintaining a predetermined bandwidth of the amplifier circuit.
    Type: Application
    Filed: May 21, 2012
    Publication date: November 21, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Shagun Dusad, Lokesh Kumar Gupta, Visvesvaraya Pentakota
  • Publication number: 20130310114
    Abstract: An amplifier includes a first lower active sub cell and a second lower active sub cell, each comprising an input terminal and an output terminal, wherein the input terminals of the lower active sub cells are connected to the amplifier input and the output terminals of the lower active sub cells are not shorted. Furthermore, the amplifier includes a first upper active sub cell and a second upper active sub cell, each including a biasing terminal, wherein the input terminals and the output terminals of the upper active sub cells are coupled between the output terminals of the lower active sub cells and the amplifier output. The amplifier includes a bias controller configured to provide a first biasing signal to the first upper active sub cell and a second biasing signal to the second upper active sub cell based on an output power of the output signal.
    Type: Application
    Filed: May 16, 2012
    Publication date: November 21, 2013
    Applicants: Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Intel Mobile Communications GmbH
    Inventors: Amr Zohny, Stephan Leuschner, Jan-Erik Mueller
  • Patent number: 8576007
    Abstract: For high speed amplifiers, the parasitic capacitances from the differential input pair introduce a zero that can affect performance. Here, a neutralization network has been provided that compensates for this zero by shifting its position. This is generally accomplished by using a pair of capacitors that are cross-coupled across the differential input pair of the amplifier.
    Type: Grant
    Filed: September 9, 2011
    Date of Patent: November 5, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Marco Corsi, Victoria W. Limketkai, Venkatesh Srinivasan
  • Publication number: 20130278339
    Abstract: Aspects of a system for improving efficiency over power control for linear and class AB power amplifiers may include a current source circuit that enables determination of a bias current level for a PA circuit within an IC die based on an amplitude of an input modulation signal. The PA circuit may enable generation of an output signal based on a differential input signal and the input modulation signal to the current source circuit. A generated bias voltage may be applied to a transformer external to the IC die, but internal to an IC package containing the IC die and/or a circuit board containing the IC package. One or more amplifier bias voltage levels may be applied to the PA circuit wherein the amplifier bias voltage levels may be derived from the generated bias voltage level and/or the determined bias current level.
    Type: Application
    Filed: June 19, 2013
    Publication date: October 24, 2013
    Inventor: Ahmadreza Rofougaran
  • Publication number: 20130278340
    Abstract: Aspects of a system for improving efficiency over power control for linear and class AB power amplifiers may include a current source circuit that enables determination of a bias current level for a PA circuit within an IC die based on an amplitude of an input modulation signal. The PA circuit may enable generation of an output signal based on a differential input signal and the input modulation signal to the current source circuit. A generated bias voltage may be applied to a transformer external to the IC die, but internal to an IC package containing the IC die and/or a circuit board containing the IC package. One or more amplifier bias voltage levels may be applied to the PA circuit wherein the amplifier bias voltage levels may be derived from the generated bias voltage level and/or the determined bias current level.
    Type: Application
    Filed: June 20, 2013
    Publication date: October 24, 2013
    Inventor: Ahmadreza Rofougaran
  • Publication number: 20130257513
    Abstract: In accordance with at least one embodiment, an improved voltage headroom self-biased receiver is provided. In accordance with at least one embodiment, tail current sources are biased so as to be cross-coupled with respect to each other. In accordance with at least one embodiment, startup control is provided to counter defect-induced current and to ensure the circuit can function properly even with large amounts of defect current. In accordance with at least one embodiment, a positive type (p type) channel metal oxide semiconductor (PMOS) tail current transistor is modulated by a negative type (n type) channel metal oxide semiconductor (NMOS) differential pair virtual negative supply voltage and a NMOS tail current transistor is modulated by a PMOS differential pair virtual positive supply voltage. The amplifier's output common mode is thus self correcting to p type to n type transistor strength differences.
    Type: Application
    Filed: March 30, 2012
    Publication date: October 3, 2013
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventor: Hector Sanchez
  • Publication number: 20130257538
    Abstract: A common mode bias circuit may include a weak common mode bias generator and a common mode bias capacitance. During a first state of the common mode bias circuit, the weak common mode bias generator may be coupled to the common mode bias capacitance and may impart to them a predefined common mode signal level. During a second state of the common mode bias circuit, the common mode bias capacitance may be coupled to differential inputs of an amplifier in a manner that establishes an input common mode level for the amplifier.
