Multiple Feedback Patents (Class 330/99)
-
Patent number: 11378447Abstract: One aspect of the present technology relates to a device. The device includes a sensor having an anode and a cathode. An operational amplifier (op-amp) having a single-ended output terminal, a non-inverting input, and an inverting input, is operatively coupled to one of the anode or the cathode of the sensor by the inverting input. A feedback resistor having a resistance of at least approximately one giga-ohm (1 G?) is operatively coupled between the single-ended output terminal and the inverting input of the op-amp. A grounded field shunt is positioned adjacent to the feedback resistor. The op-amp, grounded field shunt, and feedback resistor are disposed within an electrical shield enclosure. The single-ended output terminal of the op-amp terminates outside of the electrical shield enclosure.Type: GrantFiled: October 11, 2019Date of Patent: July 5, 2022Assignee: The Research Foundation for The State University of New YorkInventors: Anthony Costantino, Arkadii Perzov, Arvydas Matiukas
-
Patent number: 9024686Abstract: An amplifier circuit whose frequency response has almost no soft knee characteristic or no peak when inverting input capacitance Csin varies and when feedback capacitance Cf is a fixed value of small capacitance, and a feedback circuit is provided. The amplifier circuit includes a plurality of amplifiers each of which negative feedback is provided to and which are connected in series, and a feedback means (feedback circuit) which is connected to an output side of an amplifier near output of the amplifier circuit and an input side of an amplifier near input of the amplifier circuit. These amplifiers are ones in the plurality of amplifiers. One or odd numbers of amplifiers in the plurality of amplifiers are inverting amplifiers.Type: GrantFiled: August 30, 2012Date of Patent: May 5, 2015Assignee: NF CorporationInventor: Shingo Sobukawa
-
Patent number: 8866553Abstract: A driver for an analog-to-digital converter (ADC) has an overall feedback loop between its input and its output for maintaining overall accuracy, and a much faster feedback loop in its output stage that quickly compensates for output transients before the overall feedback loop can substantially react to the transients. Output voltage transients are created by the intermittent capacitive load of the ADC. The fast feedback loop can be made very fast since there are only a few components in the fast feedback path. The fast reduction of the output transients enables a shorter sampling time, leading to more accurate analog-to-digital conversion. The overall gain of the driver can be set to be greater than unity while still providing good output transient suppression.Type: GrantFiled: March 14, 2013Date of Patent: October 21, 2014Assignee: Linear Technology CorporationInventor: Thomas Lloyd Botker
-
Publication number: 20140132342Abstract: An amplifier circuit whose frequency response has almost no soft knee characteristic or no peak when inverting input capacitance Csin varies and when feedback capacitance Cf is a fixed value of small capacitance, and a feedback circuit is provided. The amplifier circuit includes a plurality of amplifiers each of which negative feedback is provided to and which are connected in series, and a feedback means (feedback circuit) which is connected to an output side of an amplifier near output of the amplifier circuit and an input side of an amplifier near input of the amplifier circuit. These amplifiers are ones in the plurality of amplifiers. One or odd numbers of amplifiers in the plurality of amplifiers are inverting amplifiers.Type: ApplicationFiled: January 23, 2014Publication date: May 15, 2014Applicant: NF CORPORATIONInventor: Shingo Sobukawa
-
Patent number: 8687821Abstract: An amplifier is disclosed, wherein the output stage is split between a primary output stage and a secondary stage. To minimize or eliminate any audible plop when the amplifier is switched on, the primary stage is connected, and the second stage is gradually connected using a switch. The gradual connection can be by means of varying the pulse-density of a pulse wave modulation on the switch, from fully open (0% pulse-density) to fully closed (100%). The inverse process can minimize or eliminate plop during switch-off. Separate feedback loops are switchable, from the primary and secondary stages; in a DC-coupled embodiment, the feedback loop from the secondary stage may include DC-offset cancelling circuitry, to both reduce or eliminate the plop and avoid and DC-offset current through the speaker.Type: GrantFiled: November 12, 2010Date of Patent: April 1, 2014Assignee: NXP B.V.Inventor: Han Martijn Schuurmans
-
Patent number: 8604873Abstract: Achievement of robust stability of a power amplifier (PA) that allows the sharing of the ground between the driver stages and the output stage is shown. A controlled amount of negative feedback is used to neutralize the local positive feedback that results from the driver-to-output stage ground sharing in the signal path, for example, a radio frequency (RF) signal path. The solution keeps a strong drive and a good performance of the PA. Exemplary embodiments are shown for the PA positive feedback neutralization. A first embodiment uses a ground signal divider while another embodiment uses a ground signal divider weighting technique.Type: GrantFiled: December 2, 2011Date of Patent: December 10, 2013Assignee: RF Micro Devices (Cayman Islands), Ltd.Inventors: Baker Scott, George Maxim, Stephen Franck, Chu Hsiung Ho
