Variable Impedance In Feedback Path Varied By Separate Control Path Patents (Class 330/86)
  • Patent number: 10050591
    Abstract: An amplifier is configured to amplify an RF signal as between an input terminal and an output terminal across a wideband frequency range. A first LC network is connected to the input terminal and has first and second reactive components. A first switching device is connected between the first and second reactive components and couples both the first and second reactive components to the input terminal in an ON state, and disconnects the second reactive component from the input terminal in an OFF state. A second LC network is connected to the output terminal and has third and fourth reactive components. A second switching device is connected between the third and fourth reactive components and couples both the third and fourth reactive components to the output terminal in an ON state and disconnects the fourth reactive component from the output terminal in an OFF state.
    Type: Grant
    Filed: March 23, 2016
    Date of Patent: August 14, 2018
    Assignee: Cree, Inc.
    Inventors: Saurabh Goel, Richard Wilson, Haedong Jang
  • Patent number: 9952332
    Abstract: A method and a PET apparatus are provided. According to an example of the method, a saturation indicia of a target detector may be determined through simulating emission of a ? photon to the target detector. The target detector is any one of SiPM detectors of a PET apparatus. The saturation indicia is for designating a maximum output voltage after amplifying an output of the target detector through a VGA when one ? photon is received by the target detector. The target VGA is a VGA corresponding to the target detector. By comparing an output voltage of the target VGA and the saturation indicia, it may determine that the target detector received a saturation event if the output voltage of the target VGA is higher than the saturation indicia. An amplifier gain of the target VGA may be adjusted until an amount of the saturation events detected by the target detector in unit time satisfies a pre-determined threshold.
    Type: Grant
    Filed: November 9, 2016
    Date of Patent: April 24, 2018
    Assignee: SHENYANG NEUSOFT MEDICAL SYSTEMS CO., LTD.
    Inventors: Yuqiu Zhao, Guodong Liang, Long Yang, Peng Gao, Gai Cui
  • Patent number: 9894308
    Abstract: Provided is an imaging apparatus, including: a vertical scanning circuit configured to output the reset signal and the image signal sequentially from each of a plurality of pixels by selecting the plurality of pixels sequentially; and an amplifier unit configured to output a plurality of image signals obtained by amplifying one image signal that is output from one of the plurality of pixels at a plurality of gains including a first gain and a second gain, in which, in a reading period, which is a period between selection of a first pixel by the vertical scanning circuit out of the plurality of pixels and subsequent selection of a second pixel out of the plurality of pixels, a number of times the amplifier unit is reset is less than a number of the plurality of amplified image signals.
    Type: Grant
    Filed: July 30, 2015
    Date of Patent: February 13, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tomoya Onishi, Shin Kikuchi
  • Patent number: 9774808
    Abstract: In a state that a plurality of capacitances are connected between input and output nodes of an amplifier, a short circuit is established between the input and output nodes of the amplifier. In a state that at least one of the capacitances is isolated from the input and output nodes of the amplifier, the plurality of capacitances are connected to the input and output nodes of the amplifier, in a case that an output from the amplifier is larger than a threshold.
    Type: Grant
    Filed: July 31, 2015
    Date of Patent: September 26, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Daisuke Yoshida, Seiji Hashimoto
  • Patent number: 9716479
    Abstract: The present disclosure provides an amplifier and associated methods of operations. An exemplary amplifier an input terminal; an output terminal; a first virtual ground node; a second virtual ground node; an operational amplifier coupled with the input terminal and the output terminal; a resistive input section coupled with an input of the operational amplifier; and a resistive feedback section coupled with an output of the operational amplifier. The resistive input section includes a fixed input resistor coupled with the input terminal and the first virtual ground node, and a switchable input resistor segment coupled with the fixed input resistor in parallel. The resistive feedback section includes a fixed feedback resistor coupled with the output terminal and the first virtual ground node, and a switchable feedback resistor segment coupled with the fixed feedback resistor in parallel.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: July 25, 2017
    Assignee: ANALOG DEVICES, INC.
    Inventor: Edward Perry Jordan
  • Patent number: 9325287
    Abstract: Provided is a programmable gain amplifier that includes controlled gain steps that dynamically control an output voltage in real-time. The programmable gain amplifier includes a first transistor and a second transistor that includes respective control ports, input ports, and output ports. The programmable gain amplifier also includes a resistor connected to the output ports of the transistors. Further, at least a third transistor is connected to the output ports, in parallel with the resistor. On applying a control voltage to the third transistor and applying an input voltage to the first control port, the second control port is selectively modified by the control voltage to produce a desired output at the first input port and the second input port.
