Square Function Patents (Class 327/349)
  • Patent number: 9379677
    Abstract: A bias circuit includes a first p-n junction element supplied with a current by a first current source connected to a low-voltage side of the first p-n junction element and a base terminal of a second transistor, a second p-n junction element supplied with a current by a second current source, the second current source connected to a low-voltage side of the second p-n junction element and a base terminal of a first transistor, the first and second transistors connected at their emitter terminals to a third current source and receiving base voltages generated by the first and second p-n junction elements, respectively. The second transistor and the first transistor constitute a differential pair in which, at a collector terminal of the second transistor, a current having a temperature coefficient that is substantially twice the temperature coefficient of the current of the second current source is obtained.
    Type: Grant
    Filed: June 28, 2014
    Date of Patent: June 28, 2016
    Assignee: Hitachi, Ltd.
    Inventors: Ichiro Somada, Takao Okazaki, Kenta Mochiduki
  • Patent number: 9218013
    Abstract: A method and system include a plurality of solar cells and a plurality of voltage controllers. Each of the plurality of solar cells is directly coupled to a dedicated one of the plurality of voltage controllers to form unique pairs of solar cells and voltage controllers. Each of a plurality of panels contain a plurality of unique pairs.
    Type: Grant
    Filed: October 17, 2008
    Date of Patent: December 22, 2015
    Assignee: TIGO ENERGY, INC.
    Inventor: Dan Kikinis
  • Patent number: 9142592
    Abstract: An integrated circuit including ESD device is disclosed. One embodiment includes a semiconductor region being electrically isolated from adjacent semiconductor regions by an isolating region. Both an ESD device and a device configured to emit radiation are formed within the semiconductor region.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: September 22, 2015
    Assignee: Infineon Technologies AG
    Inventors: Michael Mayerhofer, Joost Willemen, David Johnsson
  • Patent number: 8803546
    Abstract: An apparatus for performing power detection includes a squarer module and a calibration module that is coupled to the squarer module, where the squarer module includes a first squarer and a second squarer. The first squarer is arranged to convert an input signal of the squarer module into a first squarer output signal. In addition, the second squarer is arranged to output a second squarer output signal while a predetermined voltage level is input into an input terminal of the second squarer. Additionally, the calibration module is arranged to compare a difference between the first squarer output signal and the second squarer output signal with a reference signal to generate a comparison signal, and to compensate the difference according to the comparison signal, so as to perform a calibration on the apparatus. A method for performing power detection is also provided, and can be performed by utilizing the apparatus.
    Type: Grant
    Filed: November 27, 2011
    Date of Patent: August 12, 2014
    Assignee: MediaTek Singapore Pte. Ltd.
    Inventor: Zhiming Deng
  • Patent number: 8698544
    Abstract: A circuit for providing a DC output equal to the RMS value of a time-varying input signal, the circuit including: (i) an RMS-to-DC converter for producing the DC output and (ii) a high-order low-pass filter comprising at least first and second low-pass filters connected in series to cooperatively reduce at least one of ripple in the DC output, ripple in an denominator feedback loop, or DC error in the DC output.
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: April 15, 2014
    Assignee: Analog Devices, Inc.
    Inventors: Derek Bowers, Lewis Counts, James G. Staley
  • Publication number: 20140084987
    Abstract: A squaring circuit has current mode triplet metal oxide semiconductor (MOS) devices, including a first MOS device, a second MOS device and a third MOS device each having a source operably coupled to a first current source; and a fourth MOS device, a fifth MOS device and a sixth MOS device each having a source operably coupled to a second current source. The drain of first and fourth MOS device is operably coupled to a first supply, the drain of second and fifth MOS device is operably coupled to a first differential output port and the drain of third and sixth MOS device is operably coupled to a second differential output port. The gate of first, second and sixth MOS device is connected to a first differential input port, and the gate of third, fourth and fifth MOS device is connected to a second differential input port.
    Type: Application
    Filed: November 28, 2013
    Publication date: March 27, 2014
    Applicant: MediaTek Singapore Pte. Ltd.