-
Patent number: 8421531Abstract: A low dissipation, low distortion amplifier includes a driver amplifier stage and a main output stage, with a plurality of impedance networks providing, among other things, feedback paths from outputs of the driver and main output stages to the input of the driver stage. The impedance networks also provide coupling paths from the outputs of the driver and main output stages to the load. The impedance networks can all be formed of resistors, capacitors, or network combinations thereof. An additional feedback path can be added from the load to the driver stage to flatten out the frequency response at low frequencies. The driver and main output stages may be operated in Class AB and B modes respectively, and/or in Class G or H modes. An intermediate amplifier driver stage may be added between the driver and main output stages.Type: GrantFiled: July 6, 2011Date of Patent: April 16, 2013Assignee: THX LtdInventors: Owen Jones, Lawrence R. Fincham
-
Patent number: 8416106Abstract: In one embodiment, a comparator of a Flash analog-to-digital converter (ADC) is calibrated in the background by switching the comparator to a feedback loop, determining the comparator's current reference level, and adjusting the comparator's reference level to a target reference level by charging a reference capacitor coupled the comparator.Type: GrantFiled: April 20, 2011Date of Patent: April 9, 2013Assignee: Fujitsu LimitedInventor: Pradip Thachile
-
Patent number: 8159293Abstract: A nested transimpedance amplifier circuit including a first power source, a second power source, a charge pump module and a transimpedance amplifier. The first power source is at a first voltage. The second power source is at a second voltage. The second voltage is different than the first voltage. The charge pump module (i) receives the first voltage and the second voltage and (ii) generates a third voltage based on the first voltage and the second voltage. The first transimpedance amplifier includes an input, an output and a first operational amplifier. The input of the first transimpedance amplifier receives an input voltage. The output of the first transimpedance amplifier outputs an output voltage. The first operational amplifier receives the third voltage. The first transimpedance amplifier generates the output voltage based on the third voltage and the input voltage.Type: GrantFiled: August 17, 2010Date of Patent: April 17, 2012Assignee: Marvell International Ltd.Inventor: Sehat Sutardja
-
Patent number: 8081032Abstract: A low noise amplifier (LNA) includes an LNA input that receives a signal from an antenna. The LNA also includes an internal amplifier with an input that is coupled to the LNA input, as well as an internal filter with an input coupled to the output of the internal amplifier and an output coupled to the input of the internal amplifier. The coupling of the output of the internal filter to the input of the internal amplifier provides feedback to the input of the internal amplifier. The internal filter is configured to pass signals within a frequency range through to the output of the internal filter.Type: GrantFiled: August 29, 2008Date of Patent: December 20, 2011Assignee: Project FT, Inc.Inventor: Farbod Aram
-
Patent number: 8058931Abstract: An apparatus for an improved operational amplifier. The disclosed improved operational amplifier comprises an operational amplifier, a first feedback circuit, and one or more secondary feedback circuits. The operational amplifier include a plurality of serially coupled gain stages and is configured so that an output of each gain stage drives an input of a next gain stage and an output of a last gain stage drives a load external to the improved operational amplifier. The first feedback circuit is coupled between an output of a designated gain stage and an output of a previous gain stage to provide a first feedback to the previous gain stage. Each secondary feedback circuit provides an additional feedback to the output of the previous gain stage.Type: GrantFiled: April 27, 2010Date of Patent: November 15, 2011Assignee: Linear Technology CorporationInventor: Ping Zhou
-
Publication number: 20110267144Abstract: A differential Low Noise Amplifier (LNA) includes a first stage of resistive feedback amplifiers and second stage of complementary amplifiers, where the outputs of the first stage are coupled to the inputs of the second stage in a cross-coupled fashion. An inductive load, such as a transformer, combines signals output from the complementary amplifiers of the second stage. In one example, the LNA has an input impedance of less than 75 ohms, a noise factor of less than 2 dB, and a gain of more than 20 dB. Due to the low input impedance, the LNA is usable to amplify a signal received from a source having a similar low impedance without the use of an impedance matching network between the output of the source and the input of the LNA.Type: ApplicationFiled: May 3, 2010Publication date: November 3, 2011Applicant: QUALCOMM INCORPORATEDInventors: Manas Behera, Harish S. Muthali, Kenneth Charles Barnett
