Serial Conversions With Change In Signal Patents (Class 341/162)
  • Patent number: 7907078
    Abstract: An analog-to-digital converter is disclosed. An input signal processor sets a voltage of an input signal as an initial value of a signal voltage Vin, subtracts ½n of an input range from the nth (n is a positive integer) signal voltage based on a comparison result output from a comparator, and outputs the (n+1)th signal voltage. A reference voltage source outputs a reference voltage to be compared with the signal voltage output from the input signal processor, the reference voltage being obtained by repeatedly reducing by one half the input range. A comparator compares the signal voltage from the input signal processor with the reference voltage from the reference voltage source.
    Type: Grant
    Filed: November 18, 2009
    Date of Patent: March 15, 2011
    Assignee: Fujitsu Limited
    Inventor: Tszshing Cheung
  • Patent number: 7898449
    Abstract: A telescopic differential operational amplifier circuit for use in a pipelined A/D converter is provided with two auxiliary differential amplifiers connected to two cascode circuits, each including cascode-connected first to fourth transistors. During the sampling phase, first and second switches are turned on to apply a predetermined bias voltage to the gates of first and fourth transistors, and the input terminal of the differential operational amplifier circuit is set to a common mode voltage. During the hold phase, the first and second switches are turned off so that a voltage of each of the gates of the first and fourth transistors change to follow an input signal inputted via the input terminal with coupling capacitors operating as a level shifter of the input signal. Then the differential operational amplifier circuit performs push-pull operation operative only in a transconductance drive region, and is prevented from operating in a slewing region.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: March 1, 2011
    Assignee: Semiconductor Technology Academic Research Center
    Inventors: Shoji Kawahito, Kazutaka Honda, Yasuhide Shimizu, Kuniyuki Tani, Akira Kurauchi, Koji Sushihara, Koichiro Mashiko
  • Patent number: 7889111
    Abstract: A conversion operation B is performed with respect to a sample value R in an A/D conversion stage 101 to generate a conversion result D3, and a sampling operation A is performed with respect to this conversion result D3 in an A/D conversion stage 103. The conversion operation B is performed with respect to a sample value in an A/D conversion stage 105 to generate a conversion result D4, and the sampling operation A is performed with respect to the conversion result D4 in an A/D conversion stage 107. The conversion operation B is performed with respect to a sample value in an A/D conversion stage 107 to generate a conversion result D5, and the sampling operation A is performed with respect to this conversion result D5 in an A/D conversion stage 101. The conversion operation B is performed with respect to a sample value in the A/D conversion stage 103 to generate a conversion result D6, and the sampling operation A is performed with respect to the conversion result D6 in the A/D conversion stage 105.
    Type: Grant
    Filed: June 8, 2007
    Date of Patent: February 15, 2011
    Assignee: National University Corporation Shizuoka University
    Inventor: Shoji Kawahito
  • Patent number: 7884749
    Abstract: An A/D converting apparatus includes a first A/D converter to sample an analog input signal having a D/A converter to generate a comparative signal for successive comparison with the analog input signal, a signal generator generate a differential signal between the analog input signal and the comparative signal, and a comparator to compare the comparative signal with a standard value to generate a first digital signal exhibiting high-order bit; an amplifier to amplify the differential signal to generate a residue signal; and a second A/D converter to sample the residue signal to generate a second digital signal exhibiting low-order bit.
    Type: Grant
    Filed: January 6, 2009
    Date of Patent: February 8, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masanori Furuta, Tomohiko Ito, Takafumi Yamaji, Tetsuro Itakura
  • Patent number: 7847720
    Abstract: A pipelined analog-to-digital converter includes at least one multiplying digital-to-analog converter and at least one sub-ADC. The multiplying digital-to-analog converter includes at least one first capacitor, at least one second capacitor, an amplifier, and a plurality of switches. The amplifier is coupled to the first and the second capacitors. The switches control a connection between the first and the second capacitors according to a first control signal, a second control signal and a digital signal. In a first period, the first capacitor is connected to the second capacitor in parallel. In a second period, the first capacitor is connected to the second capacitor in series. At least one switch among the switches is composed of a transistor. The sub-ADC provides a digital signal according to the first and second control signals.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: December 7, 2010
    Assignee: Mediatek Inc.
    Inventor: Yu-Kai Chou
  • Patent number: 7839319
    Abstract: The analog-to-digital for converter (ADC) for converting an analog value into a digital equivalent using a parallel digital data path is disclosed. In one example embodiment, the ADC includes a switched capacitor DAC having an input to receive an analog value via analog sample and hold circuit. A comparator is coupled to the switched capacitor DAC. A successive approximation register (SAR) is coupled to the comparator. A plurality of logic blocks is coupled to the SAR. A plurality of thermometric encoders is coupled to the associated plurality of logic blocks. A plurality of MUXs is coupled to the associated plurality of thermometric encoders and the comparator, wherein the plurality of MUXs having associated outputs that is coupled to the input of the switched capacitor DAC.