    Inventors: Christopher Jacques Beale, Bernard Mark Tenbroek
  • Patent number: 8665127
    Abstract: Architectures of ?? difference-of-squares RMS-to-digital converters employing multiple feedback paths. Additional feedback paths enable a stable ?? closed-loop behavior in different topologies where the RMS level of the quantization error processed by the squaring non-linearity is minimized. Such feedback paths include lowpass filtered and constant gain feedback paths, lowpass and highpass filtered paths or multiple lowpass filtered paths. These can be combined with multiple integrators in the forward path, with frequency compensation provided by additional feedforward or feedback paths. Electronic configurability can further extend the total input referred dynamic range (DR) of such architectures.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: March 4, 2014
    Assignee: National Semiconductor Corporation
    Inventor: Paulo Gustavo Raymundo Silva
  • Patent number: 8665126
    Abstract: A sigma-delta (??) difference-of-squares LOG-RMS to digital converter” by merging a traditional ?? modulator with an analog LOG-RMS to DC converter based on a difference-of-squares concept. Two basic architectures include one based on two squaring cells in the feedforward and feedback paths and a second based on a single squaring cell in the forward path. High-order ?? LOG-RMS can be implemented with a loop filter containing multiple integrators and feedforward and/or feedback paths for frequency compensation. The embodiments as described allow the implementations of ?? difference-of-squares LOG-RMS to DC converters with a natural digital output and a logarithmically compressed dynamic range.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: March 4, 2014
    Assignee: National Semiconductor Corporation
    Inventors: Paulo Gustavo Raymundo Silva, Michael Hendrikus Laurentius Kouwenhoven
  • Patent number: 8665128
    Abstract: A sigma-delta (??) difference-of-squares LOG-RMS to digital converter for true RMS detection by merging a ?? modulator with an analog LOG-RMS to DC converter based on a difference-of-squares. Chopper-stabilization, implemented through commutators running at two different frequencies, can be employed to reduce sensitivity to DC offsets and low-frequency errors, resulting in an extension of the useful input-referred dynamic range. High-order ?? LOG-RMS converters can be implemented with a loop filter containing multiple integrators and feedforward and/or feedback paths for frequency compensation. The resulting implementations are ?? difference-of-squares LOG-RMS to DC converters with a natural digital output and a logarithmically compressed dynamic range.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: March 4, 2014
    Assignee: National Semiconductor Corporation
    Inventors: Paulo Gustavo Raymundo Silva, Michael Hendrikus Laurentius Kouwenhoven
  • Patent number: 8624657
    Abstract: A squaring circuit has current mode triplet metal oxide semiconductor (MOS) devices, including a first MOS device, a second MOS device and a third MOS device each having a source operably coupled to a first current source; and a fourth MOS device, a fifth MOS device and a sixth MOS device each having a source operably coupled to a second current source. The drain of first and fourth MOS device is operably coupled to a first supply, the drain of second and fifth MOS device is operably coupled to a first differential output port and the drain of third and sixth MOS device is operably coupled to a second differential output port. The gate of first, second and sixth MOS device is connected to a first differential input port, and the gate of third, fourth and fifth MOS device is connected to a second differential input port.
    Type: Grant
    Filed: July 4, 2012
    Date of Patent: January 7, 2014
    Assignee: MediaTek Singapore Pte. Ltd.
    Inventors: Christopher Jacques Beale, Bernard Mark Tenbroek
  • Patent number: 8598915
    Abstract: The CMOS programmable non-linear function synthesizer utilizes CMOS current-mode electronics to provide synthesis of arbitrary analog functions. The circuit approximates a seventh-order Taylor series expansion to synthesize an arbitrary nonlinear function. Each term of the Taylor series expansion is realized using a current-mode basic building block, and the output weighted currents of these basic building blocks are algebraically added in addition to a DC current, if needed. The CMOS current mode electronic circuit can be easily integrated, extended to include higher order terms of the Taylor series, and programmed to generate arbitrary nonlinear functions.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: December 3, 2013
    Assignee: King Fahd University of Petroleum and Minerals
    Inventors: Muhammad Taher Abuelma'atti, Abdullah Muhammad Taher Abuelmaatti
  • Publication number: 20130234775
    Abstract: A circuit for providing a DC output equal to the RMS value of a time-varying input signal, the circuit including: (i) an RMS-to-DC converter for producing the DC output and (ii) a high-order low-pass filter comprising at least first and second low-pass filters connected in series to cooperatively reduce at least one of ripple in the DC output, ripple in an denominator feedback loop, or DC error in the DC output.