-
Patent number: 8049566Abstract: A receiver includes a feedback low noise amplifier (LNA). The feedback LNA has an LNA gain and includes an LNA input configured to receive a signal from an antenna and an LNA output configured to output an amplified voltage signal. The receiver also includes a resistive element, having a resistance, coupled to the LNA output and configured to convert the amplified voltage signal into a current. The receiver also includes a current commuting mixer coupled to the resistive element and configured to receive the current from the resistive element, where the current output by the resistive element is determined at least in part by the amplified voltage signal and the resistance of the resistive element.Type: GrantFiled: August 29, 2008Date of Patent: November 1, 2011Assignee: Project FT, Inc.Inventor: Farbod Aram
-
Patent number: 8013676Abstract: A high-efficiency power amplifier is provided, including a drive amplifier and a final power amplifier, and further including a first digital pre-distortion (DPD) correction module and a second DPD correction module. The first DPD correction module is configured to pre-distort nonlinear characteristics of drive signals output by the drive amplifier, and the second DPD correction module is connected to the first DPD correction module in series, and is configured to pre-distort nonlinear characteristics of amplified signals output by the final power amplifier. Another high-efficiency power amplifier is also provided, including a drive amplifier and a final power amplifier, and further including a second multi-path control module, a fourth DPD correction module, and a second gating module. The overall efficiency of the high-efficiency power amplifier is increased by improving the working efficiency of the drive amplifier.Type: GrantFiled: June 16, 2010Date of Patent: September 6, 2011Assignee: Huawei Technologies Co., Ltd.Inventors: Yongge Su, Siqing Ye, Dandong He, Weimin Yin, Xikun Zhang, Xiaolun Wang, Qianhua Wei
-
Publication number: 20110043279Abstract: An electronic volume circuit includes a first signal processing circuit and a second signal processing circuit that are cascaded together. The first signal processing circuit includes a first operational amplifier including an input terminal and an output terminal, one or more input resistors inputting one or more signals to the input terminal of the first operational amplifier, and a feedback resistor connected between the input terminal and the output terminal of the first operational amplifier. The second signal processing circuit includes a second operational amplifier including an input terminal and an output terminal, an input capacitor inputting a signal output from the first operational amplifier to the input terminal of the second operational amplifier, and a resistor and a capacitor connected in parallel between the input terminal and the output terminal of the second operational amplifier.Type: ApplicationFiled: August 5, 2010Publication date: February 24, 2011Applicant: RICOH COMPANY, LTD.Inventor: Koichiro Adachi
-
Patent number: 7808311Abstract: A nested transimpedance amplifier circuit includes a first-order nested transimpedance amplifier having an input and an output. The first-order nested transimpedance amplifier is configured to be powered by a first voltage. A charge pump module is configured to receive the first voltage and a second voltage. The second voltage is different from the first voltage. The charge pump module generates a third voltage based on the first voltage and the second voltage. A first operational amplifier has an input and an output. The input of the first operational amplifier communicates with the output of the zero-order transimpedance amplifier, and the first operational amplifier is configured to be powered by the third voltage.Type: GrantFiled: November 30, 2009Date of Patent: October 5, 2010Assignee: Marvell World Trade Ltd.Inventor: Sehat Sutardja
-
Publication number: 20100214024Abstract: A low dissipation, low distortion amplifier includes a driver amplifier stage and a main output stage, with a plurality of impedance networks providing, among other things, feedback paths from outputs of the driver and main output stages to the input of the driver stage. The impedance networks also provide coupling paths from the outputs of the driver and main output stages to the load. The impedance networks can all be formed of resistors, capacitors, or network combinations thereof. An additional feedback path can be added from the load to the driver stage to flatten out the frequency response at low frequencies. The driver and main output stages may be operated in Class AB and B modes respectively, and/or in Class G or H modes. An intermediate amplifier driver stage may be added between the driver and main output stages.Type: ApplicationFiled: February 25, 2010Publication date: August 26, 2010Inventors: Owen Jones, Lawrence R. Fincham