    Type: Application
    Filed: April 5, 2013
    Publication date: October 3, 2013
    Applicant: LINEAR TECHNOLOGY CORPORATION
    Inventor: Dave Thomas
  • Publication number: 20130249635
    Abstract: An amplifier for an output buffer includes an operational amplifier including a first input terminal, a second input terminal, and an output terminal, the operational amplifier is configured to generate an input bias current and amplify a voltage difference between signals applied to the first input terminal and the second input terminal, and to output the amplified voltage difference; and a self-bias circuit connected to the first input terminal and the second input terminal, the self-bias circuit is configured to generate first and second current paths when the voltage difference is equal to or greater than a predetermined voltage, to generate a tail current on the first or second current path, and to add the generated tail current to the input bias current of the operational amplifier, wherein the second input terminal is connected to the output terminal.
    Type: Application
    Filed: January 30, 2013
    Publication date: September 26, 2013
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Hyung-Tae Kim, Soo-Ik Cha
  • Publication number: 20130249633
    Abstract: Techniques for designing a transconductor configurable to have a low transconductance. In one aspect, a voltage to current conversion module is coupled to a 1:N current replication module. The voltage to current conversion module may be implemented as an operational amplifier configured with negative feedback to generate a current through a transistor, wherein such current is proportional to the difference between an input voltage and a common-mode reference. The 1:N current replication module is configured to mirror the generated current in another transistor, to a predetermined ratio, such that the output current is also proportional to the difference between the input voltage and the common-mode reference. In exemplary embodiments, the output stage driving the output current may be configured to operate as a Class A, Class B, or Class AB type amplifier.
    Type: Application
    Filed: March 22, 2012
    Publication date: September 26, 2013
    Applicant: QUALCOMM INCORPORATED
    Inventors: Arash Mehrabi, Thurman S. Deyerle, IV, Guoqing Miao
  • Patent number: 8542063
    Abstract: An adaptive amplification circuit is disclosed, which includes an operational amplifier including a variable bias current source for providing a variable bias current for the operational amplifier, a simulation unit for simulating operational characteristics of the operational amplifier and transforming a simulation input voltage to a simulation output voltage, and a bias control unit for generating a bias control signal to the variable bias current source according to the simulation output voltage so as to adjust the variable bias current.
    Type: Grant
    Filed: August 2, 2011
    Date of Patent: September 24, 2013
    Assignee: NOVATEK Microelectronics Corp.
    Inventors: Xie-Ren Hsu, Chia-Hung Lin, Wei-Hsiang Hung
  • Patent number: 8542038
    Abstract: A source driver and a receiver thereof are disclosed. A two-stage amplifier of the receiver includes a first-stage circuit and a second-stage circuit. The second-stage circuit includes a first switch, a second switch, a third switch, a first node, and a second node. The first switch is coupled between the first node and a ground end; the second switch is coupled between the second node and the ground end; the third switch is coupled between the first node and the second node. When the receiver wants to wake up from a power-saving mode to a normal operation mode, the first switch and the second switch are switched to the off-state according to a control signal at first; after a period of delay time, the third switch is also switched to the off-state according to a delayed control signal.
    Type: Grant
    Filed: April 6, 2012
    Date of Patent: September 24, 2013
    Assignee: Raydium Semiconductor Corporation
    Inventors: Ren-Feng Huang, Hui-Wen Miao, Ko-Yang Tso
  • Patent number: 8536947
    Abstract: A class AB amplifier with resistive level-shifting circuitry is described. In one exemplary design, the class AB amplifier includes an input stage, a resistive level-shifting stage, a class AB output stage, and a bias circuit. The input stage receives an input signal and provides a first drive signal. The resistive level-shifting stage receives the first drive signal and provides a second drive signal. The output stage receives the first and second drive signals and provides an output signal. The bias circuit generates a bias voltage for the resistive level-shifting stage to obtain a desired quiescent current for the output stage. In one exemplary design, the resistive level-shifting stage includes a transistor and a resistor. The transistor receives the bias voltage and provides the second drive signal. The resistor is coupled to the transistor and provides a voltage drop between the first and second drive signals.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: September 17, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Cheng-Han Wang, Tzu-wang Pan, Roger Brockenbrough
  • Patent number: 8531242
    Abstract: Disclosed is an operational amplifier including an overdriving circuit capable of reaching a target voltage within an operation time by outputting a higher voltage than the target voltage when an RC delay time is greater. The operational amplifier may including an overdriving circuit, in which first and second input terminals and an output terminal may be provided, an input voltage may be applied to the first input terminal, a second input terminal may be connected to the output terminal, and the input voltage applied to the first input terminal may be overdriven to have a certain level to be outputted to the output terminal, may include: first and second overdriving units performing an overdriving operation at a rising edge and a falling edge, respectively.
