Converting Input Voltage To Output Current Or Vice Versa Patents (Class 327/103)
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Publication number: 20100194443Abstract: A dB-linear voltage-to-current (V/I) converter that is amenable to implementation in CMOS technology. In a representative embodiment, the dB-linear V/I converter has a voltage scaler, a current multiplier, and an exponential current converter serially connected to one another. The voltage scaler supplies an input current to the current multiplier based on an input voltage. The current multiplier multiplies the input current and a current proportional to absolute temperature and supplies the resulting current to the exponential current converter. The exponential current converter has a differential MOSFET pair operating in a sub-threshold mode and generating an output current that is proportional to a temperature-independent, exponential function of the input voltage.Type: ApplicationFiled: February 2, 2009Publication date: August 5, 2010Applicant: Skyworks Solutions, Inc.Inventors: Hasan Akyol, Bipul Agarwal, Dean Badillo
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Publication number: 20100176847Abstract: The voltage-current converter of the present invention includes a converter input terminal, a converter output terminal, a voltage-current conversion unit for converting voltage that is applied as input to the converter input terminal to current, and a current extraction unit for intermittently extracting current from the output terminal of the voltage-current conversion unit and supplying this current as output from the converter output terminal.Type: ApplicationFiled: June 4, 2008Publication date: July 15, 2010Inventors: Masaki Kitsunezuka, Shinichi Hori
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Publication number: 20100164553Abstract: A current sensing circuit includes a power transistor, a sensing transistor configured to copy a current flowing through the power transistor at a predetermined ratio, a current sensing resistor configured to detect a voltage from the current copied by the sensing transistor, an input resistor configured to convert an input voltage to a current, a cross self-biasing cascade block configured to adjust currents at both ends of the input resistor, and a common gate transistor and a reference resistor configured to convert a current output of the input resistor to a final sense voltage.Type: ApplicationFiled: December 21, 2009Publication date: July 1, 2010Inventors: Chang-Woo Ha, Jung-Ah Jang
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Publication number: 20100164554Abstract: According to one embodiment, a filter circuit includes: a first circuit to convert an input voltage into a current using a transfer conductance as a conversion coefficient; a capacitor connected to an output terminal of the first circuit; a second circuit connected to the first circuit and capacitor, and configured to convert an input voltage into a current using a transfer conductance as a conversion coefficient; a setting circuit to adjust the transfer conductance of the first circuit from a first signal and a second signal for gain adjustment and generate a third signal for gain adjustment. The output terminal of the first circuit is connected to an output terminal of the second circuit from which a signal inverted with respect to a signal output from the first circuit is output, the first signal is input to the second circuit, and a frequency band is adjusted by the first signal.Type: ApplicationFiled: December 21, 2009Publication date: July 1, 2010Applicant: Toshiba Storage Device CorporationInventor: Isao TSUYAMA
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Patent number: 7746120Abstract: A signal receiving device includes: a first conversion unit comprising a first input terminal to which a signal including a voltage signal and a reference voltage is inputted, and a first output terminal which output a first current signal voltage-current converted from the signal; a second conversion unit comprising a second input terminal to which the reference voltage is inputted, and a second output terminal which output a second current signal voltage-current converted from the reference voltage; a current mirror circuit comprising a third input terminal to which the second current signal is inputted, and a third output terminal which output a third current signal corresponding to the second current signal; and an output unit connected to both the first and third output terminals.Type: GrantFiled: January 26, 2009Date of Patent: June 29, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Toshiyuki Umeda, Shoji Otaka
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Publication number: 20100156471Abstract: A cost function generator circuit includes memory terms each receiving one or more input signals, and each providing inphase and quadrature output current signals. The inphase and quadrature output currents of the memory terms are summed to provide combined inphase and quadrature output currents, respectively. Transimpedance amplifiers are provided to transform the combined inphase and quadrature output currents into an inphase output voltage and a quadrature output voltage.Type: ApplicationFiled: December 19, 2008Publication date: June 24, 2010Inventor: Frederic Roger