    Type: Grant
    Filed: October 20, 2008
    Date of Patent: November 23, 2010
    Assignee: Analog Devices, Inc.
    Inventors: Srikanth Nittala, Jeremy Gorbold, Mahesh Madhavan
  • Patent number: 7839318
    Abstract: A pipelined analog-to-digital converter includes a plurality of stages each including a sample-and-hold circuit configured to output an analog signal having a current and a current mode analog-to-digital converter configured to compare the current of the analog signal output by the sample-and-hold circuit to current generated by a plurality of current sources and output a digital representation of the analog signal.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: November 23, 2010
    Assignee: SiFlare, Inc
    Inventors: Thomas L. Wolf, Rex K. Hales
  • Patent number: 7821433
    Abstract: A pipeline-type A/D converter includes: N number of stages cascade-connected; and a digital correction circuit that receives digital signals outputted from the N number of stages and outputs a final digital signal. In the converter, an Mth stage in the N number of stages includes: a sub A/D converter A/D-converting an input analog signal; a sub D/A converter D/A converting a digital signal outputted from the sub A/D converter; a differential amplifier circuit that includes a sample hold circuit and an operational amplifier, performs an sampling operation and a holding operation to obtain a difference between the input analog signal and an output signal of the sub D/A converter, and amplifies the difference; and a compensation circuit compensating a gain error of the operational amplifier in an operation of the differential amplifier circuit, the gain error being caused by parasitic capacitance between an input terminal and an output terminal of the operational amplifier, and 1?M<N.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: October 26, 2010
    Assignee: Seiko Epson Corporation
    Inventor: Akira Abe
  • Patent number: 7817077
    Abstract: In some examples, a differential comparator includes a differential amplifier configured to output differential output signals, a first switch portion configured to input the differential output signals from the differential amplifier and output the differential output signals from output terminals while alternatively changing over the output terminals, a latch portion configured to update and latch the differential output signals from the output terminals of the first switch portion, and a second switch portion configured to input output signals from the latch portion and output the latched output signals. The first switch portion and the second switch portion are changed over complementarily so that the differential output signals from the differential amplifier are always outputted from the same first and second output terminals of the second switch portion respectively.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: October 19, 2010
    Assignees: Sanyo Electronic Co., Ltd, Sanyo Semiconductor Co., Ltd
    Inventor: Hiroyuki Miyashita
  • Patent number: 7812756
    Abstract: In each of a plurality of stages, an input analog signal is quantized, so that a digital signal corresponding to each part of bits is generated. ADA conversion portion generates an analog reference signal based on the digital signal, and a remainder operation portion performs addition/subtraction and amplification by a predetermined factor with respect to the input analog signal. Then, the signal thus obtained is supplied to a subsequent stage. The DA conversion portion in the first stage where A/D conversion of a plurality of bits is performed includes primary voltage supply portions capable of outputting a reference voltage at one of a plurality of levels, and an auxiliary voltage supply portion capable of outputting a reference voltage at an auxiliary level different from the above-described level. The respective voltage supply portions selectively output the reference voltages based on a digital signal generated by an AD conversion portion.
    Type: Grant
    Filed: March 5, 2009
    Date of Patent: October 12, 2010
    Assignee: Panasonic Corporation
    Inventors: Takayasu Kito, Shinichi Ogita
  • Patent number: 7786911
    Abstract: A high-order delta-sigma analog-to-digital converter. A plurality of stages are connected to accept an analog input signal and produce a digital output signal. Each stage has a resettable ?-? converter of second order or higher. Resetting each stage before accepting a new input purges the integrators of any information related to the previous input, allowing step inputs to the system. The stability of the converter is ensured using local feedback loops at each stage. Each stage provides a digital representation of a portion of the analog input signal. A decimation filter receives the digital signals from the stages and arranges them into the digital output signal.
    Type: Grant
    Filed: November 19, 2007
    Date of Patent: August 31, 2010
    Assignee: Teledyne Licensing, LLC
    Inventors: Atul Joshi, Hakan Durmus
  • Patent number: 7750834
    Abstract: In a pipelined analog-to-digital (AD) converter, if logically incongruent signals S1 and S2 are output from an AD converter section of a converter stage of the AD converter, a digital-to-analog converter (DAC) section is to be prevented from erroneously operating. When a logically incongruent combination of signals S1 and S2, such as S1=“H” and S2=“L”, is output from comparators that compare an input voltage VI to reference voltages +REF/4 and ?REF/4, an encoder outputs a signal corresponding to a normal signal combination (S1=“L” and S2=“H”) to generate signals X, Y and Z that control switches of the DAC section. This eliminates the risk that the switches shall be turned on simultaneously, thus preventing the erroneous operation of the DAC section.
