Coarse And Fine Conversions Patents (Class 341/145)
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Patent number: 7733258Abstract: A data converter for converting analog signals to digital signals, or for converting digital signals to analog signals is provided. In one embodiment, a production self-test is provided. In one embodiment, a high-speed lower-resolution method or mode for a data converter is provided. In one embodiment, a differential data converter with a more stable comparator common mode voltage is provided. In one embodiment, the input range of a digitally calibrated data converter is provided and maintained so that there is no loss in input range due to the calibration. In one embodiment, digital post-processing of an uncalibrated result using a previously stored calibration value is provided.Type: GrantFiled: September 30, 2008Date of Patent: June 8, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Michael T. Berens, James R. Feddeler
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Patent number: 7733257Abstract: A DAC includes a gamma voltage generator for generating a plurality of gamma voltages, and a decoder for receiving an M-bit digital value for selecting one of the gamma voltages, wherein the decoder comprises a first thermometer encoder, a first selector and a second selector. The first thermometer encoder is utilized to receive N bits of the digital value to generate a first thermometer code with 2N bits, wherein N is smaller than M, and M and N are positive integers. The first selector has a plurality of selecting groups, each selecting group having 2N switches controlled by the first thermometer code to output one gamma voltage, where the second selector receives the gamma voltages outputted by the selecting groups of the first selector and outputs one gamma voltage selected from the received gamma voltages based on the (M?N) bit of the digital value.Type: GrantFiled: December 9, 2008Date of Patent: June 8, 2010Assignee: Himax Technologies LimitedInventor: Ching-Chung Lee
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Patent number: 7729300Abstract: A method and apparatus for a Gigabit Ethernet transceiver that has a Class-B amplifier in a main transmitter for higher efficiency and power handling capabilities. The output current of the main transmitter is produced by a reference voltage applied across a resistor, where the reference voltage generator, resistor and amplifier are fabricated on the same substrate, such that the output current is constant across process voltage and temperature. The transceiver also has a replica transmitter whose signal is used to cancel the main transmitter signal at the input of the receiver section of the transceiver. The replica transmitter is fabricated on the same substrate as the main transmitter, such that its output signal reflects non-linearities in the main transmitter across process voltage and temperature.Type: GrantFiled: August 19, 2005Date of Patent: June 1, 2010Assignee: National Semiconductor CorporationInventors: Ramsin Michael Ziazadeh, Varadarajan Devnath
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Patent number: 7719369Abstract: A sigma delta DAC using a single DAC to generate a first analog quantity portion and a second analog quantity portion, having a strength respectively proportionate to the most significant bits (MSBs) and least significant bits (LSBs) of a received digital value. The two portions are added to generate an analog output representing the strength of the digital value. In an embodiment, the single DAC contains a set of current sources, with some of the current sources (determined by the value of the MSBs) being connected to provide the corresponding output currents on a first path. Some of the other current sources, determined by a value of the LSBs, are controlled to be connected to provide the corresponding output currents on a second path. The time durations the currents are connected to the second path, are determined by the output of a sigma delta modulator.Type: GrantFiled: September 17, 2008Date of Patent: May 18, 2010Assignee: Texas Instruments IncorporatedInventors: Anant Shankar Kamath, Biman Chattopadhyay
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Patent number: 7714758Abstract: An integrated circuit may include an operation amplifier, a first capacitor, a plurality of second capacitors, and/or a switching circuit. The operational amplifier may have a first input terminal, a second input terminal, and/or an output terminal. The first capacitor may have a first terminal and a second terminal. The second terminal of the first capacitor may be connected to the first input terminal of the operational amplifier. The plurality of second capacitors may each have a first terminal and a second terminal. The second terminal of each of the second capacitors may be connected to the second input terminal of the operational amplifier. The switching circuit may include a plurality of switches configured to switch in response to a plurality of switching signals.Type: GrantFiled: May 22, 2008Date of Patent: May 11, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Ju Hyun Ko, Ji Woon Jung, Jong Seon Kim
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Patent number: 7710302Abstract: A digital to analog converter (DAC) system comprising, a first segment, wherein a segment comprises, a first path including an array of resistors connected in series between a first reference voltage node and a second reference voltage node, wherein the array is connected to a first switch device disposed between nodes of the array and an output node, and a third path including a second resistor in series with a second switch device, wherein the third path is connected in parallel with the first path.Type: GrantFiled: December 21, 2007Date of Patent: May 4, 2010Assignee: International Business Machines CorporationInventors: Joseph A. Iadanza, Benjamin T. Voegeli
