Serial Conversions With Change In Signal Patents (Class 341/162)
  • Patent number: 7382302
    Abstract: An A/D converter has a first voltage generation circuit, a second voltage generation circuit, a comparator, first and second switch circuits connected in series between an input terminal of an analog input voltage and an output terminal of the first voltage generation circuit, a first capacitor inserted between a connection node between the first and second switch circuits and the first input terminal, a second capacitor inserted between an output terminal of the second voltage generation circuit and the second input terminal, a third switch circuit, a fourth switch circuit, an A/D converter which generates a digital signal in accordance with signal level of the first output terminal, and a voltage setting circuit which sets a voltage to be outputted from the first and second voltage generation circuits based on the digital signal.
    Type: Grant
    Filed: July 28, 2006
    Date of Patent: June 3, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomo Muramatsu, Hirotomo Ishii
  • Patent number: 7382308
    Abstract: A reference buffer includes a first current mirror, a second current mirror, a first source follower coupled in series to a branch of the first current mirror and receiving a first initial reference voltage and outputting a first reference voltage, a second source follower coupled in series to a branch of the second current mirror and receiving a second initial reference voltage and outputting a second reference voltage, and a resistor coupled between a first node and a second node outputting the first and second reference voltages, respectively. The first node is disposed between the first current mirror and the first source follower and the second node is disposed between the second current mirror and the second source follower. The voltage difference between the first reference voltage and the first initial reference voltage is substantially same as that between the second reference voltage and the second initial reference voltage.
    Type: Grant
    Filed: February 16, 2007
    Date of Patent: June 3, 2008
    Assignee: iWatt Inc.
    Inventors: Enzhu Liang, Xuecheng Jin
  • Patent number: 7375672
    Abstract: In an analog-to-digital conversion method for converting a difference signal component representing a difference between a reference component and a signal component in an analog signal to be processed into digital data, in a first process, a signal corresponding to one of the reference component and the signal component is compared with a reference signal for conversion into the digital data. Concurrently with the comparison, counting is performed in one of a down-count mode and an up-count mode, and a count value at a time of completion of the comparison is held. In a second process, a signal corresponding to the other one of the reference component and the signal component is compared with the reference signal. Concurrently with the comparison, counting is performed in the other one of the down-count mode and the up-count mode, and a count value at a time of completion of the comparison is held.
    Type: Grant
    Filed: August 3, 2006
    Date of Patent: May 20, 2008
    Assignee: Sony Corporation
    Inventors: Yoshinori Muramatsu, Noriyuki Fukushima, Yoshikazu Nitta, Yukihiro Yasui
  • Patent number: 7372389
    Abstract: Embodiments of the invention provide an analogue to digital converter comprising a dual differential digital to analogue converter (DAC) having first and second digital inputs for first and second digital input signals respectively, and having first and second analogue differential outputs for first and second differential output signals respectively, where the first and second digital output signals are associated with the first and second digital inputs respectively; storage for storing a DAC digital input value; logic for deriving the first and second digital input signals from the DAC digital input value, such that the difference between the first and second differential output signals from the DAC represents the DAC digital input value; a comparator for comparing the first and second differential output signals from the DAC with an analogue input signal and providing a comparator output; and a controller, responsive to the comparator output, for modifying the DAC digital input value such that the DAC dig
    Type: Grant
    Filed: September 15, 2006
    Date of Patent: May 13, 2008
    Assignee: Jennic Limited
    Inventor: Andrew Gerard Whittaker
  • Patent number: 7345615
    Abstract: An A/D conversion array for an image sensor, in which the number of amplifiers and capacitors are decreased, compared with the conventional cyclic type, and a function to cancel the noise generated in the pixel section of the image sensor is provided, so that the area and power consumption are decreased. After input signal Vin is supplied to C1 and held, a reset level is applied to Vin, whereby the signal is amplified by the ratio of C1 and C2 (C1/C2). An output is held in C1, and the output is A/D-converted by a comparator so that a control signal is generated by the conversion output and a switch is turned ON. The digital signal is converted into an analog signal, and the analog signal is subtracted from the signal held in C1. This signal is amplified and is subjected to A/D conversion again, and the same operation is repeated.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: March 18, 2008
    Assignee: National University Corporation Shizuoka University
    Inventor: Shoji Kawahito
  • Patent number: 7336214
    Abstract: An image sensor may be improved by using ADCs that compensate for the effect of comparator input offset on comparator decisions. Offset compensation may be implemented in an ADC by using an amplifier section between the input of the ADC and a comparator section of the ADC to amplify the signals supplied to the comparator inputs and thereby reduce the effect of comparator offset on the comparator decision. The comparator section may be an autozeroing comparator section that is capable of performing an offset reduction operation to store offset compensation values at capacitors provided at its inputs. The amplifier section may be an autozeroing amplifier section having one or more amplifier stages that are capable of performing an offset reduction operation to store offset compensation values at capacitors provided at their inputs. Offset compensation may also be implemented using an autozeroing comparator section without a preceding amplifier section.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: February 26, 2008
    Inventor: Alexander Krymski
  • Patent number: 7330145
    Abstract: Consistent with an example embodiment, there is dual residue pipelined AD converter comprising a cascade of, preferably balanced, switched capacitor dual residue converter stages for producing from first and second residue input signals one or more digital bits and first and second residue output signals for application to the next stage in the cascade. Preferably the first and second residue input signals charge input capacitors whose charge is subsequently transferred to output capacitors by means of operational amplifiers. The switched capacitor architecture allows compensating for DC-offset voltages of the operational amplifiers. The switched capacitor architecture also allows the implementation of 1.5 bit converter stages.