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Patent number: 7737733Abstract: A current-voltage conversion circuit which converts a current to be detected into a voltage, includes a detection resistor, amplifier circuit having a first operational amplifier, and an offset adjusting current source having a third resistor and a fourth resistor which are capable of trimming. The offset adjusting current source causes an offset adjustment current to flow in the offset resistor. The current value of the offset adjustment current is controlled by adjusting the resistance of the third resistor and the fourth resistor. A voltage at a node between the first transistor and the second resistor is output.Type: GrantFiled: July 11, 2006Date of Patent: June 15, 2010Assignee: Rohm Co., Ltd.Inventors: Ichiro Yokomizo, Yutaka Shibata
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Publication number: 20100127735Abstract: A mixer circuit is provided. The mixer circuit comprises: a voltage-to-current converter stage; a switching stage comprising a plurality of switches, the switching stage being coupled with the voltage-to-current converter stage to controlled passing electrical current from the voltage-to-current converter stage through the switches; and a frequency conversion stage coupled to the switching stage. A mixer circuit arrangement is also provided.Type: ApplicationFiled: October 31, 2007Publication date: May 27, 2010Inventor: Wen Hu Zhao
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Publication number: 20100109713Abstract: A multi-phase power converter and a method for balancing a plurality of currents in the multi-phase power converter. The multi-phase power converter that includes a pulse width modulator coupled to an oscillator. A plurality of currents are generated in response to output signals from the pulse width modulator. The levels of the currents are sensed and a sense signal is transmitted to the pulse width modulator. Switching circuitry within the pulse width modulator switches signals from the oscillator in accordance with the current levels, the levels of the signals from the oscillator, and whether at least one of the signals from the oscillator is either rising or falling.Type: ApplicationFiled: November 5, 2008Publication date: May 6, 2010Inventor: Paul J. Harriman
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Publication number: 20100110064Abstract: A source driver and a liquid crystal display (LCD) device having the same. A source driver may carry a clock in a data current, and may recover a clock signal and/or a data signal without being substantially affected by external frequencies and/or resistance. A source driver may include a trans-impedance amplifier which may receive data currents, convert data currents into voltages, and/or output voltages as data voltages and/or clock voltages. A source driver may include a comparator electrically coupled to a trans-impedance amplifier, which may change levels of data and/or clock voltages applied from a trans-impedance amplifier, and/or may output level-changed voltages as data signals and/or a clock signal.Type: ApplicationFiled: October 29, 2009Publication date: May 6, 2010Applicant: Dongbu HiTek Co., Ltd.Inventors: Woo-Jae Choi, Jong-Kee Kim, Kyoo-Joon Lee
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Patent number: 7710165Abstract: A Voltage-to-Current converter includes a current mirror having first and second poles, a first transistor coupled between the first pole of the current mirror and a low voltage through a first resistor, a second transistor coupled between the second pole of the current mirror and a low voltage through a second resistor wherein the second resistor is substantially identical with the first resistor, and wherein the output current is dependent on resistance of the first resistor, the input voltage signal applied to the gate of the first transistor, and a reference voltage signal applied to the gate of the second resistor.Type: GrantFiled: September 25, 2007Date of Patent: May 4, 2010Assignee: Integrated Device Technology, Inc.Inventor: Han Bi
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Patent number: 7710185Abstract: A CMOS transconductor for cancelling third-order intermodulation is provided. The transconductor includes a transconductance circuit and a tuneable distortion circuit. The transconductance circuit takes an input voltage and generates an output current having a transconductance element and an IM3 element. The distortion circuit takes the same input voltage and generates a current having an IM3 element of equal amplitude and opposite phase to the IM3 element of the transconductance circuit. A controller circuit tunes the distortion circuit to adjust its IM3 element to substantially equal the amplitude of the IM3 of the transconductance circuit. The distortion and transconductance circuits are arranged to sum their output currents thereby effectively cancelling the IM3 elements, leaving the transconductance relatively unmodified.Type: GrantFiled: May 12, 2005Date of Patent: May 4, 2010Assignee: Icera Canada ULCInventor: Tajinder Manku