    Type: Grant
    Filed: January 22, 2009
    Date of Patent: July 6, 2010
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Seiichiro Sasaki
  • Publication number: 20100156692
    Abstract: A multi-stage dual successive approximation register analog-to-digital converter (SAR ADC) and a method of performing analog-to-digital conversion using the same are provided. The multi-stage dual SAR ADC includes: a plurality of SAR ADC stages for converting an analog input voltage into a predetermined bit digital signal, each SAR ADC stage being serially connected to one another and including two SAR ADCs; and at least one residue amplifier respectively connected between every two successive SAR ADC stages, amplifying residue voltage output from a previous SAR ADC stage to output the amplified residue voltage to a next SAR ADC stage. The two SAR ADCs of the previous SAR ADC stage share the residue amplifier.
    Type: Application
    Filed: August 11, 2009
    Publication date: June 24, 2010
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Young Deuk JEON, Young Kyun Cho, Jae Won Nam, Jong Kee Kwon
  • Patent number: 7728752
    Abstract: Pipelined converter systems include a plurality of converter stages in which some stages generate and pass a residue signal to a succeeding stage for further conversion. The generation of the residue signal can inject spurious charges into a reference source that is used in the generation. The spurious charges reduce the accuracy of the residue signal and the accuracy of the system. Residue generator embodiments are thereby formed to provide reduction charges to the reference source that are arranged to oppose and reduce the spurious charges. This reduction of spurious charges significantly enhances system accuracy and linearity.
    Type: Grant
    Filed: November 5, 2008
    Date of Patent: June 1, 2010
    Assignee: Analog Devices, Inc.
    Inventors: Ahmed Mohamed Abdelatty Ali, Gregory W. Patterson
  • Patent number: 7719452
    Abstract: Signal converter system embodiments are provided to substantially reduce symmetrical and asymmetrical conversion errors. Signal-processing stages of these embodiments may include a signal sampler in addition to successively-arranged signal converters. In system embodiments, injected analog dither signals are initiated in response to a random digital code. They combine with a system's analog input signal and the combined signal is processed down randomly-selected signal-processing paths of the converter system to thereby realize significant improvements in system linearity. Because these linearity improvements are realized by simultaneous processing of the input signal and the injected dither signal, a combined digital code is realized at the system's output. A first portion of this combined digital code corresponds to the analog input signal and a second portion corresponds to the injected analog dither signal.
    Type: Grant
    Filed: September 23, 2008
    Date of Patent: May 18, 2010
    Assignee: Analog Devices, Inc.
    Inventors: Scott Gregory Bardsley, Bryan Scott Puckett, Michael Ray Elliott, Ravi Kishore Kummaraguntla, Ahmed Mohamed Abdelatty Ali, Carroll Clifton Speir, James Carroll Camp
  • Patent number: 7719456
    Abstract: A technique for correcting errors in Bucket Brigade Device (BBD)-based pipelined devices, such as Analog-to Digital Converters (ADCs). The gain between pipeline stages is desired to be a specific amount, such as unity: that is, all net charge present in each stage ideally is transferred to the next stage. In practical BBD-based circuits, however, the charge-transfer gain is less than ideal, resulting in errors. The approach described herein provides analog correction of such errors due to both capacitor mismatch and to sub-unity charge-transfer gain. In certain embodiments the adjustment circuit may use an adjustable current source and Field Effect Transistor to introduce the correction. In still other embodiments, the adjustment circuit may determine a voltage-feedback coefficient.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: May 18, 2010
    Assignee: Kenet Incorporated
    Inventor: Michael P. Anthony
  • Patent number: 7705764
    Abstract: Provided are a method of algorithmic analog-to-digital conversion and an algorithmic Analog-to-Digital Converter (ADC). The algorithmic ADC includes a Multiplying Digital-to-Analog Converter (MDAC). The MDAC includes a Digital-to-Analog Converter (DAC) for converting a first digital signal into an analog signal, a subtractor for calculating a difference between the signal output from the DAC and an analog signal input from a first Sample and Hold Amplifier (SHA), an amplifier for amplifying the difference, a first capacitor unit connected with an output end of the first SHA and an input end of the amplifier through a first switching unit, a second capacitor unit connected with the input end and an output end of the amplifier through a second switching unit, and a third capacitor unit connected with the input end and the output end of the amplifier through a third switching unit.