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Publication number: 20100079325Abstract: A data converter for converting analog signals to digital signals, or for converting digital signals to analog signals is provided. In one embodiment, a production self-test is provided. In one embodiment, a high-speed lower-resolution method or mode for a data converter is provided. In one embodiment, a differential data converter with a more stable comparator common mode voltage is provided. In one embodiment, the input range of a digitally calibrated data converter is provided and maintained so that there is no loss in input range due to the calibration. In one embodiment, digital post-processing of an uncalibrated result using a previously stored calibration value is provided.Type: ApplicationFiled: September 30, 2008Publication date: April 1, 2010Inventors: Michael T. Berens, James R. Feddeler
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Patent number: 7683813Abstract: A current cell matrix type of digital-to-analog (D/A) converter to prevent deterioration of a.c. characteristics on a current path for digital-to-analog conversion includes a array of current source cells arranged in a matrix configuration. Each current source cell includes a current source transistor to generate the cell current. During the regular operation, the cell current is flowed on output lines via a first transistor connected in cascode to the current source transistor. During the calibration operation, the cell current is flowed into a current comparator via a second transistor connected in cascode to the current source transistor. This prevents parasitic capacitance from being additively caused in switches for the first transistor and in another switch for the second transistor to prevent deterioration of a.c. characteristics on the current path.Type: GrantFiled: June 19, 2008Date of Patent: March 23, 2010Assignee: Oki Semiconductor Co., Ltd.Inventor: Danya Sugai
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Publication number: 20100066455Abstract: A sigma delta DAC using a single DAC to generate a first analog quantity portion and a second analog quantity portion, having a strength respectively proportionate to the most significant bits (MSBs) and least significant bits (LSBs) of a received digital value. The two portions are added to generate an analog output representing the strength of the digital value. In an embodiment, the single DAC contains a set of current sources, with some of the current sources (determined by the value of the MSBs) being connected to provide the corresponding output currents on a first path. Some of the other current sources, determined by a value of the LSBs, are controlled to be connected to provide the corresponding output currents on a second path. The time durations the currents are connected to the second path, are determined by the output of a sigma delta modulator.Type: ApplicationFiled: September 17, 2008Publication date: March 18, 2010Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Anant Shankar Kamath, Biman Chattopadhyay
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Patent number: 7679538Abstract: A current-steering type digital-to-analog converter (DAC) is disclosed. The DAC includes a first sub-DAC, a second sub-DAC and a controlling device. Both the first sub-DAC and the second sub-DAC are configured to receive input signals. The controlling device selectively and periodically sends output signals of either the first sub-DAC or the second sub-DAC to a resistive load while sending output signals of the remaining one of the two sub-DACs to a dummy resistive load. An output of the DAC is provided at the resistive load.Type: GrantFiled: August 10, 2006Date of Patent: March 16, 2010Inventor: Robin M. Tsang
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Patent number: 7675449Abstract: A current steering digital-analog converter for converting a digital code into an analog signal, the converter including a substrate of semiconductor material, an array of current generators integrated in the substrate, a common summation node and switches controllable on the basis of the digital code for connecting and disconnecting the current generators to and from the common summation node. The current generators are adapted to provide the common summation node with currents having a multiple value according to a power of two compared to a unit current value provided to the summation node by a current generator of the array of generators. The current generator is divided into a base number of modular current generation elements in parallel to one another at least equal to two.Type: GrantFiled: July 14, 2008Date of Patent: March 9, 2010Assignee: STMicroelectronics S.r.l.Inventors: Pierangelo Confalonieri, Marco Zamprogno, Riccardo Martignone
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Patent number: 7675450Abstract: A digital-to-analog converter (DAC) configured to operate in high frequency and/or high resolution environments. The DAC has a segmented architecture comprising one or more least significant bit (LSB) thermometer sub-converters and one or more most significant bit (MSB) thermometer sub-converters. A binary converter can also be added. The LSB and MSB thermometer sub-converters include cell pairs with a main cell and a dummy cell. The main cell switches according to actual data, drawing power from a voltage source at each transition. To maintain a consistent voltage level at the output, the dummy cell creates a transition to draw power from the voltage source responsive to a lack of transition in the main cell. Each cell pair has a dedicated voltage source. Also, the MSB thermometer sub-converter can include a load matching circuit to match the parasitic capacitance of the LSB thermometer sub-converter at an output.Type: GrantFiled: June 13, 2008Date of Patent: March 9, 2010Assignee: Aquantia CorporationInventors: Ali Tabatabaei, Ramin Farjadrad