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Publication number: 20100097104Abstract: A control circuit is developed to adaptively operate a power converter at quasi-resonance (QR) and in a continuous current mode (CCM) to achieve high efficiency. The control circuit includes a PWM circuit generating a switching signal coupled to switch a transformer. A signal generation circuit generates a ramp signal and a pulse signal. The pulse signal is generated in response to the ramp signal for switching on the switching signal. A feedback circuit produces a feedback signal according to an output load of the power converter. The feedback signal is coupled to switch off the switching signal. A detection circuit is coupled to the transformer for generating a valley signal in response to the waveform of the transformer. The valley signal is further coupled to generate the pulse signal when the ramp signal is lower than a threshold. The level of the threshold is correlated to the feedback signal.Type: ApplicationFiled: October 21, 2008Publication date: April 22, 2010Applicant: SYSTEM GENERAL CORP.Inventors: Ta-Yung Yang, Chuh-Ching Li, Ying-Chieh Su, Chih-Chi Chang
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Patent number: 7692455Abstract: Embodiments of methods and apparatus for receiving data are disclosed. More particularly, methods of receiving a current mode signal, which can improve a signal to noise ratio (SNR) according to a change in a power supply voltage, and current mode comparators and semiconductor devices that use the methods are provided. A method of receiving a current mode signal includes receiving a reference current signal and a data current signal through a channel and generating a sensing voltage based on a difference between the reference current signal and the data current signal, varying a transconductance to reduce an input resistance of the current mode comparator in inverse proportion to an increase in a power supply voltage supplied to the current mode comparator, and converting the sensing voltage into a CMOS level output signal using the current mode comparator.Type: GrantFiled: November 9, 2007Date of Patent: April 6, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Yong-Weon Jeon, Jang-Jin Nam, Dong-Hoon Baek
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Patent number: 7683729Abstract: In general, in one aspect, the disclosure describes an apparatus that includes an inductive capacitive voltage controlled oscillator (LC VCO) to generate an output clock. A voltage to current converter is used to receive a forwarded clock and to inject the forwarded clock to the LC VCO. The output clock is a deskewed version of the forwarded clock.Type: GrantFiled: March 30, 2007Date of Patent: March 23, 2010Assignee: Intel CorporationInventors: Mozhgan Mansuri, Sudip Shekhar, Bryan K. Casper, Frank P. O'Mahony
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Publication number: 20100060324Abstract: Provided is voltage/current conversion circuit including: first and second capacitors; first and second resistors each connected to input terminal; first and second current sources; third and fourth resistors connected to current sources; differential amplifier for controlling the current sources; control unit for performing control, in first state, the input terminal is connected to the first and second capacitors; one input of the differential amplifier is connected to the first resistor and output of the first current source; the other input of the differential amplifier is connected to the second resistor and output of the second current source, and in second state, the second capacitor is connected between the output of the first current source and the one input of the differential amplifier, the first capacitor is connected between the output of the second current source and the other input of the differential amplifier.Type: ApplicationFiled: September 8, 2009Publication date: March 11, 2010Applicant: NEC Electronics CorporationInventor: Toshiyuki ETOU
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Publication number: 20100039056Abstract: A voltage-command correction unit provided between an electric-power conversion unit and a voltage-command calculation unit provides a predetermined current range including the zero level for the detected output current, and, at a first clock time when the output current enters from outside to inside of the current range, sets a zero cross timing of the output current as a clock time for switching the polarity of the correction voltage that corrects the AC voltage command calculated and output by the voltage-command calculation unit based on the first clock time and the frequency, thereby making a configuration capable of correcting the AC voltage command with the correction voltage with the same polarity as the polarity of the output current around the zero cross point of the output current.Type: ApplicationFiled: October 31, 2006Publication date: February 18, 2010Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takahiko Kobayashi, Yoshihiko Kimpara, Manabu Yoshimura
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Patent number: 7663409Abstract: A voltage/current converter circuit includes a bridge configuration having a first current path with a first resistor, a first transistor, and an input node to receive a ramp voltage to be converted, and a second current path with a second resistor and a second transistor. A current passes through the second current path. An amplifier arrangement balances the bridge configuration by providing an output signal to a control terminal of the first transistor and/or to a control terminal of the second transistor.Type: GrantFiled: July 25, 2007Date of Patent: February 16, 2010Assignee: Austriamicrosystems AGInventor: Pramod Singnurkar
