Recirculating Patents (Class 341/163)
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Patent number: 7777662Abstract: An analogue-to-digital (A/D) converter converts an analogue input signal to a digital code representing the analogue input signal. The A/D converter includes a comparator for comparing the input signal with a reference signal, a search logic block for determining the digital code, and an A/D converter arranged for receiving input from the search logic block and for providing the reference signal to be applied to the comparator. At least a first portion of the A/D converter is implemented with equal capacitors and may be controlled by a thermometer coded signal. Additionally, the A/D converter may include a second portion implemented using binary weighted capacitors controlled by a thermometer coded or binary coded signal. The A/D converter may also include a plurality of A/D converters coupled by an analogue addition circuit or a weighted summing amplifier.Type: GrantFiled: October 23, 2008Date of Patent: August 17, 2010Assignee: Stichting IMEC NederlandInventors: Guy Meynants, Juan Santana, Richard van den Hoven
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Patent number: 7773023Abstract: A successive approximation type A-to-D converter includes a cyclic D-to-A converter (11), a comparator (12) for comparing an analog value with an output value of the D-to-A converter (11), and memory means (13) for sequentially storing an output value of the comparator (12) and supplying the stored value to the D-to-A converter (11) in a reverse order.Type: GrantFiled: November 30, 2007Date of Patent: August 10, 2010Assignee: Panasonic CorporationInventors: Shiro Dosho, Takashi Morie, Kazuo Matsukawa
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Patent number: 7764215Abstract: An Analog-to-Digital Converter (ADC) has a Successive-Approximation-Register (SAR) driving a digital-to-analog converter (DAC) that generates an analog voltage compared to an input voltage by a series of stages. The last stage feeds a compare signal to the SAR. Each stage has a dual-input differential amplifier that operates as a unity gain op amp during an auto-zeroing phase and as a high-speed low-gain amplifier during an amplifying phase. The dual-input differential amplifier has two pairs of differential inputs. A secondary pair has an offset-storing capacitor across it, and connects to the output pair through feedback switches during auto-zeroing. A primary pair connects to stage inputs through input switches during the amplifying phase. Since two pairs of differential inputs are provided to the dual-input differential amplifier, the offset capacitor is completely isolated from the input pair. The current sink in the dual-input differential amplifier is adjusted higher during the amplifying period.Type: GrantFiled: December 31, 2008Date of Patent: July 27, 2010Assignee: Hong Kong Applied Science and Technology Research Institute Co., Ltd.Inventors: Ho Ming Karen Wan, Yat To William Wong, Kwai Chi Chan, Kwok Kuen David Kwong
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Patent number: 7746262Abstract: A method for coding a digital to analog converter of a successive approximation register analog to digital converter includes the steps of first switching capacitors associated with a bit from ground to a reference voltage. Next, a determination is made of whether a logical value of the bit is a first or a second value. If the logical value is the first value, capacitors associated with a next bit are switched from ground to a reference voltage. If the logical value is the second value, one half of the capacitors associated with the bit currently connected are switched from the reference voltage to ground.Type: GrantFiled: December 19, 2005Date of Patent: June 29, 2010Assignee: Silicon Laboratories Inc.Inventors: Golam R. Chowdhury, Douglas S. Piasecki, Bruce Del Signore, Kevin Kwak
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Patent number: 7724174Abstract: A successive approximation ADC is disclosed. A comparator receives and compares a sampled input signal and an output of a DAC. Non-binary successive approximation register (SAR) control logic controls sampling of the input signal and controls a sequence of comparisons based on comparison result of the comparator. The SAR control logic controls each comparison when signal or charge in the DAC has not been completely settled. A binary-error-tolerant corrector is then used to compensate the sampling error.Type: GrantFiled: October 7, 2008Date of Patent: May 25, 2010Assignees: Himas Media Solutions, Inc., NCKU Research and Development FoundationInventors: Soon-Jyh Chang, Chun-Cheng Liu, Chih-Haur Huang
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Patent number: 7701377Abstract: A current steering circuit includes a multitude of current stages each including an associated current source transistor, and first and second cascode transistors coupled in series with the associated current source transistor. The first and second cascode transistors respectively receive first and second reference voltages and are biased such that a voltage appearing across any terminal pairs of the transistors is less than a predefined value. Each current stage includes a first switch supplying the current flowing through the transistors to a first resistive load in response to a control signal, and a second switch supplying the current to a second resistive load in response to a complement of the control signal. An amplifier responsive to an analog multiplexer's output provides a biasing voltage to each of the current stages. The analog multiplexer supplies a different output voltage in response to different counts of a counter.Type: GrantFiled: June 17, 2008Date of Patent: April 20, 2010Assignee: Marvell International Ltd.Inventor: Sasan Cyrusian