-
Patent number: 7696820Abstract: An amplifier circuit includes first, second, and third amplifiers each having an input and an output. The amplifier circuit further includes first and second capacitances and a resistance. The input of the second amplifier communicates with the output of the first amplifier. The first capacitance communicates with the input of the first amplifier and the output of the second amplifier. The input of the third amplifier communicates with the output of the second amplifier. The second capacitance communicates with the output of the third amplifier and the input of the second amplifier. The resistance directly communicates with the output of the third amplifier and the input of the first amplifier.Type: GrantFiled: September 5, 2008Date of Patent: April 13, 2010Assignee: Marvell International Ltd.Inventor: Thart Fah Voo
-
Patent number: 7652531Abstract: The present invention provides a cost-effective and power-effective solution to a high performance amplifier design over conventional Class A and Class B/AB amplifiers. Without increasing cost or losing simplification of conventional Class B/AB amplifier configuration, two kinds of unique local feedback loops, which cover the second and third stages and further offer a feedback shifting feature over frequency range, are disclosed to replace the traditional Miller compensation capacitor to suppress dominant distortion, which is usually generated by the two last stages while maintaining stability of the amplifier, through high frequency end.Type: GrantFiled: March 2, 2008Date of Patent: January 26, 2010Inventors: Zhenwu Wang, Dong An, Huixing Jin
-
Patent number: 7633338Abstract: An amplifier circuit comprises a first capacitance having one end that communicates with an input of a first amplifier stage. An amplifier has a first gain, an input that communicates with an opposite end of the first capacitance, and an output. A second capacitance has a first end that communicates with the output of the amplifier and an opposite end that communicates with an input of a second amplifier stage. A broadband buffer has an input that communicates with the output of the amplifier and an output that communicates with the one end of the second capacitance.Type: GrantFiled: July 18, 2008Date of Patent: December 15, 2009Assignee: Marvell International, LtdInventor: Farbod Aram
-
Patent number: 7626453Abstract: A nested transimpedance amplifier (TIA) circuit comprises a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an output and an input that communicates with said output of said zero-order TIA. A first power supply input applies a first voltage to the zero-order TIA. A second power supply input receives a second voltage. A charge pump module develops a third voltage based on the first voltage and the second voltage, wherein the third voltage is applied to the opamp.Type: GrantFiled: July 9, 2008Date of Patent: December 1, 2009Assignee: Marvell World Trade Ltd.Inventor: Sehat Sutardja
-
Patent number: 7616057Abstract: A differential transimpedance amplifier circuit comprises a first operational amplifier having a first inverting input, a first non-inverting input, a first inverting output and a first non-inverting output. A second operational amplifier has a second inverting input, a second non-inverting input, a second inverting output and a second non-inverting output. The second inverting output communicates with the first non-inverting input and the second non-inverting output communicates with the first inverting input. A first feedback element communicates with the first non-inverting input and the first inverting output. A second feedback element communicates with the first inverting input and the first non-inverting output. A third feedback element communicates with the second inverting input and the first inverting output. A fourth feedback element communicates with the first non-inverting input and the first non-inverting output.Type: GrantFiled: December 21, 2006Date of Patent: November 10, 2009Assignee: Marvell World Trade Ltd.Inventor: Sehat Sutardja
-
Patent number: 7605649Abstract: A transimpedance amplifier comprises a first operational amplifier having an input and an output. A second operational amplifier has an input and an output that communicates with the input of the first operational amplifier. A first feedback element has one end that communicates with the input of the first operational amplifier and another end that communicates with the output of the first operational amplifier, wherein the first feedback element comprises a first capacitance. A second feedback element communicates with the input of the first operational amplifier and another end that communicates with the output of the first operational amplifier.Type: GrantFiled: December 21, 2006Date of Patent: October 20, 2009Assignee: Marvell World Trade Ltd.Inventor: Sehat Sutardja
-