    Type: Grant
    Filed: January 24, 2014
    Date of Patent: April 26, 2016
    Assignee: APPLIED MICRO CIRCUITS CORPORATION
    Inventors: Nanda Govind Jayaraman, Tarun Gupta
  • Patent number: 9287841
    Abstract: The present invention discloses a gain control circuit capable of easing leakage current influence. According to an embodiment of the present invention, the gain control circuit comprises: at least one signal input end for receiving at least one input signal; a signal output end for outputting an output signal; an amplifier coupled between an amplifier input end and the signal output end; and a plurality of gain schemes. Each of the gain schemes is set between the at least one signal input end and the signal output end; and when one of the gain schemes is activated to generate the output signal, the rest gain schemes are inactivated to stop gain production and concurrently discharge leakage currents through their respective grounding paths.
    Type: Grant
    Filed: July 17, 2014
    Date of Patent: March 15, 2016
    Assignee: REALTEK SEMICONDUCTOR CORPORATION
    Inventors: Ming-Cheng Chiang, Yuan-Ping Hsu, Li-Lung Kao
  • Patent number: 9143108
    Abstract: A variable gain amplifier includes: a first input terminal, a second input terminal and an output terminal; an operational amplifier; a first resistor interposed between the first input terminal and an inverted input terminal of the operational amplifier; second and third resistors interposed between the inverted input terminal and the output terminal; and a fourth variable resistor having a first terminal connected to a node between the second resistor and the third resistor and a second terminal connected to the non-inverted input terminal, wherein the fourth variable resistor includes a resistance pass including a resistor and a switch.
    Type: Grant
    Filed: May 17, 2013
    Date of Patent: September 22, 2015
    Assignee: Rohm Co., Ltd.
    Inventor: Hisashi Sugie
  • Patent number: 9112510
    Abstract: A reference voltage generation circuit has: a first PN junction element; a second PN junction element having a higher forward direction voltage than the first PN junction element; a first differential amplifier inputting an anode of the first PN junction element and a first connection node between a first and a second resistor disposed in series between a first output of the first differential amplifier and a first potential, and generating a first output voltage at the first output; and a second differential amplifier inputting an anode of the second PN junction element and a second connection node between a fourth and a third resistor disposed in series between a second output of the second differential amplifier and the first output of the first differential amplifier, and generating a reference voltage at the second output. A resistance ratio between the third and the fourth resistors is variable.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: August 18, 2015
    Assignee: SOCIONEXT INC.
    Inventor: Kiyoshi Ishikawa
  • Patent number: 9112465
    Abstract: A programmable gain amplifier (PGA) includes an op amp, an input circuit, a feedback circuit, and a calibration circuit. The input circuit is connected between a PGA input node and an op-amp input node and selectively applies the analog input signal to the op-amp input node. The feedback circuit is connected between an op-amp output node and the op-amp input node and applies the amplified analog output signal as a feedback signal to the op-amp input node. The calibration circuit is connected between a calibration reference node and the op-amp input node and selectively connects the calibration reference node directly to the op-amp input node without traversing any of the input circuit. The PGA may be implemented as a single-ended or differential amplifier. The PGA avoids reduced linearity resulting from series combinations of switches in the input circuit when configured for its normal operating mode.
    Type: Grant
    Filed: October 31, 2013
    Date of Patent: August 18, 2015
    Assignee: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Sanjoy K. Dey, Mayank Jain
  • Patent number: 9065400
    Abstract: A device comprises a first amplifier, a first resistive element that comprises a first resistor and a first dummy switch, a second amplifier, a second resistive element that comprises a second resistor and a second dummy switch, and a programmable resistive gain element operable to receive control input, wherein a resistance value of the programmable resistive gain element is based at least in part on the received control input, wherein a first end of the programmable resistive gain element is connected to both the first inverting input of the first amplifier and to a second end of the first dummy switch, and wherein a second end of the programmable resistive gain element is connected to both the second inverting input of the second amplifier and to a second end of the second dummy switch.
    Type: Grant
    Filed: September 20, 2013
    Date of Patent: June 23, 2015
    Assignee: Honeywell International Inc.