    Type: Grant
    Filed: August 26, 2008
    Date of Patent: April 27, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seung Chul Lee, Jae Won Nam, Young Deuk Jeon, Jong Kee Kwon
  • Patent number: 7697051
    Abstract: An apparatus has a pixel that includes (i) a buffer transistor having an input, (ii) first and second capacitive storage elements each of which selectively can be coupled to the input of the buffer transistor, and (iii) a photosensitive element having an output which selectively can be coupled to the input of the buffer transistor. A readout circuit selectively can be coupled to an output of the buffer transistor. A first signal level, sensed by the photosensitive element, can be stored by the first capacitive storage element, and a second signal level, sensed by the photosensitive element, can be stored by the second capacitive storage element. The first and second signal levels can be read out from the pixel.
    Type: Grant
    Filed: April 11, 2006
    Date of Patent: April 13, 2010
    Assignee: Aptina Imaging Corporation
    Inventor: Alexander I. Krymski
  • Patent number: 7683819
    Abstract: Disclosed is a pipeline ADC in which an operational amplifier is shared between circuit blocks that construct local A/D converters of nth and (n+1)th stages, a sampling capacitor of the nth stage is divided into a plurality of sampling capacitors, and some of the plurality of sampling capacitors thus divided in the nth stage are adopted as sampling capacitors of the (n+1)th stage.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: March 23, 2010
    Assignee: NEC Electronics Corporation
    Inventor: Akira Kurauchi
  • Patent number: 7675452
    Abstract: An SAR ADC provides increased immunity to noise introduced by time varying noise components provided on reference potentials (VREF). Reference voltage noise contributions are canceled by introducing a reference voltage component to a pair of binary weighted capacitor arrays (NDAC and PDAC) during bit trials, which are presented to a differential comparator as a common mode signal and rejected. During sampling, select elements in either the PDAC or the NDAC also obtain a reference voltage contribution. Although the sampled VREF signal may have a noise contribution, the noise is fixed at the time of bit trials, which can improve performance. Generally, the scheme provides a 50% reduction in noise errors over the prior art for the same VREF noise. Additional embodiments described herein can reduce noise errors to 25% or even 12.5% over prior art systems.
    Type: Grant
    Filed: May 1, 2008
    Date of Patent: March 9, 2010
    Assignee: Analog Devices, Inc.
    Inventors: Mahesh K Madhavan, Srikanth Aruna Nittala
  • Patent number: 7663516
    Abstract: In a method and apparatus for compensating non-linearity of a gain of a residual amplifier (RA), a pipelined analog-to-digital converter (ADC) converts an analog input to a digital output (DO). The ADC includes a plurality of pipelined stages (PPS). Each stage, which includes an instance of the RA, provides a digital code corresponding to an output of the RA included in a preceding stage. A memory stores a piecewise linear representation for modeling the non-linearity of the gain. A calibrated gain of the RA corresponding to each region of a plurality of linear operating regions of the RA is stored in the memory. A gain adjuster adjusts the digital code for each one of the PPS in accordance with a gain factor derived from the calibrated gain for each one of the PPS. A constructor constructs the DO from the adjusted digital code received from each one of the PPS.
    Type: Grant
    Filed: August 25, 2008
    Date of Patent: February 16, 2010
    Assignee: Texas Instruments Incorporated
    Inventor: Gaurav Chandra
  • Patent number: 7665006
    Abstract: A block code error correcting system is used in a compact disk reading system to increase the decoding capability of the compact disk reading system. The system includes a data slicer, a data bit to channel bit modulation pulse width determinator, a demodulator, an erase address detector and an error correction code (ECC) decoder. A pulse width of an eight-to-sixteen modulation (EFM+) signal is detected to thereby produce an erase control signal when the pulse width of the EFM+ signal is in a predefined window or is an illegal pulse width. A codeword corresponding to the EFM+ signal is set as an erasure, and accordingly an erase address is produced.
    Type: Grant
    Filed: September 20, 2006
    Date of Patent: February 16, 2010
    Assignee: Sunplus Technology Co., Ltd.
    Inventors: Fong-Hwa Song, Wen-Chun Feng
  • Patent number: 7652611
    Abstract: Embodiments of the present invention provide a pipeline ADC front-end sampling structure that provides a continuous time input signal to a flash comparator for sampling. By providing a continuous time input signal to the flash comparator, no delay is introduced from the need to transfer a DC charge representing the sampled input to the flash comparator. Matching sampling networks in the residual generator and the flash comparator are avoided due to the high bandwidth response requirements of the residual generator and the flash comparator when operating on high frequency input signals.