    Type: Grant
    Filed: February 24, 2011
    Date of Patent: September 10, 2013
    Assignee: Magnachip Semiconductor, Ltd.
    Inventor: Kyu-Young Chung
  • Publication number: 20130214865
    Abstract: Capacitive level-shifting circuits and methods are provided for adding DC offsets to the output of a current-integrating amplifier. For example, a current-integrating amplifier includes an input amplifier stage and an output offset circuit. The input amplifier stage includes an input node, a first output node, and a first switch connected between the first output node and a power supply node. The output offset circuit is connected to the first output node of the input amplifier stage and to a second output node of the current-integrating amplifier. The output offset circuit includes a first series capacitor coupled between the first output node of the input amplifier stage and the second output node of the current-integrating amplifier. The output offset circuit switchably connects a bias voltage to the second output node and charges the first series capacitor to add a DC offset to the second output node of the current-integrating amplifier.
    Type: Application
    Filed: February 17, 2012
    Publication date: August 22, 2013
    Applicant: International Business Machines Corporation
    Inventors: John F. Bulzacchelli, Steven M. Clements, Sergey V. Rylov
  • Patent number: 8502603
    Abstract: A circuit includes a differential amplifier having a folded cascode architecture with a pair of cascode transistors. A sensing circuit senses a common mode input voltage of a differential input signal applied to the differential amplifier. A bias generator circuit generates a bias voltage for application to the pair of cascode transistors in the folded cascode architecture. The bias generator circuit is connected to an output of the sensing circuit such that the generated bias voltage has a value which is dependent on the sensed common mode input voltage. This dependence stabilizes a common mode output voltage from the differential amplifier in response to changes in the common mode input voltage.
    Type: Grant
    Filed: January 7, 2013
    Date of Patent: August 6, 2013
    Assignee: STMicroelectronics International N.V.
    Inventors: Tapas Nandy, Surendra Kumar
  • Publication number: 20130187620
    Abstract: Embodiments and methods herein operate as two-stage voltage controlled current sources (i.e., dynamic current sources) operating in class AB mode. Phase-delayed current injection circuits are associated with first-stage bias, second-stage bias, or both. The current injection circuits operate to quickly re-charge inter-stage parasitic capacitance associated with the active side of the class AB dynamic current source shortly after that side becomes inactive. Doing so quickly dissipates an otherwise slowly-decaying residual drive signal to prevent the output stage from continuing to conduct after the associated side of the current source becomes inactive. Excessive current consumption and possible destructive operation of the output stage are mitigated as a result.
    Type: Application
    Filed: January 24, 2012
    Publication date: July 25, 2013
    Inventor: Charles Parkhurst
  • Patent number: 8493150
    Abstract: An output stage of a class-AB amplifier, including: a first transistor of a first channel type between a first terminal of application of a first voltage and an output terminal of the stage, having its gate connected to a first input terminal of the stage; a first transistor of a second channel type between this output terminal and a second terminal of application of the first voltage, having its gate connected to a second input terminal of the stage; and second and third transistors of the second channel type between the output terminal and the first transistor of the second channel type, the gate of the second transistor being connected to the midpoint of a resistive dividing bridge between said output terminal and the gate of the third transistor of the second channel type, and the gate of the third transistor being biased to a fixed voltage.
    Type: Grant
    Filed: October 17, 2011
    Date of Patent: July 23, 2013
    Assignee: STMicroelectronics (Grenoble 2) SAS
    Inventors: Roland Mazet, Christophe Forel
  • Patent number: 8487695
    Abstract: A differential amplifier comprising a first upper device and a first lower device series coupled between two power supplies and a second upper device and a second lower device series coupled between the two power supplies. A first DC voltage enables the first upper device and the second upper device and a second DC voltage regulates current flow in the first lower device and the second lower device. An AC signal component is coupled to the first upper device and the second lower device while the AC signal complement is coupled to the first lower device and the second upper device. A first output signal between the first upper device and the first lower device. Separate RC networks couple the AC signals to their respective device. A first and second output signal forms between the upper device and the lower device, respectively. All the devices are same channel type.
