Having Digital Device (e.g., Logic Gate, Flip-flop, Etc.) Patents (Class 327/107)
  • Publication number: 20130093471
    Abstract: A time-to-digital system, such as a frequency synthesizer, includes a power management circuit and a time-to-digital converter (TDC). Said power management circuit is coupled to a frequency reference clock and a variable clock, and arranged to output a delayed frequency reference clock and a single pulse of said variable clock ahead of a transition of said delayed frequency reference clock. Said TDC is coupled to said power management circuit and arranged to produce a digital TDC output.
    Type: Application
    Filed: April 18, 2012
    Publication date: April 18, 2013
    Applicant: MEDIATEK Inc.
    Inventors: Yi-Hsien Cho, Robert Bogdan Staszewski
  • Publication number: 20130082743
    Abstract: A splitter circuit in a semiconductor device includes a first inverter that receives an input signal and outputs an inverted signal, a second inverter that receives the inverted signal and outputs a non-inverted signal (a first output signal), a third inverter that receives the input signal and outputs an inverted signal (a second output signal) and an auxiliary inverter that shares an output signal line with the third inverter. The third inverter and the auxiliary inverter use an inverted signal of the input signal as power supplies.
    Type: Application
    Filed: September 11, 2012
    Publication date: April 4, 2013
    Applicant: Elpida Memory, Inc.
    Inventors: Takenori SATO, Shinya Miyazaki
  • Publication number: 20130063183
    Abstract: A signal generating apparatus includes: a direct digital synthesizer configured to generate an output signal of a frequency according to first control data based on a reference clock; and a controller configured to provide the direct digital synthesizer with the first control data at a timing synchronized with the reference clock, wherein the controller includes a table which stores second setting data for controlling the frequency of the output signal based on jitter information and provides the direct digital synthesizer with the second setting data in the table as the first control data at the timing.
    Type: Application
    Filed: July 30, 2012
    Publication date: March 14, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Yoshinori Nakane, Yoshito Koyama, Koji Nakamuta
  • Patent number: 8390334
    Abstract: A synthesizer includes: a synthesizer unit that outputs an oscillation signal based on a reference oscillation signal; a temperature detecting unit that detects a temperature; a time variation detecting unit that detects a time variation in frequency of the reference oscillation signal based on a result of temperature detection by the temperature detecting unit; and a control unit that adjusts a frequency of the oscillation signal outputted from the synthesizer unit based on a result of detection by the time variation detecting unit. With such a configuration, frequency compensation control is performed on a transducer having a large temperature coefficient.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: March 5, 2013
    Assignee: Panasonic Corporation
    Inventors: Yasunobu Tsukio, Akihiko Namba
  • Publication number: 20130052975
    Abstract: In one embodiment, the present invention includes a mixer circuit to receive and generate a mixed signal from a radio frequency (RF) signal and a master clock signal, a switch stage coupled to an output of the mixer circuit to rotatingly switch the mixed signal to multiple gain stages coupled to the switch stage, and a combiner to combine an output of the gain stages.
    Type: Application
    Filed: October 30, 2012
    Publication date: February 28, 2013
    Inventors: Aslamali A. Rafi, Alessandro Piovaccari
  • Patent number: 8381146
    Abstract: A computer-readable, non-transitory medium stores therein a design support program that causes a computer capable of accessing a storage device storing therein for each cell, an output voltage value of the cell, for each elapsed time period from a start of variation of an input voltage applied to the cell, to execute a process. The process includes extracting from the storage device, the output voltage value for each elapsed time period related to an cell under design selected from circuit information of a circuit under design; determining based on a specific voltage value, an extracted elapsed time period to be corrected; adding a time constant of an output from the cell under design to the elapsed time period determined to correction; and outputting the output voltage value for each corrected elapsed time period and the output voltage value for each elapsed time period that is not determined for correction.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: February 19, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventor: Mitsuru Onodera
  • Patent number: 8369476
    Abstract: A clock generator is illustrated. The clock generator mentioned above includes a multimodulus frequency divider and a delta-sigma modulator. The multimodulus frequency divider is archived by switching the phase thereof. The multimodulus frequency divider increases the operating frequency of the clock generator effectively, and has a characteristic with half period resolution for reducing the jitter of an output clock signal when its spectrum is spread. Besides, the delta-sigma modulator increases the accuracy of the triangle modulation and reduces error of quantization by adding a few components therein. Thus, the clock generator could be expanded to a programmable clock generator.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: February 5, 2013
    Assignee: Industrial Technology Research Institute
    Inventors: Wei-Sheng Tseng, Hong-Yi Huang, Kuo-Hsing Cheng, Yuan-Hua Chu
  • Patent number: 8362805
    Abstract: In an embodiment, an integrated circuit may include one or more power managed blocks and a power manager circuit. The power manager circuit may be configured to generate a block enable for each power managed block and a block enable clock. The power managed block may generate local block enables to various power switches in the power managed block, staggering the block enables over two or more block enable clock cycles. In particular, the power managed block may include a set of series-connected flops that receive the block enable from the power manager circuit. The output of each flop may be coupled to a respective set of power switches and may enabled those switches. The change in current flow due to enabling and/or disabling the power managed block may thus be controlled. In an embodiment, the frequency of the block enable clock may be set to a defined value independent of process, voltage, and temperature conditions in the integrated circuit.