    Inventor: Mark R. Larson
  • Patent number: 8988146
    Abstract: According to some embodiments, a switch having an “on” state and an “off” state is exhibiting a low impedance in the “on” state, and a very high impedance in the “off” state. The switch comprises three series MOS transistors, the first transistor having its drain connected to the input. The switch also comprises additional circuitry which reduces, in the “off” state, the leakage current of the MOS transistor connected to the input of the switch by connecting its source and bulk to an electrical node replicating the voltage of the input node. According to some embodiments, the said switch is used in a voltage amplifier for capacitive sensing devices, such as MEMS gyroscopes and MEMS microphones; the voltage amplifier uses an operational amplifier used in a trans-capacitance configuration, with the feedback path comprising the said switch and a capacitor, wherein the said switch is connected to the input of, the voltage amplifier.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: March 24, 2015
    Inventor: Ion E. Opris
  • Patent number: 8975964
    Abstract: A high performance digitalized Programmable Gain Amplifier (PGA). In prior art circuit, a dual-ladder DAC is employed for gain control, the back gate leakage of NMOS resistors in the fine ladder conquers fine ladder nominal current and it produces non-monotonic gain scallop. Two new art design techniques: (1) adaptively control the fine ladder; and (2) use dummy PMOS brunch device leakage compensates for the NMOS resistor device leakage, are proposed so that the non-monotonic scallops are substantially eliminated and 13-bit resolution/accuracy PGA has been achieved.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: March 10, 2015
    Assignee: Texas Instruments Incorporated
    Inventors: Qunying Li, Wenxiao Tan, Gregory Swize
  • Patent number: 8941438
    Abstract: An apparatus for limiting the bandwidth of an amplifier provides for the design of an input impedance, a feedback impedance, and a load impedance such that the load impedance is proportional to the sum of the input impedance and feedback impedance. A sampling circuit has a load impedance including a resistor and capacitor in series to reduce the effective amplifier transconductance, which decreases bandwidth without increasing noise density or making this circuit more difficult to drive than a conventional circuit.
    Type: Grant
    Filed: November 5, 2012
    Date of Patent: January 27, 2015
    Assignee: Analog Devices, Inc.
    Inventors: Ronald A. Kapusta, Youn-Jae Kook
  • Patent number: 8933751
    Abstract: A first trimming capacitor having a first terminal and a second terminal is coupled in parallel between a first terminal and a second terminal of a first capacitor. The first trimming capacitor comprises a first plurality of switched capacitors having different capacitances coupled in parallel. Each of the switched capacitors comprises a switch capacitor and a switch coupled in series. In an illustrative application the first capacitor and the first trimming capacitor are coupled between an output terminal of an operational amplifier (op-amp) and an inverting input terminal of the op-amp. A second capacitor and a second trimming capacitor similar to the first capacitor and the first trimming capacitor are coupled between an input and the inverting input terminal of the op-amp.
    Type: Grant
    Filed: May 18, 2012
    Date of Patent: January 13, 2015
    Assignee: Altera Corporation
    Inventors: Wilson Wong, Weiqi Ding, Shuxian Chen, Simardeep Maangat, Albert Ratnakumar
  • Patent number: 8884693
    Abstract: A variable gain amplifier circuit is provided. The circuit includes an operational amplifier for amplifying and outputting an input signal according to a cutoff frequency and a gain, a feedback resistor for changing a first resistance according to a first digital control code value which determines the cutoff frequency, and an input resistor for changing a second resistance according to a second digital control code value which is determined based on a difference of the first digital control code value and a gain code value. The gain is determined by a ratio of the first resistance and the second resistance and linearly changes on a decibel (dB) basis according to the first digital control code value, the cutoff frequency is inversely proportional to the first resistance and linearly changes on a log scale, and the variable gain can be easily set using the control code.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: November 11, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jong-Woo Lee
  • Patent number: 8854126
    Abstract: A semiconductor device includes: an amplifier circuit that has an inverting input terminal, a non-inverting input terminal, and an output terminal; a first variable voltage source that generates a first bias voltage having a voltage value corresponding to a first set value; a second variable voltage source that generates a second bias voltage having a voltage value corresponding to a second set value; a first resistor whose one end is connected to the inverting input terminal; a second resistor that is connected between the output terminal and the inverting input terminal; a third resistor whose one end is connected to the non-inverting input terminal; and a fourth resistor that is connected between the second variable voltage source and the non-inverting input terminal. The first bias voltage is provided to the other end of the first resistor. An input signal is provided to the other end of the third resistor.
