Field Effect Transistor Patents (Class 341/136)
  • Patent number: 7154423
    Abstract: A successive approximation type of analog-to-digital converter fabricated in a MOS type semiconductor integrated circuit includes a comparison voltage generator for generating a comparison voltage to be compared with an analog signal voltage, a comparator for sequentially comparing the comparison voltage with the analog signal voltage to produce a comparison result, and a comparison result processor for developing the comparison result to an output register connected to a bus and feeding the comparison voltage generator with a comparison voltage value determined according to the comparison result. The comparator includes two sets of P-channel transistors connected in serial. In each set, one transistor is connected in parallel to, and larger in driving capacity than, the other transistor. The one transistor is controlled in switching timing different from the other transistor.
    Type: Grant
    Filed: January 12, 2005
    Date of Patent: December 26, 2006
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Mamoru Kondo
  • Patent number: 7129871
    Abstract: A wide gain range current digital-to-analog converter (DAC) is presented that includes a unit current cell having a current source module biased by a current source voltage bias, a differential switch module, a main cascode module biased by a first bias voltage and an attenuation cascode module biased by a second bias voltage, configured such that a particular current gain range is obtained at the main cascode module output when a unit current cell current is at or above a current threshold. The output current at the attenuation cascode module output can be input into a current attenuator when the unit current cell current is below the current threshold to obtain additional current gain range. The current attenuator can include a plurality of attenuator cells that can be programmed to a desired level of current gain in linear decibels or linear step intervals. Smaller step sizes can be obtained by programming a current source within the step intervals.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: October 31, 2006
    Assignee: Broadcom Corporation
    Inventors: Arnoldus Venes, Yonghua Cong
  • Patent number: 7126511
    Abstract: Circuit arrangement (1) for the delay adjustment of analog-to-digital converters (4-1, . . . 4-N, 504) operating in a temporally offset manner, having at least two analog-to-digital converters (4-1, . . . 4-N, 504) each having a signal path, which receive an analog signal (VI) present at an input (2) of the circuit arrangement (1) and in each case convert it into a digital intermediate signal (Z1, . . . ZN), the analog-to-digital converters (4-1, . . . 4-N, 504) in each case being clocked by clock signals (CLK1, . . . CLKN) which have a predetermined time offset with respect to one another; having a logic circuit (7), which interconnects the digital intermediate signals (Z1, . . . ZN) for the purpose of generating a digital output signal (ZD) of the circuit arrangement (1); it being possible to set the bandwidth of the signal paths of the analog-to-digital converters (4-1, . . . 4-N, 504) in each case in such a way that a deviation of the clock signal (CLK1, . . .
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: October 24, 2006
    Assignee: Infineon Technologies AG
    Inventors: Dieter Draxelmayr, Franz Kuttner, Christian Vogel
  • Patent number: 7098829
    Abstract: A unit cell for a digital to analog conversion circuit that includes a current source (CS); a first data switch (S1) coupled to the current source (CS); a second data switch (S2) coupled to the current source (CS); a first phase switch (Phi1) coupled between the current source (CS) and the first data switch (S1); a second phase switch (Phi2) coupled between the current source (CS) and the second data switch (S2); a controller arranged to switch between the first (Phi1) and second (Phi2) phase switches in a Break Before Make alternating sequence, and to switch the first (S1) and second (S2) data switches in a Make Before Break sequence.
    Type: Grant
    Filed: March 19, 2003
    Date of Patent: August 29, 2006
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Jan Roelof Westra
  • Patent number: 7098825
    Abstract: I describe and claim an improved digital-to-analog conversion device and method. The device comprises a current supply circuit to generate a plurality of control currents responsive to a plurality of digital signals. An input voltage generating circuit is adapted to generate a plurality of input voltages responsive to the digital signals and the control currents. And a plurality of operational amplifiers is adapted to output a plurality of analog signals responsive to the input voltages.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: August 29, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Kwang-Il Park
  • Patent number: 7091892
    Abstract: An accurate high current mirror circuit produces a mirrored current that matches an input current to produce an accuracy at the output of a subsequent stage of amplification of greater than 0.01%. A plurality of transistor devices are arranged in a symmetrical configuration and divided into two groups. The transistors in each of the two groups are connected in parallel to produce a high mirror current from a high input current. A distribution of a source voltage produces the same source voltage at each of the plurality of transistors. An input current metallization and a mirror current metallization are formed within the symmetrical configuration to have a same value of impedance. A plurality of P-channel transistors within the current mirror circuit control a voltage of a point on the input metallization to be the same as a reference voltage, thus causing the mirror current to be referenced around the reference voltage.