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Patent number: 7663442Abstract: According to one embodiment, a system, apparatus, and method for receiving high-speed signals using a receiver with a transconductance amplifier is presented. The apparatus comprises a transconductance amplifier to receive input voltage derived from an input signal, a clocked current comparator to receive output current from the transconductance amplifier, and a storage element to receive a binary value from the clocked current comparator.Type: GrantFiled: March 28, 2005Date of Patent: February 16, 2010Assignee: Intel CorporationInventors: Zuoguo Wu, Feng Chen
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Patent number: 7663410Abstract: A current-mode differential transmitter, receiving a single-end input voltage signal and accordingly generating a differential output current signal, is provided. The transmitter includes a first switch, a second switch and a current mirror. The first switch is coupled in a first current path and controlled by the single-end input voltage signal. The second switch is coupled in a second current path and controlled by an inverted signal of the single-end input voltage signal. The current mirror mirrors a reference current to the first current path when the first switch is turned on, and mirrors the reference current to the second current path when the second switch is turned on. The differential output current signal is derived from the currents on the first and second current paths.Type: GrantFiled: October 4, 2007Date of Patent: February 16, 2010Assignee: Himax Technologies LimitedInventors: Chih-Haur Huang, Yuan-Kai Chu
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Patent number: 7652509Abstract: The present invention relates to a transconductance circuit intended to convert a differential input voltage, supplied as two signals to two inputs, IN+ and IN? respectively, into a differential output current. According to the invention, each of the two signals of said differential input voltage is supplied to each input, IN+ and IN? respectively, through a follower transistor, TF+ and TF? respectively, connected to said input, IN+ and IN? respectively, by its emitter and receiving said signal on a control electrode.Type: GrantFiled: October 6, 2004Date of Patent: January 26, 2010Assignee: ST-Ericsson SAInventors: Sébastien Prouet, Hervé Marie
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Patent number: 7642816Abstract: A transconductor to convert an input voltage to an output current, includes: a primary transconductance stage to provide the output current from the input voltage and a driving current; an adaptive transconductance stage coupled in series with the primary transconductance stage to generate the driving current from the input voltage; and a bias circuit coupled to provide a primary bias voltage to the primary transconductance stage and an adaptive bias voltage to the adaptive transconductance stage.Type: GrantFiled: October 10, 2007Date of Patent: January 5, 2010Assignee: Industrial Technology Research InstituteInventors: Ming-Ching Kuo, Pei-Ling Tsai, Chih-Hung Chen
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Publication number: 20090295434Abstract: A signal receiving device includes: a first conversion unit comprising a first input terminal to which a signal including a voltage signal and a reference voltage is inputted, and a first output terminal which output a first current signal voltage-current converted from the signal; a second conversion unit comprising a second input terminal to which the reference voltage is inputted, and a second output terminal which output a second current signal voltage-current converted from the reference voltage; a current mirror circuit comprising a third input terminal to which the second current signal is inputted, and a third output terminal which output a third current signal corresponding to the second current signal; and an output unit connected to both the first and third output terminals.Type: ApplicationFiled: January 26, 2009Publication date: December 3, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Toshiyuki UMEDA, Shoji OTAKA
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Patent number: 7626449Abstract: A method for tuning a filter is provided. The method includes: enabling a VCO circuit, wherein at least a portion of the VCO circuit is selected from the filter; generating an oscillation signal by the VCO circuit according to a driving signal; comparing the oscillation signal with a reference signal and generating a comparison result; and adjusting the driving signal according to the comparison result.Type: GrantFiled: June 16, 2008Date of Patent: December 1, 2009Assignee: Mediatek Inc.Inventors: Wei-Hsuan Tu, Tse-Hsiang Hsu