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Patent number: 7671769Abstract: A multistage analog/digital converter for converting in multi-step cycles an input signal into respective digital codes, each cycle step resolving at least one bit of a respective digital code. The converter includes: a sampling circuit inputting the signal and outputting a first sequence of analog samples; a generation block of a pseudorandom sequence of samples; a summing node, such as to input the first sequence and the pseudorandom sequence, obtaining in output a second sequence of analog samples including non-pseudorandom samples; a converter having a controllable digital gain receiving the second sequence and outputting bits of the digital codes; a feedback loop with a loop gain and including an analog amplifier; a digital calibration block to match the digital gain to the loop gain and including a prediction block to produce a digital estimation of said input signal starting from the bits resulting from converting the non-pseudorandom samples.Type: GrantFiled: August 26, 2008Date of Patent: March 2, 2010Assignee: STMicroelectronics S.r.l.Inventors: Giovanni Antonio Cesura, Roberto Giampiero Massolini
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Patent number: 7652613Abstract: The method and device include the filtering and the analog/digital conversion of an intermediate signal. The intermediate signal is processed by a filtering and analog/digital conversion circuit that is configurable using switched passive capacitor technology. The various configurations successively adopted by the circuit provide filtering and analog/digital conversion to be successively carried out.Type: GrantFiled: January 16, 2008Date of Patent: January 26, 2010Assignee: STMicroelectronics SAInventors: Loïc Joet, Stéphane Le Tual
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Patent number: 7652612Abstract: Some embodiments include apparatus and methods having a first module with a capacitor network configured to receive a sample of an analog input signal and an amplifier configured to couple to the capacitor network in a plurality of arrangements to successively generate a plurality of residue signals at an amplifier output node of the amplifier without resetting the amplifier between generation of least two of the plurality of residue signals, and a second module configured to generate a digital signal based on a plurality of intermediate codes generated from the sample signal and the plurality of residue signals, the digital signal including a digital value of the sample.Type: GrantFiled: March 10, 2008Date of Patent: January 26, 2010Assignee: Atmel CorporationInventor: Renaud Dura
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Patent number: 7649488Abstract: A low-power column parallel cyclic analog-to-digital converter and an imaging device using the same. The analog-to-digital converter comprises one stage and is optimized to reduce power, noise and capacitor settling time. The one stage analog-to-digital converter comprises a multiplying circuit for performing a multiplication operation during conversion phases and a sub-analog-to-digital converter connected to receive analog output signals from the multiplying circuit. The sub-analog-to-digital converter converts, during the conversion phases, the analog output signals into portions of an N-bit digital code. The multiplying circuit switches configurations between conversion phases and uses the portions of the digital code during the conversion phases to generate new analog output signals for subsequent conversion by the sub-analog-to-digital converter.Type: GrantFiled: June 25, 2008Date of Patent: January 19, 2010Assignee: Aptina Imaging CorporationInventor: Robert Johansson
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Patent number: 7642946Abstract: A system and method are provided allowing for successive approximation analog to digital conversion. A first differential voltage is sampled and held during a first cycle. The first differential voltage is converted to a differential current. A second differential voltage is generated based on the differential current flowing through parallel-coupled respective first and second variable resistances. First and second portions of the second differential voltage are compared to produce a comparison result therefrom. Successive approximation is used to generate a signal based on the comparison result, the signal being an output signal and being used to control resistances of respective ones of the first and second variable resistances during subsequent cycles.Type: GrantFiled: April 7, 2008Date of Patent: January 5, 2010Assignee: Broadcom CorporationInventors: Ark-Chew Wong, Marcel L. Lugthart, Andrew R. Chen