    Type: Grant
    Filed: September 23, 2011
    Date of Patent: July 16, 2013
    Assignee: Tensorcom, Inc.
    Inventor: Zaw Soe
  • Publication number: 20130169364
    Abstract: An amplifier and a transceiver including the amplifier are provided. The amplifier includes an input terminal; a first transistor of a first conductivity and a second transistor of a second conductivity, each transistor comprising a source terminal, a gate terminal and a drain terminal respectively, the source terminal of the first transistor being coupled to the source terminal of the second transistor, and the gate terminal of the first transistor and the gate terminal of the second transistor being coupled to the input terminal; and an output terminal coupled to the drain terminal of the first transistor and the drain terminal of the second transistor.
    Type: Application
    Filed: May 25, 2011
    Publication date: July 4, 2013
    Applicant: AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH
    Inventors: Hyouk Kyu Cha, Yuan Gao, Xiaojun Yuan
  • Publication number: 20130169363
    Abstract: A body biasing device for an amplifier which has a P-type differential pair and outputs an output signal at an output node according to a differential input signal pair is disclosed. The body biasing device includes a detection unit coupled to the operational amplifier for detecting a detected voltage related to the differential input signals and accordingly outputting a control signal; and a selection unit coupled to the detection unit and the operational amplifier for outputting a body bias to the P-type differential pair according to the control signal.
    Type: Application
    Filed: March 7, 2012
    Publication date: July 4, 2013
    Inventors: Wen-Yen Chen, Ming-Hung Chang
  • Patent number: 8476973
    Abstract: A switch device includes a plurality of differential switches formed in a semiconductor substrate. Each of the plurality of differential switches includes first and second differential transistors. The plurality of differential switches are placed in such a manner that the first differential transistors are adjacent to each other and the second differential transistors are adjacent to each other.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: July 2, 2013
    Assignee: Panasonic Corporation
    Inventor: Heiji Ikoma
  • Patent number: 8471636
    Abstract: A bias current is generated for an unbalanced differential pair that is proportional to the transconductance gain of the differential pair. When the transconductance gain varies (e.g., due to temperature variations), the bias current varies in proportion thereby maintaining a constant offset voltage. In some implementations, a voltage to current converter circuit generates the bias current from a constant reference voltage that is independent of temperature and voltage supply variations (e.g., a bandgap reference voltage).
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: June 25, 2013
    Assignee: Atmel Rousset S.A.S.
    Inventors: Jimmy Fort, Thierry Soude, Michel Cuenca, Florent Garcia, Franck Strazzieri
  • Patent number: 8471635
    Abstract: Bias circuits, amplifiers and methods are provided, such as those for providing bias signals over a range of common mode inputs for an amplifier to output a constant current. One example of a bias circuit is configured to generate a bias signal having a voltage magnitude according to a reference signal. The reference signal is indicative of a common mode input level of an input signal of the amplifier circuit and the bias circuit is further configured to adjust the bias signal over a range of common mode input levels. An amplifier receiving the bias signal is configured to generate an output signal in response to an input signal and drive an output current based on the voltage magnitude of the bias signal provided by the bias circuit.
    Type: Grant
    Filed: May 4, 2011
    Date of Patent: June 25, 2013
    Assignee: Micron Technology, Inc.
    Inventors: Ryan Jurasek, Aaron Willey
  • Patent number: 8456337
    Abstract: A system to interface analog-to-digital converters to inputs with arbitrary common-modes includes a common-mode voltage amplifier circuit and a PGA circuit connected to the common-mode voltage amplifier circuit. The common-mode voltage amplifier and PGA circuits receive first and second analog input signals. The PGA circuit eliminates the arbitrary common-modes from the first and second analog input signals based on an output of the common-mode voltage amplifier circuit.
    Type: Grant
    Filed: April 10, 2012
    Date of Patent: June 4, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Siddhartha Gopal Krishna
  • Patent number: 8456234
    Abstract: A bias current control method for an operational amplifier is disclosed, which includes detecting a slew rate operating signal, determining signal period length of the slew rate operating signal to generate a determination signal, and generating a high bias modulation signal or a low bias modulation signal to the operational amplifier according to the determination signal and the slew rate operating signal.