    Type: Grant
    Filed: December 12, 2013
    Date of Patent: October 7, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Junichi Ishigami, Yasuhiro Koga
  • Patent number: 8836322
    Abstract: Embodiments of the invention described herein provide a magnetic sensor interface capable of adjusting signal conditioning dynamically using a speed signal of a target such that the true positive and negative peaks of the input signal are maintained for the given target across its entire speed range (0-Max rpm), therefore increasing the signal to noise ratio at low speeds and avoiding clipping or distortion at high speeds. In one aspect, a method comprises receiving an alternating differential voltage signal from a sensor. The differential voltage signal has an amplitude that changes relative to a change in speed of a target. The alternating differential voltage signal is converted to an attenuated single-ended voltage signal that can be dynamically scaled. The attenuated single-ended voltage signal can be scaled by multiplying the attenuated single-ended voltage signal by a scaling factor.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: September 16, 2014
    Assignee: General Electric Company
    Inventors: James Merrill Roylance, Daniel Zahi Abawi, Biplab Deb
  • Patent number: 8680920
    Abstract: A reconfigurable network arrangement of resistors and switches is constructed so that it can be coupled to one or more operational amplifiers and selectively programmed so as to set the gain of the resulting amplifier. The configuration of the network arrangement of resistors and switches to include resistors that can be connected in the feedback path in series and in parallel with each other is such as to provide a wider selection of gain settings, without the need to increase the physical area of the switches on a integrated circuit arrangement.
    Type: Grant
    Filed: August 16, 2010
    Date of Patent: March 25, 2014
    Assignee: THAT Corporation
    Inventor: Gary Hebert
  • Patent number: 8643434
    Abstract: An adjustable gain audio power amplifying circuit includes an input unit, an audio amplifying unit connected to the input unit, a gain adjusting unit connected to the audio amplifying unit, a controlling unit connected to the gain adjusting unit, a comparing unit connected between the gain adjusting unit and the controlling unit and an output unit connected to the audio amplifying unit. The comparing unit compares an outputted signal of the output unit with a common-mode reference voltage, outputs a gain adjustment controlling signal and sends the gain adjustment controlling signal into the controlling unit. When the outputted signal equals the common-mode reference voltage, the gain adjustment controlling signal turns over and then the controlling unit detects the turnover and sends a received gain adjustment signal into the gain adjusting unit. Based on the received gain adjustment signal, the gain adjusting unit controls gains of the adjustable gain audio power amplifying circuit.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: February 4, 2014
    Assignee: IPGoal Microelectronics (Sichuan) Co., Ltd.
    Inventor: Guojun Zhu
  • Patent number: 8570139
    Abstract: Provided is an analog amplifier for amplifying an analog signal and an analog filter, and in particular, an apparatus and method for controlling gain and cutoff frequency of the variable gain amplifier and the variable cutoff frequency filter that is capable of changing the gain and cutoff frequency. The variable resister includes a plurality of resister segments in the variable resister and, when a plurality of resistance candidates for the variable resister are arranged in order of size, the resistance candidates form a geometric series.
    Type: Grant
    Filed: July 25, 2011
    Date of Patent: October 29, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jongwoo Lee
  • Patent number: 8558612
    Abstract: An electronic device comprising an amplifier having at least a first input transistor of a first doping type. A first transistor is coupled with a channel as a feedback path between an output of the amplifier and a control gate of the first input transistor forming an input of the amplifier. A diode-coupled second transistor is coupled with a channel between a first current source and the output of the amplifier wherein a control gate of the first transistor is coupled between the first current source and the diode-coupled second transistor and the first transistor is of a second doping type which is opposite to the first doping type of the first input transistor of the amplifier.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: October 15, 2013
    Assignee: Texas Instruments Deutschland GmbH
    Inventors: Carlo Peschke, Ernst Muellner
  • Patent number: 8519786
    Abstract: Provided is a variable gain amplifier. The variable gain amplifier includes an operational amplifier, a variable feedback impedance unit, a variable compensation impedance unit, and a variable current source. The variable feedback impedance unit is connected between an inverting input terminal and output terminal of the operational amplifier, and has a feedback impedance value which varies for gain control. The variable compensation impedance unit is connected to the inverting input terminal, and has a compensation impedance value which varies in response to change of the feedback impedance value for maintaining a constant feedback factor. The variable current source is connected to the inverting input terminal, and supplies an output current, which varies in response to change of the compensation impedance value, to the variable compensation impedance unit.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: August 27, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seunghyun Jang, Jae Ho Jung
  • Patent number: 8514017
    Abstract: A variable gain amplifier, to amplify an audio input signal to output an audio output signal at an adjustable gain, includes an operational amplifier having an inverting input terminal, a non-inverting input terminal, and an output terminal to output the audio output signal; an attenuation-rate adjustable feedback circuit to feed back the audio output signal from the output terminal of the operational amplifier to the inverting input terminal of the operational amplifier as a feedback signal, and attenuate the audio output signal and output the feedback signal to the inverting terminal; and an attenuation-rate adjustable attenuator to attenuate the audio input signal for output it as an attenuated signal to the non-inverting input terminal of the operational amplifier. Settings of the attenuation rates of the feedback circuit and the attenuator are combined and a resolution of level of the audio output signal is increased.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: August 20, 2013
    Assignee: Ricoh Company, Ltd.