    Type: Application
    Filed: March 12, 2012
    Publication date: September 12, 2013
    Inventors: Derek Bowers, Lewis Counts, James G. Staley
  • Patent number: 8305133
    Abstract: Implementing a piecewise-polynomial-continuous function in a translinear circuit generally involves translinear elements that form translinear loops that are linked by a clamp transistor. A first translinear loop controls a first portion of the piecewise-polynomial-continuous function in a first area of operation. A second translinear loop controls a second portion of the piecewise-polynomial-continuous function in a second area of operation. When activated in the second area of operation, the clamp transistor draws current through one of the translinear elements without drawing current away from another translinear element of the translinear circuit.
    Type: Grant
    Filed: October 1, 2010
    Date of Patent: November 6, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Roy Alan Hastings
  • Patent number: 7902901
    Abstract: An RF squarer circuit comprises a first RF multiplier and a first variable gain transimpedance amplifier (TIA). The first RF multiplier receives an RF input signal RFIN and provides a first output current. The first TIA receives the first output current as an input. The first TIA provides an output voltage VOUT.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: March 8, 2011
    Assignee: Scintera Networks, Inc.
    Inventor: Frederic Roger
  • Patent number: 7795948
    Abstract: A circuit includes a multi-tanh cell having a common-emitter node to receive a bias current, and an extra transistor coupled to the common-emitter node to dynamically divert a portion of the bias current from the multi-tanh cell. The circuit may be arranged as a multiplier with an input network arranged to apply two or more input signals to the multi-tanh cell. A second multi-tanh cell with an extra transistor may be arranged in a feedback loop where the outputs of the first and second multi-tanh cells are coupled together at an integrating node. A buffer drives the final output and feedback cell to cancel nonlinearities in the multiplier cells.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: September 14, 2010
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 7791400
    Abstract: A square-function circuit includes an input field-effect transistor (FET) having a gate that is driven by an input voltage and is configured to conduct an output current. The circuit also includes a feedback circuit coupled to a source of the input FET, the feedback circuit being configured to drive a source of the input FET based on the output current to set a magnitude of the output current to be substantially equal to a square of the input voltage.
    Type: Grant
    Filed: August 12, 2008
    Date of Patent: September 7, 2010
    Assignee: Texas Instruments Incorporated
    Inventor: Qunying Li
  • Patent number: 7777551
    Abstract: Disclosed is a multiplier circuit including first and second squaring circuits comprising first and second differential MOS transistors respectively connected in cascode to first and second diode-connected MOS transistors. The first squaring circuit receives a differential sum voltage of a first input voltage and a second input voltage. The second squaring circuit receives a differential subtraction voltage of the first input voltage and the second input voltage. Outputs of the first and second squaring circuits are first and second terminal voltages of the first and second diode-connected MOS transistors. A differential voltage between the first and second terminal voltages corresponds to the product of the first and second input voltages.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: August 17, 2010
    Assignee: NEC Electronics Corporation
    Inventor: Katsuji Kimura
  • Publication number: 20100127754
    Abstract: A power measurement circuit comprises: a transconductance rectifier arrangement including an input and configured to receive a sinusoidal input voltage signal; and an averaging filter for producing a time averaged DC output signal proportional to the mean square of the voltage at the input of the transconductance rectifier arrangement and representative of the average power of the input voltage signal within a range of voltages at the input.
    Type: Application
    Filed: November 25, 2008
    Publication date: May 27, 2010
    Applicant: Linear Technology Corporation
    Inventor: John P. MYERS
  • Publication number: 20100127755
    Abstract: A power measurement circuit and method are described. The circuit comprises: a transconductance rectifier arrangement including an input and configured to receive a periodically varying input voltage signal having an approximate 50% duty cycle; and an averaging filter for producing a time averaged DC output signal proportional to the mean square of the voltage at the input of the transconductance rectifier arrangement and representative of the average power of the input voltage signal within a range of voltages at the input.