    Type: Grant
    Filed: June 2, 2011
    Date of Patent: June 4, 2013
    Assignee: NOVATEK Microelectronics Corp.
    Inventors: Wei-Hsiang Hung, Chia-Hung Lin
  • Publication number: 20130127537
    Abstract: A circuit includes a differential amplifier having a folded cascode architecture with a pair of cascode transistors. A sensing circuit senses a common mode input voltage of a differential input signal applied to the differential amplifier. A bias generator circuit generates a bias voltage for application to the pair of cascode transistors in the folded cascode architecture. The bias generator circuit is connected to an output of the sensing circuit such that the generated bias voltage has a value which is dependent on the sensed common mode input voltage. This dependence stabilizes a common mode output voltage from the differential amplifier in response to changes in the common mode input voltage.
    Type: Application
    Filed: January 7, 2013
    Publication date: May 23, 2013
    Applicant: STMICROELECTRONICS INTERNATIONAL N.V.
    Inventor: STMICROELECTRONICS INTERNATIONAL N.V.
  • Publication number: 20130113567
    Abstract: A semiconductor integrated circuit includes: a first capacitance element and a second capacitance element; a first amplification circuit that amplifies a potential difference of a first voltage signal and a second voltage signal supplied via the first capacitance element and the second capacitance element, respectively, to output a first amplification signal and a second amplification signal; a first resistance element that feeds back the first amplification signal to one input terminal of the first amplification circuit; a second resistance element that feeds back the second amplification signal to another input terminal of the first amplification circuit; a voltage generator that generates a predetermined voltage; and a third resistance element that transmits the predetermined voltage generated by the voltage generator to each input terminal of the first amplification circuit.
    Type: Application
    Filed: October 27, 2012
    Publication date: May 9, 2013
    Applicant: RENESAS MOBILE CORPORATION
    Inventor: Renesas Mobile Corporation
  • Patent number: 8436682
    Abstract: Apparatus and methods disclosed herein operate to receive a differential input signal at a first-stage pair of transconductance devices. The differential signal is amplified by a second-order factor at a positive-side or a negative-side first-stage transconductance device, depending upon the polarity of the differential input signal, to create a second-order signal at the output of the appropriate first-stage device. The second-order output signal is then amplified by another second-order factor at a corresponding second-stage transconductance device. A resulting fourth-order signal is made available at an output node as a quartic-response current source. The quartic-response current source may be utilized as a dynamic bias source in conjunction with a linear amplifier to provide a high slew rate amplifier.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: May 7, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Charles Parkhurst, Mark Hamlyn
  • Patent number: 8421536
    Abstract: Apparatus and methods for electronic amplification are provided. In one embodiment, a method amplifying a differential input voltage signal using a first NMOS transistor and a second NMOS transistor is provided. The method includes controlling a drain-source voltage of the first NMOS transistor using a first high voltage NMOS transistor and a first high voltage PMOS transistor. The first high voltage NMOS and PMOS transistors are electrically connected in parallel and to a drain of the first NMOS transistor. The method further includes controlling a drain-source voltage of the second NMOS transistor using a second high voltage NMOS transistor and a second high voltage PMOS transistor. The second high voltage NMOS and PMOS transistors are electrically connected in parallel and to a drain of the second NMOS transistor.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: April 16, 2013
    Assignee: Analog Devices, Inc.
    Inventor: Mark Reisiger
  • Patent number: 8416969
    Abstract: An amplifier circuit comprises differential amplification circuitry comprising an input stage having first and second differential inputs, and an output stage, having respective first and second amplifier components with first and second differential outputs. The first amplifier component of the output stage comprises a first power transistor operably coupled to the first differential output and driven by a first differential output of the input stage, and a third power transistor operably coupled to the first differential output of the amplifier circuit and driven by a second output of the input stage. The second amplifier component comprises a second power transistor operably coupled to the second differential output and driven by a second output of the input stage, and a fourth power transistor operably coupled to the second differential output and driven by the first output of the input stage.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: April 9, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Jerome Enjalbert, Zakaria Mengad
  • Publication number: 20130076434
    Abstract: A Sallen-Key filter requires an operational amplifier with a large input impedance and a small output impedance to meet the external filter characteristics. The operational amplifier requires an internal feedback path for stability that limits performance. This invention eliminates the need for internal feedback and increases the gain of a source follower which has characteristics matching the operational amplifier in the Sallen-Key filter. The source follower provides 6 dB of AC voltage gain and is substituted for the operational amplifier in the Sallen-Key filter. The Sallen-Key filter requires a differential configuration to generate all the required signals with their compliments and uses these signals in a feed forward path. Furthermore, since the source follower uses only two n-channel stacked devices, the headroom voltage is maximized to several hundred millivolts for a 1.2V voltage supply in a 40 nm CMOS technology.