    Inventor: Ryuichi Araki
  • Patent number: 8497791
    Abstract: A temperature dependence adjustable operational amplifier circuit which suppresses a change in a gain caused by a change in an input voltage is provided. In an operational amplifier including a first input terminal and an output terminal, an operational amplifier having an inverting input terminal and a non-inverting input terminal, an input resistance circuit, and a feedback resistance circuit, each of the input and feedback resistor circuits has a resistor and a trimming resistor, which are different in temperature coefficient from each other, connected in series with each other, and a source-drain path of a MOS transistor included in the trimming resistor circuit is disposed between resistance and an inverting input terminal, and a substrate potential thereof is set to a potential of the inverting input terminal of the operational amplifier.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: July 30, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Okumura, Ryusuke Sahara, Mitsugu Kusunoki
  • Patent number: 8497462
    Abstract: A trans-impedance amplifier (TIA) with an adjustable bandwidth is disclosed. The TIA of the present invention includes the amplifying stage and the emitter follower stage arranged in the downstream of the amplifying stage. The transistor in the amplifying stage includes a diode in the emitter thereof to provide a substantial emitter level to the transistor. This diode is biased by another current source with a variable function. The operating point of the diode, in particular, the differential resistance thereof, is variable by the current source, which adjusts the bandwidth of the TIA without affecting the phase characteristic of the TIA.
    Type: Grant
    Filed: May 19, 2011
    Date of Patent: July 30, 2013
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Yoshiyuki Sugimoto
  • Patent number: 8476974
    Abstract: A differential amplifier comprises a first amplifier (A1) with a signal input (Inp) and a signal output (Out1) that is fed back to a first feedback input (In1) of the first amplifier (A1) and is also connected to a first output (outp) of the differential amplifier. Furthermore, a buffer circuit (Buff) is connected to the first output (outp). A nonlinear resistor circuit (Rnl1, Rnl2) is coupled via a first output node (Vmid1) with the first output (outp) and via a second output node (Vmid2) with the buffer circuit (Buff).
    Type: Grant
    Filed: March 22, 2011
    Date of Patent: July 2, 2013
    Assignee: AMS AG
    Inventors: Thomas Carl Froehlich, Wolfgang Duenser
  • Patent number: 8461922
    Abstract: Techniques are disclosed for canceling an offset component (e.g., dc component or dc offset) in an amplifier circuit. For example, an apparatus comprises an amplifier circuit with an amplifier element and a feedback resistor network coupled between an output of the amplifier element and an input of the amplifier element. The apparatus also comprises a current source coupled to the feedback resistor network, the current source generating a current signal that generates a voltage in a first portion of the feedback resistor network that cancels an offset component present in an input signal received by the amplifier circuit. A second portion of the feedback resistor network may be adjustable so that a gain applied to the input signal is adjustable while the offset component is canceled from the input signal. One or more resistors in the feedback resistor network may be composed of the same or substantially similar material as one or more resistors associated with the current source.
    Type: Grant
    Filed: February 24, 2011
    Date of Patent: June 11, 2013
    Assignee: LSI Corporation
    Inventor: Robert Alan Norman
  • Publication number: 20130120060
    Abstract: A variable gain analog amplifier is described that uses pulse-density modulation in the form of a sigma-delta modulator (SDM) to produce a gain by modulating the selection of a switch that selects the amount of resistance in a negative feedback loop of the amplifier. The output of the SDM is dithered to increase the gain resolution of the analog amplifier, wherein the increased resolution produces a quiet, inaudible transition between changes in gain setting at an output of the variable gain amplifier and in addition produces a quiet, inaudible mixing and merging of audio signals..
    Type: Application
    Filed: November 18, 2011
    Publication date: May 16, 2013
    Applicant: DIALOG SEMICONDUCTOR GMBH
    Inventor: Sebastian Loeda
  • Patent number: 8410846
    Abstract: A variable gain amplifier includes an integrator having an input, an output and a feedback loop connected between the input and output, a plurality of input chains connected in parallel between the amplifier input and the input of the integrator, each input chain including a resistor and a first switch and a plurality of second switches, each second switch connected between an intermediate node between the resistor and first switch of a respective input chain and the feedback loop of the integrator, wherein the resistance of the resistors in the input chains is scaled by a scaling factor with respect to one another and the on-resistances of the first and second switches connected to each intermediate node are scaled by the corresponding scaling factor.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: April 2, 2013
    Assignee: Cambridge Silicon Radio Limited
    Inventor: Hashem Zare-Hoseini
  • Patent number: 8405455
    Abstract: An amplifier circuit and method are described for linearizing the gain of a voltage or current feedback amplifier that is non-linear.