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Patent number: 7642945Abstract: A successive approximation type AD converter circuit for comparing an analog input signal with an output analog signal of a DA converter with a comparator to input a digital signal output in accordance with a comparison result to the DA converter to determine a digital signal obtained if the output analog signal of the DA converter is equal to the analog input signal, as an AD-converted output signal, includes: an AD converter for AD-converting the analog input circuit in accordance with a sampling period for sampling the analog input signal and a comparison period for comparing the sampled analog input signal with the output analog signal of the DA converter with the comparator; and setting means for independently setting a cycle time of a first clock signal for determining the sampling period and a cycle time of a second clock signal for determining the comparison period.Type: GrantFiled: February 22, 2008Date of Patent: January 5, 2010Assignee: Fujitsu Microelectronics LimitedInventors: Suguru Tachibana, Ikuo Hiraishi, Azusa Saito
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Patent number: 7623056Abstract: Providing a configuration that, when an AD converter is provided for each of pixel columns, enables each of the elements to be arranged without increasing the element arrangement pitch. A photoelectric conversion apparatus according to the present invention includes a plurality of AD converters. The AD converter includes: an arithmetic operation amplifying circuit unit, a comparator circuit unit for comparing, with a reference signal, an output from the arithmetic operation amplifying circuit unit; a DA converted circuit unit for DA converting a signal based on a signal from the comparator circuit unit; and a sampling and holding unit arranged at an input section of the arithmetic operation amplifying circuit unit. The DA converted circuit unit is arranged between the comparator circuit unit and the arithmetic operation amplifying circuit unit.Type: GrantFiled: July 2, 2008Date of Patent: November 24, 2009Assignee: Canon Kabushiki KaishaInventor: Yuichiro Yamashita
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Patent number: 7609184Abstract: Provided is a D-A conversion apparatus that outputs an analog output voltage according to digital input data, which includes a capacitance array main D-A converter that supplies a main voltage according to the input data to an output terminal of the D-A conversion apparatus, a correction data output section that outputs correction data according to the input data, a capacitance array correction D-A converter that outputs a correction voltage according to the correction data, and a voltage dividing capacitor connected serially between an output end of the correction D-A converter and an output end of the main D-A converter.Type: GrantFiled: November 8, 2007Date of Patent: October 27, 2009Assignees: Advantest Corporation, Tokyo Institute of TechnologyInventors: Yasuhide Kuramochi, Akira Matsuzawa
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Patent number: 7605741Abstract: An analog to digital converter having improved differential non-linearity is provided. The converter has a memory which is used to look up the actual weight or a weight error corresponding to the bits that have been kept as part of the SAR process to form an output correction value A part of this, for example a residue (the part following the decimal point in a decimal representation) is used to drive a correction DAC which causes a correction to be applied to the trial value presented to a comparator used by the ADC.Type: GrantFiled: December 5, 2006Date of Patent: October 20, 2009Assignee: Analog Devices, Inc.Inventor: Christopher Peter Hurrell
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Patent number: 7595748Abstract: The invention provides a method of gain error calibration in a pipelined analog-to-digital converter (ADC). In one embodiment, a first stage and a second stage of the pipelined ADC share a common operational amplifier. The first stage is requested to generate the stage output signal thereof according to a first correction number. The second stage is also requested to generate the stage output signal thereof according to a second correction number. A plurality of stage output values generated by stages of the pipelined ADC are collected. The stage output values are respectively correlated with the first correction number and the second correction number to estimate a first gain error estimate of the first stage and a second gain error estimate of the second stage. The first gain error estimate and the second gain error estimate are weighted to obtain a predicted gain error for gain error calibration in the first stage and the second stage.Type: GrantFiled: May 9, 2008Date of Patent: September 29, 2009Assignee: Mediatek Inc.Inventor: Yu-Hsuan Tu
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Patent number: 7589659Abstract: A successive approximation analog to digital converter comprising a plurality of capacitors which during a successive approximation conversion are selectively connectable to a first reference or a second reference under the command of a controller. During a conversion step where the connections of a given capacitor may be varied, the switches to the given capacitor are both placed in a high impedance state during a decision period of a comparator.Type: GrantFiled: July 3, 2007Date of Patent: September 15, 2009Assignee: Analog Devices, Inc.Inventor: Christopher Peter Hurrell
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Patent number: 7579975Abstract: A residue block in a stage of a pipeline ADC processing differential signals contains multiple pairs of capacitors. During a hold phase of operation, one capacitor of a pair is connected to a positive reference voltage, and the other capacitor is connected to a negative reference voltage if the input signal exceeds a corresponding threshold voltage. When the input signal does not exceed the corresponding threshold voltage, both capacitors of the pair are connected either to the positive or the negative reference voltage. As a result, the need for a common mode reference voltage may be eliminated, and the residue block can be implemented with a smaller area.Type: GrantFiled: December 11, 2007Date of Patent: August 25, 2009Assignee: Texas Instruments IncorporatedInventors: Sandeep Mallya Perdoor, Abhaya Kumar, Shakti Shankar Rath