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Patent number: 7671775Abstract: A converter of 6-bit input includes a reference voltage generating circuit generating 17 reference voltages, a first switch circuit having 19 switch pairs each including MOS transistors for selecting two adjacent reference voltages in accordance with the four most significant bits, a second switch circuit including a series circuit of MOS transistors for dividing the selected two reference voltages into four to obtain three intermediate voltages, and a third switch circuit for selectively outputting the lower of the selected two reference voltages or one of the three intermediate voltages. In a second mode in which a gray level having a smaller ON-resistance of a MOS transistor than that in the first mode is selected, the number of MOS transistors used in the first and second switch circuits for voltage division is increased.Type: GrantFiled: September 23, 2008Date of Patent: March 2, 2010Assignee: Panasonic CorporationInventors: Yasuyuki Doi, Kurumi Nakayama, Makoto Hattori, Hideki Ikeda
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Publication number: 20100045502Abstract: A current output type digital-analog conversion circuit which outputs a current signal includes a decoder for decoding higher-order bits of input digital data, a plurality of binary current generators, and a current adder. Each of the binary current generators includes a device for outputting a binary current which increases linearly as binary values according to lower-order bits of the input digital data, and a device for outputting a predetermined all-ON current. Either the device for outputting the binary current or the element for outputting the all-ON current of the binary current generator is selected according to a decode signal output by the decoder. The current adder adds up and outputs the binary currents and the all-ON currents output by the plurality of binary current generators.Type: ApplicationFiled: November 5, 2007Publication date: February 25, 2010Applicant: NEC CORPORATIONInventor: Osamu Ishibashi
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Patent number: 7656333Abstract: In a signal processing arrangement, a digital-to-analog converter (DAC1) of the finite impulse response type converts a serial bitstream (BSL) into an analog output signal (AL). The digital-to-analog converter (DAC1) comprises at least two current source arrays (CCA1, CC A2). In a first current source array (CCA1), a current definition cell (CD1) generates a first basic current, and a plurality of first current copy cells ( . . . , CC40, CC41, . . . ) provide respective scaled copies of the first basic current to constitute first filter coefficient currents ( . . . , IP40, IP41, . . . ). In a further current source array (CCA2), a further current definition cell (CD2) generates a further basic current, and a plurality of current further copy cells (CC1, CC2, . . . , CC80) provide respective scaled copies of the further basic current to constitute further filter coefficient currents (IP1, IP2, . . . , IP80).Type: GrantFiled: August 23, 2006Date of Patent: February 2, 2010Assignee: NXP B.V.Inventor: Paulus Petrus Franciscus Maria Bruin
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Patent number: 7652607Abstract: In a digital to analogue converter, a plurality of digital inputs are used to select one of first and second binary voltage levels as binary inputs (10) to the converter. A capacitor circuit (C, 2C, . . . , 32C) is associated with each input, and these are controlled to output an effective voltage to an output load comprising the first binary voltage level, the second binary voltage level or an average of the first and second binary voltage levels in dependence on the bits of the digital input word. The plurality of capacitor circuits can be operated in either a voltage divider mode (to provide an average output) or a resistor mode depending on the value of the digital data. Operation of the capacitor circuits in this way can result in a reduction in the currents flowing and can therefore reduce the power consumption.Type: GrantFiled: March 23, 2005Date of Patent: January 26, 2010Assignee: Chi Mei Optoelectronics CorporationInventor: Martin J. Edwards
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Patent number: 7646235Abstract: A programmable current generator includes a decoder unit to generate a first and a second set of control signals as a function of a current control word. The current generator further includes a first and a second array of current sources, wherein the current sources of the first array generate a first current and an auxiliary current, each depending on the first set of control signals and on a reference current. The second array of current sources generates a second current depending on a second set of control signals and on the auxiliary current. An output current is generated depending on the first and the second current.Type: GrantFiled: February 13, 2007Date of Patent: January 12, 2010Assignee: Infineon Technologies AGInventor: Volker Christ
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Patent number: 7646321Abstract: Provided is a digital/analog converter including a voltage dividing unit that includes a plurality of voltage dividing elements and divides a reference voltage by voltage division; a first decoder that selects a plurality of voltages among the voltages divided by the voltage dividing unit; a first voltage output unit that is connected to nodes among adjacent voltage dividing elements of the voltage dividing unit and the first decoder, and outputs a plurality of voltages selected by the first decoder; a second decoder that selects any one of the plurality of voltages output from the first voltage output unit; and a second voltage output unit that is connected to the first voltage output unit and the second decoder and outputs the voltage selected by the second decoder.Type: GrantFiled: January 31, 2008Date of Patent: January 12, 2010Assignee: Samsung Electro-Mechanics Co., LtdInventors: Byung Hoon Kim, Won Tae Choi