    Type: Grant
    Filed: October 18, 2004
    Date of Patent: February 12, 2008
    Assignee: NXP B.V.
    Inventor: Hendrik Van Der Ploeg
  • Patent number: 7289055
    Abstract: An input analog signal is fed to an amplifier circuit and an AD converter circuit. The AD converter circuit converts the input analog signal into a digital value of a predetermined number of bits, and outputs the digital value to an encoder (not shown) A DA converter circuit converts the digital value of a predetermined number of bits output from the AD converter circuit into an analog signal. The amplifier circuit samples and amplifies the input analog signal by a factor of ? (greater than 1). A subtracter circuit subtracts an output of the DA converter circuit amplified by a factor of ? from an output of the amplifier circuit.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: October 30, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Shigeto Kobayashi, Kuniyuki Tani, Atsushi Wada, Noriaki Kojima
  • Patent number: 7286074
    Abstract: A semiconductor integrated circuit having a built-in A/D conversion circuit which enables, where the A/D conversion circuit is to be built into a semiconductor chip, the required capacitance of the stabilization capacitor to be connected to the output terminals of reference voltage generators for generating reference voltages to be reduced is to be provided to contribute to preventing the number of external terminals and the chip size from increasing.
    Type: Grant
    Filed: July 27, 2005
    Date of Patent: October 23, 2007
    Assignee: Renesas Technology Corporation
    Inventors: Junya Kudoh, Kouichi Yahagi, Tatsuji Matsuura
  • Patent number: 7271758
    Abstract: A SAR analog-to-digital Converter (ADC) is disclosed with variable gain having a SAR capacitor array with a plurality of switched capacitors therein with varying weights and a SAR controller for sampling an input voltage thereon in a sampling phase, and redistributing the charge stored thereon in a conversion phase in accordance with a SAR conversion algorithm. A gain adjust register is provided for defining an amount of charge to be added or subtracted from the capacitor array prior to the conversion phase relative to a predetermined amount of charge. A charge control device varies the amount of charge stored in the array prior to the conversion phase in accordance with the contents of the gain adjust register such that the amount of charge redistributed during the conversion phase is adjusted.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: September 18, 2007
    Assignee: Silicon Laboratories Inc.