    Type: Application
    Filed: December 18, 2008
    Publication date: May 27, 2010
    Applicant: Linear Technology Corporation
    Inventor: John P. MYERS
  • Patent number: 7622981
    Abstract: A square cell comprises first and second bipolar transistors each having an emitter, collector and base, the bases of the transistors being connected for receiving an input voltage, and first and second resistors in series with the first and second bipolar transistors respectively and with a source of reference voltage. The collectors are commonly connected to an output node to supply an output current having a component proportional to the square of the input voltage. Enhanced square law conformance may be produced by adding further pairs of bipolar transistors to the cell, with offset voltage elements coupled between bases of successive transistors on each side of the cell.
    Type: Grant
    Filed: December 6, 2006
    Date of Patent: November 24, 2009
    Assignee: Linear Technology Corporation
    Inventor: Min Z. Zou
  • Publication number: 20090237068
    Abstract: A system includes a first circuit and a second circuit. The first circuit includes a first MOS transistor having a gate and a drain. The first circuit is configured to receive a radio frequency (RF) signal at the gate of the first MOS transistor. The drain of the first MOS transistor is configured to output a first current that is proportional to the square of the input voltage of the RF signal while receiving the RF signal. The second circuit includes a second MOS transistor having a source configured to receive a first current from the first circuit. The second MOS transistor is biased in a triode region and has a channel resistance between the source and a drain. The second circuit is configured to output a voltage proportional to the value of the power of the RF signal received by the first circuit.
    Type: Application
    Filed: March 19, 2009
    Publication date: September 24, 2009
    Applicant: Entropic Communications, Inc.
    Inventor: Sameer Vora
  • Patent number: 7546332
    Abstract: Apparatus and methods for implementation of mathematical functions apparatus providing both speed and accuracy. Disclosed are specific circuits and methods of operation thereof that may be used for the purpose of implementing an exponential function, a squaring function, and a cubic function, using the same basic circuit. By applying a desired weighting function on a current source, an output current provides a value that corresponds exactly to the desired mathematical functions at discrete points, and closely tracks values in between the discrete points. The precision is defined by the selection of a voltage reference for the circuit. Various embodiments are disclosed, as well as embodiments implementing other exemplary functions.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: June 9, 2009
    Assignee: Theta Microelectronics, Inc.
    Inventor: Spyridon Vlassis
  • Patent number: 7514980
    Abstract: The present invention relates to an exponential function generator which is realized with only CMOS element without BJT element, not limited by the physical properties of the element or a square circuit, and not complicated in its configuration, and a variable gain amplifier using the same. The exponential function generator includes a voltage-current converter, 1st to nth curve generators for mirroring the current from the voltage-current converter, outputting a current adjusted according to a predetermined ratio, and an output end for outputting the sum of the current from the 1st to nth curve generators. The exponential current generator is configured to generate the current exponentially adjusted according to the control voltage.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: April 7, 2009
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Jeong Ki Choi, Won Jin Baek, Hyun Hwan Yoo, Seung Min Oh
  • Publication number: 20090045865
    Abstract: A square-function circuit includes an input field-effect transistor (FET) having a gate that is driven by an input voltage and is configured to conduct an output current. The circuit also includes a feedback circuit coupled to a source of the input FET, the feedback circuit being configured to drive a source of the input FET based on the output current to set a magnitude of the output current to be substantially equal to a square of the input voltage.
    Type: Application
    Filed: August 12, 2008
    Publication date: February 19, 2009
    Inventor: QUNYING LI
  • Publication number: 20080136491
    Abstract: A square cell comprises first and second bipolar transistors each having an emitter, collector and base, the bases of the transistors being connected for receiving an input voltage, and first and second resistors in series with the first and second bipolar transistors respectively and with a source of reference voltage. The collectors are commonly connected to an output node to supply an output current having a component proportional to the square of the input voltage. Enhanced square law conformance may be produced by adding further pairs of bipolar transistors to the cell, with offset voltage elements coupled between bases of successive transistors on each side of the cell.