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Patent number: 7639166Abstract: A multi-bit D/A converter circuit that prevents a bit inversion and requires a reduced layout area is offered. A first switching circuit is provided in order to select a pair of analog voltages generated across one of resistors in a first resistor string. The selected pair of analog voltages is provided as reference voltages to a second resistor string. A second switching circuit is provided in order to select a pair of analog voltages generated across one of the resistors in the second resistor string. The selected pair of analog voltages is provided as reference voltages to a third resistor string. A third switching circuit is provided in order to select one of analog voltages generated in the third resistor string.Type: GrantFiled: June 12, 2008Date of Patent: December 29, 2009Assignees: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.Inventor: Takashi Iijima
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Publication number: 20090309776Abstract: A variable resistor is connected to each terminal of (2?n)?1 resistors R connected in series. The variable resistors have resistances RH and RL determined according to a digital signal containing m lower bits LoB<m?1:0>.Type: ApplicationFiled: June 9, 2009Publication date: December 17, 2009Inventors: Takahiro Inoue, Hideki Shioe
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Patent number: 7629908Abstract: A D/A converter of the current switching type has a first current mirror circuit that D/A converts the upper (n?m) digits in n bit data to be converted and a weighting current circuit block or a second current mirror circuit that D/A converts the lower m digits in the data, by cascade connecting the weighting current circuit block or the second current mirror circuit at the upstream or at the downstream side of an output side transistor other than the output side transistors of the first current mirror circuit. In this manner, current flowing through the output side transistor flows as diverting currents to the weighting current circuit block or the second current mirror circuit corresponding to the digit weights of the lower m digits, and the diverting currents are taken out at the outputs of the D/A conversion circuit as analog converted currents of the lower m digits.Type: GrantFiled: September 26, 2006Date of Patent: December 8, 2009Assignee: Rohm Co., Ltd.Inventors: Kouichi Matumoto, Shinichi Abe, Yuji Shimada
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Patent number: 7626528Abstract: A digital-to-analog converter with high driving capability includes a voltage generator for generating voltages, a voltage division circuit coupled to the voltage generator for outputting a plurality of reference voltages according to voltages generated by the voltage generator, a decode unit for decoding a digital signal, a switch circuit coupled to the voltage division circuit and the decode unit for switching to output one of the plurality of reference voltages, and a current generator coupled to the voltage division circuit for generating currents to the voltage division circuit.Type: GrantFiled: July 11, 2007Date of Patent: December 1, 2009Assignee: NOVATEK Microelectronics Corp.Inventors: Tsung-Hau Chang, Kuang-Feng Sung
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Patent number: 7609191Abstract: A digital/analog converting driver and a digital/analog converting method, in which the digital/analog converting driver converts digital data having M+N (M and N are integers) bits into an analog voltage and includes a first converting unit, a second converting unit, and an analog voltage outputting unit. The first converting unit converts successive M bits of the digital data into a first voltage. The second converting unit converts successive N bits of the digital data into a second voltage. The analog voltage outputting unit adds the first voltage and the second voltage and outputs the added voltage as the analog voltage. The output range of the first voltage is different from that of the second voltage.Type: GrantFiled: November 6, 2006Date of Patent: October 27, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Il-Kwon Chang, Yong-Weon Jeon, Ji-Woon Jung
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Patent number: 7602326Abstract: An analog-to-digital converter has a resistor string that generates a series of voltages. An upper selector selects voltages at the upper end of the series. A lower selector selects voltages at the lower end of the series. A pair of midrange selectors select a pair of adjacent voltages in the middle range of the series. A midrange voltage generator generates further voltages spaced between the two selected midrange voltages. An output selector selects one of the further voltages. The selectors are controlled by various bits of a digital input signal. The voltage selected by the upper selector, lower selector, or output selector becomes an analog output signal. This analog-to-digital converter has comparatively few resistors and transistors and can generate accurate voltages for driving a gray-scale display.Type: GrantFiled: March 12, 2008Date of Patent: October 13, 2009Assignee: Oki Semiconductor Co., Ltd.Inventor: Shiming Lan