    Type: Grant
    Filed: May 20, 2008
    Date of Patent: January 26, 2010
    Assignee: Analog Devices, Inc.
    Inventors: Michael Elliott, Frank Murden
  • Patent number: 7612700
    Abstract: In a pipeline type A/D converter apparatus including A/D converter circuit parts connected in cascade with each other and A/D converting a sample hold signal in a pipeline form, each A/D converter circuit part includes a pre-A/D converter circuit for A/D converting an input signal into a digital signal, and a multiplying D/A converter circuit for D/A converting the digital signal into an analog control signal, and D/A converting the input signal by sampling, holding and amplifying the input signal using a sampling capacitor based on the analog control signal. A precharge circuit precharges a sampling capacitor before sampling so as to attain a predetermined output value in accordance with a digital input to output characteristic substantially adapted to an input to output characteristic of each A/D converter circuit part that presents an output signal corresponding to the input signal to each A/D converter circuit part.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: November 3, 2009
    Assignee: Semiconductor Technology Academic Research Center
    Inventors: Shoji Kawahito, Kazutaka Honda, Yasuhide Shimizu, Kuniyuki Tani, Akira Kurauchi, Koji Sushihara
  • Patent number: 7602323
    Abstract: The invention provides circuits and methods for estimating and correcting nonlinear error in analog to digital converters that is introduced by nonlinear circuit elements, for example one or more residue amplifiers in a pipelined analog to digital converter integrated circuit. In a preferred method of the invention, pseudo random calibration sequences are introduced into the digital signal to be converted by a flash digital to analog converter in one or more initial stages of the pipelined analog to digital converter circuit. A digital residue signal of the output of the one or more initial pipelined analog to digital converter stages is sampled. Intermodulation products of the pseudo random calibration sequences that are present in the digital residue signal are determined to estimate nonlinear error introduced by the residue amplifier in the one or more stages. A digital correction signal is provided to the output of the one or more stages to cancel estimated nonlinear error.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: October 13, 2009
    Assignee: The Regents of the University of California
    Inventors: Ian Galton, Andrea Panigada
  • Patent number: 7598896
    Abstract: An A/D converter comprises capacitors C1, C2, C3, C4, and C5 coupled via a plurality of switches to a differential input/differential output amplifier 1. The capacitor C5 determines a gain of the amplifier 1. A reset level is stored in the capacitor C1, and a signal level is stored in the capacitor C2. One terminal of the capacitor C1 and one terminal of the capacitor C2 are coupled to the respective differential inputs, and the other terminals of the capacitors C1, C2 are coupled to each other, whereby the amplifier 1 generates a difference signal between the reset level and the signal level. The cyclic A/D conversion of this difference signal is performed by switching the capacitors C1, C2, C3, and C4 coupled via a plurality of switches to the differential-input/differential-output amplifier 1, thereby obtaining an A/D conversion value with reduced random noise.
    Type: Grant
    Filed: September 7, 2006
    Date of Patent: October 6, 2009
    Assignee: National University Corporation Shizuoka University
    Inventor: Shoji Kawahito
  • Patent number: 7576668
    Abstract: A stage of a pipeline ADC which uses separate pairs of sampling network and amplifier (in a sample and hold circuit (SHA)) to provide inputs to quantizer (which generates a sub-code) and a switched capacitor network (implementing a DAC, a subtractor and amplification). Due to the use of separate components/paths to provide the input signal, the throughput performance of the ADC is enhanced.
    Type: Grant
    Filed: November 2, 2007
    Date of Patent: August 18, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: Anand Hariraj Udupa, Vikas Kumar Sinha, Nitin Agarwal, Visvesvararaya A. Pentakota, Sandeep Oswal
  • Patent number: 7576677
    Abstract: A first stage of a pipeline A/D converter is configured to output a sub analog signal at a level within a predetermined output voltage range even if a level of an input analog signal exceeds a predetermined input voltage range. Therefore, as compared with an example where a limiter circuit is provided on an input side of each stage, a pipeline A/D converter occupying a small area, consuming low power, and having small errors can be provided.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: August 18, 2009
    Assignee: Renesas Technology Corp.
    Inventor: Yasuo Morimoto
  • Patent number: 7561095
    Abstract: A semiconductor integrated circuit device provided with a pipeline A-D conversion circuit in which the enhancement of accuracy and the reduction of power consumption are accomplished is provided. The pipeline A-D conversion circuit is connected in series with an input terminal to which an analog signal to be converted is inputted and has a plurality of stages. The stages other than the first stage connected with the input terminal through at least one stage, including the first stage that receives input signals from the input terminal are constructed as follows: each of the other stages is comprised of two or more sample and hold circuits and an amplifier connected in common with the two or more sample and hold circuits. The two or more sample and hold circuits are caused to perform interleave operation.