Patent number: 7554477Abstract: An amplifier array circuit is provided. An amplifier array includes a main amplifier array comprising a plurality of first amplifiers and a plurality of reference voltages, wherein the first amplifier is coupled to an input signal and the reference voltage corresponding to the first amplifier. A first reversed reference voltage amplifier array is located on one side of the main amplifier array and has a plurality of second amplifiers coupled to the input signal and the reference voltages, respectively. A second reversed reference voltage amplifier array is located on the other side of the main amplifier array and has a plurality of third amplifiers coupled to the input signal and the reference voltages respectively. The averaging network is coupled to a first output terminal and a second output terminal of the first, second and third amplifiers.Type: GrantFiled: November 12, 2007Date of Patent: June 30, 2009Assignee: National Taiwan UniversityInventors: Chien-Kai Hung, Hsin-Shu Chen
-
Patent number: 7551024Abstract: A nested transimpedance amplifier (TIA) circuit includes a zero-order TIA having an input and an output, and a first operational amplifier (opamp). The opamp includes an input that communicates with said output of said zero-order TIA, a first transistor driven by said input, a second transistor that is driven by a first bias voltage and communicates with said first transistor, a first current source that communicates with said second transistor, and an output at a node between the first transistor and the second transistor.Type: GrantFiled: July 28, 2006Date of Patent: June 23, 2009Assignee: Marvell World Trade Ltd.Inventor: Sehat Sutardja
-
Patent number: 7541869Abstract: A feedback architecture for a PWM switching audio amplifier is, capable of compensating the effects of the demodulation filter through at least two feedback paths of the voltage applied to a load without degrading the overall loop gain of the device. Each of the feedback paths may include a respective network or filter for compensating a respective frequency pole of the cascade low-pass filter+load and establishing a certain band pass. These networks or filters may be passive networks.Type: GrantFiled: March 28, 2007Date of Patent: June 2, 2009Assignee: STMicroelecronics S.r.l.Inventors: Pietro Mario Adduci, Edoardo Botti
-
Patent number: 7495514Abstract: A low noise amplifier including a first-stage signal amplifier, a second-stage signal amplifier and a gain control unit is disclosed. The first-stage signal amplifier is for receiving an input signal and outputting a first output signal accordingly. The second-stage signal amplifier is coupled to the first-stage signal amplifier for outputting a second output signal according to the first output signal. The second-stage signal amplifier includes a first output transistor for outputting the second output signal. The gain control unit includes a first variable resistance device coupled to an input terminal of the first output transistor for adjusting voltage gain of the second output signal.Type: GrantFiled: February 17, 2006Date of Patent: February 24, 2009Assignees: Himax Technologies Limited, NCKU Research and Development FoundationInventors: Da-Rong Huang, Huey-Ru Chuang, Yuan-Kai Chu
-
Patent number: 7444123Abstract: With a dual mode transmitter capable of handling two modulation methods for nonconstant amplitude modulation and constant amplitude modulation, respectively, speed-up of transition between modes is implemented. In a mode handling the constant amplitude modulation, first capacitors included in a low-pass filter constituting an AM loop, and a second capacitor included in an integrator are kept recharged from a first constant-voltage power supply and a second constant-voltage power supply by use of a first switch and a second switch, respectively. By doing so, a value of voltage to be recharged at the time of a mode changeover is decreased, and further, a first variable-gain amplifier starts control of a gain while avoiding a region where the output voltage of the first variable-gain amplifier has slow response against an input voltage.Type: GrantFiled: January 20, 2006Date of Patent: October 28, 2008Assignee: Renesas Technology Corp.Inventors: Taizo Yamawaki, Yoshiaki Harasawa
-
Patent number: 7405616Abstract: A differential transimpedance amplifier circuit comprises first, second, third and fourth operational amplifiers having a first inverting input, a first non-inverting input, a first inverting output and a first non-inverting output. A first feedback element communicates with the second non-inverting input and the second inverting output. A second feedback element communicates with the second inverting input and the second non-inverting output. A third feedback element communicates with the third non-inverting input and the first inverting output. A fourth feedback element communicates with the third inverting input and the first non-inverting output. A fifth feedback element communicates with the fourth inverting input and the first inverting output. A sixth feedback element communicates with the fourth non-inverting output and the first non-inverting output.Type: GrantFiled: December 21, 2006Date of Patent: July 29, 2008Assignee: Marvell International Ltd.Inventor: Sehat Sutardja
-