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Patent number: 7595747Abstract: A digital-to-analog converter (DAC) and a digital-to-analog converting method are provided. The DAC includes a first capacitor, an operation amplifier having a first input terminal connected to the first capacitor, a second input terminal, and an output terminal, where the first input terminal is a (?) input terminal and the second input terminal is a (+) input terminal; and a switching circuit having a plurality of switches each being switched in response to a corresponding switching signal from among a plurality of switching signals. The switching circuit performs switching so that the difference between a first voltage and a second voltage can be stored in the first capacitor connected to the operation amplifier during a first period, and performs switching so that an output signal can be output by reflecting a third voltage in the difference stored in the first capacitor during a second period.Type: GrantFiled: January 9, 2008Date of Patent: September 29, 2009Assignee: Samsung Electroncis Co., LtdInventors: Yun Seung Shin, Ji Woon Jung, Myung Hee Lee
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Patent number: 7595746Abstract: A digital-to-analog converter (DAC) includes coarse interpolation DACs configured to produce a current range based on an input digital signal, and fine interpolation DACs configured to produce an output current that is based on an input digital signal and that is within the current range produced by the coarse interpolation DACs.Type: GrantFiled: December 26, 2007Date of Patent: September 29, 2009Assignee: Teradyne, Inc.Inventors: Cosmin Iorga, Alan Hussey
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Patent number: 7592940Abstract: A digital-to-analog converter (DAC) can minimize the increase of an area caused by increase of number of bits. The DAC includes a coarse resistor-string digital-to-analog conversion unit for selectively outputting 2N-level analog voltages in response to upper N-bit digital data, wherein N is a natural number greater than or equal to 2, a fine resistor-string digital-to-analog conversion unit for selectively outputting 2N-level analog voltages in response to lower N-bit digital data, wherein the 2N-level analog voltages is obtained by dividing a level of unit voltage of the coarse resistor-string digital-to-analog conversion unit into 2N-levels, and a voltage combining unit for outputting 22N-level analog output signals by combining the output of the coarse resistor-string digital-to-analog conversion unit and the output of the fine resistor-string digital-to-analog conversion unit.Type: GrantFiled: December 20, 2007Date of Patent: September 22, 2009Assignee: MagnaChip Semiconductor, Ltd.Inventor: Yoo-Chang Sung
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Patent number: 7589655Abstract: Provided is a method and system for controlling current characteristics in a transceiver having a transmitter. The method includes identifying a phase control signal from an adjacent current cell preceding the particular current cell in time and logically ORing the phase control signal from the preceding cell with a phase control signal from the particular current cell.Type: GrantFiled: September 4, 2008Date of Patent: September 15, 2009Assignee: Broadcom CorporationInventors: Yee Ling Cheung, Kevin T. Chan, Jan Mulder
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Patent number: 7589653Abstract: A digital to analog converter (DAC) circuit operates over an upper range and a lower range. An upper voltage node is designated AVDD; a middle voltage node is designated HVDD; and a lower voltage node designated ground. An upper DAC stage has at least one NMOS transistor that produces an output to an upper range output node when the output is in the upper range. A lower DAC stage has at least one PMOS transistor that produces an output to a lower range output node when the output is in the lower range. A body bias control circuit couples the body of the upper NMOS transistor to a voltage source equal to HVDD?Vbe and connects the body of the lower PMOS transistor to voltage source equal to HVDD+Vbe.Type: GrantFiled: January 29, 2008Date of Patent: September 15, 2009Assignee: STMicroelectronics Asia Pacific Pte. Ltd.Inventors: Yannick Guedon, Yoseph Adhi Darmawan
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Patent number: 7580288Abstract: An adjustable voltage supply (310) may have a plurality of levels of adjustment, such as a coarse select circuit (471) and a fine select circuit (473), to generate an adjustable voltage (e.g. Vout 364 of FIGS. 3 and 4) with fine resolution across a wide voltage range. In one embodiment, the adjustable voltage may be used as an adjustable read voltage to measure the threshold voltages of bitcells in a memory array (300). From the distribution of these threshold voltages, it is possible to determine the marginality of the bitcells with regard to the voltage which is required to read the bitcells. In one embodiment, the adjustable voltage supply (310) may also be used to provide an adjustable voltage to one or more integrated circuit pwells and/or nwells in order to apply electrical stress. An adjustable voltage supply (310) may be used in any desired context, not just memories.Type: GrantFiled: May 24, 2006Date of Patent: August 25, 2009Assignee: Freescale Semiconductor, Inc.Inventors: Jon S. Choy, Chen He
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Patent number: 7579972Abstract: An RFIC controller configured for executing multiple tasks. A serial interface is included having a serial bus for receiving a data stream having control bits and data bits. One or more registers are coupled to the serial bus for storing the control bits and data bits as they are received. Control circuitry is also included. The data stream is formatted such that the control bits are received before the data bits, the control bits specifying an operation. The control circuitry is configured to examine the control bits as they are received to determine the operation specified by the control bits before the data bits are received. A task corresponding to the operation specified by the control bits is then initiated before the data bits are received.Type: GrantFiled: November 30, 2007Date of Patent: August 25, 2009Assignee: ITT Manufacturing Enterprises, Inc.Inventors: David George Copeland, Patrick Arthur McCabe, Rocky Ardy Ilen, Jonathan Borui Kang