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Publication number: 20090273374Abstract: A system and method for performing voltage to current conversion, the system comprising of a first set of devices that senses the input voltage signal through its input terminal and replicates said input voltage across a second set of devices which then converts said replicated input voltage signal to an output current signal; a third set of devices that transfers the output current signal to output terminals; a differential feedback loop comprising an amplifier positioned between a first one of the first set of devices and a first one of the third set of devices; and a common mode feedback loop that regulates the output average voltage to a reference voltage.Type: ApplicationFiled: May 5, 2008Publication date: November 5, 2009Applicant: Newport Media, Inc.Inventor: Dejun Wang
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Publication number: 20090261864Abstract: A method and a circuit for current mode data sensing and propagation by using voltage amplifier are provided. Example embodiments may include providing an output signal from a voltage amplifier in response to the voltage amplifier receiving an input signal. The method may include providing a current output signal from a voltage-to-current converter in response to the voltage-to-current converter receiving the output signal. The output signal may be used to drive a current sense amplifier.Type: ApplicationFiled: April 22, 2008Publication date: October 22, 2009Inventor: Donald M. Morgan
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Patent number: 7605645Abstract: A transconductor for receiving a differential voltage signal and outputting a differential current signal, includes two transconductors for receiving the differential voltage signal and outputting a single-end current signal. An inversion input terminal of one of the two transconductors is connected with a non-inversion input terminal of the other. The transconductor outputs a current signal output from each of the two transconductors as the differential current signal.Type: GrantFiled: December 22, 2006Date of Patent: October 20, 2009Assignee: Panasonic CorporationInventors: Takashi Morie, Akinori Matsumoto, Shiro Dosho
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Patent number: 7605635Abstract: Calibration circuitry and method for maintaining constant signal detection thresholds for multiple signal receivers that receive data signals in the form of current signals. A value of one of the incoming current signals having a predetermined signal pattern is detected and used to generate threshold control signals for each of the signal receivers to control the data signal detection thresholds.Type: GrantFiled: May 24, 2007Date of Patent: October 20, 2009Assignee: National Semiconductor CorporationInventors: Adam Fish, John Lynch
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Publication number: 20090259418Abstract: A current-voltage conversion circuit which converts a current to be detected into a voltage, includes a detection resistor, amplifier circuit having a first operational amplifier, and an offset adjusting current source having a third resistor and a fourth resistor which are capable of trimming. The offset adjusting current source causes an offset adjustment current to flow in the offset resistor. The current value of the offset adjustment current is controlled by adjusting the resistance of the third resistor and the fourth resistor. A voltage at a node between the first transistor and the second resistor is output.Type: ApplicationFiled: July 11, 2006Publication date: October 15, 2009Applicant: ROHM CO., LTD.Inventors: Ichiro Yokomizo, Yutaka Shibata
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Patent number: 7602220Abstract: A resistor-input transconductor includes a circuit configured to generate a common-mode compensation current. The common-mode compensation current is used to compensate for the common-mode voltage of the inputs. A current output of the resistor-input transconductor is proportional to a voltage difference between the two inputs and essentially independent of a common-mode voltage of the two inputs. The resistor input transconductor may be applied in a variety of applications including, for example, communications.Type: GrantFiled: June 24, 2008Date of Patent: October 13, 2009Assignee: Gigle Semiconductor, Ltd.Inventors: Adrià Bofill-Petit, Robert K. Henderson, Jonathan Ephriam David Hurwitz
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Publication number: 20090243664Abstract: A data transfer circuit comprises a voltage/current converter circuit for converting a first binary voltage data of n bits (n is an integer equal to or larger than two) to multi-value current data of 2n values which is output to a single data transfer line. A current comparator circuit converts the multi-value current data on the data transfer line to binary current data of (2n?1) bits, and a current/voltage converter circuit converts the binary current data of the (2n?1) bits to second binary voltage data of (2n?1) bits. A counter circuit restores the first binary voltage data of the n bits from the second binary voltage data of the (2n?1) bits.Type: ApplicationFiled: February 4, 2009Publication date: October 1, 2009Inventor: Toshiaki Inoue