    Inventors: Douglas Piasecki, Michael Odland
  • Patent number: 7265704
    Abstract: An analog to digital conversion architecture defining a process of converting an analog signal into equivalent digital signal which uses a method comprising of a set of functional units, each capable of performing parametric analog to digital conversion, connected in special arrangement such that each functional unit receives as input a set of parameters which are directly connected to output bits produced by a subset of functional units which are assigned to produce bits of higher significance. The method of analog to digital conversion wherein a function that defines the relationship between the input parameters, analog input value, a given reference value and a set of output bits can be implemented in a single device hence largely simplifying the analog to digital conversion process and making conversion faster and more efficient.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: September 4, 2007
    Inventor: Jyotindra Raj Shakya
  • Patent number: 7265705
    Abstract: A first stage circuit for a high-speed, high-resolution pipeline analog-to-digital converter (ADC) implements operational amplifier (opamp) sharing and capacitor sharing to combine the sample-and-hold (SAH) and the MDAC (multiplying digital to analog converter) functions in the first residue stage of the pipeline ADC. In one embodiment, the first stage circuit includes a sampling capacitor, an amplifier, a feedback capacitor array and a comparator. The sampling capacitor and the feedback capacitor array are configured by switches to operate in a sampling/MDAC mode, a discharge mode and a hold mode. In this manner, the sample-and-hold operation and the MDAC operation are merged into the first stage circuit of the pipeline ADC to achieve low power and high speed of operation.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: September 4, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Byung-Geun Lee, Byung-Moo Min
  • Patent number: 7248198
    Abstract: A reference voltage driving circuit and a pipelined analog to digital converter including the reference voltage driving circuit capable of providing a stable reference voltage even during a high speed/high resolution of analog-to-digital conversion using source follower circuits. Furthermore, a MDAC (Multiplying Digital to Analog Converter) requiring a high precision and a flash ADC (Analog to Digital Converter) requiring a relatively low precision are driven by respectively separate reference voltage driving circuits to thereby enable to curb an introduction of noise from the flash ADC into the MDAC requiring a high precision. Accordingly, there is no need of using a large capacity of capacitor for stabilizing the reference voltage, thereby enabling an embodiment with a smaller area and reducing the power consumption.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: July 24, 2007
    Assignee: LG Electronics Inc.
    Inventor: Jung Woong Moon
  • Patent number: 7233275
    Abstract: An analog-to-digital converter device capable of measuring inputs beyond a supply voltage including: an N bit analog-to-digital converter powered by a supply voltage and a reference voltage; a range resolution stage capable of receiving inputs at higher voltages than the supply voltage, providing an input to the analog-to-digital converter, and outputting a logic value of one for the N+1th bit in response to an input signal higher than the reference voltage; and a bootstrapped input multiplexer stage for connecting low voltage input signals directly to the analog-to-digital converter and for connecting input signals that can exceed the supply voltage to the range resolution stage.
    Type: Grant
    Filed: November 16, 2005
    Date of Patent: June 19, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Devrim Y. Aksin, Mohammad A. Al-Shyoukh
  • Patent number: 7224306
    Abstract: A first amplifier circuit samples an input analog signal and holds the sampled signal for a predetermined period of time. A first analog-to-digital converter circuit samples the input analog signal and converts the sampled signal into a digital value of a predetermined number of bits. A first digital-to-analog converter circuit converts an output signal from the first analog-to-digital converter circuit into an analog signal.
    Type: Grant
    Filed: December 13, 2005
    Date of Patent: May 29, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Shigeto Kobayashi
  • Patent number: 7218264
    Abstract: An analog-to-digital converter includes a plurality of analog stages. Each stage produces, in response to analog input, a digital output that corresponds to a most significant bit of the stage's input and an analog output that corresponds to the remainder of the input. The input of each stage except the first stage is the analog output of the preceding stage.
    Type: Grant
    Filed: December 28, 2005
    Date of Patent: May 15, 2007
    Inventor: Mordechai Shefer
  • Patent number: 7212143
    Abstract: A circuit for selectively converting at least one analog signal into corresponding digital codes. The circuit includes a management block having a plurality of inputs, each adapted for receiving a respective request signal carrying a request to convert the at least one analog signal. The management block is adapted to assign a priority level to the request signals based upon the input where the request signals are received, and is further operative to select one of the request signals based upon the assigned priority level and output a conversion start-up signal corresponding to the selected request signal. The circuit has a conversion block for receiving east one analog signal input and is connected to the management block to receive the conversion start-up signal as input, and start up conversion of the at least one analog signal.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: May 1, 2007
    Assignee: STMicroelectronics S.R.L.
    Inventors: Pierangelo Confalonieri, Marco Zamprogno, Francesca Girardi, Angelo Nagari
  • Patent number: 7181635
    Abstract: A method for placing a device in a selected mode of operation. The method comprises the steps of initializing a device select signal into a first logic state, asserting the device select signal in a second logic state, and returning the device select signal to the first logic state within a first user-controlled time window. A device is also described that includes means for detecting logic state transitions at a device select input and a clock input, and means for changing operating mode of the device in response to a predetermined number of logic state transitions at the clock input, occurring between logic state transitions at the device select input. The selected operating mode may be a reduced power consumption mode, for example, or another operating mode of the device, such as a daisy-chain mode of operation, or a mode that accommodates programming of analog input range.