Patent number: 7403067Abstract: An amplifier circuit comprises a first capacitance having one end that communicates with an input of a first amplifier stage. An amplifier has a first gain, an input that communicates with an opposite end of the first capacitance, and an output. A second capacitance has a first end that communicates with the output of the amplifier and an opposite end that communicates with an input of a second amplifier stage. A broadband buffer has an input that communicates with the output of the amplifier and an output that communicates with the one end of the second capacitance.Type: GrantFiled: December 2, 2005Date of Patent: July 22, 2008Assignee: Marvell International Ltd.Inventor: Farbod Aram
-
Patent number: 7366427Abstract: A method and apparatus to provide bandwidth control in a high speed line driver circuit is described.Type: GrantFiled: June 22, 2004Date of Patent: April 29, 2008Assignee: Intel CorporationInventor: Shenggao Li
-
Patent number: 7355471Abstract: A circuit having multiple overlapped feedback loops for DC offset cancellation is provided with applying in one of multistage amplifier, multistage filter, and the combination thereof. The circuit includes a plurality of negative feedback variable bandwidth switches coupled to each stage of the above mentioned multistage devices, the output of the last stage is coupled to an input of a low-pass filter loop. The circuit includes a plurality of variable gain amplifiers, output of each variable gain amplifier is coupled to the series contact of each stage respectively, and input of each variable gain amplifier is thereof coupled to an output of the low-pass filter loop. Therefore, the circuit achieves to cancel the DC offset for multistage overlapped feedback path with less area and low power consumption.Type: GrantFiled: June 9, 2006Date of Patent: April 8, 2008Assignee: Via Technologies Inc.Inventors: Kuan Da Chen, Chunwei Hsu
-
Patent number: 7352246Abstract: A generalized amplifier architecture is described which employs noise-shaping feedback, and for which the output waveform closely resembles the input waveform.Type: GrantFiled: September 7, 2007Date of Patent: April 1, 2008Assignee: Cirrus Logic, Inc.Inventors: Babak Mazda, Farzad Sahandiesfanjani, Adya S. Tripathi
-
Patent number: 7304536Abstract: A nested transimpedance amplifier (TIA) circuit includes a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an input that communicates with the output of the zero-order TIA and an output. A first feedback resistor has one end that communicates with the input of the zero-order TIA and an opposite end that communicates with the output of the first opamp. A first capacitance has a first end that communicates with the input of the first opamp and a second end that communicates with the output of the zero-order TIA. The gain-bandwidth product of the nested TIA is increased. Differential mode TIAs also have increased gain-bandwidth products.Type: GrantFiled: April 14, 2005Date of Patent: December 4, 2007Assignee: Marvell International Ltd.Inventor: Sehat Sutardja
-
Patent number: 7304535Abstract: A balanced amplifier is disclosed as comprising an input stage connected with a second stage, in which the input stage outputs signals to the second stage, and the first stage includes a first differential amplifier for receiving balanced input signals and is provided with two pairs of feedback loops, at least one of the pair of feedback loops for feedbacking part of signals outputted by the second stage to the first differential amplifier, and the second stage includes a second differential amplifier for amplifying signals received from the first stage and for maintaining the balanced signals.Type: GrantFiled: February 10, 2006Date of Patent: December 4, 2007Inventor: Chi Ming John Lam
-
Patent number: 7292097Abstract: In some embodiments, an apparatus includes an amplifier circuit and a bias circuit coupled to the amplifier. The amplifier circuit includes an input port and an output port, an input port circuit element coupled to the input port, an output port circuit element coupled to the output port, and an internal signal path to couple the input port circuit element to the output port circuit element. The output port is coupled to the input port, the bias circuit, and the internal signal path.Type: GrantFiled: December 10, 2004Date of Patent: November 6, 2007Assignee: Intel CorporationInventor: Stewart S. Taylor
-
Patent number: 7283840Abstract: A dual-mode analog baseband circuit is implementable on a single IC with reduced chip area. The baseband portion of the IC includes a single dual-mode complex filter that is reconfigurable to be a filter for Bluetooth signals or for wireless local area network (wireless LAN) format signals, such as 802.11b, and includes a single dual-mode amplifier that is reconfigurable to amplify Bluetooth signals or wireless LAN format signals.Type: GrantFiled: February 6, 2004Date of Patent: October 16, 2007Assignee: Chrontel, Inc.Inventor: Thomas Cho
-