    Type: Grant
    Filed: February 15, 2010
    Date of Patent: January 29, 2013
    Assignee: Apple Inc.
    Inventors: Shingo Suzuki, Vincent R. von Kaenel, Toshinari Takayanagi, Conrad H. Ziesler, Daniel C. Murray
  • Patent number: 8362932
    Abstract: Calibration data for calibrating time to digital conversion is obtained by switching a feed circuit of a time to digital converter between a normal operating mode or a calibration mode. A delay circuit with a delay circuit input and a plurality of taps outputs. A sampling register samples data from the data inputs. The feed circuit provides for selection of transitions of the oscillator signal that control timing of a first active transition at the clock circuit after a transition at the delay circuit input. A control circuit switches the feed circuit between normal operating mode and calibration mode, and controls the feed circuit successively to select a plurality of different transitions to control timing of the first active transition in the calibration mode. The control circuit reads out resulting data from the sampling register for each selection and determines calibration data for the oscillator signal from said data.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: January 29, 2013
    Assignee: ST-Ericsson SA
    Inventors: Nenad Pavlovic, Manel Collados Asensio, Xin He, Jan Van Sinderen
  • Patent number: 8355431
    Abstract: A Decision Feedback Equalizer (DFE) capable of preventing incremental increases of a jitter of a recovered clock and reduction of a voltage margin of decided data due to delay of feedback data. The DFE includes a combiner for combining received data with feedback data and outputting the combined data as equalization data, a decision circuit for deciding recovery data by receiving the equalization data, a feedback loop for supplying the recovery data to the combiner as feedback data and a clock recovery circuit for removing a delay data component from the equalization data through the feedback loop, recovering a clock with respect to the other equalization data except the delay data component and supplying the recovered clock for decision operation of the decision circuit.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: January 15, 2013
    Assignee: Hynix Semiconductor, Inc.
    Inventor: Ki-Hyuk Lee
  • Patent number: 8347123
    Abstract: Exemplary techniques for turning off the clock signal to flip flops are described, which may reduce power consumption by electronic devices. In an implementation, a clock-gating logic turns off the clock signal to a flip flop when a data input of the flip flop remains untoggled. The reduction in power consumption is envisioned to also reduce heat generation.
    Type: Grant
    Filed: December 8, 2009
    Date of Patent: January 1, 2013
    Assignee: LSI Corporation
    Inventor: Richard Thomas Schultz
  • Patent number: 8339160
    Abstract: A clock generating device includes: a DDS circuit that generates a periodic signal; and a comparator that compares an input signal and a reference signal and outputs a binary signal. The clock generating device includes a rate-of-change correcting unit that applies correction for increasing a rate of change at a crossing point with the reference signal to the periodic signal generated by the DDS circuit.
    Type: Grant
    Filed: November 17, 2009
    Date of Patent: December 25, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Hideaki Yamada
  • Publication number: 20120293213
    Abstract: In forming a frequency synthesizer by using PLL using processing of digital signals, an A/D converting unit is not required. By the integration of a digital value that depends on a set frequency, a saw-tooth wave serving as a phase signal is generated. A frequency signal output from a voltage-controlled oscillator is input via a frequency divider to an edge detecting unit, which then detects a rising edge or a falling edge of the frequency signal to generate a rectangular-wave signal that depends on a frequency of the frequency signal. Then, a latched circuit latches a value of the saw-tooth wave in response to the rectangular-wave signal, and this value is integrated in a loop filter and the resultant is used as a control voltage of the voltage-controlled oscillator.
    Type: Application
    Filed: May 17, 2012
    Publication date: November 22, 2012
    Applicant: Nihon Dempa Kogyo Co., Ltd.