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Patent number: 7576678Abstract: A successive approximation analog/digital converter is provided, which includes a successive approximation register supplying a digital/analog converter, first means of comparing an input signal of the analog/digital converter to an output signal of the digital/analog converter delivering a first comparison signal, said successive approximation analog/digital converter being synchronised by a clock signal coming from a conversion clock. A method such as this includes dynamic adaptation of the conversion clock period based on at least one parameter.Type: GrantFiled: October 26, 2007Date of Patent: August 18, 2009Assignee: Atmel Nantes SAInventors: Joel Chatal, Abdellatif Bendraoui
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Publication number: 20090128390Abstract: Disclosed herein is a signal level conversion circuit for increasing the dynamic range of an Analog-to-Digital Converter (ADC). A comparison and calculation unit compares the value of an input signal Vin and the value of a first reference signal Vref1 and compares the value of the input signal Vin and the value of a second reference signal Vref2, and calculates and outputs respective differences therebetween. A signal leveling circuit unit converts signal levels of the respective output signals of the comparison and calculation unit so that the output signals fall within the dynamic range of an ADC. The ADC digitizes the output signal Vo of the signal leveling circuit unit and the output signals Vack1 and Vack2 of the comparison and calculation unit.Type: ApplicationFiled: June 4, 2008Publication date: May 21, 2009Applicant: Korea Advanced Institute of Science and TechnologyInventors: Songcheol HONG, Joon Ho Oum
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Patent number: 7495596Abstract: 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: GrantFiled: May 21, 2007Date of Patent: February 24, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Suhwan Kim, Jong-Kwan Woo, Han Yang
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Patent number: 7486218Abstract: An A/D converter includes an A/D conversion circuit, a multiplying D/A converter, a switch circuit, and a control circuit. The control circuit prevents an A/D output of the A/D conversion circuit from being input to the D/A converter and controls the switch circuit so that an input voltage to be A/D-converted is recycled through the switch circuit and the multiplying D/A converter. As a result, the input voltage is amplified to a suitable level for A/D conversion. Then, the control circuit allows the A/D output to be inputted to the D/A converter and controls the switch circuit so that the amplified voltage is recycled through the switch circuit, the multiplying D/A converter, and the A/D conversion circuit. As a result, the amplified voltage is A/D-converted.Type: GrantFiled: September 20, 2007Date of Patent: February 3, 2009Assignee: Denso CorporationInventor: Masakiyo Horie
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Patent number: 7474238Abstract: 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: GrantFiled: January 31, 2007Date of Patent: January 6, 2009Assignee: Sanyo Electric Co., Ltd.Inventor: Shigeto Kobayashi
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Publication number: 20080309542Abstract: An A/D converter circuit has a first ring delay line and a second ring delay line configured to vary respective characteristics in the same manner relative to a change in the ambient temperature. A reference voltage, which is free from a change in temperature, is fed as a power supply voltage to the second ring delay line. Digital data produced by the first ring delay line is temperature-compensated by digital data produced by the second ring delay line.Type: ApplicationFiled: May 15, 2008Publication date: December 18, 2008Applicant: DENSO CORPORATIONInventor: Yukihiko Tanizawa
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Publication number: 20080291067Abstract: Automatic range shifting for an analog to digital converter (ADC) includes combining an external analog input and a DAC output to provide an input to the ADC, detecting whether the range of the output of the ADC is above a predetermined upper range limit or below a predetermined lower range limit, and generating an adjustment code to increase the DAC output if the ADC output is above the upper range limit and to decrease the DAC output if the ADC output is below the lower range limit for decreasing the ADC input when the ADC output is above the upper limit and to increase the ADC input when the ADC output is below the lower limit to keep the ADC input within the ADC range.Type: ApplicationFiled: May 22, 2008Publication date: November 27, 2008Inventors: John O'Dowd, Kevin Jennings, Tadhg Creedon
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Patent number: 7443333Abstract: 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: GrantFiled: February 13, 2007Date of Patent: October 28, 2008Assignee: Freescale Semiconductor, Inc.Inventors: Douglas A. Garrity, David R. Locascio