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Publication number: 20090243662Abstract: A MOS integrated circuit includes: a voltage-to-current conversion circuit configured to convert first and second voltages to a first current having a current value corresponding to the first voltage and a second current having a current value corresponding to the second voltage; and a current comparison circuit configured to compare the respective current values of the first and second currents and to output a voltage showing the comparison result. Oxide films of MOS transistors of the current comparison circuit are thinner than oxide films of MOS transistors of the voltage-to-current conversion circuit.Type: ApplicationFiled: March 11, 2009Publication date: October 1, 2009Inventor: Masahiro AOIKE
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Publication number: 20090189650Abstract: A Phase-Locked Loop (PLL) circuit includes a voltage-controlled oscillator. The voltage-controlled oscillator includes a voltage-current conversion circuit and a current-controlled oscillation circuit. The voltage-current conversion circuit includes an input transistor having a gate terminal connecting a control voltage, a first transistor connected in series to the input transistor, a second transistor connected as a current-mirror to the first transistor, to generate a control current, and a current source connected in parallel to the first transistor. The current-controlled oscillation circuit oscillates at a frequency according to the control current.Type: ApplicationFiled: January 23, 2009Publication date: July 30, 2009Applicant: NEC Electronics CorporationInventors: Satoshi Fujino, Ryota Yamamoto
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Publication number: 20090167365Abstract: A regulator circuit and a method for regulating an output voltage. The regulator circuit includes an undervoltage protection stage capable of operating in a plurality of operating modes. In one mode, the undervoltage protection stage compensates for a low undervoltage appearing in the output voltage and in another mode it compensates for a large undervoltage appearing in the output voltage. When the output voltage has a low undervoltage, a portion of the current from a current source is routed to a feedback network to balance the input voltages of the undervoltage protection stage and to place the voltage regulator in a steady state operating mode. When the output voltage has a large undervoltage, the undervoltage protection stage turns on a current sourcing transistor that cooperates with the current from the current source to quickly charge a compensation capacitor and increase the power appearing at the output of the voltage regulator.Type: ApplicationFiled: April 18, 2006Publication date: July 2, 2009Inventors: Joel Turchi, Christophe Basso
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Patent number: 7551005Abstract: An output circuit includes a constant current circuit that generates and supplies a constant current to an output terminal of the output circuit. Based on the constant current, the output circuit converts an input signal to an output signal having a voltage within a voltage range specified by upper and lower clamp voltages. The output signal is feedback to the constant current circuit. The constant current circuit changes the amount of the constant current in accordance with the output signal in such a manner that the constant current increases with an increase in the output signal and becomes zero when the output signal decreases to or below a threshold voltage. Thus, the upper clamp voltage is made as close to a power supply voltage as possible and the lower clamp voltage is made as close to a ground voltage as possible.Type: GrantFiled: October 26, 2006Date of Patent: June 23, 2009Assignee: DENSO CORPORATIONInventors: Takanori Makino, Kazuyoshi Nagase
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Patent number: 7548096Abstract: A current to voltage converter that includes a first voltage generator to generate a first voltage according to an input current. a reference voltage generator to output a first reference voltage which is higher than the first voltage, a second voltage generator to generate a second voltage which is lower than the first voltage and fluctuate with a delay in response to a fluctuation in the first voltage, a first comparing unit to compare the first reference voltage with the second voltage and select either the first reference voltage or the second voltage and a second comparing unit to compare the second reference voltage with the first voltage.Type: GrantFiled: June 8, 2007Date of Patent: June 16, 2009Assignee: NEC Electronics CorporationInventor: Yuji Fujita
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Publication number: 20090140775Abstract: A multiplexing circuit comprising an converter for converting an input voltage signal to an input current signal. A plurality of first current mirrors for mirroring the input current signal. A switching unit selectively switches each first current mirror to a corresponding output.Type: ApplicationFiled: November 2, 2007Publication date: June 4, 2009Inventor: Michael D. Keane
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Publication number: 20090140776Abstract: An exemplary aspect of an embodiment of the present invention is a voltage-current converter converting an input voltage input to an input terminal to a current to output the current, the voltage-current converter including a first current generating circuit including an input transistor having a gate connected to the input terminal and generating an output current according to a current flowing in the input transistor, and a second current generating circuit including a transistor having a gate having a potential different from potential of a source and a drain, the second current generating circuit generating a superimposed current according to the current flowing in the transistor to supply the superimposed current to the input transistor.Type: ApplicationFiled: November 3, 2008Publication date: June 4, 2009Applicant: NEC Electronics CorporationInventor: Kazunosuke Hirai