    Inventors: Kazuo AKAIKE, Tsukasa KOBATA
  • Publication number: 20120229171
    Abstract: One of the advantages of direct frequency synthesis technique (e.g., flying-adder architecture) is its capability of generating arbitrary frequency by utilizing the time-average-frequency concept. In the clock output of the direct frequency synthesizer, instead of one type of cycle, there are two types of cycles. Unlike the conventional one-type-cycle clock wherein clock energy is concentrated at its designed frequency, Time-Average-Frequency based clock spreads some of its energy into spurious tones, which could be harmful to certain applications. The spurious tones are caused by the periodic carry sequence generated from a fractional part accumulator inside the frequency synthesizer. The invention suggests a method and an apparatus to break this periodicity and convert the spurious tones into broadband noise.
    Type: Application
    Filed: March 6, 2012
    Publication date: September 13, 2012
    Applicant: Novatek Microelectronics Corp.
    Inventors: Liming Xiu, Ming-Chieh Lin
  • Publication number: 20120218005
    Abstract: A semiconductor device having an on-chip voltage regulator to control on-chip voltage regulation and methods for on-chip voltage regulation are disclosed. A semiconductor device includes a circuit positioned between a ground bus and a power bus. A power switch array is positioned between the circuit and one of the ground bus or the power bus to generate a virtual voltage across the circuit. A monitor is positioned between the ground bus and the power bus. The monitor is configured to simulate a critical path of the circuit and to output a voltage adjust signal based on an output of the simulated critical path. A controller is configured to receive the voltage adjust signal and to output a control signal to the power switch array to control the virtual voltage.
    Type: Application
    Filed: February 25, 2011
    Publication date: August 30, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: Lew G. Chua-Eoan, Charles Matar, Matthew L. Severson, Xiaohua Kong
  • Patent number: 8237481
    Abstract: A programmable Local Clock Buffer has a single inverter between the clock input and the delayed clock output. A transistor switch modulates the single inverter stage between a clock signal transmit state and a non-transmitting state. A combination of delay select bits control the timing of the beginning and ending of the transmit state of the inverter relative to the clock input via the transistor switch.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: August 7, 2012
    Assignee: International Business Machines Corporation
    Inventors: Yuen H. Chan, Rolf Sautter, Michael J. Lee, Juergen Pille
  • Patent number: 8179945
    Abstract: Transmitter device which includes at least: a) one delay line designed to output M signals which are delayed in relation to each other, where M is an integer greater than 1; b) a memory, designed to store at least M digital samples of a waveform, where each digital sample contains N bits, and to output each of the M digital samples successively on N output lines respectively under the control of one of the M delayed signals; and c) a digital-analog converter which includes N inputs linked to N output lines, designed to convert the M digital samples received as input from the N output lines of the memory and to successively output, on an output of the digital-analog converter, each of the M analog converted digital samples which together form an analog signal which is representative of the waveform.
    Type: Grant
    Filed: February 19, 2008
    Date of Patent: May 15, 2012
    Assignee: Commissariat a l'Energie Atomique
    Inventor: David Lachartre
  • Patent number: 8174293
    Abstract: A time to digital converter includes: a delay circuit having a plurality of delay stages that delay an input clock signal in multiple stages, at least one of the delay stages being a variable delay stage; a plurality of flip flops that capture outputs of the delay stages corresponding thereto in a one-to-one relation in response to input of a reference signal; an edge detecting circuit that detects changing edges of respective outputs of the flip flops; a counter circuit that counts a number of edges detected by the edge detecting circuit; and a control circuit that controls a delay amount of the variable delay stage according to the number of edges counted by the counter circuit.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: May 8, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Yoshihara, Hiroyuki Kobayashi
  • Publication number: 20120105111
    Abstract: Provided is a transmitter including a polar modulation circuit which adjusts a timing lag between an amplitude component and a phase component more accurately than a conventional art.
    Type: Application
    Filed: April 9, 2010
    Publication date: May 3, 2012
    Applicant: PANASONIC CORPORATION
    Inventor: Masakatsu Maeda
  • Patent number: 8120389
    Abstract: To make Flying-Adder architecture even more powerful, a new concept, time-average-frequency, is incorporated into the clock generation circuitry. This is a fundamental breakthrough since it attacks the clock generation problem from its root: how is the clock signal used in real systems? By investigating from this direction, a much more powerful architecture, fixed-VCO-Flying-Adder architecture, is created. Furthermore, based on fixed-VCO-Flying-Adder frequency synthesizer and time-average-frequency, a new type of component called Digital-to-Frequency Converter (DFC) is born.