    Type: Application
    Filed: December 6, 2006
    Publication date: June 12, 2008
    Inventor: Min Z. Zou
  • Patent number: 7342431
    Abstract: An RMS to DC converter squares an a-c input signal to obtain a squared direct current voltage signal. The squared direct current voltage signal is applied to successive stages, each stage amplifying its received signal and detecting the amplified level of the signal within a confined range. The detected levels detected in the successive stages are added to produce an output d-c signal that is variable in linear proportion to logarithmic change in RMS voltage of the input signal. The voltage level of the squared direct current voltage signal can be clamped to a predetermined maximum voltage. To expand the range of detection, the squared direct current voltage signal is attenuated prior to detection in one or more of the stages.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: March 11, 2008
    Assignee: Linear Technology Corporation
    Inventor: Min Z. Zou
  • Patent number: 7340013
    Abstract: A receiver for iterative decoding of a received, encoded signal employs slot-based scaling of soft samples. Iterative decoding employs a constituent maximum a priori (MAP) decoder for each constituent encoding of information of the encoded signal. Root mean square (RMS) values for soft samples over a slot are selected for dynamic range scaling. Squared RMS values are combined and equal the squared RMS value for a frame multiplied by a control constant, and this relationship may be employed to derive scaling constants for each slot. Alternatively, the square root of the RMS value multiplied by a constant serves as an SNR estimator that may be employed to scale samples to reduce dynamic range and modify logarithmic correction values for max* term calculation during log-MAP decoding.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: March 4, 2008
    Assignee: Agere Systems Inc.
    Inventors: Gerhard Ammer, Jan-Enno F. Meyer, Shuzhan Xu
  • Patent number: 7327183
    Abstract: A squaring cell combines first and second exponential currents to approximate square law behavior. The exponential currents can be generated by current stacks having pairs of series-connected junctions. The exponential currents can be altered to change the shape of the exponential currents to better approximation true square law behavior. A multiplier combines four exponential currents to approximate a multiplication function. The exponential currents in the multiplier can be generated by current stacks that are cross-connected so as to generate two output currents, the difference of which represents the multiplication of two input signals.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: February 5, 2008
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 7301387
    Abstract: A current squaring cell is provided for producing an output current that correlates to the square of an input signal current. The current squaring cell comprises a first circuit portion, which receives a first tail current that is positively proportional to the input signal current, and a second circuit portion, which connects to the first circuit portion and receives a second tail current that is negatively proportional to the input signal current.
    Type: Grant
    Filed: October 20, 2005
    Date of Patent: November 27, 2007
    Assignee: Linear Technology Corporation
    Inventor: Min Z Zou
  • Patent number: 7268608
    Abstract: A squaring cell comprises a first circuit responsive to an input voltage to produce a corresponding current, and a second circuit, preferably in the form of an absolute modulator circuit, responsive to the current produced by the first circuit and to the input voltage to produce an output current that corresponds to the square of the input voltage. In one embodiment, the first circuit comprises an absolute value voltage-to-current converter; in another, the first circuit comprises a linear voltage-to-current converter. Techniques to improve accurate square law performance of the cell, independent of temperature, and of broad input voltage range and frequency, are presented.
    Type: Grant
    Filed: August 18, 2005
    Date of Patent: September 11, 2007
    Assignee: Linear Technology Corporation
    Inventor: Min Z. Zou
  • Patent number: 7081787
    Abstract: An analog circuit for calculating square and reciprocal of a current is provided. It is an analog integrated circuit and can make the input and output signals become currents in the current field of the same type of analog integrated circuit. The output current can be the square or reciprocal of the input current. The square and reciprocal functions can be implemented by using three identical BJTs. Those three BJTs are independent and the bases and collectors of the BJTs are coupled to ground. Hence, the circuit can be implemented by the standard CMOS and can be applied to the other complicated system. In addition, the operational amplifier and the capacitor in the circuit are required to stabilize this circuit. This circuit has a simple structure.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: July 25, 2006
    Assignee: Winbond Electronics Corp.