    Type: Grant
    Filed: December 9, 2004
    Date of Patent: August 15, 2006
    Assignee: Dialog Semiconductor GmbH
    Inventors: David Tester, Gary Hague, Jorg Medwed
  • Patent number: 7089146
    Abstract: A circuit for temperature sensing receives a differential voltage that corresponds to the voltage across a forward-biased PN junction. The circuit for temperature sensing provides a first current to the PN junction, and subsequently provides a second current. Also, the temperature of the PN junction is determined based on the difference between the differential voltage when the first current is applied and the differential voltage when the second current is applied. Further, the circuit for temperature sensing self-biases half of the differential signal. The other half of the differential signal is level-shifted by an amount that is fixed and predetermined based on the self-biasing to provide a sub-ranging voltage. A sub-ranging analog-to-digital conversion is performed on the differential voltage in which the sub-ranging voltage is subtracted from the differential voltage during the conversion.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: August 8, 2006
    Assignee: National Semiconductor Corporation
    Inventors: Dan D'Aquino, Mehmet Aslan
  • Patent number: 7081844
    Abstract: There is provided a digital to an analog converter (DAC) comprising a current source, a first logic circuit, wherein the first logic circuit receives a first switching signal and a low-power mode signal, a first switch controlled by the first logic circuit, wherein the first switch selectively couples the current source to a ground in response to a signal from the first logic circuit, and a second switch controlled by a second switching signal, wherein the second switch selectively couples the current source to a load in response to the second switching signal. The first switching signal and the second switching signal may be complementary and are based on a digital signal that is being converted into an analog signal. The low-power mode signal is provided to selectively switch the DAC into a lower power consumption mode.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: July 25, 2006
    Assignee: ESS Technology, Inc.
    Inventors: Elim Huang, Xun Xie
  • Patent number: 7071858
    Abstract: Provided are a method and system for reducing glitch in a switch circuit. A system includes a current-steering switch circuit including a main differential pair switch coupled to a first tail current having a first current value. Also included is an auxiliary differential pair switch connected to the main differential pair switch. The auxiliary differential pair switch is coupled to a second tail current and configured to substantially reduce a feed-through current associated with the main differential pair switch.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: July 4, 2006
    Assignee: Broadcom Corporation
    Inventor: Hui Pan
  • Patent number: 7068194
    Abstract: Multiple switching circuits and current source circuits are arranged to operate as part of a compact unary DAC cell. The compact unary DAC cell can be combined with additional compact unary DAC cells to provide a scalable unary DAC system that may be segmented, non-segmented, single-ended, differential, or some other DAC topology that may employ one or more unary DAC cells. Each unary DAC cell is preferably comprised of transistors of a single type such that the maximum circuit density can be achieved. The current source circuits may each have equal current magnitudes. The total output current from the unary DAC cell corresponds to the combined currents from each of the current sources that are enabled.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: June 27, 2006
    Assignee: National Semiconductor Corporation
    Inventor: Robert Callaghan Taft
  • Patent number: 7064696
    Abstract: A first current mirror circuit that operates at the time of a rise in a first signal is connected to a current source, a second current mirror circuit that operates at the time of a rise in the first signal is connected to the first current mirror circuit, and a third current mirror circuit that operates at the time of a rise in a second signal is respectively connected to the current source and the point of connection between the first current mirror circuit and the second current mirror circuit. A pulse generation circuit for generating first and second signals from an external signal is provided. The second signal rises in sync with the first signal, and falls before the first signal.
    Type: Grant
    Filed: December 23, 2004
    Date of Patent: June 20, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Manabu Ohkubo, Masayuki Ozasa
  • Patent number: 7064695
    Abstract: A differential switching circuit has a first transistor connected between a first output node and a common node and a second transistor connected between a second output node and the common node. A switching driver generates first and second driving signals in response to an input data signal so as to complementarily drive the first and second transistors. A voltage level of at least one of the first and second driving signals is maintained so as to cause at least one of the first and second transistors to operate in a saturation region regardless of a voltage variation of at least one of the first or second output nodes when the at least one of the first and second transistors is turned on. Output impedance of the device is enhanced because the first and second transistors operate in the saturation region.
    Type: Grant
    Filed: December 9, 2004
    Date of Patent: June 20, 2006
    Assignee: Samsung Electronics, Co., Ltd.