    Type: Application
    Filed: September 23, 2011
    Publication date: March 28, 2013
    Applicant: Tensorcom, Inc.
    Inventor: Zaw Soe
  • Publication number: 20130076408
    Abstract: A phase lock loop (PLL) is an important component in wireless systems. CMOS technology offers voltage controlled oscillator designs operating at 60 GHz. One of the difficulties is dividing the high frequency clock down to a manageable clock frequency using conventional CMOS. Although injection locked dividers can divide down this clock frequency, these dividers have limitations. A divide by 2 is presented that uses several techniques; feed forward, clock amplification and series peaked inductors to overcome these limitations.
    Type: Application
    Filed: September 23, 2011
    Publication date: March 28, 2013
    Applicant: Tensorcom, Inc.
    Inventor: Zaw Soe
  • Patent number: 8405458
    Abstract: A current mirror circuit provided in an emitter follower configuration achieves linearly output over a range of input currents by operating in response to a bias current that is a replica of the input current. The current mirror may include a pair of transistors and a pair of resistors, in which: a first resistor and a base of a first transistor are coupled to a first input terminal for a first input current, an emitter of the first transistor and a base of the second transistor are coupled to a second input terminal for a second input current, the first and second input currents being replicas of each other, an emitter of the second transistor being coupled to the second resistor, a collector of the second transistor being coupled to an output terminal of the current mirror, and a collector of the first transistor and the two resistors are coupled to a common node.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: March 26, 2013
    Assignee: Analog Devices, Inc.
    Inventor: Sandro Herrera
  • Publication number: 20130070365
    Abstract: A current sensor is disclosed comprising a differential amplifier including a first node, a second node, and an output. The current sensor further comprises a first resistor having a first end coupled to the first node and a second end for coupling to a transducer, and a second resistor having a first end coupled to the second node and a second end. When the second end of the second resistor is unconnected and the differential amplifier is driven with a supply voltage, the first node is biased by a first leakage current and the second node is biased by a second leakage current such that the output represents a current flowing through the transducer.
    Type: Application
    Filed: September 16, 2011
    Publication date: March 21, 2013
    Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventor: DENNIS W. HOGG
  • Patent number: 8400218
    Abstract: A current mode power amplifier includes a current steering stage configured to steer a scaled current based on differential voltage inputs, a filtered current mirror connected to the current steering stage to receive the scaled current and produce a filtered output current, and a resonant load configured to receive the output current and generate an output voltage signal for transmission.
    Type: Grant
    Filed: November 15, 2010
    Date of Patent: March 19, 2013
    Assignee: QUALCOMM, Incorporated
    Inventors: Cheol-Woong Lee, Sunghyun Park, Jonghoon Choi
  • Publication number: 20130063210
    Abstract: For high speed amplifiers, the parasitic capacitances from the differential input pair introduce a zero that can affect performance. Here, a neutralization network has been provided that compensates for this zero by shifting its position. This is generally accomplished by using a pair of capacitors that are cross-coupled across the differential input pair of the amplifier.
    Type: Application
    Filed: September 9, 2011
    Publication date: March 14, 2013
    Applicant: Texas Instruments Incorporated
    Inventors: Marco Corsi, Victoria L. Wang Limketkai, Venkatesh Srinivasan
  • Patent number: 8395446
    Abstract: Method and apparatus for amplification in an IC are described. A dual mode isolation amplifier having two modes of operation is provided. In the first mode of operation for a resistor-loaded differential transconductance with additional gain, a first switch circuit is placed in a substantially nonconductive state for electrically decoupling from a first current source node and a second current source node. A second switch circuit is placed in a substantially conductive state for electrically coupling a capacitor thereof to the first current source node and the second current source node. At high frequencies, a first resistance associated with the capacitor coupled in parallel with a resistive load is substantially reduced. The resistive load is coupled between the first current source node and the second current source node. The first resistance is reduced by approximating a short circuit by the capacitor during high-frequency operation.
    Type: Grant
    Filed: January 22, 2010
    Date of Patent: March 12, 2013
    Assignee: Xilinx, Inc.