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Patent number: 7576608Abstract: An amplifier circuit with a voltage interpolation function includes an N-type differential pair and a P-type differential pair. The N-type differential pair includes a first transconductance value, and has a first differential input terminal coupled to a first voltage and a second differential input terminal coupled to a voltage output terminal. The P-type differential pair includes a second transconductance value, and has a first differential input terminal coupled to a second voltage and a second differential input terminal coupled to the voltage output terminal. The N-type differential pair and the P-type differential pair are further coupled to the voltage output terminal through an output stage, and voltages outputted by the voltage output terminal are interpolation results of the first voltage and the second voltage weighted by the first transconductance value and the second transconductance value.Type: GrantFiled: May 15, 2008Date of Patent: August 18, 2009Assignee: NOVATEK Microelectronics Corp.Inventor: Ju-Lin Huang
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Publication number: 20090201187Abstract: A DA conversion device includes the following elements. A higher-bit current source cell portion includes uniformly weighted higher-bit current source cells to generate an identical constant current. A lower-bit current source cell portion includes a lower-bit current source cells that are weighted to generate 1/two-to-the-power-of-certain-numbers constant currents. A constant current source selection controller includes a lower-bit controller having a scaler that uses clocks scaled down to 1/two-to-the-power-of-certain-numbers to select the lower-bit current source cells, and a higher-bit controller having shift registers and using a signal indicating a carry bit or a borrow bit used in the lower-bit controller to sequentially activate shift outputs of the shift registers, and uses the shift outputs to select the higher-bit current source cells. Constant current outputs of the selected current source cells are added and output so that an output current corresponding to the digital input signal is obtained.Type: ApplicationFiled: April 20, 2009Publication date: August 13, 2009Applicant: Sony CorporationInventors: Go ASAYAMA, Noriyuki Fukushima, Yoshikazu Nitta, Yoshinori Muramatsu, Kiyotaka Amano
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Patent number: 7573411Abstract: A digital-to-analog converter outputting an analog data voltage corresponding to n-bit data, includes a chopping amplification unit adapted to receive an upper bit voltage corresponding to upper x bits of the n-bit data and a lower bit voltage corresponding to lower y bits of the n-bit data and to output the analog data voltage. The chopping amplification unit may include a sample and hold capacitor adapted to be charged with the upper bit voltage in a non-inverting mode, and a chopping amplifier adapted to supply the upper bit voltage to the sample and hold capacitor in the non-inverting mode and adapted to output a voltage corresponding to the sum of the upper bit voltage and the lower bit voltage as the analog data voltage in an inverting mode.Type: GrantFiled: January 9, 2008Date of Patent: August 11, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Yun-seung Shin, Ju-hyun Ko
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Patent number: 7567196Abstract: An analog-to-digital converter having 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: April 30, 2008Date of Patent: July 28, 2009Assignee: Aptina Imaging CorporationInventor: Christian Boemler
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Publication number: 20090179785Abstract: A mixed signal integrated circuit device, e.g., digital-to-analog converter (DAC), has a serial interface communication protocol that accesses volatile and/or non-volatile memory and allows a preprogrammed output voltage whenever the mixed signal device is powered-up. However, unlike conventional DACs, DACs with non-volatile memory may need special interface communication protocols for effective operation of the DAC and communications between a system master controller unit (MCU). Interface communications protocols that do not violate standard serial bus communications protocols are provided for communicating between the volatile and non-volatile memories of the DAC so that the MCU may access the DAC's memories (non-volatile and/or volatile memories). The mixed signal integrated circuit device has a user programmable address.Type: ApplicationFiled: December 17, 2008Publication date: July 16, 2009Inventors: Thomas Youbok Lee, Yann Johner, Philippe Gimmel, Tim Sherman, Jonathan Jackson, John Austin
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Publication number: 20090167583Abstract: A digital-to-analog converter (DAC) includes coarse interpolation DACs configured to produce a current range based on an input digital signal, and fine interpolation DACs configured to produce an output current that is based on an input digital signal and that is within the current range produced by the coarse interpolation DACs.Type: ApplicationFiled: December 26, 2007Publication date: July 2, 2009Inventors: Cosmin Iorga, Alan Hussey