    Type: Grant
    Filed: August 15, 2007
    Date of Patent: July 14, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Fumiyasu Sasaki, Eiki Imaizumi, Takanobu Anbo
  • Patent number: 7554470
    Abstract: A pipeline analog-to-digital converter (ADC) having a digital calibrating circuit is described. The pipeline ADC includes a pipeline converting circuit and a digital calibrating circuit. The pipeline converting circuit has a plurality of one-bit stages, and converts an analog input signal into a first digital signal having a plurality of bits. The digital calibrating circuit extracts calibration coefficients for the one-bit stages, and calibrates a feedback signal based on the calibration coefficients and the first digital signal to generate a second digital signal having a plurality of bits. The pipeline ADC may perform digital calibration automatically with good linearity.
    Type: Grant
    Filed: November 5, 2007
    Date of Patent: June 30, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Ho-Young Lee
  • Patent number: 7535400
    Abstract: A technique for correcting errors in Bucket Brigade Device (BBD)-based pipelined devices, such as Analog-to Digital Converters (ADCs). The gain between pipeline stages is desired to be a specific amount, such as unity: that is, all net charge present in each stage ideally is transferred to the next stage. In practical BBD-based circuits, however, the charge-transfer gain is less than ideal, resulting in errors. The approach described herein provides analog correction of such errors due to both capacitor mismatch and to sub-unity charge-transfer gain. In certain embodiments the adjustment circuit may use an adjustable current source and Field Effect Transistor to introduce the correction. In still other embodiments, the adjustment circuit may determine a voltage-feedback coefficient.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: May 19, 2009
    Assignee: Kenet, Incorporated
    Inventor: Michael P. Anthony
  • Patent number: 7532147
    Abstract: An analog voltage latch for use in a controller for controlling a motor equipped electric bicycle, includes a window comparator for comparing an analog voltage latch output and an analog input voltage to produce a comparison result, an S-R latch for producing HIGH or LOW according to the comparison result, a selector for selecting an operation, an up/down counter for counting up or down according to the HIGH or LOW from the S-R latch, and holding the counted result according to the selector result, and a DA converter for converting the counted result to analog signal.
    Type: Grant
    Filed: January 23, 2008
    Date of Patent: May 12, 2009
    Assignees: Panasonic Corporation, Panasonic Semiconductor Asia Pte. Ltd.
    Inventors: Kian Teck Teo, Tien Yew Kang
  • Patent number: 7528759
    Abstract: One embodiment of the present invention includes a pipelined analog-to-digital converter (ADC) comprising a plurality of pipeline stages. At least one of the plurality of pipeline stages comprises a feedback transistor-follower combination interconnected between a positive source voltage and a summation node and configured to set a voltage of the summation node approximately equal to a sample-and-hold voltage associated with a preceding one of the plurality of pipeline stages. The at least one of the plurality of pipeline stages also comprises a current mirror coupled to the feedback transistor-follower combination configured to provide a first current that is approximately equal to a second current that is associated with the feedback transistor-follower combination. The at least one of the plurality of pipeline stages further comprises an output resistor configured to set an output voltage of the respective at least one of the plurality of pipeline stages based on the first current.
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: May 5, 2009
    Assignee: Texas Instruments Incorporated
    Inventors: John William Fattaruso, Marco Corsi
  • Patent number: 7515083
    Abstract: A novel analog-to-digital converter (ADC) architecture using subranging successive approximation approach is disclosed. The ADC architecture is capable of achieving high sampling rate, low power consumption and low complexity. It is also able to advance the chip production yield and area utilization ratio. The new proposed ADC is formed by combining a flash converter having high sampling rate and low resolution with a successive approximation converter having low power consumption and low sampling rate.