    Type: Grant
    Filed: September 27, 2010
    Date of Patent: March 26, 2013
    Assignee: EADS North America, Inc.
    Inventor: John R. Coupland
  • 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: 20120293353
    Abstract: A temperature dependence adjustable operational amplifier circuit which suppresses a change in a gain caused by a change in an input voltage is provided. In an operational amplifier including a first input terminal and an output terminal, an operational amplifier having an inverting input terminal and a non-inverting input terminal, an input resistance circuit, and a feedback resistance circuit, each of the input and feedback resistor circuits has a resistor and a trimming resistor, which are different in temperature coefficient from each other, connected in series with each other, and a source-drain path of a MOS transistor included in the trimming resistor circuit is disposed between resistance and an inverting input terminal, and a substrate potential thereof is set to a potential of the inverting input terminal of the operational amplifier.
    Type: Application
    Filed: May 10, 2012
    Publication date: November 22, 2012
    Inventors: Atsushi OKUMURA, Ryusuke Sahara, Mitsugi Kusunoki
  • Patent number: 8299850
    Abstract: A programmable device includes an operational amplifier and circuitry. The operational amplifier is configured to generate an output voltage based on input voltages at input terminals thereof. The circuitry is configured to provide the input voltages to the operational amplifier. The configuration of the circuitry allows the programmable device to implement discrete-time or continuous-time functions. The circuitry includes a resistor network and a capacitor network configured to be selectively coupled to the operational amplifier.
    Type: Grant
    Filed: February 7, 2012
    Date of Patent: October 30, 2012
    Assignee: Cypress Semiconductor Corporation
    Inventors: Harold Kutz, Warren Snyder, Monte Mar, Dennis Seguine, Gajender Rohilla, Eashwar Thiagarajan
  • Publication number: 20120249235
    Abstract: A variable gain amplifier circuit (200) comprising an amplifier element (202) having an input (208, 210) and an output (220, 222); a feedback loop (224, 226) having a feedback impedance (228, 230) connected between the input (208, 210) and output (232, 234) of the amplifier element (202); an input branch (212, 214) having an input resistance connected between an input of the variable gain amplifier circuit and the input (208, 210) of the amplifier element (202); and a plurality of switches for selecting a gain of the variable gain amplifier circuit (200); characterised in that the variable gain amplifier circuit (200) further comprises an intermediate element (204) having an input and an output, the input being connected to a node between one of the switches and the feedback impedance (228, 230), such that the output can provide a signal which can be used to attenuate a signal component in the output (220, 222) of the amplifier element (202) caused by a non-linearity in the plurality of switches.
    Type: Application
    Filed: November 26, 2009
    Publication date: October 4, 2012
    Applicant: Cambridge Silicon Radio Limited
    Inventors: Hashem Zare-Hoseini, Ian Sabberton
  • Publication number: 20120218036
    Abstract: Techniques are disclosed for canceling an offset component (e.g., dc component or dc offset) in an amplifier circuit. For example, an apparatus comprises an amplifier circuit with an amplifier element and a feedback resistor network coupled between an output of the amplifier element and an input of the amplifier element. The apparatus also comprises a current source coupled to the feedback resistor network, the current source generating a current signal that generates a voltage in a first portion of the feedback resistor network that cancels an offset component present in an input signal received by the amplifier circuit. A second portion of the feedback resistor network may be adjustable so that a gain applied to the input signal is adjustable while the offset component is canceled from the input signal. One or more resistors in the feedback resistor network may be composed of the same or substantially similar material as one or more resistors associated with the current source.
    Type: Application
    Filed: February 24, 2011
    Publication date: August 30, 2012
    Inventor: Robert Alan Norman
  • Publication number: 20120200350
    Abstract: An amplifier system can include a feedback amplifier circuit having an amplifier, a feedback capacitor connected between an input terminal and an output terminal of the amplifier by at least one first switch, and a reset capacitor connected across the feedback capacitor by at least one second switch and between a pair of reference voltages by at least one third switch. During an input-signal processing phase of operation, a control circuit may close the at least one first switch and open the at least one second switch to electrically connect the feedback capacitor between the input and output terminals to engage feedback processing by the feedback amplifier circuit, and close the third switch to electrically connect the reset capacitor between the first and second voltages to charge the reset capacitor to a selectable voltage difference.
    Type: Application
    Filed: February 9, 2011
    Publication date: August 9, 2012
    Applicant: ANALOG DEVICES, INC.