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Patent number: 7541844Abstract: A voltage interpolation buffer for interpolating voltages by adjusting ratio of bias currents includes a first difference voltage to current unit for outputting corresponding difference current according to a first voltage, a first bias current and voltage of a voltage output end, a second difference voltage to current unit for outputting corresponding difference current according to a second voltage, a second bias current and the voltage of the voltage output end, and a current to voltage unit coupled to the first difference voltage to current unit, the second difference voltage to current unit and the voltage output end for outputting a interpolation result of the first voltage and the second voltage corresponding to a ratio of the first bias current and the second bias current according to the difference currents outputted by the first difference voltage to current unit and the second difference voltage to current unit.Type: GrantFiled: September 27, 2007Date of Patent: June 2, 2009Assignee: NOVATEK Microelectronic Corp.Inventors: Wei-Ta Chiu, Wen-Shian Shie
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Patent number: 7538585Abstract: Disclosed is a transconductor including: first and second transistors each having first and second gates, the first and second gates being independently controlled, differential voltage input being supplied between the one first gate and the other first gate, the one source and the other source being connected, a first control voltage being commonly given to both of the second gates, and the drains being differential current output terminals; third and fourth transistors each having the same connection as the first and second transistors, each of the one drain and the other drain being connected with either of the one drain and the other drain of the first and the second transistors so that polarities are opposite to each other; and a current source connected with both of the sources of the first and the second transistors and both of the sources of the third and the fourth transistors.Type: GrantFiled: August 30, 2007Date of Patent: May 26, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Rui Ito, Tetsuro Itakura
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Patent number: 7538626Abstract: A voltage controlled oscillator circuit includes a ring oscillator including a plurality of delay circuits that are connected like a ring and a voltage to current converter circuit for controlling current flowing in the ring oscillator so as to change an oscillation frequency thereof. The voltage to current converter circuit 11 is provided with a shunt circuit for shunting a part of current obtained by converting input voltage, and the shunted part of the current is used for controlling the current flowing in the ring oscillator.Type: GrantFiled: July 26, 2006Date of Patent: May 26, 2009Assignee: Fujitsu LimitedInventors: Tatsuya Yamaguchi, Kazunori Hayami, Satoshi Yamamoto
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Patent number: 7532045Abstract: An active transconductance is provided by converting an input voltage into a current, and providing the current to a node which is maintained at a generally fixed voltage. Current is mirrored from the fixed voltage node to an output node. Such an active transconductance circuit can meet conventional performance specifications, but at a lower supply current, and/or with lower circuit complexity, and/or with a lower circuit area requirement.Type: GrantFiled: February 8, 2005Date of Patent: May 12, 2009Assignee: SiTel Semiconductor B.V.Inventor: Adrianus Gerardus Mulders
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Publication number: 20090115461Abstract: The present invention is intended to achieve a transconductance amplifier and a voltage/current converting method which can provide a sufficient amplitude and a high degree of design freedom. The method comprises the steps of converting a first voltage signal to a first current signal; converting a second voltage signal to a second current signal; obtaining the common-mode components of the first and second current signals; and subtracting the common-mode components from the first and second current signals to obtain third and fourth signals, and further, subtracting the fourth current signal from the third current signal to generate a first output, while subtracting the third current signal from the fourth current signal to generate a second output.Type: ApplicationFiled: June 22, 2006Publication date: May 7, 2009Applicant: NEC CORPORATIONInventor: Hiroyuki Okada
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Patent number: 7525348Abstract: A circuit and method for comparing and providing a signal indicative of a difference in magnitude between a differential signal voltage and a differential reference voltage.Type: GrantFiled: April 19, 2005Date of Patent: April 28, 2009Assignee: National Semiconductor CorporationInventor: Ramsin M. Ziazadeh