    Inventors: Bingxue Shi, Jiwei Chen
  • Patent number: 7002394
    Abstract: An RMS-to-DC converter implements the difference of squares function using two squaring cells operating in opposition to attain a balance. Each of the squaring cells is implemented as a grounded-base transistor and a two-transistor current mirror. The emitter of the grounded-base transistor is coupled to the input terminal of the current mirror at a node which receives the input signal. The collector of the grounded-base transistor and the output of current mirror are coupled together to generate an output current having a square-law relationship to the input signal. One of the squaring cells receives the input signal and operates at high frequencies (HF), while the other receives a feedback signal and operates in a quasi-DC mode. In a measurement node, a nulling circuit closes a feedback loop around the DC squaring cell to null the output currents from the squaring cells.
    Type: Grant
    Filed: October 23, 2000
    Date of Patent: February 21, 2006
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 6989694
    Abstract: A voltage ramp generator includes a capacitance and a charging circuit that permits generation of a charging current for the capacitance. The charging circuit for the capacitance includes a current generator having a resistance Rg2. The charging circuit for the capacitance includes components, such as resistance Re, that enables the capacitance charging current to be proportional to (Re/Rg2)2. The voltage ramp generator is applicable to circuits for DC voltage converters operating in a current mode.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: January 24, 2006
    Assignee: STMicroelectronics SA
    Inventors: Christophe Garnier, Pascal Debaty
  • Patent number: 6861890
    Abstract: A squaring cell combines first and second exponential currents to approximate square law behavior. The exponential currents can be generated by current stacks having pairs of series-connected junctions. The exponential currents can be altered to change the shape of the exponential currents to better approximation true square law behavior. A multiplier combines four exponential currents to approximate a multiplication function. The exponential currents in the multiplier can be generated by current stacks that are cross-connected so as to generate two output currents, the difference of which represents the multiplication of two input signals.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: March 1, 2005
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Publication number: 20040239398
    Abstract: A squaring cell combines first and second exponential currents to approximate square law behavior. The exponential currents can be generated by current stacks having pairs of series-connected junctions. The exponential currents can be altered to change the shape of the exponential currents to better approximation true square law behavior. A multiplier combines four exponential currents to approximate a multiplication function. The exponential currents in the multiplier can be generated by current stacks that are cross-connected so as to generate two output currents, the difference of which represents the multiplication of two input signals.
    Type: Application
    Filed: January 27, 2004
    Publication date: December 2, 2004
    Inventor: Barrie Gilbert
  • Patent number: 6815997
    Abstract: A FET square multiplier is disclosed that transforms an input signal into two currents I1 and I2, the difference of which is proportional to the square of the input signal. A first and a second FET are connected at their drains and are source-coupled to the source of a third FET whose transconductance is twice the transconductance of the first and the second FET. The common source node is biased by a constant current source. The FETs are operated in the saturation region to exploit the square dependency of the drain current on the difference of the gate-source voltage and the treshold voltage of an FET.
    Type: Grant
    Filed: April 9, 2001
    Date of Patent: November 9, 2004
    Inventors: Lutz Dathe, Wolfram Kluge
  • Patent number: 6717454
    Abstract: A switching mode N-order circuit comprises a first unit, a second unit and a comparator. The first unit includes an operational amplifier integral circuit to integrate a first voltage. The second unit has one or more stages of subunits in cascade each including an operational amplifier integral circuit to integrate a second voltage stage by stage. Each of the operational amplifier integral circuits is equipped with a switch to be controlled by the comparator to be discharged. The output of the N-order circuit is derived from the output of the second unit.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: April 6, 2004
    Assignee: Frontend Analog and Digital Technology Corporation
    Inventors: Ming-Hsiang Chiou, Chen-Yu Hsiao
  • Patent number: 6623375
    Abstract: A golf club iron has a club head having a generally planar generally rectangular front face for impacting a ball with a horizontal top edge and a horizontal bottom edge. The front face is symmetrical about an imaginary upright center line at right angles to a transverse line and equidistant between the sides so that the upright center line and the transverse center line intersect at an imaginary center point of the front face. The club head defines an imaginary horizontal center line at right angles to the transverse line passing through the imaginary center point of the front face and substantially through the center of gravity of the head. A tubular shaft hosel is integrally attached to the rear face of the club head with an axis of the tubular hosel at the club head coaxial with the axis of the shaft. The hosel is arranged so that the axis of the shaft and the hosel intersects the imaginary horizontal center line at a position reward of the center of gravity.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: September 23, 2003
    Inventor: Laurence W. Davies
  • Patent number: 6559682
    Abstract: A loss of signal detection circuit using Gilbert mixers. A differential input signal is provided to an input Gilbert mixer. Reference signals are provided to a reference Gilbert mixer. The two Gilbert mixers pull reference lines in opposing directions such that a one line is higher than another line when the differential input signal provides valid data.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: May 6, 2003
    Assignee: Vitesse Semiconductor Corporation
    Inventors: Ian Kyles, Tao Xiang
  • Patent number: 6549057
    Abstract: An RMS-to-DC converter implements the difference-of-squares function by utilizing two identical squaring cells operating in opposition to generate two signals. An error amplifier nulls the difference between the signals. When used in a measurement mode, one of the squaring cells receives the signal to be measured, and the output of the error amplifier, which provides a measure of the RMS value of the input signal, is connected to the input of the second squaring cell, thereby closing the feedback loop around the second squaring cell. When used in a control mode, a set-point signal is applied to the second squaring cell, and the output of the error amplifier is used to control a variable-gain device such as a power amplifier which provides the input to the first squaring cell, thereby closing the feedback loop around the first squaring cell.