    Type: Grant
    Filed: August 5, 2009
    Date of Patent: February 21, 2012
    Assignee: Texas Instruments Incorporated
    Inventor: Liming Xiu
  • Patent number: 8116418
    Abstract: A clock data recovery comprises a phase detector, a phase interpolator, an initial phase detector, and an initial phase decoder. The phase detector receives an incoming data stream and an interpolated clock signal and output an early/late value indicating timing relationship between the incoming data stream and the interpolated clock signal. The phase interpolator receives the early/late signal and at least one reference clock signal and generate an interpolated clock signal considering the early/late value and the at least one reference clock signal. The initial phase detector receives the incoming data stream and output a first data indicating a phase of the incoming data stream. The initial phase decoder receives data indicating a phase of the incoming data stream and select the at least one reference clock signal from a plurality of clock signals considering the data indicating a phase of the incoming data stream.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: February 14, 2012
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Jinn-Yeh Chien
  • Patent number: 8115519
    Abstract: A phase accumulator generates phase data for a direct digital synthesis (DDS) device based on a reference phase to provide analog sinusoidal outputs that are locked to the reference phase and thus phase coherent. The frequency of a sinusoidal DDS output may be controlled by changing a frequency control word (FCW) provided to the phase accumulator without affecting the incrementing reference phase. The sinusoidal DDS output is based on a multiple of the FCW and the reference phase and thus remains locked to the reference phase, providing phase coherency even when the FCW changes to change the frequency.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: February 14, 2012
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventor: Steven E. Turner
  • Patent number: 8063669
    Abstract: Described is an apparatus that includes a frequency source and a plurality of time domain direct digital synthesizers each having an input connected to an output of the frequency source and an output providing an output frequency signal. A particular time domain direct digital synthesizer includes a sigma-delta modulator that functions as a second order multi-stage noise shaping sigma-delta modulator. In one exemplary embodiment sigma-delta modulator outputs provide a unitary-weighted word used to switch certain unit capacitors that comprise part of a delay modulator to produce a time-varying delay having a time-averaged value that directly corresponds to a binary value appearing on a plurality of phase accumulator outputs.
    Type: Grant
    Filed: November 6, 2008
    Date of Patent: November 22, 2011
    Assignee: Nokia Corporation
    Inventors: Saska Lindfors, Kari Stadius, Liangge Xu, Tapio Rapinoja, Jussi Ryynanen, Risto H. S. Kaunisto, Aarno Parssinen
  • Patent number: 8040971
    Abstract: The present invention is related to a digital circuit for use in a mixed-signal circuit.
    Type: Grant
    Filed: May 5, 2008
    Date of Patent: October 18, 2011
    Assignee: Agilent Technologies, Inc.
    Inventor: Frank Van De Sande
  • Patent number: 8013641
    Abstract: There is provided a digital lock detector and a frequency synthesizer using the same. The digital lock detector includes a comparator unit receiving a plurality of control bits, and generating a bit signal to notice a lock condition of the plurality of control bits; a delay cell block generating a plurality of delay signals based on the bit signal, and outputting a clock signal by combining the bit signal and the plurality of delay signals; and a detection unit detecting a shift time of the clock signal, and generating a lock indication signal according to the detection result.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: September 6, 2011
    Assignee: Electronics and Telecommunications Resarch Instittute
    Inventors: Ja Yol Lee, Seong Do Kim, Mun Yang Park, Cheon Soo Kim, Hyun Kyu Yu
  • Patent number: 7999578
    Abstract: Provided is a waveform generating apparatus that generates a signal having an arbitrary waveform, comprising a waveform memory that stores a plurality of pieces of waveform data that each include a sequence of signal values; a filtering section that (i) reads from the waveform memory a piece of waveform data serving as a basis for a waveform to be generated, from among the plurality of pieces of waveform data, (ii) performs a conversion by filtering the read piece of waveform data to obtain a piece of converted waveform data, and (iii) writes to the waveform memory the piece of converted waveform data; and a waveform output section that reads the piece of converted waveform data from the waveform memory and outputs a signal having a waveform corresponding to the sequence of signal values of the read piece of converted waveform data.
    Type: Grant
    Filed: November 9, 2009
    Date of Patent: August 16, 2011
    Assignee: Advantest Corporation
    Inventors: Takeshi Takahashi, Masayuki Tomita
  • Patent number: 7990186
    Abstract: A circuit for signal conditioning including a first stage with a digital/analog converter, a second stage with an I/Q-modulator, and at least one third stage with a mixer. Instead of a multiplicity of independent oscillators, a shared oscillator is provided for the first, second, and third stages, from an output signal of which a respective oscillator signal and clock-pulse signal for each stage of the first, second, and third stages is derived. The oscillator signal and respective clock-pulse signal of the oscillator are supplied via a frequency divider to at least one stage of the first, second, and third stages, or the oscillator signal of the oscillator is supplied via a frequency multiplier to at least one stage. Also, the oscillator signal of the oscillator is supplied as a reference signal to a frequency synthesizer of at least one stage of the first, second, and third stages.