    Type: Grant
    Filed: November 19, 2007
    Date of Patent: April 7, 2009
    Assignee: Industrial Technology Research Institute
    Inventors: Bo-Wei Chen, Szu-Kang Hsien
  • Publication number: 20090085790
    Abstract: A pipeline analog-to-digital converter includes a conversion unit receiving an analog input signal and outputting a plurality of digital signals corresponding to quantization values obtained by quantizing the input signal, the conversion unit including a plurality of stages that output the plurality of digital signals, the plurality of stages being connected in a cascade manner, each of the stages receiving a residue analog signal from a previous stage, and a first stage receiving an analog input signal and a digital correction logic receiving the plurality of digital signals, correcting an error, and outputting a digital output signal corresponding to the input signal, wherein a first reference voltage is applied to the plurality of stages, a second reference voltage, which is different from the first reference voltage, is applied to at least one of the plurality of stages, at least one of the plurality of stages includes a plurality of unit capacitors that sample the residue analog signal, and at least one
    Type: Application
    Filed: September 29, 2008
    Publication date: April 2, 2009
    Inventor: Kang-Jin Lee
  • Patent number: 7501972
    Abstract: A reference voltage generation circuit for a plurality of reference generation voltages and a pipe line analog-to-digital converter (ADC) using the same are provided. The reference voltage generation circuit including a charging capacitor for stabilizing the reference voltages charges the charging capacitor prior to the generation of the reference voltages, thus decreasing the time for the pipe line ADC to operate stably.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: March 10, 2009
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Takeshi Wakamatsu
  • Patent number: 7495596
    Abstract: A signal converter such as a multi-channel pipelined signal converter includes a plurality of pipelined signal converters and a decision unit. Each of the pipelined signal converters has a respective plurality of stage cells coupled in series with switched coupling between the pipelined signal converters. The decision unit determines a respective selected path through the stage cells of the plurality of pipelined signal converters for each of a plurality of input signals during a signal path selection mode.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: February 24, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Suhwan Kim, Jong-Kwan Woo, Han Yang
  • Patent number: 7482966
    Abstract: Provided is an algorithm analog-to-digital converter (ADC). The algorithm ADC obtains two digital outputs through different capacitor connections for one analog input signal and adds the digital output signals to obtain a final output value, so that a mismatch factor of the capacitor is removed to minimize a linearity limitation resulting from the capacitor mismatch. In addition, the algorithm ADC minimizes power consumption by making the operating frequency slow at a cycle requiring a high resolution and making the operating frequency fast at a cycle requiring a low resolution, i.e., outputting different operating clock frequencies according to a required resolution.
    Type: Grant
    Filed: November 28, 2007
    Date of Patent: January 27, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seung Chul Lee, Young Deuk Jeon, Kwi Dong Kim, Jong Kee Kwon
  • Patent number: 7474238
    Abstract: An A-D converter includes a group of resistors, a group of comparators, an encoder and an output unit. The output unit includes a correction circuit. An inverter constitutes the correction circuit. The encoder is shared in a case where the A-D converter converts an inputted analog signal to a two-bit binary code and a case where the A-D converter converts the inputted analog signal to a 4-bit binary code. The correction circuit corrects the output of the encoder when the A-D converter is to convert the inputted analog signal to the 2-bit binary code.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: January 6, 2009
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Shigeto Kobayashi
  • Patent number: 7471228
    Abstract: A mechanism for discharging parasitic capacitance at an input of an operational amplifier, which is shared between two stages of a pipelined analog-to-digital converter and/or two channels of signal processing circuitry, before the amplifier configuration of the stages/channels is switched. The discharging act occurs when a short reset pulse is generated between two clock phases. The short reset pulse is applied to a switch connected to the operational amplifier input. When the reset pulse closes the switch, a discharge path is created and any parasitic capacitance at the operational amplifier input is discharged through the path. The discharging of the parasitic capacitance substantially mitigates the memory effect and the problems associated with the memory effect.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: December 30, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Taehee Cho, Sandor L. Barna, Andrew M. Lever, Kwang-Bo Cho, Chiajen Lee
  • Patent number: 7471227
    Abstract: In accordance with one embodiment, there is provided a pipelined analog-to-digital converter (ADC) device. The pipelined ADC includes a first stage and a second stage. The first and second stages are configured to share a sub-ADC and a sub-digital-to-analog converter.
    Type: Grant
    Filed: August 18, 2006
    Date of Patent: December 30, 2008
    Assignee: Micron Technology, Inc.
    Inventor: Taehee Cho
  • Patent number: 7471229
    Abstract: An analog to digital converter system includes at least one stage for providing a first full precision, full latency output and a second output providing a less than full latency, less than full precision coarse level indicator signal.
    Type: Grant
    Filed: April 2, 2007
    Date of Patent: December 30, 2008
    Assignee: Analog Devices, Inc.