    Type: Grant
    Filed: October 23, 2000
    Date of Patent: April 15, 2003
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 6373317
    Abstract: An IC multiplier circuit has four cells having bipolar transistors to give an exponential input-output function. Each cell has a squaring bipolar transistor and an emitter follower. Differential output signals are taken from the squaring bipolar transistor. The voltage follower is an emitter follower with the bias current through it is substantially larger, e.g. about 10 times larger, than the bias current through the squaring bipolar transistor, which has an emitter resistor.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: April 16, 2002
    Assignee: Nokia Mobile Phones Ltd.
    Inventors: Pekka Kostiainen, Kari Halonen, Tuomas Huikko
  • Patent number: 6348829
    Abstract: A high-frequency RMS-DC converter having extended dynamic range operates by dynamically at low cost by adjusting the scaling factor (denominator) of a detector cell such as a squaring cell. The output from the squaring cell is averaged to generate a final output signal which can be fed back to a scaling input for operation in a measurement mode, or used to drive a power amplifier in a controller mode. By implementing the squaring cell as a transconductance cell using a modified multi-tanh structure, the scaling factor can be adjusted by dynamically changing the tail current through the cell which, in the measurement mode, is achieved by connecting the averaged output back to the squaring cell. An exponentially responding amplifier can be used in the feedback loop to provide a linear-in-dB output characteristic.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: February 19, 2002
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 6204719
    Abstract: An RMS-to-DC converter implements the difference-of-squares function by utilizing two identical squaring cells operating in opposition to generate two signals. An error amplifier nulls the difference between the signals. When used in a measurement mode, one of the squaring cells receives the signal to be measured, and the output of the error amplifier, which provides a measure of the RMS value of the input signal, is connected to the input of the second squaring cell, thereby closing the feedback loop around the second squaring cell. When used in a control mode, a set-point signal is applied to the second squaring cell, and the output of the error amplifier is used to control a variable-gain device such as a power amplifier which provides the input to the first squaring cell, thereby closing the feedback loop around the first squaring cell.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: March 20, 2001
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 6201430
    Abstract: The computational circuit adds a drain current of a first MIS transistor which is driven by inputting a signal obtained by superimposing an AC signal to a DC voltage, and a drain current of a second MIS transistor which is driven by inputting a signal obtained by superimposing the same AC signal as above but reversal in phase to the DC voltage, and subtracts a drain current of a third MIS transistor driven by supplying the DC voltage to the gate thereof so as to erase DC components of the outputs of the first and second MIS transistors. Thereby, it is possible to produce a current in proportional to square of the AC signal.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: March 13, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideyuki Hagino, Susumu Hoshino
  • Patent number: 6172549
    Abstract: An RMS-to-DC converter implements the difference of squares function using two squaring cells operating in opposition to attain a balance. Each of the squaring cells is implemented as a grounded-base transistor and a two-transistor current mirror. The emitter of the grounded-base transistor is coupled to the input terminal of the current mirror at a node which receives the input signal. The collector of the grounded-base transistor and the output of current mirror are coupled together to generate an output current having a square-law relationship to the input signal. One of the squaring cells receives the input signal and operates at high frequencies (HF), while the other receives a feedback signal and operates in a quasi-DC mode. In a measurement node, a nulling circuit closes a feedback loop around the DC squaring cell to null the output currents from the squaring cells.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: January 9, 2001
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 6107858
    Abstract: An OTA having a completely linear transconductance characteristic or a squarer having an accurate square-law characteristic is provided, which is comprised of first and second differential circuits. The first differential circuit has a first differential pair of first and second MOSFETs whose sources are coupled together and a third MOSFET serving as a bypass transistor for the first differential pair. The first differential pair is driven by a first constant tail current. The second MOSFET is driven by a first constant driving current. The second differential circuit has a second differential pair of fourth and fifth MOSFETs whose sources are coupled together and a sixth MOSFET serving as a bypass transistor for the second differential pair. The second differential pair is driven by a second constant tail current. The fifth MOSFET is driven by a second constant driving current.