    Type: Grant
    Filed: November 6, 2006
    Date of Patent: August 2, 2011
    Assignee: Rohde & Schwarz GmbH & Co. KG
    Inventors: Martin Roth, Mattias Jelen, Gottfried Holzmann, Albert Moser, Martin Oetjen
  • Publication number: 20110151804
    Abstract: A semiconductor device comprises synthesized frequency generation logic arranged to receive a reference signal, and to provide an output frequency signal. The synthesized frequency generation logic comprises divider logic arranged to receive the reference signal and to generate a divided signal comprising a frequency with a period equal to N times that of the reference signal. The synthesized frequency generation logic is further arranged to generate the synthesized frequency signal comprising a frequency with a period equal to 1/M that of the divided signal. The synthesized frequency generation logic comprises or is operably coupled to decision logic module and comprises or is operably coupled to a switching logic module such that the decision logic module is arranged to determine whether a near-integer spur arises in using the synthesized frequency signal, and configures the switching logic module to select the synthesized frequency signal in response thereto.
    Type: Application
    Filed: August 26, 2008
    Publication date: June 23, 2011
    Applicant: Freescale Semiconductor ,Inc.
    Inventors: Norman Beamish, Niall Kearney, Aidan Murphy
  • Patent number: 7956658
    Abstract: There is provided a digital lock detector and a frequency synthesizer using the same. The digital lock detector includes a comparator unit receiving a plurality of control bits, and generating a bit signal to notice a lock condition of the plurality of control bits; a delay cell block generating a plurality of delay signals based on the bit signal, and outputting a clock signal by combining the bit signal and the plurality of delay signals; and a detection unit detecting a shift time of the clock signal, and generating a lock indication signal according to the detection result.
    Type: Grant
    Filed: October 28, 2009
    Date of Patent: June 7, 2011
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Ja Yol Lee, Seong Do Kim, Mun Yang Park, Cheon Soo Kim, Hyun Kyu Yu
  • Patent number: 7948274
    Abstract: A method includes generating a plurality of reference phases of a reference signal and selecting a sub-phase from each of the plurality of reference phases to form a set of selected sub-phases. In the method selecting operates in response to synchronized outputs of a multi-phase phase accumulator that operates synchronously in accordance with one of the sub-phases of the set of sub-phases, and where the outputs of the multi-phase phase accumulator may be synchronized using at least one additional sub-phase.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: May 24, 2011
    Assignee: Nokia Corporation
    Inventors: Tapio Rapinoja, Liangge Xu
  • Publication number: 20110095791
    Abstract: Techniques for synthesizing a signal having a desired frequency from an oscillation signal. In an aspect, a reference signal having a known frequency may be periodically used to determine a ratio between the desired frequency and the frequency of the oscillation signal. The oscillation signal may be decimated by the ratio to generate a synthesized signal having approximately the desired frequency. In an aspect, the decimation may be performed by generating a pulse in response to the output of an accumulator that accumulates in steps of the ratio. To save power, the oscillation signal may be derived from a low-power oscillator, while the reference signal may be turned on only during periodic calibration. Further aspects for improving the frequency accuracy of the synthesized signal are disclosed.
    Type: Application
    Filed: October 27, 2009
    Publication date: April 28, 2011
    Applicant: QUALCOMM Incorporated
    Inventors: Daniel Filipovic, Hongbo Yan
  • Patent number: 7928881
    Abstract: The present invention relates to a direct digital frequency synthesizer using a variable sine wave-weighted digital to analog converter with improved size and efficiency and a synthesizing method thereof. The direct digital frequency synthesizer and the synthesizing method thereof are capable of simplifying a configuration for matching output data of a phase accumulator to sine wave amplitude without increase in complexity of a DAC by applying a nonlinear DAC for directly generating a current corresponding to base points with sine weights and a variable sine wave-weighted DAC for generating fine currents to be combined with variable weights based on the base points. Accordingly, it is possible to provide a high quality output, reduce a size and power consumption, and increase a speed.
    Type: Grant
    Filed: December 27, 2009
    Date of Patent: April 19, 2011
    Assignees: Chung-Ang University Industry—Academy Cooperation Foundation, ZARAMTECHNOLOGY Co. Ltd.