    Inventor: Hyung-Woan Koo
  • Patent number: 7049991
    Abstract: A semiconductor device having a voltage-current conversion function, a digital-analog conversion function, and a gamma correction function is provided. A digital input signal (voltage) is input from an input terminal of a switching circuit. The switching circuit selects a current source to be connected to the input terminal according to the value of the digital input signal. Each current source outputs a predetermined value of current according to the signal from the input terminal. In this manner, by switching a current source for outputting current according to a digital input signal, gamma correction can be performed as well as digital-analog conversion.
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: May 23, 2006
    Inventor: Hajime Kimura
  • Patent number: 7042374
    Abstract: A current source cell includes a current source providing a first current where the first current can be calibrated, first and second switches coupled to steer the first current to respective first and second output terminals in response to respective first and second control signals, and a latch circuit generating the first and second control signals. The latch circuit drives the first and second control signals to a first logical state to cause the first and second switches to open. The first current is then calibrated. After calibration, the latch circuit drives the first and second control signals to have logical states that correspond to a data signal as triggered by a clock signal where the first and second control signals have inverse logical states. One of the first and second switches is closed to steer the first current to a respective one of the first and second output terminals.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: May 9, 2006
    Assignee: National Semiconductor Corporation
    Inventor: Gabriele Manganaro
  • Patent number: 7038603
    Abstract: Analog-valued floating-gate transistors are used as trimmable circuit components for modifying and/or controlling the gain, phase, offset, frequency response, current consumption, and/or transfer function of signal pathways in parallel and/or serial processing circuits in radio frequency, analog, or mixed-signal integrated circuits.
    Type: Grant
    Filed: February 10, 2005
    Date of Patent: May 2, 2006
    Assignee: Impinj, Inc.
    Inventors: Christopher J. Diorio, Todd E. Humes, Ronald A. Oliver, William T. Colleran, Scott A. Cooper
  • Patent number: 7023367
    Abstract: A current source cell includes a current source providing a first current at a first node where variations of a first voltage at the first node results in variations of the first current, and first and second switches coupled between the first node and respective first and second output terminals. A control signal is coupled to selectively apply a first drive voltage to a selected one of the first and second switches to close the selected switch to steer the first current to the corresponding output terminal. The current source cell further includes a voltage adjustment circuit coupled to detect variations in the first voltage and vary the first drive voltage in response to the variations in the first voltage. The first drive voltage applied to the selected switch is varied to reduce the variations in the first voltage, thereby maintaining the first voltage at a substantially stable voltage value.
    Type: Grant
    Filed: March 10, 2005
    Date of Patent: April 4, 2006
    Assignee: National Semiconductor Corporation
    Inventor: Gabriele Manganaro
  • Patent number: 7019676
    Abstract: A current output type D/A converter for converting a digital signal into an analog signal comprises a control signal input terminal for receiving a control signal supplied from the outside, and an output load element having a switching mechanism for electrically connecting or disconnecting the output load element to/from an analog output node on the basis of the control signal applied to the control input terminal.
    Type: Grant
    Filed: June 10, 2004
    Date of Patent: March 28, 2006
    Assignee: Matsushita Electric Industrial Co, Ltd.
    Inventors: Heiji Ikoma, Koji Oka
  • Patent number: 7012597
    Abstract: A data line drive circuit is equipped with a single line driver 300 and a gate voltage generation circuit 400. The single line driver 300 is constructed such that N groups (where N is an integer 2 or larger) of series connections of drive transistors 21 to 28 and switching transistors 81 to 88 are connected in parallel. The gate voltage generation circuit 400 includes two transistors 71 and 72 constituting a current mirror circuit, a drive transistor 73, and a constant voltage generation transistor 31. The range of an output current Iout can be controlled by changing any of the design values of the parameters including: relative values Ka and Kb of the gain coefficient for the transistors 31 and 32, the source voltage VDREF of the gate voltage generation circuit 400, and the gate signal VRIN of the drive transistor 73.