    Inventor: Toan D. Tran
  • Patent number: 8390371
    Abstract: A transconductance-capacitance (Gm-C) filter of arbitrary order is provided that is biased by a bias circuit such that the Gm-C filter is robust to variations in process corner and temperature as well as input supply noise. The bias circuit includes a biased transistor that has a width-to-length ratio that is a factor X times larger than a corresponding transistor in the Gm-C filter. The biased transistor couples to ground through a switched capacitor circuit.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: March 5, 2013
    Assignee: TiaLinx, Inc.
    Inventor: Mohammad Ardehali
  • Patent number: 8390379
    Abstract: Various apparatuses, methods and systems for boosting an amplifier slew rate are disclosed herein. For example, some embodiments of the present invention provide an apparatus including a pair of inputs connected to a pair of differential input devices in an amplifier, a current source, a first current path connected to the current source, a second current path connected to the current source and to the pair of differential input devices, a switch in the first current path, and a voltage difference signal connected between the pair of inputs and the switch. The voltage difference signal represents the voltage difference between the pair of inputs. The conductance of the switch is inversely proportional to the voltage difference signal.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: March 5, 2013
    Assignee: Texas Instruments Deutschland GmbH
    Inventors: Martijn Fridus Snoeij, Margarita Alenina
  • Patent number: 8385877
    Abstract: Fully integrated compact cross-coupled low noise amplifier. A circuitry implementation that includes two pairs of metal oxide semiconductor field-effect transistors (MOSFETs) (either N-type of P-type) operates as an LNA, which can be used within any of a wide variety of communication devices. A majority of the elements are integrated within the design and need not be implemented off-chip, and this can provide for a reduction in area required by the circuitry. A differential 100? input impedance is provided by this design. A higher than typical power supply voltage can be employed (if desired) to accommodate one possible implementation that includes two parallel implemented resistors to ground.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: February 26, 2013
    Assignee: Broadcom Corporation
    Inventors: Yuyu Chang, Hooman Darabi
  • Patent number: 8384055
    Abstract: An output circuit includes a bias circuit that operates when a power supply voltage equal to or larger than a predetermined voltage is applied, a differential amplifier circuit that outputs signals according to input differential signals upon receiving a bias current or bias voltage generated when the bias circuit is operated, an output stage circuit that receives differential signals according to an output from the differential amplifier circuit and outputs output signals according to the differential signals, the output stage circuit having fewer number of stages of elements connected in series than the bias circuit, and a pull-down circuit that forcibly sets a level of one of the differential signals received by the output stage circuit to a ground voltage to fix the level of the output signals output from the output stage circuit when the bias current or the bias voltage generated by the bias circuit is not supplied.
    Type: Grant
    Filed: October 18, 2010
    Date of Patent: February 26, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Masafumi Shimizu, Satoshi Yoshimura
  • Publication number: 20130043950
    Abstract: A common mode bias circuit may include a weak common mode bias generator and a common mode bias capacitance. During a first state of the common mode bias circuit, the weak common mode bias generator may be coupled to the common mode bias capacitance and may impart to them a predefined common mode signal level. During a second state of the common mode bias circuit, the common mode bias capacitance may be coupled to differential inputs of an amplifier in a manner that establishes an input common mode level for the amplifier.
    Type: Application
    Filed: August 16, 2012
    Publication date: February 21, 2013
    Applicant: Linear Technology Corporation
    Inventor: DAVE THOMAS
  • Publication number: 20130043877
    Abstract: An operational amplifier with different power supply voltages includes an input stage and an output stage. The input stage includes a current source for providing a bias current, and a differential input circuit for receiving the bias current and differential input voltage signals, and converting the differential input voltage signal to differential input currents. The input stage is supplied by a first power supply voltage. The output stage includes a load circuit coupled to the differential input voltage signal and for receiving the differential input currents, and outputting a single ended output voltage signal. The output stage is supplied by a second power supply voltage. The second power supply voltage is lower than the first power supply voltage.
    Type: Application
    Filed: September 6, 2011
    Publication date: February 21, 2013
    Inventor: Xiaohu TANG
  • Patent number: 8378747
    Abstract: A differential amplifier circuit includes a differential input stage comprising first and second transistors whose sources are connected with each other, a constant current source connected between the sources of the first and second transistors and a ground, a current mirror circuit comprising third and fourth transistors whose sources are connected with a power supply source, a fifth transistor of a same conductive type as that of the first transistor, connected at a drain to a drain of the third transistor, connected at a source to a drain of the first transistor and connected at a gate to a reference voltage source; and a sixth transistor of a same conductive type as that of the second transistor, connected at a drain to a drain of the fourth transistor, connected at a source to a drain of the second transistor, and connected at a gate to the reference voltage source.