    Inventors: Kwang-Hyun Baek, Hong Chang Yeoh, Jae-Hun Jung, Yun-Hwan Jung, Joon Hyun Baek
  • Patent number: 7928780
    Abstract: A phase-locked loop circuit comprises a phase error detector for receiving a multi-phase reference signal and a synchronized phase signal of the phase-locked-loop circuit, and for performing a rotational transformation to convert the multi-phase reference signal into two-phase quantities at a synchronous rotation d-q reference frame. A monotonic transfer module receives the two-phase quantities, and generates a monotonic phase error signal which is monotonic when a phase difference between the multi-phase reference signal and the synchronized phase signal ranges from ?180 degrees to 180 degrees. A regulator receives the monotonic phase error signal, and generates a synchronized rotation frequency. An integrator receives the synchronized rotation frequency, and generates the synchronized phase signal.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: April 19, 2011
    Assignee: General Electric Company
    Inventors: Xiaoming Yuan, Zhuohui Tan, Robert William Delmerico, Haiqing Weng, Robert Allen Seymour
  • Patent number: 7928773
    Abstract: Generation of multiple clocks having a synchronized phase relationship may reduce the size, complexity, power consumption, jitter and cost of circuitry while improving its functionality, performance, reliability and fault coverage. A multiple frequency clock generator may comprise an independent digital control oscillator (DCO) for generating a first clock and dependent DCOs for generating additional clocks that align at a common multiple frequency with the first clock with or without adjustment thereof. The independent and dependent DCOs may generate the first and additional clocks from a delay lock loop (DLL) by selecting a sequence of tap select signals. Tap select signals may be adjusted to maintain a desired phase and/or frequency of the first and additional clocks. Dependent DCOs may generate sequences of tap select signals based on the sequence of tap select signals generated by the independent DCO to incorporate adjustments, e.g., PLL error corrections.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: April 19, 2011
    Assignee: Integrated Device Technology, Inc
    Inventors: Yi Li, Ji Fu Chi
  • Patent number: 7920002
    Abstract: A high-level period of each of n first pulse signals partially or wholly overlaps a period during which all of n second pulse signals are at the low level. A high-level period of each of the n second pulse signals partially or wholly overlaps a period during which all of the n first pulse signals are at the low level. Each of n first drive transistors includes a source connected to a ground node, a drain connected to a first node, and a gate receiving a corresponding one of the first pulse signals. Each of n second drive transistors includes a source connected to the ground node, a drain connected to a second node, and a gate receiving a corresponding one of the second pulse signals. A current mirror circuit allows a current corresponding to a current flowing through the second node to flow through the first node.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: April 5, 2011
    Assignee: Panasonic Corporation
    Inventors: Shiro Sakiyama, Yusuke Tokunaga, Shiro Dosho, Akinori Matsumoto, Takashi Morie, Kazuaki Sogawa, Yukihiro Sasagawa, Masaya Sumita
  • Publication number: 20110074469
    Abstract: A method includes generating a plurality of reference phases of a reference signal and selecting a sub-phase from each of the plurality of reference phases to form a set of selected sub-phases. In the method selecting operates in response to synchronized outputs of a multi-phase phase accumulator that operates synchronously in accordance with one of the sub-phases of the set of sub-phases, and where the outputs of the multi-phase phase accumulator may be synchronized using at least one additional sub-phase.
    Type: Application
    Filed: September 30, 2009
    Publication date: March 31, 2011
    Inventors: Tapio Rapinoja, Liangge Xu
  • Patent number: 7911242
    Abstract: There is provided a signal generating apparatus for generating an output signal corresponding to pattern data supplied thereto. The signal generating apparatus includes a timing generating section that generates a periodic signal, a shift register section including a plurality of flip-flops in a cascade arrangement through which each piece of data of the pattern data is propagated sequentially in response to the periodic signal, a waveform generating section that generates the output signal whose value varies in accordance with a cycle of the periodic signal, based on data values output from the plurality of flip-flops, and an analog circuit that enhances a predetermined frequency component in a waveform of the output signal generated by the waveform generating section.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: March 22, 2011
    Assignee: Advantest Corporation
    Inventors: Daisuke Watanabe, Toshiyuki Okayasu
  • Patent number: 7898345
    Abstract: A digital frequency synthesizer can be implemented with single source design, a multiplexer design, a fractional divider design, or a frequency multiplier and frequency divider design. Implementations can utilize a controller dithering circuit or a delta-sigma modulator. The frequency synthesizer can be implemented in a CMOS structure and can utilize a clean up phase locked loop (PLL).