    Type: Grant
    Filed: July 30, 2002
    Date of Patent: March 14, 2006
    Assignee: Seiko Epson Corporation
    Inventor: Toshiyuki Kasai
  • Patent number: 6992608
    Abstract: A latch architecture for driving unit current cell of a current-steering digital-to-analog converter (DAC) which reduces the drain-source voltage variation of the output current-source transistors and reduces the coupling of unwanted injection of input digital signals as well as clock signals is presented herein. Moreover, this latch helps to achieve lower glitch during code transition with improved dynamic performance. The latch effectively uses the intrinsic RC delay of most transistors within the latch architecture in order to achieve optimal crossing points of complementary control signals. Unwanted input injection or cross-talk is reduced by introducing transistors (904, 906, 932 and 934) that are off during code transitions without compromising the DAC update speed. Conflicts between currently held and new inputs are avoided in an effort to reduce the harmonic distortion.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: January 31, 2006
    Assignee: Texas Instruments Incorporated
    Inventors: Weibiao Zhang, Bertan Bakkaloglu
  • Patent number: 6992609
    Abstract: The present invention provides a high speed digital-to-analog converter (DAC), and components for a high speed DAC. One embodiment of the present invention provides a novel current switching circuit that surmounts parasitic capacitance of the circuit elements. In another embodiment, the DAC includes a novel built-in-test circuit, which allows tests of the DAC at high speeds. One feature of the DAC constructed according to the present invention, is that it enables direct digital synthesis of communication waveforms. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: January 31, 2006
    Assignee: Pulselink, Inc.
    Inventors: Denis Zelenin, Dalius Baranauskas
  • Patent number: 6987476
    Abstract: A system (e.g., a digital-to-analog converter (DAC)) includes a digital section and an analog section. The digital section has a driver portion that generates drive signals based on received respective digital input signals. The drive signals are received at respective switches in the analog section. The driver portion includes logic gates that are used to generate the drive signals, such that a rise and fall time of complementary pairs of drive signals are substantially equal. The driver portion can optionally include an acceleration system to accelerate the rise and fall times of the drive signals. The switches generate respective analog signals from the drive signals.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: January 17, 2006
    Assignee: Broadcom Corporation
    Inventor: Hongwei Wang
  • Patent number: 6977600
    Abstract: A method for determining analog error of a signal includes receiving an input signal and sampling the input signal to generate a first sampled signal. The method also includes communicating the first sampled signal using a first communication path and a second communication path and sampling the first sampled signal from the first communication path to generate a second sampled signal. The method further includes converting the first sampled signal from the second communication path into a digital signal, storing the digital signal using a digital memory, comparing the second sampled signal to the digital signal, and determining an analog error of the input signal based on the comparison.
    Type: Grant
    Filed: April 8, 2004
    Date of Patent: December 20, 2005
    Assignee: Fujitsu Limited
    Inventors: Jian H. Jiang, Yasuo Hidaka
  • Patent number: 6972703
    Abstract: A voltage detection circuit. A second NMOS transistor has a gate coupled to the gate of a first NMOS transistor. A comparator has input terminals, and an output terminal. A first resistor is coupled between the first input terminal and the source of the first NMOS transistor, a second resistor is coupled to the comparator and the first resistor, a third resistor is coupled between the second resistor and the comparator, and a fourth resistor is coupled between the second and third resistors, and ground. A first PMOS transistor has a gate coupled to the gates of the first and second NMOS transistors. A second PMOS transistor has a connected gate and drain, a source coupled to the gates of first and second NMOS transistors, a drain coupled to ground, and an n-well directly connected to the gates of the first and second NMOS transistors.
    Type: Grant
    Filed: December 16, 2004
    Date of Patent: December 6, 2005
    Assignee: Faraday Technology Corp.
    Inventors: Wen-Cheng Yen, Chao-Chi Lee
  • Patent number: 6970125
    Abstract: An analog-to-digital converter with a pipeline architecture for converting an analog input signal into a digital output signal with a predefined resolution includes a plurality of stages, each stage having a circuit for converting an analog local signal into a digital local signal with a local resolution lower than the predefined resolution, a circuit for determining an analog residue indicative of a quantization error of the converting circuit, a circuit for amplifying the analog residue by an inter-stage gain corresponding to the local resolution to generate the analog local signal for a next stage, and a circuit for combining the digital local signals of all the stages into the digital output signal weighting each digital local signal according to a digital weight depending on the corresponding inter-stage gain.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: November 29, 2005
    Assignee: STMicroelectronics S.r.l.
    Inventors: Giovanni Cesura, Andrea Panigada, Alessandro Bosi
  • Patent number: 6961012
    Abstract: The data-line driver circuit receives data currents from an external signal source and drives the pixel group of electro-luminescence display device. The data-line driver circuit has a first circuit group, a second circuit group and a shift register. The shift register controls the first circuit group to receive the data currents and controls the second circuit group to duplicate the data currents and then send them to the pixel group.
    Type: Grant
    Filed: April 8, 2004
    Date of Patent: November 1, 2005
    Assignee: Toppoly Optoelectronics Corp.