    Inventors: Cathal MURPHY, Michael COLN, Gary CARREAU, Alain Valentin GUERY, Bruce AMAZEEN
  • Patent number: 8228121
    Abstract: An automatic gain control circuit including a variable gain amplifier (11) adapted to receive a received signal (R) and to output an amplified signal (A) to an analog to digital converter (20), and a gain controller (12) which is connected to said variable gain amplifier (11) for receiving said amplified signal (A) and for controlling a gain of said variable gain amplifier (11). The gain controller (12) is adapted to determine an occurrence of a threshold event each time the amplified signal (A) has reached a predetermined threshold, decrease the gain of the variable gain amplifier (11) at each occurrence of a threshold event, measure a delay since the last threshold event, increase the gain of the variable gain amplifier (11) if the delay is greater than a delay specified value and if the gain of the variable gain amplifier (11) is not maximum.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: July 24, 2012
    Assignee: Tyco Electronics Services GmbH
    Inventors: Franck Benhamouda, Ros Kiri Ing, Jean-Michel Linotte
  • Patent number: 8207492
    Abstract: The exemplary embodiments provide a method, system, and device for identifying chemical species in a sample. According to one embodiment, the method, system, and device may include introducing a sample gas into a differential ion mobility device, ionizing at least a portion of the sample gas to generate at least one ion species, filtering the at least one ion species between a pair of filter electrodes, generating a detection signal in response to the at least one ion species depositing a charge on a collector electrode, and detecting a spectral peak associated with the at least one ion species.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: June 26, 2012
    Assignee: Chemring Detection Systems, Inc.
    Inventors: Matthew Todd Griffin, John Michael Alfred Petinarides, Paul Joseph Rauch, Jerome Paul Dahl, Robert Francis McAtee
  • Patent number: 8183916
    Abstract: A non-inverting amplifier includes an operational amplifier, an input resistor, and a feedback resistor. The operational amplifier amplifies and outputs a difference between an input voltage and a voltage of a control node. The input resistor is connected between a reference voltage port and the control node. The feedback resistor is connected to an output port of the operational amplifier and the control node. The non-inverting amplifier supplies a control current to the control node for controlling an offset voltage of the output port.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: May 22, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sang-Woog Byon
  • Patent number: 8179200
    Abstract: An amplifier circuit includes an amplifier unit that amplifies a signal received by an input terminal and outputs the amplified signal to an output terminal, a feedback capacitor that is connected between the input terminal of the amplifier and the output terminal, and a controller that varies a capacitance in the feedback capacitor for a certain period when a potential of the output terminal in the amplifier unit becomes higher or lower than a certain potential.
    Type: Grant
    Filed: June 11, 2010
    Date of Patent: May 15, 2012
    Assignee: Renesas Electronics Corporation
    Inventor: Tadashi Jahana
  • Patent number: 8131232
    Abstract: A method for tuning a transmitter in order to improve impedance matching to an antenna or to intermediate radio frequency stages uses an error detector that senses a deviation of the amplitude or phase angle of a load current of a power amplifier driver or of a power amplifier. A controller calculates a correction and dynamically adjusts tunable transmitter parameters, which may include values of components in matching networks or bias voltages in the power amplifier or the power amplifier driver, so as to reduce the deviation and thereby improve the impedance matching. The load current of the power amplifier may alternatively be sensed by measuring the duty cycle of its switching mode power supply. A transmitter having a power amplifier and one or more tunable circuit elements incorporates an error detector that senses the amplitude or phase of a load current and a controller that adjusts one or more tunable parameters to reduce impedance mismatch.
    Type: Grant
    Filed: October 9, 2009
    Date of Patent: March 6, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Khurram Muhammad
  • Patent number: 8115545
    Abstract: Some embodiments regard a circuit comprising: a high voltage transistor providing a resistance; an amplifier configured to receive a current and to convert the current to a first voltage that is used in a loop creating the current; and an automatic level control circuit that, based on an AC amplitude of the first voltage, adjusts a second voltage at a gate of the high voltage transistor and thereby adjusts the resistance and the first voltage; wherein the automatic level control circuit is configured to adjust the first voltage toward the first reference voltage if the first voltage differs from a first reference voltage.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: February 14, 2012
    Inventors: Chiang Pu, Ming-Chieh Huang, Chan-Hong Chern, Tien-Chun Yang
  • Patent number: 8111097
    Abstract: A programmable system includes a programmable analog device including an operational amplifier to generate an output voltage based on input voltages at terminals of the operational amplifier. The programmable system also includes a system controller to direct the programmable analog device to reconfigure analog circuitry providing the input voltages to the operational amplifier. The reconfiguration of the analog circuitry allows the programmable analog device to implement discrete-time or continuous-time functions.