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Publication number: 20090140902Abstract: Disclosed are a digital-analog converter and a camera module having the same. The digital-analog converter includes a plurality of decoders for receiving bits of a digital input signal by dividing the bits in a predetermined bit unit except for lower bits of the digital input signal, and decoding the bits into thermometer code signals, a delay unit for delaying output of the lower bits of the digital input signal, a latch unit for synchronizing output signals of the decoders with an output signal of the delay unit, and a current source for converting a digital signal output from the latch unit into an analog signal.Type: ApplicationFiled: August 14, 2007Publication date: June 4, 2009Inventor: Cheong Yong Park
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Publication number: 20090140901Abstract: An RFIC controller configured for executing multiple tasks. A serial interface is included having a serial bus for receiving a data stream having control bits and data bits. One or more registers are coupled to the serial bus for storing the control bits and data bits as they are received. Control circuitry is also included. The data stream is formatted such that the control bits are received before the data bits, the control bits specifying an operation. The control circuitry is configured to examine the control bits as they are received to determine the operation specified by the control bits before the data bits are received. A task corresponding to the operation specified by the control bits is then initiated before the data bits are received.Type: ApplicationFiled: November 30, 2007Publication date: June 4, 2009Applicant: ITT MANUFACTURING ENTERPRISES, INC.Inventors: David George Copeland, Patrick Arthur McCabe, Rocky Ardy Ilen, Jonathan Borui Kang
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Patent number: 7535396Abstract: A digital-to-analog converter (DAC) having filter sections with differing polarity provides a low-noise, low area bipolar output solution in delta-sigma modulator based DACs. A shift register receives an input bit-stream and provides a series of tap outputs that are used to control application of a number of current sources to output summing nodes. The current sources are divided into mutually-exclusive sets of positive polarity and negative polarity current sources, which are not necessarily contiguous. In one embodiment, half of one of the sets of current sources precedes the other set of current sources, and the other half of the divided set of current sources provides the final set of output taps. The number of current sources in each set may be equal, so that the midpoint of the output corresponds to zero current.Type: GrantFiled: March 20, 2008Date of Patent: May 19, 2009Assignee: Cirrus Logic, Inc.Inventor: John L. Melanson
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Patent number: 7535395Abstract: Embodiments of a digital potentiometer are disclosed that require lesser numbers of components than conventional digital potentiometers. A first string of elemental impedance devices, and at least one bulk impedance device, are provided between first and second reference terminals. The first string of elemental impedance devices is tapped by wiper switches. The at least one bulk impedance device has an impedance greater than an impedance of the first string. If desired, second and third bypassable impedance device strings also may be provided between the first and second reference terminals, with the impedance of the respective second and third strings being between the impedance of the first string and the impedance of one bulk impedance device. One or more dummy structures each including an impedance device in parallel with a permanently-on switch also may be between the first and second reference terminals to improve linearity.Type: GrantFiled: October 30, 2007Date of Patent: May 19, 2009Assignee: Catalyst Semiconductor, Inc.Inventors: Gelu Voicu, Radu H. Iacob, Otilia Neagoe
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Patent number: 7535394Abstract: A high-speed arbitrary waveform generator (AWG) that utilizes multiple digital-to-analog converters (D/A converters) and overcomes bandwidth limitations of individual D/A converters to produce high-speed waveforms.Type: GrantFiled: July 10, 2007Date of Patent: May 19, 2009Assignee: LeCroy CorporationInventor: Peter J. Pupalaikis
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Patent number: 7535397Abstract: A digital-to-analog converter (DAC) is provided for converting an (X+Y)-bit input word, which includes an X-bit MSB subword and a Y-bit LSB subword, into a current signal. The DAC has an X-bit voltage DAC section and a Y-bit current DAC section. The X-bit voltage DAC section generates an intermediate voltage corresponding to the X-bit MSB subword. The Y-bit current DAC section generates a reference current corresponding to the intermediate voltage and outputs the current signal derived by multiplying the reference current by a factor corresponding to the Y-bit LSB subword. In addition, a method for digital-to-analog conversion of an (X+Y)-bit input word into a current signal is also provided.Type: GrantFiled: April 9, 2008Date of Patent: May 19, 2009Assignee: Himax Technologies LimitedInventors: Yu-Wen Chiou, Jiunn-Yau Huang
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Patent number: 7532142Abstract: A digital to analog converter (DAC) system includes a resistor network providing enhanced response time and steady state characteristics.Type: GrantFiled: June 13, 2008Date of Patent: May 12, 2009Assignee: International Business Machines CorporationInventors: Benjamin Thomas Voegeli, Bradford Hunter
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Patent number: 7532140Abstract: Digital to analog converter circuits and methods are provided for producing an analog output voltage indicative of a digital input signal with at least partial insensitivity to error gradients. Described are split-core resistive elements, which include a plurality of one-dimensional or multi-dimensional resistive strings, that may be used to reduce or substantially eliminate the effects that error gradients have on the linearity of the analog output voltages of a resistive string or interpolating amplifier DACs. The resistor strings that make up the split-core resistive elements are configured in such a manner that combining respective output voltages from each of the resistor strings results in an analog output voltage that is at least partially insensitive to the effects of error gradients.Type: GrantFiled: July 13, 2006Date of Patent: May 12, 2009Assignee: Linear Technology CorporationInventors: William C Rempfer, Hassan Malik, James L Brubaker