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: August 22, 2000
    Assignee: NEC Corporation
    Inventor: Katsuji Kimura
  • Patent number: 6031408
    Abstract: A square-law clamping circuit (99, 120) sinks a current from an input/output terminal proportional to a square of a difference between a voltage thereon and a reference voltage. A first MOS transistor (130) has a source for receiving the reference voltage, a gate, and a drain coupled to its gate. A current source (134) coupled to the drain of the first MOS transistor (130) sources a predetermined current therefrom. A second MOS transistor (132) has a source providing the input/output terminal (100, 121), a gate coupled to the drain of the first MOS transistor (130), and a drain. A current sink (135) coupled to the drain of the second MOS transistor (132) sinks a current therefrom.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: February 29, 2000
    Assignee: Motorola, Inc.
    Inventor: Stephen Flannagan
  • Patent number: 5909136
    Abstract: A four-quadrant multiplier which is constructed from two squaring circuits using the quarter-square technique and is suitable for an integrated circuit (IC) or a large-scale integrated circuit (LSI). Each of the squaring circuits has a pair of differential input terminals, an output terminal and two differential pairs. Each of differential pairs is composed of first and second transistors whose sources or emitters are connected in common, receives a differential input voltage impressed between the differential input terminals. In each differential pair, a constant current source of a predetermined current value and an dynamic bias current source are inserted in parallel between the common sources or the common emitters and the grounding point. The dynamic bias current source is realized by a current mirror circuit which outputs current equal to the drain current or the collector current of the second transistor.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: June 1, 1999
    Assignee: NEC Corporation
    Inventor: Katsuji Kimura
  • Patent number: 5770965
    Abstract: A compensation circuit (106) corrects for nonlinearities in a sensor signal representing the physical state of a sensor (100). A transducer (102) produces a non-linear component in a transducer voltage signal. A voltage-current converter (104) converts the tranducer voltage signal to a transducer current which contains the non-linear component. A compensation circuit (106) squares the transducer current (I.sub.216) and uses a scaling current (I.sub.412) to generate a compensation current (I.sub.408) equal to the non-linear component. The current (I.sub.216) and scaled compensation current (I.sub.408) are summed at a summing junction (418) to produce an output current (I.sub.OUT) which is a substantially linear representation of the physical state of the sensor.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: June 23, 1998
    Assignee: Motorola, Inc.
    Inventors: George B. Gritt, Jr., Ira E. Baskett
  • Patent number: 5581211
    Abstract: In a squaring circuit which responds to an input voltage to produce an output current and which is specified by a squaring characteristic between the input voltage and the output current, first, second, and third transistors are connected in common to a constant current source while the first and the second transistors are connected to input terminals for the input voltage and also connected in common to a single output terminal. The third transistor is connected to another output terminal and supplied with a d.c. voltage as a control signal. The output current appears between the output terminals as a differential output current. The squaring characteristic is kept even when the input voltage is widely varied. Each of the first through the third transistors may be either a bipolar transistor or a MOS transistor.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: December 3, 1996
    Assignee: NEC Corporation
    Inventor: Katsuji Kimura