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Patent number: 7439898Abstract: 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: GrantFiled: May 31, 2007Date of Patent: October 21, 2008Assignee: Analog Devices, Inc.Inventors: Srikanth Nittala, Jeremy Gorbold, Mahesh Madhavan
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Patent number: 7432844Abstract: A Successive Approximation Routine converter is provided in which a comparator is responsive to an output of a first Digital to Analog Converter, and an output of a second Digital to Analog Converter and to a DAC common mode output reference voltage, and wherein the comparator provides data to a SAR controller indicating which one of the DAC outputs is greater than the other, and how a common mode voltage on the DAC outputs compares to the reference voltage. On this basis the SAR controller can add or subtract a common mode offset to the trial words being presented at a given bit trial such that both differential and common mode convergence is achieved.Type: GrantFiled: December 4, 2006Date of Patent: October 7, 2008Assignee: Analog Devices, Inc.Inventors: Michael Mueck, Michael Christian Wohnsen Coln
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Patent number: 7414562Abstract: An asynchronous cyclic current-mode analog-to-digital converter (ADC) is disclosed. The ADC comprises a plurality of sub-ADCs cascading from the first stage to the last stage, each sub-ADC comprising a current-mode ADC having a digital output, an analog current input, a reference current input and an analog current output. The analog current input of each stage, except the first stage, is operatively connected to the analog current output of the immediately preceding stage. The plurality of sub-ADCs are configured to operate without synchronization with each other.Type: GrantFiled: July 25, 2006Date of Patent: August 19, 2008Assignee: Intellectual Ventures Fund 27 LLCInventors: Chi Wah Kok, Wing Shan Tam
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Patent number: 7391354Abstract: One input terminals of switches respectively coupled to capacitors of a capacitance array type D/A converter configured as a main DAC are coupled to a first external terminal of an IC. On the other hand, a current switching type D/A converter of a resistance string type D/A converter configured as a sub DAC that causes a DC current to flow therethrough is coupled to a second external terminal of the IC.Type: GrantFiled: January 25, 2007Date of Patent: June 24, 2008Assignee: Renesas Technology Corp.Inventors: Hiroyuki Tsunakawa, Akihiro Kitagawa
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Patent number: 7385547Abstract: An analog-to-digital converter comprising a minimal amount of circuitry for conversion of an input analog signal to a series of digital bits. A differential comparator is provided for generating digital values to which the digital bits correspond. A pair of digital-to-analog converters are provided for generating, via successive approximation, a differential feedback analog signal based on bits previously generated by the differential comparator. The analog-to-digital converter compares the differential feedback analog signal to the input analog signal, and based on the comparison generates a digital value that corresponds to a digital bit. In the method of the invention, an analog signal is converted to a digital value using the analog-to-digital converter, and a pair of digital-to-analog converters each generate, via successive approximation, a differential feedback analog signal that is applied to a differential comparator for comparison to the input analog signal being digitized.Type: GrantFiled: March 1, 2006Date of Patent: June 10, 2008Assignee: Micron Technology, Inc.Inventor: Christian Boemler
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Publication number: 20080129573Abstract: A Successive Approximation Routine converter is provided in which a comparator is responsive to an output of a first Digital to Analog Converter, and an output of a second Digital to Analog Converter and to a DAC common mode output reference voltage, and wherein the comparator provides data to a SAR controller indicating which one of the DAC outputs is greater than the other, and how a common mode voltage on the DAC outputs compares to the reference voltage. On this basis the SAR controller can add or subtract a common mode offset to the trial words being presented at a given bit trial such that both differential and common mode convergence is achieved.Type: ApplicationFiled: December 4, 2006Publication date: June 5, 2008Applicant: Analog Devices, Inc.Inventors: Michael Mueck, Michael Christian Wohnsen Coln
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Patent number: 7382302Abstract: 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: GrantFiled: July 28, 2006Date of Patent: June 3, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Tomo Muramatsu, Hirotomo Ishii
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Patent number: 7382308Abstract: 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: GrantFiled: February 16, 2007Date of Patent: June 3, 2008Assignee: iWatt Inc.Inventors: Enzhu Liang, Xuecheng Jin
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Patent number: 7372389Abstract: 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 digType: GrantFiled: September 15, 2006Date of Patent: May 13, 2008Assignee: Jennic LimitedInventor: Andrew Gerard Whittaker