    Type: Grant
    Filed: November 26, 2003
    Date of Patent: February 20, 2007
    Assignee: Analog Devices, Inc.
    Inventors: Michael Byrne, Nicola O'Byrne, Colin Price, Derek Hummerston
  • Patent number: 7170438
    Abstract: In one embodiment, a decision feedback equalizer helps mitigate intersymbol interference in a bi-directional signaling environment. In the particular embodiment, the decision feedback equalizer includes a voltage-to-current converter to source a received differential current to first and second node, a latch to provide logic signal when comparing currents sourced to the first and second nodes, a memory unit to store the logic signals, and a mapping circuit to source first and second feedback currents to the first and second nodes. This embodiment further includes a transmitter to transmit data over a transmission line during receiving, and a digital-to-analog converter to provide a differential current to the first and second nodes to substantially cancel that part of the received differential currents contributed by the transmitter.
    Type: Grant
    Filed: September 8, 2004
    Date of Patent: January 30, 2007
    Assignee: Intel Corporation
    Inventors: James E. Jaussi, Bryan K. Casper
  • Patent number: 7148831
    Abstract: An A/D converter suitable for use in a system in which the signal power of noise increases with the signal power of the signal, such as an imaging system, utilizes a variable quantization system for converting analog signals into digital signals. The variable quantization is controlled so that at low signal levels the quantization is similar or identical to conventional A/D converters, while the quantization level is increased at higher signal levels. Thus, higher resolution is provided at low signal levels while lower resolution is produced at high signal levels.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: December 12, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Alexander Krymski
  • Patent number: 7148834
    Abstract: The invention provides a clocked analog/digital converter for successive approximation which is designed using a jointly used amplifier and a dynamic range expansion facility by means of a special design for the comparison circuit in the first converter stage. The comparison circuits in the analog/digital converter allow decisions to be made for the further signal processing previously in a preceding time period. Two respective generator circuits in successive converter stages share one amplifier. This reduces the amount of space taken up and current drawn, increases the clock rate and simplifies signal processing for signals with high levels.
    Type: Grant
    Filed: January 17, 2006
    Date of Patent: December 12, 2006
    Assignee: Infineon Technologies AG
    Inventor: Victor Manuel da Fonte Dias
  • Patent number: 7148833
    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: August 26, 2005
    Date of Patent: December 12, 2006
    Assignee: Micron Technology, Inc.
    Inventors: Taehee Cho, Sandor L. Barna, Andrew M. Lever, Kwang-Bo Cho, Chiajen Lee
  • Patent number: 7129881
    Abstract: The pipeline analog-to-digital converter has a number of subsequent comparator stages (2) where the thresholds of the comparator stages are adjusted in accordance with the digital conversion results from previous stages (18, 28, 38) so as to implement a non-linear conversion scale. In particular, the pipeline analog-to-digital converter consists of a number of comparator stages (2), which operate in accordance with a common clock signal. The comparator stages are connected in series in such a way that a residue signal from a previous stage is used as input signal of a subsequent stage for comparison during the next clock period of the clock signal. At least some of said comparator stages have, according to the invention, a threshold generator (25, 35, 45) for adjusting the threshold value of the respective comparator (22, 32, 42) in accordance with comparison results of previous comparator stages (18, 28, 38).
    Type: Grant
    Filed: September 7, 2004
    Date of Patent: October 31, 2006
    Assignee: Alcatel
    Inventor: Bernd Franz
  • Patent number: 7126523
    Abstract: An amplifier sharing technique in an analog to digital converter (ADC) in which a cascaded combination of a pre-amplifier and main amplifier is used to provide the required amplification for a first stage, and only the main amplifier is used to provide the amplification for the second stage. Switches and capacitors are used in conjunction such that the sampling and feedback capacitors of the first stage are connected across the cascaded combination in a first phase, and sampling and feedback capacitors of the second stage are connected across the main amplifier in a second phase. By appropriate choice of parameter values for various components, the second poles due to the pre-amplifier may be located at the higher frequency ranges obtaining the required unity gain bandwidth (UGB) without Miller compensation and/or additional gain.
    Type: Grant
    Filed: November 3, 2005
    Date of Patent: October 24, 2006
    Assignee: Texas Instruments Incorporated
    Inventor: Preetam Charan Anand Tadeparthy
  • Patent number: 7098834
    Abstract: A multi-mode analog to, digital converter (ADC). The novel ADC includes an input terminal for receiving an analog input signal; a plurality of processing stages, each processing stage adapted to generate an output signal from an input to that processing stage; and a mechanism for determining a mode of operation and in accordance therewith connect the processing stages and the input terminal in a predetermined configuration. In an illustrative embodiment, the ADC can be configured as a subranging ADC, and the mechanism for determining, the mode of operation includes a signal processor for automatically selecting the mode of operation based on the frequency components of the input signal.