    Type: Grant
    Filed: December 12, 2008
    Date of Patent: March 1, 2011
    Assignee: Orca Systems, Inc.
    Inventor: Kartik M. Sridharan
  • Patent number: 7888978
    Abstract: A frequency synthesizer includes first and second frequency dividers for receiving and frequency-dividing a signal generated by a voltage-controlled oscillator, a frequency mixer for mixing output signals of the first and second frequency dividers, and a third frequency divider for receiving and frequency-dividing a signal having one frequency of two frequencies that are output by the frequency mixer. The first, second third and frequency dividers and the frequency mixer are provided in a feedback loop within a PLL circuit between the voltage-controlled oscillator and the phase comparator. The phase comparator has a first input terminal to which a signal to which a signal that is output by the third frequency divider is input and a second input terminal to which a reference clock signal that is output by a reference signal generator is input. A loop filter supplies the voltage-controlled oscillator with a voltage that is based upon result of the phase comparison by a phase comparator.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: February 15, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Hidehiko Kuroda
  • Publication number: 20110006811
    Abstract: A frequency synthesizer for a time base generator of a level measuring device which works according to the radar principle, with at least one first output for output of a first frequency signal, with at least one second output for output of a second frequency signal, and with a reference oscillator for producing a reference frequency signal, the first frequency signal and the second frequency signal having a small difference frequency relative to one another, the first frequency signal being producible by interaction of the reference oscillator with a direct digital synthesizer. The first frequency signal and second frequency signal can be generated with especially low noise by the second frequency signal being derived from the reference oscillator without interconnection of a direct digital synthesizer and the direct digital synthesizer being operated such that only a noise spectrum is produced which is at least partially minimized.
    Type: Application
    Filed: July 9, 2010
    Publication date: January 13, 2011
    Applicant: KROHNE MESSTECHNIK GMBH
    Inventor: Michael GERDING
  • Publication number: 20100327916
    Abstract: A method for reducing noise in a frequency synthesizer includes selecting a design variable k, calibrating a feedback time delay (Td), such that Td=kTVCO, where TVCO is the period of the synthesizer output signal. The method further includes estimating an instantaneous quantization error to a number of bits equal to q, defining a reference bias current of Icp/(k2q), where Icp is a charge pump current signal, and applying the estimated instantaneous quantization error to a current array to produce a down modification signal (?I). The current array is biased by the reference bias current. The down modification signal (?I) is summed with the charge pump current signal Icp to modulate a down current portion of the charge pump current signal Icp.
    Type: Application
    Filed: June 25, 2009
    Publication date: December 30, 2010
    Applicant: QUALCOMM Incorporated
    Inventors: Mahmoud R. Ahmadi, Jafar Savoj
  • Patent number: 7847616
    Abstract: A balanced input inverter circuit includes a first P-type MOS transistor including a gate terminal connected to an input, a source terminal connected to a first power source potential, and a drain terminal connected to an output, a first N-type MOS transistor including a gate terminal connected to the input, a drain terminal connected to the output, and a source terminal connected to a second power source potential, a first inverter circuit including an input terminal connected to an inverted input, and an output terminal connected to a back gate terminal of the first N-type MOS transistor, a first diode connected between the first power source potential and a first power source terminal of the first inverter circuit, a second inverter circuit including an input terminal connected to the inverted input, and an output terminal connected to a back gate terminal of the first P-type MOS transistor, and a second diode connected between the second power source potential and a second power source terminal of the sec
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: December 7, 2010
    Assignee: Fujitsu Limited
    Inventor: Yasuhiro Hashimoto
  • Patent number: 7847602
    Abstract: A digitally controlled frequency generator includes an oscillator module for generating a first clock signal having an oscillating frequency, a programmable control module operable so as to generate a control signal corresponding to a desired frequency, and a direct digital frequency synthesizer coupled to the oscillator module and the programmable control module for receiving the first clock signal and the control signal therefrom, and for generating a second clock signal having the desired frequency based on the first clock signal from the oscillator module and the control signal from the programmable control module.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: December 7, 2010
    Assignee: Taitien Electronics Co., Ltd.