    Inventor: Wei-Chieh Hsueh
  • Patent number: 6958719
    Abstract: Digital-to-analog converter circuits can include independently sized first and second current source transistors coupled to respective pluralities of first and second current provider transistors in current mirror configurations. The first and second current provider transistors can be sized proportionally to the first and second current source transistors respectively.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: October 25, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Kyeong-tae Moon
  • Patent number: 6950047
    Abstract: Method and apparatus for combining outputs of multiple DACs for increased bit resolution. A method for providing an increased bit resolution to a data converter operable to convert digital information to analog values. A first current Digital-to-Analog (IDAC) converter is controlled to provide current to a first output node, the first IDAC having a first current step size associated with the Least Significant Bit (LSB) thereof. A second IDAC is controlled to provide current to the first output node, the second IDAC having a second current step size associated with the LSB thereof that is smaller than the first current step size. The combination of the first and second IDACs increases the bit resolution of the first IDAC when driving the first output node with the second IDAC.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: September 27, 2005
    Assignee: Silicon Labs CP, Inc.
    Inventors: Douglas Piasecki, James Dub Austin, Douglas Holberg, Kenneth Fernald
  • Patent number: 6943718
    Abstract: A system (e.g., a digital-to-analog converter (DAC)) includes a digital section and an analog section. The digital section has drivers that generate drive signals based on received digital input signals. The drive signals are received at switches in the analog section of the DAC. The switches generate analog signals therefrom. Swing values of the drive signals are limited to a predetermined amount to substantially eliminate glitch in the analog signals. The drivers can be coupled between first and second nodes that receive different power signal values. Controlling the power signal values allows for the limiting of the swing values. Limiting the swing values limits stored charged in the first and second switches, which substantially eliminates glitch in the analog signals. This can be done regardless on environmental variances (e.g., temperature variance) during operation of the DAC.
    Type: Grant
    Filed: August 30, 2004
    Date of Patent: September 13, 2005
    Assignee: Broadcom Corporation
    Inventor: Hongwei Wang
  • Patent number: 6940439
    Abstract: A multi-track speech synthesizer comprises a plurality of volume control units, a plurality of signal transform units, a plurality of current switch units, a comparison unit and a current output unit. Each current switch units includes a pair of complementary outputs to send out a current with its zero point at zero, and the output terminals of the current switch units are directly coupled together to form two connected output terminals. The comparison unit compares the voltages of the connected output terminals and then sends out a control signal to control the current output unit. Under the control of the control signal, the current output unit sends out a current of push-pull type with direct connection. Due to the zero point of the current from the current switch unit at 0, the direct current component by the direct connection will not be accumulated, thereby reducing the power consumption in comparison with traditional DAC multi-track speech synthesizers with (wire OR) direct connection.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: September 6, 2005
    Assignee: Elan Microelectronics Corporation
    Inventors: Wuu-Trong Shieh, Ying-Pin Ho
  • Patent number: 6927714
    Abstract: A current steering digital-to-analog (DAC) having improved dynamic performance and output signal quality (i.e. improved SFDR characteristic). The DAC includes current steering segments each having differential transistors to steer a current from a summing node to either the positive or negative output. The DAC further comprises a control circuit to reduce the variation of the voltage present at each summing node. More specifically, the control circuit includes a first circuit that controls the threshold voltage of the corresponding differential transistors that are electrically connected to the positive output in response to the sensed positive output voltage such that the voltages at the corresponding summing nodes remain constant.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: August 9, 2005
    Assignee: Maxim Integrated Products, Inc.
    Inventor: Jerzy A. Teterwak
  • Patent number: 6924759
    Abstract: A multi-channel circuit (1) comprising a plurality of on-chip channels (CH1 to CH4), each of which comprises a DAC (3) for converting digital data into analogue output signals independently of each other under the control of an interface and control logic circuit (11). The analogue output signals from the DACs (3) are outputted on output terminals (7) of the respective channels (CH1 to CH4). The digital input data and control and address signals for controlling the conversion of the digital data in the DACs (3) are inputted to the interface and control logic circuit (11) through an I/O port (10). DAC registers (9) are provided in the respective channels (CH1 to CH4) for storing the digital words to be converted in the corresponding DACs (3). Analogue input terminals (20) are provided for receiving analogue input signals (20), for example, analogue signals from external systems which may be controlled by the output signals from the DACs (3).
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: August 2, 2005
    Assignee: Analog Devices, Inc.