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Publication number: 20090096489Abstract: A system comprising an over-current detector configured to receive a switching voltage signal and to produce a first and a second current signal; an current-to-voltage converter configured to convert the first and second current signals into a first and a second voltage signal; and a current mirror amplifier configured to utilize the first and second voltage signals to output an over-current condition signal when the switching signal has exceeded a threshold value.Type: ApplicationFiled: October 16, 2007Publication date: April 16, 2009Applicant: BROADCOM CORPORATIONInventors: Wong Tak Ying, Rickey Setiawan
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Publication number: 20090096490Abstract: A transconductor to convert an input voltage to an output current, includes: a primary transconductance stage to provide the output current from the input voltage and a driving current; an adaptive transconductance stage coupled in series with the primary transconductance stage to generate the driving current from the input voltage; and a bias circuit coupled to provide a primary bias voltage to the primary transconductance stage and an adaptive bias voltage to the adaptive transconductance stage.Type: ApplicationFiled: October 10, 2007Publication date: April 16, 2009Inventors: Ming-Ching Kuo, Pei-Ling Tsai, Chih-Hung Chen
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Publication number: 20090091356Abstract: A current-mode differential transmitter, receiving a single-end input voltage signal and accordingly generating a differential output current signal, is provided. The transmitter includes a first switch, a second switch and a current mirror. The first switch is coupled in a first current path and controlled by the single-end input voltage signal. The second switch is coupled in a second current path and controlled by an inverted signal of the single-end input voltage signal. The current mirror mirrors a reference current to the first current path when the first switch is turned on, and mirrors the reference current to the second current path when the second switch is turned on. The differential output current signal is derived from the currents on the first and second current paths.Type: ApplicationFiled: October 4, 2007Publication date: April 9, 2009Applicant: HIMAX TECHNOLOGIES LIMITEDInventors: Chih-Haur Huang, Yuan-Kai Chu
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Publication number: 20090079603Abstract: A ramp voltage generation circuit suitable for an A/D converter preventing a variation in a digital value obtained by an A/D conversion operation. The circuit comprises a stabilization voltage source Vref, an operation amplifier AMP1 having a non-inversion input terminal receiving a voltage VREF from the Vref and an inversion input terminal connected to a switched capacitor equivalent resistance Req, and a transistor MNSF for conducting a current Ick to the Req based on an output voltage of the AMP1. Both ends of a conductive load Cint charged and discharged based on a current Iint2 generated by a current mirror of the Ick are connected to an output terminal and an inversion input terminal of an operation amplifier AMPint, a voltage of a stabilization voltage source Vc is applied to a non-inversion input terminal, and an output voltage of the AMPint is outputted to the outside as a ramp voltage.Type: ApplicationFiled: January 24, 2008Publication date: March 26, 2009Applicant: SHARP KABUSHIKI KAISHAInventor: Masahiko MARUYAMA
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Publication number: 20090079470Abstract: A Voltage-to-Current converter includes a current mirror having first and second poles, a first transistor coupled between the first pole of the current mirror and a low voltage through a first resistor, a second transistor coupled between the second pole of the current mirror and a low voltage through a second resistor wherein the second resistor is substantially identical with the first resistor, and wherein the output current is dependent on resistance of the first resistor, the input voltage signal applied to the gate of the first transistor, and a reference voltage signal applied to the gate of the second resistor.Type: ApplicationFiled: September 25, 2007Publication date: March 26, 2009Inventor: Han Bi
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Patent number: 7508241Abstract: A data transfer circuit comprises a voltage/current converter circuit for converting a first binary voltage data of n bits (n is an integer equal to or larger than two) to multi-value current data of 2n values which is output to a single data transfer line. A current comparator circuit converts the multi-value current data on the data transfer line to binary current data of (2n?1) bits, and a current/voltage converter circuit converts the binary current data of the (2n?1) bits to second binary voltage data of (2n?1) bits. A counter circuit restores the first binary voltage data of the n bits from the second binary voltage data of the (2n?1) bits.Type: GrantFiled: July 8, 2004Date of Patent: March 24, 2009Assignee: Pioneer CorporationInventor: Toshiaki Inoue