Patent number: 7279970Abstract: For reducing various adverse effects due to provision of a low-pass filter, while suppressing an oscillation generated therein, there is provide a feedback circuit, having at least one operational amplifier, having a low-pass filter in an output portion thereof, for feeding a signal from the output portion back thereto, including: a first feedback circuit portion for negatively feeding a signal from an input terminal of the low-pass filter back to an inverted input terminal of the operational amplifier; and a second feedback circuit portion for negatively feeding a signal from an output terminal of the low-pass filter back to the inverted input terminal of the operational amplifier.Type: GrantFiled: August 10, 2005Date of Patent: October 9, 2007Assignee: Flying Mole CorporationInventors: Kenji Yokoyama, Yasuo Yamada, Hiroshi Ogawa
-
Patent number: 7276965Abstract: A nested transimpedance amplifier (TIA) circuit includes a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an input that communicates with the output of the zero-order TIA and an output. A first feedback resistance has one end that communicates with the input of the zero-order TIA and an opposite end that communicates with the output of the first opamp. A first feedback capacitance has a first end that communicates with the input of the zero-order TIA and a second end that communicates with the output of the zero-order TIA. A capacitor has one end that communicates with the input of the zero-order TIA.Type: GrantFiled: June 11, 2003Date of Patent: October 2, 2007Assignee: Marvell International Ltd.Inventor: Sehat Sutardja
-
Patent number: 7239202Abstract: A transimpedance amplifier (TIA) circuit comprises a first operational transconductance amplifier (OTA) having an input and an output. A second OTA has an input and an output. A third OTA has an input that communicates with the output of the first OTA and an output that communicates with the input of the second OTA. A first feedback path communicates with the input and the output of the first OTA and that includes a first resistor. A second feedback path communicates with the input and the output of the second OTA and that includes a first resistance. A third feedback path communicates with the input of the first OTA and the output of the second OTA.Type: GrantFiled: August 7, 2006Date of Patent: July 3, 2007Assignee: Marvell International Ltd.Inventor: Farbod Aram
-
Patent number: 7173486Abstract: A nested transimpedance amplifier (TIA) circuit comprises a zero-order TIA having an input and an output. A first transconductance amplifier has an input that communicates with said output of said zero-order TIA and an output. A first feedback resistance has one end that communicates with said input of said zero-order TIA and an opposite end that communicates with said output of said first transconductance amplifier. A first feedback capacitance has a first end that communicates with said input of said zero-order TIA and a second end that communicates with said output of said zero-order TIA. A capacitance has one end that communicates with said input of said zero-order TIA.Type: GrantFiled: June 19, 2006Date of Patent: February 6, 2007Assignee: Marvell International Ltd.Inventor: Sehat Sutardja
-
Patent number: 7116164Abstract: An amplifier circuit includes a first operational transconductance amplifier (OTA) having an input and an output. A second OTA has an input that communicates with the output of the first OTA and an output. A first feedback path communicates with the input and the output of the first OTA and includes a first resistance. A second feedback path communicates with the input and the output of the second OTA and includes a second resistance. A third feedback path communicates with the input of the first OTA and the output of the second OTA. The first and second resistances are variable resistances that have resistance values that decrease as frequency increases.Type: GrantFiled: December 6, 2005Date of Patent: October 3, 2006Assignee: Marvell International Ltd.Inventor: Farbod Aram
-
Patent number: 7023271Abstract: A transimpedance amplifier (TIA) circuit according to the present invention includes a first opamp having an input and an output. A second opamp has an input that communicates with the first opamp and an output. A first feedback path communicates with the input and the output of the first opamp and includes a first resistance. A second feedback path communicates with the input and the output of the second opamp and includes a second resistance. A third feedback path communicates with the input of the first opamp and the output of the second opamp.Type: GrantFiled: March 31, 2004Date of Patent: April 4, 2006Assignee: Marvell International Ltd.Inventor: Farbod Aram
-
Patent number: 7010284Abstract: A multi-stage amplifier is coupled with a power detector. The multi-stage amplifier includes a plurality of amplifier stages in series, with a signal path extending through them. The power detector is coupled to an interior node of the amplifier along the signal path, and is operable to sample a first signal being transmitted on the signal path. The power detector outputs a second signal reflective of a power of the first signal. In one embodiment, the interior node is in a matching network of the amplifier disposed between a first amplifier stage and a final amplifier stage of the amplifier. The second signal may be used in a feedback network to adjust an amount of amplification of the first signal by the amplifier.Type: GrantFiled: June 10, 2003Date of Patent: March 7, 2006Assignee: TriQuint Semiconductor, Inc.Inventors: Li Liu, Christopher C. Souchuns, Ping Li, Gregory N. Henderson