    Inventor: Todd S. Tignor
  • Patent number: 7825702
    Abstract: To provide a synthesizer module that can be used not only in a destination area but also in the whole world and that can be readily set in output frequency. In the synthesizer module, a calculation formula table of a nonvolatile memory stores a plurality of frequency modes and the calculation formula of carrier frequencies corresponding to those frequency modes, and further stores, in its certain area, a frequency mode set during an initial setting of the device. A CPU, when receiving a channel number from a rotary SW during a frequency setting, calculates, based on a calculation formula corresponding to a currently set frequency mode, a carrier frequency corresponding to the channel number. This carrier frequency is set to a CONT of a PLL part.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: November 2, 2010
    Assignee: Nihon Dempa Kogyo Co., Ltd
    Inventor: Tsuyoshi Shiobara
  • Publication number: 20100271072
    Abstract: There is provided a digital lock detector and a frequency synthesizer using the same. The digital lock detector includes a comparator unit receiving a plurality of control bits, and generating a bit signal to notice a lock condition of the plurality of control bits; a delay cell block generating a plurality of delay signals based on the bit signal, and outputting a clock signal by combining the bit signal and the plurality of delay signals; and a detection unit detecting a shift time of the clock signal, and generating a lock indication signal according to the detection result.
    Type: Application
    Filed: October 28, 2009
    Publication date: October 28, 2010
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Ja Yol LEE, Seong Do Kim, Mun Yang Park, Cheon Soo Kim, Hyun Kyu Yu
  • Patent number: 7808283
    Abstract: An apparatus for clock generation is presented. In one embodiment, the apparatus comprises a phase interpolator that generates an output with a phase value within reference phases associated with two input clocks. Logic units are coupled to determine a number of phase settings for the phase interpolator. A divider is coupled to the phase interpolator to generate an output clock based on a modifiable divider setting.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: October 5, 2010
    Assignee: Intel Corporation
    Inventors: Praveen Dani, Robert Fulton, Andrew M. Volk, Surya Musunuri
  • Patent number: 7804927
    Abstract: A digital waveform synthesiser (1) is implemented as a single chip integrated circuit on a single chip (2) and comprises a direct digital synthesiser (10) which produces a synthesised output signal waveform on an output terminal (4) which is substantially phase and frequency locked to the phase and frequency of an externally generated input signal applied to an input terminal (5).
    Type: Grant
    Filed: December 15, 2005
    Date of Patent: September 28, 2010
    Assignee: Analog Devices, Inc.
    Inventor: Hans Juergen Tucholski
  • Patent number: 7782091
    Abstract: Some embodiments include an output driver having a first circuit to provide a plurality of first parallel circuit paths between an output node and a first supply node, a second circuit to provide a plurality of second parallel circuit paths between the output node and a second supply node, and a control circuit responsive to a voltage at the output node to vary a value of a current in the plurality of first parallel circuit paths and a value of a second current in the plurality of second parallel circuit paths to control a signal shape of the output signal. Additional apparatus, systems, and methods are disclosed.
    Type: Grant
    Filed: November 14, 2006
    Date of Patent: August 24, 2010
    Assignee: Aptina Imaging Corporation
    Inventor: Yan Lee
  • Patent number: 7772893
    Abstract: A digital frequency synthesizer and a method thereof are provided. In the digital frequency synthesizer, a plurality of multiphase signals (MPSs) is generated by a phase delay locked loop array, and a transition reference values is generated by a programmable transition value generator. An operation result obtained according to an input signal and an accumulated value is compared with the transition reference values to generate a phase selection control signal. A phase signal is selected among the MPSs according to the phase selection control signal. After that, a sampling control is performed to the selected phase signal to generate a synthetic signal. The digital frequency synthesizer and the method thereof are flexible and are easy to produce tiny analytic phase, thus, not only fine tuning phases is added but also the resolution of the synthetic signal is improved.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: August 10, 2010
    Assignee: Novatek Microelectronics Corp.
    Inventors: Hsiang-Chih Chen, Don-Chen Hsin
  • Patent number: RE41981
    Abstract: A waveform generator includes a plurality of delay elements such as in a delay line circuit of a free-running oscillator, phase locked loop (PLL) circuit or delay locked loop (DLL) circuit, an algebra module, a switching module and an output module. The oscillator includes a plurality of delay elements and a plurality of taps disposed between the delay elements, with each tap providing a uniquely phased, oscillating transition signal. The algebra module includes an algebra data input port, a clock input port and an algebra data output port. The algebra module generates a signal at the algebra data output port indicating a first rising edge of the arbitrary waveform in response to a signal received at the algebra data input port. The switching module includes a switch input port in electrical communication with the algebra data output port, a plurality of switch tap input ports in electrical communication oscillator taps and switch output port.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: December 7, 2010
    Assignee: Altera Corporation
    Inventors: Adam L. Carley, Daniel J. Allen