    Type: Grant
    Filed: January 20, 2011
    Date of Patent: February 19, 2013
    Assignee: Ricoh Company, Ltd.
    Inventor: Katsuhiko Aisu
  • Patent number: 8378749
    Abstract: Systems and methods may include an amplifier having at least a first input port, where the amplifier includes a first capacitance associated with the first input port; a first bias circuit, where the first bias circuit comprises a series connection of a first charging circuit and a first discharging circuit, wherein a first node between the first charging circuit and the first discharging circuit is connected to the first input port, wherein responsive to an RF input signal having at least a first predetermined level being received at the first input port, the first charging circuit charges the first capacitance associated with the first input port during a first portion of a cycle of the RF input signal, and discharges the first capacitance associated with the first input port during a second portion of the cycle, thereby controlling a DC bias voltage level available at the first input port.
    Type: Grant
    Filed: July 29, 2011
    Date of Patent: February 19, 2013
    Assignee: Samsung Electro-Mechanics
    Inventors: Woonyun Kim, Jeonghu Han, Ki Seok Yang, Jae Joon Chang, Chang-Ho Lee
  • Publication number: 20130027135
    Abstract: Systems and methods may include an amplifier having at least a first input port, where the amplifier includes a first capacitance associated with the first input port; a first bias circuit, where the first bias circuit comprises a series connection of a first charging circuit and a first discharging circuit, wherein a first node between the first charging circuit and the first discharging circuit is connected to the first input port, wherein responsive to an RF input signal having at least a first predetermined level being received at the first input port, the first charging circuit charges the first capacitance associated with the first input port during a first portion of a cycle of the RF input signal, and discharges the first capacitance associated with the first input port during a second portion of the cycle, thereby controlling a DC bias voltage level available at the first input port.
    Type: Application
    Filed: July 29, 2011
    Publication date: January 31, 2013
    Applicant: SAMSUNG ELECTRO-MECHANICS COMPANY
    Inventors: Woonyun Kim, Jeonghu Han, Ki Seok Yang, Jae Joon Chang, Chang-Ho Lee
  • Patent number: 8358991
    Abstract: Embodiments of an RF receiver front-end are presented herein. In an embodiment, the RF receiver front-end comprises a transconductance LNA, a passive mixer, and a gm-enhanced common-gate buffer. The transconductance LNA is configured to convert an RF voltage signal to an RF current signal and provide the RF current signal at an output. The passive mixer is coupled to the output of the transconductance LNA and is configured to mix the RF current signal with a local oscillator signal to produce a frequency translated current signal. The gm-enhanced common-gate buffer is configured to receive the frequency translated current signal at an input and convert the frequency translated current signal to a frequency translated voltage signal. In an embodiment, the input of the gm-enhanced common-gate buffer is configured to provide a low input impedance to limit a voltage swing of the frequency translated current signal.
    Type: Grant
    Filed: January 26, 2010
    Date of Patent: January 22, 2013
    Assignee: Broadcom Corporation
    Inventors: Xinyu Chen, Calvin (Shr-Lung) Chen, John Leete
  • Publication number: 20130009705
    Abstract: Memories, sense amplifiers, and methods for amplifying a current input are disclosed, including a sense amplifier including a bias circuit configured to provide a bias voltage having a magnitude responsive to maintaining a substantially constant loop gain, and further including an amplifier stage coupled to the bias circuit to receive the bias voltage and configured to amplify a input current at an input-output node, a loop gain of the current amplifier stage is controlled at least in part to the bias voltage.
    Type: Application
    Filed: September 14, 2012
    Publication date: January 10, 2013
    Applicant: Micron Technology, Inc.
    Inventor: Seong-Hoon Lee
  • Patent number: 8350624
    Abstract: Biasing methods and devices for amplifiers are described. The described methods generate bias voltages proportional to the amplifier output voltage to control stress voltages across transistors used within the amplifier.
    Type: Grant
    Filed: September 1, 2010
    Date of Patent: January 8, 2013
    Assignee: Peregrine Semiconductor Corporation
    Inventor: Fleming Lam