    Type: Grant
    Filed: October 20, 2004
    Date of Patent: August 29, 2006
    Assignee: Raytheon Company
    Inventors: Lloyd F. Linder, Michael F. Clingempeel, William W. Cheng, William J. Rinard, Benjamin Felder
  • Patent number: 7095352
    Abstract: An AD converter includes therein a plurality of amplifier circuits such as first to fourth amplifier circuits. Among the plurality of amplifier circuits an amplifier circuit that requires higher accuracy is placed nearer to a power source. An amplifier circuit that receives the first input of an input analog signal is placed nearest to the power source. That is, the first amplifier circuit in the embodiment is disposed closest to the power source. The amplifier circuit that receives the first input of an input analog signal is disposed closest to the power source compared to the other amplifier circuits. The first amplifier circuit, the second amplifier circuit, the third amplifier circuit and the fourth amplifier circuit in the embodiment are placed in this order of how close to the power source.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: August 22, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kuniyuki Tani, Atsushi Wada, Shigeto Kobayashi
  • Patent number: 7084803
    Abstract: A first amplifier circuit amplifies an input signal by a factor of ?. A first AD converter circuit is configured at an LSB voltage of VA and converts an input analog signal into a digital value of arbitrary N1 bits. A first DA converter circuit converts the digital value output from the first AD converter circuit into an analog signal. A subtracter circuit subtracts an output of the first DA converter circuit from an output of the first subtracter circuit. A second amplifier circuit amplifies an output of the subtracter circuit by a factor of ?. A second AD converter is configured at an LSB voltage of VB and converts an input analog signal into a digital value of arbitrary N2 bits. In this circuit, the relation VA*?*?=VB*2N2 holds.
    Type: Grant
    Filed: February 2, 2005
    Date of Patent: August 1, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Shigeto Kobayashi, Kuniyuki Tani, Atsushi Wada
  • Patent number: 7084804
    Abstract: A modified pipeline architecture allows the simple implementation of a foreground calibration technique with the continuous calibration benefits of the background calibration techniques. To calibrate a stage in the pipeline, a calibration voltage is presented to the input instead of the output from the previous stage. To prevent loss of information, the output data of the previous stage is passed on to a stage further down.
    Type: Grant
    Filed: July 13, 2005
    Date of Patent: August 1, 2006
    Assignee: Analog Devices, Inc.
    Inventor: Gil Engel
  • Patent number: 7042373
    Abstract: A pipeline ADC includes a pipeline structure having a plurality of analog-to-digital converting units cascaded in series; and a correcting unit coupled to the pipeline structure for correcting an output value of the pipeline structure according to a set of calibration constants. One of the analog-to-digital converting units contains a capacitor switching circuit. During error measurement of the pipeline ADC, the capacitor switching circuit switches to change capacitance allocation of the analog-to-digital converting unit so as to obtain the set of calibration constants.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: May 9, 2006
    Assignee: Realtek Semiconductor Corp.
    Inventors: Jui-Yuan Tsai, Wen-Chi Wang, Chia-Liang Chiang, Chao-Cheng Lee
  • Patent number: 7034736
    Abstract: Differential processing systems are provided that reduce even-order harmonic energy. The reduction may be selectively converted to, for example, random noise. This effects a tradeoff for processing systems that can afford to accept some increase in noise to thereby gain the benefits of reduction in even-order harmonic energy. In one system embodiment, first and second signal portions of a differential signal are respectively processed along first and second signal paths in a first processing mode and along the second and first signal paths in a second processing mode. The modes are selected to perform the desired conversion of even-order harmonic energy. In another system embodiment, first and second signal portions of a differential signal are processed along first and second signal paths in a first processing mode and inverted versions of these signals are processed along the first and second signal paths in a second processing mode. In addition, output signals are inverted in the second processing mode.
    Type: Grant
    Filed: November 2, 2004
    Date of Patent: April 25, 2006
    Assignee: Analog Devices, Inc.