-
Patent number: 7002409Abstract: A compensation circuit is provided for an amplifier including at least first and second amplifier stage. The circuit includes a first capacitance including one end that communicates with an input of the first amplifier stage. An amplifier includes a first gain, an input that communicates with an opposite end of the first capacitance, and an output. A second capacitance includes a first end that communicates with the output of the amplifier and an opposite end that communicates with an input of the second amplifier stage. A first impedence includes one end that communicates with the input of the first amplifier stage and an opposite end that communicates with an output of the second amplifier stage.Type: GrantFiled: February 11, 2004Date of Patent: February 21, 2006Assignee: Marvell International Ltd.Inventor: Farbod Aram
-
Patent number: 6836182Abstract: A nested transimpedance amplifier (TIA) circuit includes a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an input that communicates with the output of the zero-order TIA and an output. A first feedback resistor has one end that communicates with the input of the zero-order TIA and an opposite end that communicates with the output of the first opamp. A capacitor has one end that communicates with the input of the zero-order TIA. The gain-bandwidth product of the nested TIA is increased. Differential mode TIAs also have increased gain-bandwidth products.Type: GrantFiled: May 3, 2004Date of Patent: December 28, 2004Assignee: Marvell International Ltd.Inventor: Sehat Sutardja
-
Patent number: 6801087Abstract: An integrated circuit includes an analog amplifier connected to a terminal pad and has a Miller compensation of a section of the analog amplifier. The Miller compensation circuit is connected to a terminal for reference-ground potential through a capacitive element. An EMC interference radiation that can be coupled in through the terminal pad is attenuated by the capacitive element. The operating points of the internal nodes of the analog amplifier are, thereby, stabilized.Type: GrantFiled: December 30, 2002Date of Patent: October 5, 2004Assignee: Infineon Technologies AGInventor: Udo Ausserlechner
-
Patent number: 6762644Abstract: A nested transimpedance amplifier (TIA) circuit includes a zero-order TIA having an input and an output. A first operational amplifier (opamp) has an input that communicates with the output of the zero-order TIA and an output. A first feedback resistor has one end that communicates with the input of the zero-order TIA and an opposite end that communicates with the output of the first opamp. A capacitor has one end that communicates with the input of the zero-order TIA. The gain-bandwidth product of the nested TIA is increased. Differential mode TIAs also have increased gain-bandwidth products.Type: GrantFiled: February 6, 2002Date of Patent: July 13, 2004Assignee: Marvell International, Ltd.Inventor: Sehat Sutardja
-
Patent number: 6756851Abstract: Transimpedance amplifier having an input stage (1) to which an input current to be amplified is fed and an output stage (2) which outputs an output voltage (uo) corresponding to the amplified input current. By means of a current control circuit (4) the current (Ic) flowing through the amplifying element (Q1) of the input stage (1) is detected and controlled in such a way that said current is independent of the ambient temperature and of the supply voltage (Vcc). To detect the current (Ic) a dummy transimpedance amplifier (5) is used in combination with a current mirror circuit (6), the current (Ic) being controlled in that the control voltage (Uc) of a further transistor (Qc) coupled to the amplifying element (Q1) configured as a transistor is adjusted accordingly.Type: GrantFiled: February 21, 2003Date of Patent: June 29, 2004Assignee: Infineon Technology AGInventor: Jaafar Mejri
-
Patent number: 6580326Abstract: A voltage buffer and follower includes a single ended output, a source follower, and a current feedback loop. The current feedback loop is coupled to the source follower and to the single ended output. When two voltage followers are used in a differential configuration, the voltage followers can become part of a high bandwidth gain cell. The high bandwidth gain cell includes a first and a second source follower circuit that are coupled to the first and the second current feedback loops, respectively. The first and the second source follower circuits are further coupled to a first and a second current mirror circuit, respectively. The first and second current mirror circuits are coupled to a load, which is coupled to a common-mode feedback circuit. The common-mode feedback circuit controls a constant current source that sinks mirrored direct currents that flow through the first and the second current mirror circuits.Type: GrantFiled: May 25, 2001Date of Patent: June 17, 2003Assignee: Infineon Technologies North America Corp.Inventors: Elmar Bach, Thomas Blon, Sasan Cyrusian, Stephen Franck