    Inventors: John Wynne, Donal P. Geraghty, Albert C. O'Grady
  • Patent number: 6922162
    Abstract: A two-dimensional matrix decoder of a digital-to-analog converter comprises an array of current cells, the cells having a current source means or a current divider means and a switching means, all cells being activatable in a pre-determined sequence. The matrix decoder comprises: a selection means outputting a first selection signal for selecting a cell, a cell state signaling means outputting a cell state signal determining whether a cell comes before or after the selected cell in the pre-determined sequence, and matrix logic associated with each cell for generating a control signal suitable for controlling the switching means of that cell for switching current from the current source means or current divider means of that cell to at least one of a first node or a second node, the control signal being generated depending on the first selection signal and the cell state signal.
    Type: Grant
    Filed: March 26, 2004
    Date of Patent: July 26, 2005
    Assignee: AMI Semiconductor Belgium BVBA
    Inventors: Pavel Horsky, Ivan Koudar
  • Patent number: 6917319
    Abstract: A method and structure for a digital-to-analog converter comprising a voltage source supply; a voltage division stack connected to the voltage source supply; a multiplexer connected to the voltage division stack; a digital circuit connected to the multiplexer; an analog circuit connected to the multiplexer; and an input binary word source connected to the digital circuit, wherein outputs of the digital circuit are input into the analog circuit and converted as analog output. According to the invention, the multiplexer comprises any of an NFET and/or a PFET. The digital-to-analog converter further comprises a capacitor connected to the analog circuit and a binary-weighted tunneling current device connected to the digital circuit. The multiplexer and the capacitor are made of thick oxide (at least 5 nm thick). The tunneling current device outputs tunneling current, wherein the tunneling current is adjusted in proportion to a binary weight of the input binary word source.
    Type: Grant
    Filed: March 30, 2004
    Date of Patent: July 12, 2005
    Assignee: International Business Machines Corporation
    Inventors: Wagdi W. Abadeer, John A. Fifield
  • Patent number: 6911926
    Abstract: A D/A conversion circuit with a small area is provided. In the D/A conversion circuit, according to a digital signal transmitted from address lines of an address decoder, one of four gradation voltage lines is selected. A circuit including two N-channel TFTs is connected in series to a circuit including two P-channel TFT, and a circuit including the circuits connected in series to each other is connected in parallel to each of the gradation voltage lines. Further, an arrangement of the circuit including the two N-channel TFTs and the circuit including the two P-channel TFTs is reversed for every gradation voltage line. By this, the crossings of wiring lines in the D/A conversion circuit becomes small and the area can be made small.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: June 28, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jun Koyama, Mitsuaki Osame, Yukio Tanaka, Munehiro Azami, Naoko Yano, Shou Nagao
  • Patent number: 6909316
    Abstract: Variable delay circuits and methods for delaying a waveform by an adjustable time delay are disclosed herein. One such variable delay circuit comprises a delay range limitation circuit having a first differential input, a first differential output, and a second differential output. The first differential input is configured to receive an input waveform. The first differential output is configured to output the waveform with a maximum delay, and the second differential output is configured to output the waveform with a minimum delay. The variable delay circuit further comprises a delay mixing circuit having second and third differential inputs, first and second control inputs, and a third differential output. The second differential input is connected to the first differential output. The third differential input is connected to the second differential output. The first and second control inputs are configured to receive control voltages V1 and V2, which are related to a selected time delay.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: June 21, 2005
    Assignee: Agilent Technologies, Inc.
    Inventors: Ronnie E. Owens, Barbara J. Duffner
  • Patent number: 6909389
    Abstract: A method and apparatus for calibrating an electronic circuit which required scaled matching of some or all of its electronic components with nonvolatile programmably trimmable parameter sources (current, voltage, resistance, capacitance) is carried out in a top-down (highest order bit first, lowest order bit last) fashion without an analog division step. The method and apparatus are applicable, for example, to current-steering digital-to-analog converters (DACs), voltage-controlled oscillators (VCOs), voltage-steering DACs, and the like. In each of these applications the method and apparatus is used to match successive device outputs according to a desired scale factor, proceeding top-down from large output devices to smaller output devices, thereby successively shrinking the cross-device errors which accrue during the matching process.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: June 21, 2005
    Assignee: Impinj, Inc.