    Inventor: Ahmed Mohamed Abdelatty Ali
  • Patent number: 7026972
    Abstract: A voltage-to-time conversion circuit compares a ramp-wave voltage, which steps up at a certain gradient, with each of a reference voltage, an input voltage, and a reference voltage, and produces a PB pulsating signal representing the times which the voltages require for having a predetermined relationship to the ramp-wave voltage. An encoder circuit converts the times into coded data items according to the ratios of the times to a common unit time. A normalization circuit determines a conversion characteristic curve on the basis of the coded data items, into which the times required by the reference voltages are converted, and A/D-converted values predefined for the reference voltages, and fits the coded data, into which the time required by the input voltage is converted, to the characteristic curve. Thus, the A/D-converted value of the input voltage Vin is calculated.
    Type: Grant
    Filed: February 17, 2005
    Date of Patent: April 11, 2006
    Assignee: Denso Corporation
    Inventor: Hirofumi Isomura
  • Patent number: 7023373
    Abstract: The invention provides a clocked analog/digital converter for successive approximation which is designed using a jointly used amplifier and a dynamic range expansion facility by means of a special design for the comparison circuit in the first converter stage. The comparison circuits in the analog/digital converter allow decisions to be made for the further signal processing previously in a preceding time period. Two respective generator circuits in successive converter stages share one amplifier. This reduces the amount of space taken up and current drawn, increases the clock rate and simplifies signal processing for signals with high levels.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: April 4, 2006
    Assignee: Infineon Technologies AG
    Inventor: Victor Manuel da Fonte Dias
  • Patent number: 7015854
    Abstract: A new architecture is provided in which a master A/D converter of limited precision controls the adjustment-charge steering of a set of similar slave A/D converter pipelines. This architecture relieves the layout constraints imposed by prior architectures and also reduces power consumption of the device. By spatially interleaving the slave pipelines in an array, the new architecture also improves accuracy.
    Type: Grant
    Filed: July 12, 2004
    Date of Patent: March 21, 2006
    Assignee: Massachusetts Institute of Technology
    Inventor: Michael P. Anthony
  • Patent number: 7002507
    Abstract: A need exists to provide an AD converter which is well balanced between an increase in processing speed and a decrease in circuit area. The AD converter performs an analog-to-digital conversion separately in four steps, while performing pipelined processing on an AD conversion of the first stage by a first AD conversion circuit and AD conversions of the second to fourth steps by a second AD conversion circuit. A DA conversion circuit, a subtractor circuit, and an amplifier circuit are utilized in a DA conversion, subtraction, and amplification in the first step as well as in DA conversions, subtractions, and amplifications in the second to fourth steps, thus shared in all the steps.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: February 21, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Shigeto Kobayashi, Kuniyuki Tani, Atsushi Wada
  • Patent number: 6999020
    Abstract: A frequency detecting circuit 10 detects frequency of a sampling pulse SP, and outputs the detected frequency as a detection value VOUT. A current adjusting circuit 20 adjusts a power supply current Ivd to be supplied to an AD converter 30 in accordance with the detection value VOUT. The power supply current Ivd varies continuously so as to follow the sampling frequency. As a result, an optimum power supply current Ivd can always be supplied in accordance with the operating frequency of the AD converter 30. That is, power consumption of the AD converter 30 can be reduced. Since the power supply current Ivd can be adjusted in accordance with the sampling frequency, it is possible to form the AD converter 30 that has a wide frequency band and allows great versatility.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: February 14, 2006
    Assignee: Fujitsu Limited
    Inventors: Tatsuhiro Mizumasa, Atsushi Hitaka
  • Patent number: 6977606
    Abstract: An arithmetic circuit includes a sample hold portion, an adding portion, a subtracting portion, an A/D sub-converter and a D/A sub-converter. The adding portion adds first and second residual voltages provided from a preceding stage. In a first hold mode, the subtracting portion subtracts an analog voltage from a voltage produced by the addition by the adding portion, and provides a voltage produced by the subtraction as a first residual voltage in this stage to a next stage. In a second hold mode, the subtracting portion interchanges internal capacitors with each other, subtracts the analog voltage from a voltage produced by the addition by the adding portion, and provides a voltage produced by the subtraction as a second residual voltage to the next stage.