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Patent number: 7342530Abstract: A successive approximation analog/digital converter converting an analog input signal into a digital output value by means of a plurality of successive conversion cycles, comprises at least one first input for injecting an analog input signal, a controllable capacitive network which is connected downstream of the first input and which is divided into at least two capacitive subnetworks and, at least two parallel-connected and parallel-operating comparators for defining a number of comparator thresholds which corresponds to the number of parallel comparators. The comparators are respectively connected downstream of one of the capacitive subnetworks and the comparators output a corresponding number of digital intermediate signals on the basis of the comparisons in the comparators. The analog/digital converter further comprises a register set by the intermediate signals.Type: GrantFiled: June 29, 2006Date of Patent: March 11, 2008Assignee: Infineon Technologies AGInventor: Franz Kuttner
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Patent number: 7336214Abstract: 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: GrantFiled: December 16, 2005Date of Patent: February 26, 2008Inventor: Alexander Krymski
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Patent number: 7330145Abstract: 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: GrantFiled: October 18, 2004Date of Patent: February 12, 2008Assignee: NXP B.V.Inventor: Hendrik Van Der Ploeg
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Patent number: 7330146Abstract: An improved analog-to-digital converter wherein a minimal amount of circuitry is provided for conversion of an analog signal to a series of digital bits. A comparator is provided for generating digital values to which the digital bits correspond. A digital-to-analog converter is provided for generating, via successive approximation, a feedback analog signal based on bits previously generated by the comparator. The analog-to-digital converter compares the feedback analog signal to the input analog signal, and based on the comparison generates a digital value that corresponds to a digital bit. In the method of the invention, an analog signal is converted to a digital value using the analog-to-digital converter, and a digital-to-analog converter comprising two capacitors and a reference selector generates, via successive approximation, a feedback analog signal that is applied to a comparator for comparison to the input analog signal being digitized.Type: GrantFiled: December 5, 2005Date of Patent: February 12, 2008Assignee: Micron Technology, Inc.Inventor: Christian Boemler
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Patent number: 7321329Abstract: An electronic apparatus includes a CMOS image sensor and a signal processor operable to process an output signal from the CMOS image sensor. The CMOS image sensor includes the following elements: an imaging region; a reference signal generator operable to generate a reference signal; a comparator operable to compare the reference signal generated by the reference signal generator with a signal transmitted from the imaging region; a counter operable to count, in parallel with comparison performed by the comparator, a predetermined count clock and to hold a count value at the time of completion of comparison performed by the comparator; and a reference signal supply interface unit operable to supply the reference signal generated by the reference signal generator to a plurality of comparators via different signal lines, respectively.Type: GrantFiled: July 6, 2006Date of Patent: January 22, 2008Assignee: Sony CorporationInventors: Takayuki Tooyama, Atsushi Suzuki, Noriyuki Fukushima, Yukihiro Yasui, Yoshikazu Nitta
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Patent number: 7271758Abstract: 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: GrantFiled: June 29, 2005Date of Patent: September 18, 2007Assignee: Silicon Laboratories Inc.Inventors: Douglas Piasecki, Michael Odland
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Patent number: 7265706Abstract: An improved analog-to-digital converter wherein a minimal amount of circuitry is provided for conversion of an analog signal to a series of digital bits. A comparator is provided for generating digital values to which the digital bits correspond. A digital-to-analog converter is provided for generating, via successive approximation, a feedback analog signal based on bits previously generated by the comparator. The analog-to-digital converter compares the feedback analog signal to the input analog signal, and based on the comparison generates a digital value that corresponds to a digital bit. In the method of the invention, an analog signal is converted to a digital value using the analog-to-digital converter, and a digital-to-analog converter comprising two capacitors and a reference selector generates, via successive approximation, a feedback analog signal that is applied to a comparator for comparison to the input analog signal being digitized.Type: GrantFiled: December 5, 2005Date of Patent: September 4, 2007Assignee: Micron Technology, Inc.Inventor: Christian Boemler