    Inventors: John D. Hyde, David L. Kaplan
  • Patent number: 6903671
    Abstract: Disclosed is a digital-to-analog (D/A) converter with low skew and glitches. The D/A converter has current cells each outputting a different current amount and current switches selectively enabling the current cells, and obtains an analog signal from voltages corresponding to output currents of the current cells by operating the current switches, characterized in that the current switches are each provided with MOS transistors each having an adjusted aspect ratio so as to have a constant capacitance load regardless of the output current amounts from the current cells. In such a D/A converter, parasitic capacitances of MOS transistors provided in the current switches are adjusted constant regardless of output current amounts, so that the D/A converter can operate at a high speed with low skew and glitch.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: June 7, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dae-hoon Kwon, Gae-ok Cho, Jae-jun Moon
  • Patent number: 6897799
    Abstract: A digital-to-analog converter having a differential signal path, and a current parking circuit that is independent of the signal path, thereby avoiding a source of imbalance that caused output anomalies in conventional digital-to-analog circuitry. In one embodiment of the invention, a pair of diodes in the current parking circuit are connected through their own independent load resistors to a voltage source. In another embodiment, a single diode is used instead of the pair of diodes, and in a third embodiment the current parking circuit comprises a single load resistor connected to the voltage source, and no diodes at all.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: May 24, 2005
    Assignee: Northrop Grumman Corporation
    Inventors: Harry S. Harberts, Jeffrey M. Hinrichs
  • Patent number: 6870493
    Abstract: An digital-to-analog converting circuit of a display, used for a current-type data driver. The digital-to-analog converting circuit is characterized in that the ratio of channel-width to channel-length (W/L) for each transistor thereof is identical, such that no deviation occurs to the current of data output.
    Type: Grant
    Filed: November 29, 2002
    Date of Patent: March 22, 2005
    Assignee: Au Optronics Corporation
    Inventor: Chien-Sheng Yang
  • Patent number: 6870495
    Abstract: A pipelined analog-to-digital converter features an amplifier block that includes a switching network to implement a double sampling and double conversion principle of operation. The amplifier block utilizes both phases of a clock for sampling and conversion. Additionally, each stage of the analog-to-digital converter is associated with two independent processing blocks. The analog-to-digital converter can achieve double throughput for approximately the same level of power consumption. Alternatively, throughput may be maintained, but the gain-bandwidth of the amplifier block may be reduced by half, thereby halving the DC bias current consumed by the amplifier. Additionally, the output signal of the amplifier itself is not reset to a common mode voltage.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: March 22, 2005
    Assignee: Micron Technology, Inc.
    Inventors: Ali E. Zadeh, Lin P. Ang
  • Patent number: 6859159
    Abstract: Switched-capacitor structures are provided that reduce distortion and noise in their processed signals because they increase isolation between structural elements and ensure that selected elements are securely turned off in one mode and quickly turned on in another mode.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: February 22, 2005
    Assignee: Analog Devices, Inc.
    Inventor: Christopher Michalski
  • Patent number: 6853323
    Abstract: A digital-to-analog converter (DAC) for use in high-speed wireless communications. The DAC of the invention comprises a plurality of current steering cells to bi-directionally provide a differential current output. When the DAC sets the differential current output to zero for example, each of the current steering cells establishes dummy branches between a pair of current sources and thereby prevents the current sources from floating. This in turn enables the DAC to operate with a higher update rate.
    Type: Grant
    Filed: May 4, 2004
    Date of Patent: February 8, 2005
    Assignee: Integrated Programmable Communications, Inc.
    Inventors: Yi-Huei Chen, Po-Chiun Huang, Chieh-Hung Chen
  • Patent number: 6844835
    Abstract: A digital-analog converter (DAC) cell circuit. The circuit includes a current source, a first resistor, a second resistor, a first MOSFET, a second MOSFET, a third MOSFET and a forth MOSFET. The first MOSFET has a source and a drain connected to the current source and the first resistor, respectively, and a gate receiving a first control signal. The second MOSFET has a source and a drain connected to the current source and the second resistor, respectively, and a gate receiving a second control signal. The third MOSFET has a source and a drain connected to the source and drain of the first MOSFET, respectively, and a gate receiving a third control signal. The fourth MOSFET has a source and a drain connected to the source and drain of the second MOSFET, respectively, and a gate receiving a fourth control signal. The third control signal is a signal delayed of the first signal and the forth control signal is a signal delayed of the second signal.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: January 18, 2005
    Assignee: MediaTek Inc.