    Type: Grant
    Filed: August 19, 2004
    Date of Patent: December 20, 2005
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Mutsuo Daito
  • Patent number: 6972707
    Abstract: A pipelined analog-to-digital converter in which signal value samples are represented differentially by pairs of charges and which uses charge-coupled-devices (CCDs) for delay and arithmetic operations on the charges is presented. In the pipeline, each successive stage resolves an equal or smaller charge difference. After a certain number of pipeline stages, the common-mode component of the signal-charge pair is reduced. The pipeline stages following this common-mode-charge reduction stage have a reduced charge capacity and size, allowing more sensitive charge comparison. The result is improved A/D converter resolution and reduced power consumption.
    Type: Grant
    Filed: July 12, 2004
    Date of Patent: December 6, 2005
    Assignee: Massachusetts Institute of Technology
    Inventor: Michael P. Anthony
  • Patent number: 6967611
    Abstract: An algorithmic or cyclic data converter uses an RSD stage having a switched capacitor network for efficiently scaling at least one externally supplied reference voltage. A reference voltage is scaled by using capacitor ratios that also function to provide an output voltage used as a residue output of the RSD A/D converter. The residue is used to generate a bit value corresponding to the magnitude of the residue. Two RSD stages cycle back and forth generating a logic value each half clock cycle until the desired bit resolution is achieved. In one form, the RSD stage scales the externally supplied reference voltage only by factors of less than one. In another form, the RSD stage scales the reference voltage by any scaling factor. A reference voltage scaling circuit separate from the RSD stage is avoided.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: November 22, 2005
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Ahmad H. Atriss, Steven P. Allen, Douglas A. Garrity
  • Patent number: 6963300
    Abstract: DNL and INL errors are minimized in a pipelined converter that is arranged to use reference pre-sampling. An example first stage in the pipelined converter includes a sample/hold amplifier (SHA) circuit, an evaluator circuit, and a multiplying digital-to-analog converter (MDAC) circuit. The evaluator circuit evaluates the input signal in the converter while the SHA circuit samples the input signal. The MDAC samples the SHA output at substantially the same time it samples a reference voltage, where the reference voltage is adjusted in response to the output of the evaluator circuit. Errors due to capacitor mismatching are minimized such that the settling characteristics of the various amplifiers in the circuits dominate the DNL/INL performance.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: November 8, 2005
    Assignee: National Semiconductor Corporation
    Inventor: Bumha Lee
  • Patent number: 6958724
    Abstract: A method of controlling an analog actual signal to conform to a digital desired signal uses a comparator with two input ports and one output port and a digital-to-analog converter. The analog actual signal to be converted is fed to one input port of the comparator and a analog output signal of the digital-to-analog converter is fed to the other input port of the comparator. The digital input signal fed to the digital-to-analog converter is adapted as a function of the output signal of the comparator in a definable number of iterative steps, between a definable lower and a definable upper threshold, according to the balancing method. The digital input signal fed to the digital-to-analog converter corresponds to the digital desired signal to which the analog actual signal is converted.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: October 25, 2005
    Assignee: EADS Deutschland GmbH
    Inventor: Heinrich-Martin Boehm
  • Patent number: 6940444
    Abstract: The domino asynchronous successive approximation (ASA) analog-to-digital converter (ADC) converts an analog signal to an n-bits digital signal. The domino ASA ADC is made out of n-blocks, corresponding to the number of n-bits of the digital output. Each of these n-blocks generates a conversion bit and calibrates all following blocks, comparable to a domino structure. One key advantage of the domino ASA ADC is its modular structure; each block is independent from all others. The unity capacitors used need to be matched only within their specific blocks. The architecture is very flexible; it is possible to increase the resolution by adding more blocks of the same kind. The ASA ADC is very fast, its speed is only limited the RC constants during the sampling and measurement phase and the speed of the comparators used.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: September 6, 2005
    Assignee: Dialog Semiconductor GmbH
    Inventor: Antonello Arigliano
  • Patent number: 6933876
    Abstract: A cell phone is provided that may be used with multiple radio formats, such as GSM and CDMA. The cell phone includes a receiver that receives radio signals and converts them into electrical signals. An analog to digital converter is connected to the receiver and converts an analog input to a digital output having an adjustable number of bits at an adjustable sampling frequency. A cell phone application specific integrated circuit is connected to the analog to digital converter, which is used to process the digital output to extract encoded telecommunications data in one of the supported radio formats.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: August 23, 2005
    Assignee: Skyworks Solutions, Inc.
    Inventors: Paul A. Underbrink, Kelly H. Hale, Guang-Ming Yin, Patrick D. Ryan, Joseph H. Colles, Daryush Shamlou
  • Patent number: 6909392
    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: October 29, 2003
    Date of Patent: June 21, 2005
    Assignee: Micron Technology, Inc.