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Patent number: 7525470Abstract: Embodiments include a system for performing dispersion compensation on an electromagnetic signal received over a communication channel, the electromagnetic signal bearing information at a symbol rate. An interleaved analog to digital converter (“ADC”) block may be used, wherein the interleaved ADC block may be configured to generate a plurality of digitally sampled signals from the electromagnetic signal. An interleaved equalizer block may be configured to digitally process each of the digitally sampled signals generated by the ADC block to generate a plurality of digitally equalized signals. A multiplexer may be configured to aggregate the digitally equalized signals into a composite output signal.Type: GrantFiled: August 27, 2007Date of Patent: April 28, 2009Assignee: Broadcom CorporationInventors: Vasudevan Parthasarthy, Sudeep Bhoja, Vivek Telang, Afshin Momtaz
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Patent number: 7522082Abstract: A DA conversion device includes the following elements. A higher-bit current source cell portion includes uniformly weighted higher-bit current source cells to generate an identical constant current. A lower-bit current source cell portion includes a lower-bit current source cells that are weighted to generate 1/two-to-the-power-of-certain-numbers constant currents. A constant current source selection controller includes a lower-bit controller having a scaler that uses clocks scaled down to 1/two-to-the-power-of-certain-numbers to select the lower-bit current source cells, and a higher-bit controller having shift registers and using a signal indicating a carry bit or a borrow bit used in the lower-bit controller to sequentially activate shift outputs of the shift registers, and uses the shift outputs to select the higher-bit current source cells. Constant current outputs of the selected current source cells are added and output so that an output current corresponding to the digital input signal is obtained.Type: GrantFiled: October 12, 2007Date of Patent: April 21, 2009Assignee: Sony CorporationInventors: Go Asayama, Noriyuki Fukushima, Yoshikazu Nitta, Yoshinori Muramatsu, Kiyotaka Amano
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Patent number: 7522081Abstract: For reducing device areas required by digital-to-analog converters used in source driving circuits of a liquid crystal display device, a compound circuit structure based on a pre-decoder, a binary decoder, and ROM decoders is set forth to meet the demand for cutting down the device areas. The pre-decoder is configured to decode a first sub-signal of a digital data signal for generating a plurality of control signals. Each of the ROM decoders is configured to select a gamma reference voltage out of one corresponding set of gamma reference voltages based on the control signals and a second sub-signal of the digital data signal. The binary decoder is configured to select one of the gamma reference voltages selected by the ROM decoders based on a third sub-signal of the digital data signal for outputting an output voltage. The number of transistors used by the compound circuit structure is then reduced significantly.Type: GrantFiled: January 24, 2008Date of Patent: April 21, 2009Assignee: Himax Technologies LimitedInventors: Cheng-Lung Chiang, Ming-Cheng Chiu, Ting-Jung Ku
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Patent number: 7515072Abstract: A circuit for converting from an input serial pulse code modulated (PCM) digital signal to an output pulse width modulated (PWM) digital signal for driving a switching audio amplifier requiring a pulse width modulated input signal, the circuit comprising a sample rate converter receiving the input serial PCM digital signal at a first sampling frequency and converting the input serial PCM digital signal to a second serial PCM digital signal at a second frequency if the first sampling frequency is lower than the second frequency, a digital filter stage for up-sampling the second serial PCM digital signal to a third frequency and converting the second serial PCM digital signal to a parallel digital signal, a volume control stage receiving the parallel digital signal and generating a volume adjusted parallel digital signal in accordance with a digital volume command control signal, a digital cross-point estimator stage for calculating a cross-point between the volume adjusted parallel digital signal and a digitalType: GrantFiled: September 21, 2004Date of Patent: April 7, 2009Assignee: International Rectifier CorporationInventor: Ana Borisavljevic
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Publication number: 20090085787Abstract: An integrated circuit memory cell and voltage ladder design that adapts techniques typically applied to Static Random Access Memory (SRAM) circuits to implement a compact array of analog Voltage Random Access Memory (VRAM) locations. The memory cells in the VRAM each store a digital value that controls a corresponding switch. The switch couple a particular voltage from a set of voltages generated by the ladder, to be output when that location is enabled. Multiple analog output voltages are provided by simply providing additional rows of cells.Type: ApplicationFiled: December 10, 2008Publication date: April 2, 2009Applicant: Kenet, Inc.Inventors: Michael P. Anthony, Lawrence J. Kushner