    Type: Grant
    Filed: April 16, 2010
    Date of Patent: February 7, 2012
    Assignee: Cypress Semiconductor Corporation
    Inventors: Harold Kutz, Warren Snyder, Monte Mar, Dennis Seguine, Gajender Rohilla, Eashwar Thiagarajan
  • Publication number: 20120019318
    Abstract: Provided is an analog amplifier for amplifying an analog signal and an analog filter, and in particular, an apparatus and method for controlling gain and cutoff frequency of the variable gain amplifier and the variable cutoff frequency filter that is capable of changing the gain and cutoff frequency. The variable resister includes a plurality of resister segments in the variable resister and, when a plurality of resistance candidates for the variable resister are arranged in order of size, the resistance candidates form a geometric series.
    Type: Application
    Filed: July 25, 2011
    Publication date: January 26, 2012
    Applicant: SAMSUNG ELECTRONICS CO. LTD.
    Inventor: Jongwoo LEE
  • Patent number: 8093944
    Abstract: A line driver includes an output terminal set for outputting an output signal, a differential amplifier for amplifying an input signal, a series resistor set coupled between the differential amplifier and the output terminal set, a negative-feedback resistor set coupled to the differential amplifier, a feedback variable resistor set coupled between the differential amplifier and the output terminal set, and an adjusting unit coupled to the feedback variable resistor set. The adjusting unit is operable to adjust resistances of the feedback variable resistor set according to the output signal.
    Type: Grant
    Filed: November 11, 2009
    Date of Patent: January 10, 2012
    Assignee: Realtek Semiconductor Corp.
    Inventor: Su-Liang Liao
  • Publication number: 20110260789
    Abstract: A variable gain amplifier circuit includes: an operational amplifier having a non-inverting input terminal applied with a predetermined voltage; a feedback resistor having one end connected to an inverting input terminal of the operational amplifier and the other end connected to an output terminal of the operational amplifier; and a variable resistor having one end applied with an input voltage and the other end connected to the inverting input terminal of the operational amplifier.
    Type: Application
    Filed: October 21, 2010
    Publication date: October 27, 2011
    Applicants: SANYO SEMICONDUCTOR CO., LTD., Joint-stock company of Japan, SANYO ELECTRIC CO., LTD., Joint-stock company of Japan
    Inventors: Takahiro Kawashima, Rui Kurihara
  • Patent number: 8044718
    Abstract: An integrated programmable gain amplifier circuit that receives at an input an analog signal, circuit including an operational amplifier and a gain setup network comprising resistive elements and selection elements, which may be controlled in order to setup the gain of the amplifier circuit. The gain setup network further includes capacitive elements, for defining, together with the resistive elements and the operational amplifier, an anti-aliasing filter of the active RC type.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: October 25, 2011
    Assignee: STMicroelectronics S.r.l.
    Inventors: Germano Nicollini, Angelo Nagari
  • Patent number: 8022758
    Abstract: A circuit comprises an amplifier circuit and a trimming circuit. The amplifier circuit includes an operational amplifier. The operational amplifier has a first input configured to receive input signals, and the operational amplifier also has a second input and an amplifier output. One of the first input or the second input is a negative input. The trimming circuit is coupled to the amplifier output. The trimming circuit includes a termination resistor coupled in parallel with at least one trimming resistor. The termination resistor is coupled to a first switch in series, and the trimming resistor is coupled to a second switch in series. The amplifier output is connected back to the negative input through the first switch.
    Type: Grant
    Filed: January 6, 2010
    Date of Patent: September 20, 2011
    Assignee: Ralink Technology Corp.
    Inventors: Hsin-Hsien Li, Chin-Chun Lin, Tsung-Hsien Hsieh, Zi-Long Huang
  • Patent number: 8013672
    Abstract: There is provided an integrated circuit having a programmable gain amplifier and an embedded filter. The programmable gain amplifier and the filter comprise a gain element having an inverting input for receiving an input and a feedback signal, a non-inverting input coupled to ground, and an output. The gain element also has one or more feedback loops coupling the output of the gain element to the inverting input of the gain element. Each feedback loop has a switch coupled in series with at least one passive component. Each switch has a first state to connect the corresponding feedback loop and a second state to disconnect the corresponding feedback loop. Each switch is programmatically configurable to provide a first gain and a first bandwidth and a second gain and a second bandwidth such that the first bandwidth is substantially equal to the second bandwidth.
    Type: Grant
    Filed: January 6, 2010
    Date of Patent: September 6, 2011
    Assignee: Hong Kong Applied Science and Technology Research Institute Company Limited
    Inventors: Huimin Guo, Shuzuo Lou, Gang Qian, Wai Po Wong