    Inventors: Eric R. Fossum, Sandor L. Barna
  • Patent number: 6900749
    Abstract: Digital signals of the most significant bit to the least significant bit are supplied to a digital calibration operation unit from a redundancy correction circuit, and an intermediate high order 2-bit digital signal is supplied to a correction value selection circuit. A DC control signal is supplied to the correction value selection circuit. A plurality of groups of correction values corresponding to the values of the intermediate high order 2-bit digital signal are stored in advance in a correction value ROM. The correction value selection circuit reads out a correction value from the correction value ROM based on the DC control signal and the intermediate high order 2-bit digital signal. The digital calibration operation unit adds the correction value AM to the digital signals of the most significant bit to the least significant bit, and outputs a resulting value as a digital output value.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: May 31, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kuniyuki Tani, Atsushi Wada, Shigeto Kobayashi
  • Patent number: 6850180
    Abstract: An analog-to-digital converter that does not use an external clock signal to convert an incoming analog signal to a digital output signal including two or more comparators configured to receive an analog input signal, a digital-to-analog converter configured to produce a reference signal for the comparators, and asynchronous logic configured to sample comparator results and adjust a digital output signal accordingly.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: February 1, 2005
    Assignee: SLICEX, Inc.
    Inventor: Rex K. Hales
  • Publication number: 20040246160
    Abstract: Self calibrating SAR analog-to-digital converter. A data converter for converting analog data on a differential data input having a positive analog input terminal and a negative analog input terminal to digital data. The data converter includes a first single ended successive approximation register (SAR) analog-to-digital converter for converting the analog signal on the positive analog input terminal to a first digital signal and a second single ended successive approximation register (SAR) analog-to-digital converter for converting the analog signal on the negative analog input terminal to a second digital signal. A circuit for combining the first and second digital signals as a digital output signal for the data converter that represents the difference between the analog signals on the positive and negative analog input terminals.
    Type: Application
    Filed: June 3, 2003
    Publication date: December 9, 2004
    Inventors: Ka Y. Leung, Kafai Leung
  • Publication number: 20040246159
    Abstract: Open loop common mode driver for switched capacitor input to SAR. A method for controlling the operation of a SAR conversion cycle. The method includes the steps of first initiating the SAR conversion cycle by connecting one side of a plurality of capacitors in a capacitor array to a first capacitor reference voltage and the other side of the plurality of capacitors to the input of a comparator. This is followed by the step of sequentially switching in a plurality of compare cycles the one side of a select one or ones of the capacitors to a second capacitor reference voltage to change the voltage on the input of the comparator. Then, a compare operation is initiated after initiation of each compare cycle to compare the value on the input of the comparator with a compare reference voltage after a predetermined settling time has elapsed from the beginning of the initiation of each compare cycle.
    Type: Application
    Filed: December 12, 2003
    Publication date: December 9, 2004
    Inventors: Ka Y. Leung, Doug Piasecki
  • Publication number: 20040239547
    Abstract: A method of controlling an analog actual signal to conform to a digital desired signal uses a comparator with two input ports and one output port and a digital-to-analog converter. The analog actual signal to be converted is fed to one input port of the comparator and an analog output signal of the digital-to-analog converter is fed to the other input port of the comparator. The digital input signal fed to the digital-to-analog converter is adapted as a function of the output signal of the comparator in a definable number of iterative steps, between a definable lower and a definable upper threshold, according to the balancing method. The digital input signal fed to the digital-to-analog converter corresponds to the digital desired signal to which the analog actual signal is converted.
    Type: Application
    Filed: January 27, 2004
    Publication date: December 2, 2004
    Inventor: Heinrich-Martin Boehm
  • Patent number: 6819280
    Abstract: Systems and techniques to readout array-based analog data with reduced power requirements and reduced fixed pattern noise. An image sensor on an integrated circuit may include a sensor array to provide array-based analog data, a parallel sampling circuitry to receive the array-based analog data in parallel, a pipelined amplification circuitry to serially amplify the received array-based analog data, and an analog-to-digital converter to convert the amplified array-based analog data into digital data.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: November 16, 2004
    Assignee: Micron Technology, Inc.
    Inventors: Steve Huang, Lin Ping Ang
  • Publication number: 20040085237
    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: Application
    Filed: October 29, 2003
    Publication date: May 6, 2004
    Inventors: Eric R. Fossum, Sandor L. Barna