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Patent number: 7265707Abstract: An A/D converter of an successive approximation type according to the present invention comprises a sample hold circuit, a reference voltage generating circuit, a comparator for comparing the reference voltage generated by the reference voltage generating circuit to a value of the input analog signal retained in the sample hold circuit, a control circuit for successively controlling the reference voltage generating circuit so that a value of the reference voltage approximates to the value of the input analog signal retained in the sample hold circuit, a buffering circuit for outputting an output value corresponding to an output voltage of the comparator, a latch circuit for retaining the output value of the buffering circuit corresponding to the output value of the comparator per bit as a digital value, and a buffering control circuit for blocking a power supply to the buffering circuit during the sampling period is provided.Type: GrantFiled: April 20, 2006Date of Patent: September 4, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yukihiro Mizukami, Ichirou Yamane, Kazuhisa Raita
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Patent number: 7259708Abstract: A cyclic pipeline analog to digital converter includes a sample/hold module, a sub-analog/digital converting module, and an alternate digital/analog converting module. The sample/hold module generates a sample signal according to an analog-input signal and a residue signal. The sub-analog/digital converting module generates a first control signal and a second control signal alternately in different time according to the converting result of the sample signal. The alternate digital/analog converting module decides to receive a first reference signal and a second reference signal separately according to the first control signal and the second control signal.Type: GrantFiled: June 7, 2006Date of Patent: August 21, 2007Assignee: VIA Technologies, Inc.Inventor: Woody Lu
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Patent number: 7250896Abstract: A method for pipelining an analog-to-digital conversion of an analog input signal into an N-bit digital output signal is disclosed where a multiplexer is used for the selection of pre-processed digital approximation values from a plurality of adders and subtractors. The selection is set after the decoding of the selected digital approximation values. Thus, considerable more time of the total iteration cycle is available for the pre-amplifier to settle at very high operation frequencies.Type: GrantFiled: June 1, 2006Date of Patent: July 31, 2007Assignee: Infineon Technologies AGInventor: Marc Hesener
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Patent number: 7248199Abstract: In an analog-to-digital (A-D) converter, an A-D conversion circuit samples an analog signal and converts it to a digital value of a predetermined bit number less than a targeted bit number. An amplifier circuit is provided in parallel to the A-D conversion circuit, and holds the signal sampled by the A-D conversion circuit or amplifies it by a predetermined gain. A first source follower circuit for the amplifier circuit and a second source follower circuit for the A-D conversion circuit are provided separately at the output side of a sample-and-hold circuit.Type: GrantFiled: March 3, 2006Date of Patent: July 24, 2007Assignee: Sanyo Electric Co., Ltd.Inventors: Takashi Asano, Atsushi Wada, Shigeto Kobayashi
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Patent number: 7239255Abstract: A technique for correcting charge transfer inefficiencies in a Charge Coupled Device (CCD). The basic approach is to estimate the charge entering at a given stage in a CCD pipeline, and to then determine an estimate of the error introduced by the accumulated leftover charge that will be present at a second point, farther down the pipeline. The error is then corrected by injecting a correcting charge at a third point, farther still down the CCD pipeline. The invention is used, in one embodiment, to correct the output of a charge to digital converter, although principals of the invention may be used for other types of circuits.Type: GrantFiled: October 19, 2005Date of Patent: July 3, 2007Assignee: Kenet, Inc.Inventors: Jeffery D. Kurtze, Michael P. Anthony
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Patent number: 7233276Abstract: In a pipelined analog to digital converter with multiple stages of sub-converters, capacitor mismatch error can be reduced by splitting the capacitors into multiple numbers and randomly selecting part of the split capacitors as feedback capacitors. The selection of feedback capacitors can be made according to a digital output, clock phase, stage number of the sub-converter or the combination thereof. The approach of the present invention can be applied to the most significant bit (MSB) stage for a pipelined ADC. Moreover, a method for implementing the same is also proposed.Type: GrantFiled: November 29, 2005Date of Patent: June 19, 2007Assignee: Himax Technologies, Inc.Inventor: Chih-haur Huang
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Patent number: 7230560Abstract: Techniques employable to compress and decompress images are presented herein.Type: GrantFiled: August 5, 2005Date of Patent: June 12, 2007Assignee: Microsoft CorporationInventors: Jack T Lee, Peter T. Barrett
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Patent number: 7218259Abstract: A method of operating a digital to analog converter comprising the steps of operating the converter in a first mode to obtain a first conversion result, operating the converter in a correction mode in which one or more correction conversions are made, and wherein each correction conversion takes the result of a preceding result as a valid starting point.Type: GrantFiled: November 3, 2005Date of Patent: May 15, 2007Assignee: Analog Devices, Inc.Inventors: Christopher Peter Hurrell, Gary Robert Carreau