    Inventor: Hsueh-Wu Kao
  • Patent number: 6842132
    Abstract: Methods and devices for code independent switching in signal processing circuit such as a digital-to-analog converter (DAC) are described, which provide code independent switching activity. A steering cell receives a digital data input signal that is defined at data intervals, and produces multiple representative analog output signals. For each data interval, each analog output signal depends only on the present state of the digital data input signal, independently of any previous state of the digital data input signal. In addition, the signal processing circuit apart from the analog output signals is substantially free of data dependent disturbances.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: January 11, 2005
    Assignee: Analog Devices, inc.
    Inventor: Bernd Schafferer
  • Patent number: 6836234
    Abstract: A system (e.g., a digital-to-analog converter (DAC)) includes a digital section and an analog section. The digital section has a driver portion that generates drive signals based on received respective digital input signals. The drive signals are received at respective switches in the analog section. The driver portion includes logic gates that are used to generate the drive signals, such that a rise and fall time of complementary pairs of drive signals are substantially equal. The driver portion can optionally include an acceleration system to accelerate the rise and fall times of the drive signals. The switches generate respective analog signals from the drive signals.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: December 28, 2004
    Assignee: Broadcom Corporation
    Inventor: Hongwei Wang
  • Patent number: 6836228
    Abstract: Methods and apparatus for converting analog signals to digital signals using a switched integrator. A method includes receiving the analog signal at a summing junction, receiving a clock signal transitioning between a first level and a second level, connecting an output of the summing junction to an integrator when the clock signal is at the first level, and disconnecting the output of the summing junction from the integrator when the clock signal is at the second level. An output signal is provided, and is determined by the polarity of an output of the integrator when the clock signal transitions from the first level to the second level. The output signal is delayed, and received with a digital-to-analog converter; which provides an output to the summing junction.
    Type: Grant
    Filed: November 20, 2002
    Date of Patent: December 28, 2004
    Assignee: Xicor, Inc.
    Inventors: Roger Levinson, Phillip J. Benzel
  • Publication number: 20040257251
    Abstract: A digital voltage/analog current converting circuit includes a plurality of controllable current paths and a driving current output terminal. The driving current output terminal is in communication with the plurality of controllable current paths. At least one of the controllable current paths includes a driving current output path and a bypass path for selectively flowing therethrough a current in response to a control signal, and the current flowing through the driving current output path is outputted to the driving current output terminal.
    Type: Application
    Filed: June 4, 2004
    Publication date: December 23, 2004
    Inventor: Wei-Chieh Hsueh
  • Patent number: 6833801
    Abstract: Low distortion current switches for high speed current steering digital-to-analog converters. The current switches use a compensation method for improving the spurious peformance of a CMOS current steering DAC for high output frequencies caused by the capacitance of the common node of the switch transistors. For this purpose, a replica switch is provided, with the voltage change on the common node of the replica switch being used to provide a corresponding charge to the common node of the main switch in an amount equal to the charge needed to change the voltage on the common node of the main switch by the same amount as the voltage change on the common node of the replica switch. Multiple embodiments are disclosed.
    Type: Grant
    Filed: December 1, 2003
    Date of Patent: December 21, 2004
    Assignee: Maxim Integrated Products, Inc.
    Inventors: Geir Sigurd Ostrem, Paul W. Kalthoff
  • Publication number: 20040227653
    Abstract: Binary indications are converted to an analog representation with significant reduction in ringing at the transitions between successive binary indications and in the period during each binary indication. The binary indications are disposed in a row-and-column matrix to provide a thermometer code. Each stage of the converter includes a decoder and latch arranged so the decoder inputs settle before the latch is set by the clock pulses. The stages are implemented in complementary CMOS. Complementary transistors are biased so one transistor of the pair is driven to the rail while the other transistor of the pair floats. A dummy CMOS transistor is used to balance the number of transistors in the decoder paths.
    Type: Application
    Filed: March 26, 2004
    Publication date: November 18, 2004
    Applicant: Broadcom Corporation
    Inventors: Klaas Bult, Chi-Hung Lin
  • Patent number: 6819277
    Abstract: A method is used for reducing spikes in a digital-to-analog converter (DAC), which includes a plurality of digit circuits for transforming a digital voltage signal into an analog voltage signal. The method includes receiving the digital voltage signal, setting the digit circuit corresponding to a predetermined bit of the digital voltage signal closest to an output module, and outputting an analog voltage signal corresponding to the digital voltage signal, wherein the predetermined bit of the digital voltage signal is the bit with least signal variation among the bits of the digital voltage signal.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: November 16, 2004
    Assignee: Au Optronics Corp.
    Inventors: Jen-Yi Hu, Wein-Town Sun