    Inventors: William George John Schofield, Joseph Bradford Bannon, Carroll Speir, Scott Bradsley
  • Patent number: 7443333
    Abstract: A converter (200) adapted to convert an analog input signal into a digital output signal includes an analog input terminal (205) for receiving the analog input signal, a Redundant Signed Digit (RSD) stage (210) coupled to the analog input terminal, and a digital section (220). The RSD stage is configured to receive the analog input signal at the analog input terminal, produce a first number of bits at a digital output from the analog input signal during a first half of a first clock cycle, provide a residual feedback signal of the analog input signal at the analog input terminal during a second half of the first clock cycle, and produce a second number of bits at the digital output from the residual feedback signal during a first half of a second clock cycle, the second number of bits less than the first number of bits.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: October 28, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Douglas A. Garrity, David R. Locascio
  • Patent number: 7436344
    Abstract: The present invention provides a pipeline A/D converter having resolution, allowable conversion processing rate and power consumption satisfying the requests of a system incorporating the pipeline A/D converter. The pipeline A/D converter in accordance with the present invention comprises a control section for outputting a control signal according to the operation state of an apparatus incorporating the pipeline A/D converter, and a pipeline A/D conversion section, the resolution and/or allowable conversion processing rate of which are switched by switching the capacitance in a built-in operational amplifier according to the control signal.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: October 14, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shinichi Ogita, Mitsuhiko Otani, Kouji Yamaguchi
  • Patent number: 7414564
    Abstract: Converter systems are provided which complement sample capacitors in at least one converter stage with replica capacitors. The replica capacitors are switched to receive replica charges from the analog input signal during the same operational mode in which the sample capacitors receive undesirable remnant charges. In an initial portion of a subsequent operational mode, the remnant capacitors are briefly switched to the sample capacitors to substantially cancel the remnant charges. The sample capacitors then participate in obtaining input-signal samples during the remainder of the subsequent operational mode. Because the remnant charges have been substantially canceled, the accuracy of the subsequent operational mode is considerably enhanced. In another system embodiment, the replica capacitor is replaced by a discharge switch which provides a discharge path in an initial portion of the subsequent operational mode.
    Type: Grant
    Filed: June 18, 2007
    Date of Patent: August 19, 2008
    Assignee: Analog Devices, Inc.
    Inventor: Ahmed Mohamed Abdelatty Ali
  • Patent number: 7408496
    Abstract: A mechanism for discharging parasitic capacitance at an input of an operational amplifier, which is shared between two stages of a pipelined analog-to-digital converter and/or two channels of signal processing circuitry. The operational amplifier contains two input circuits that are time multiplexed in a manner that allows capacitance to be discharged at one input circuit while the other input circuit is inputting signals into the amplifier. The discharging of the parasitic capacitance substantially mitigates the memory effect and the problems associated with the memory effect.
    Type: Grant
    Filed: August 21, 2006
    Date of Patent: August 5, 2008
    Assignee: Micron Technology, Inc.
    Inventor: Taehee Cho
  • Publication number: 20080143576
    Abstract: A novel analog-to-digital converter (ADC) architecture using subranging successive approximation approach is disclosed. The ADC architecture is capable of achieving high sampling rate, low power consumption and low complexity. It is also able to advance the chip production yield and area utilization ratio. The new proposed ADC is formed by combining a flash converter having high sampling rate and low resolution with a successive approximation converter having low power consumption and low sampling rate.
    Type: Application
    Filed: November 19, 2007
    Publication date: June 19, 2008
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Bo-Wei Chen, Szu-Kang Hsien
  • Patent number: RE41519
    Abstract: An image sensor system using offset analog to digital converters. The analog to digital converters require a plurality of clock cycles to carry out the actual conversion. These conversions are offset in time from one another, so that at each clock cycle, new data is available. A system includes a CMOS active pixel image sensor having an array for photoreceptors to convert an image into an analog signal. The CMOS image sensor converts the analog signal into a digital signal using a pipelined analog to digital converter.
    Type: Grant
    Filed: June 21, 2007
    Date of Patent: August 17, 2010
    Assignee: Round Rock Research, LLC
    Inventors: Eric R. Fossum, Sandor L. Barna
  • Patent number: RE41730
    Abstract: An image sensor system using offset analog to digital converters. The analog to digital converters require a plurality of clock cycles to carry out the actual conversion. These conversions are offset in time from one another, so that at each clock cycle, new data is available.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: September 21, 2010
    Assignee: Round Rock Research, LLC
    Inventors: Eric R. Fossum, Sandor L. Barna
  • Patent number: RE42117
    Abstract: An image sensor system using offset analog to digital converters. The analog to digital converters require a plurality of clock cycles to carry out the actual conversion. These conversions are offset in time from one another, so that at each clock cycle, new data is available. Systems are disclosed in which an image sensor converts an analog signal into a digital signal using a pipelined analog to digital converter.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: February 8, 2011
    Assignee: Round Rock Research, LLC
    Inventors: Eric R. Fossum, Sandor L. Barna