With Sampling Patents (Class 327/9)
  • Patent number: 11043263
    Abstract: A device includes an amplifier, a plurality of selector circuitries, and a plurality of fabric dies. The amplifier is configured to output a supply power signal. Each selector circuitry of the plurality of selector circuitries receives the supply power signal from the amplifier. Each fabric die of the plurality of fabric dies has a corresponding selector circuitry of the plurality of selector circuitries. Each selector circuitry corresponding to a die of the plurality of dies is configured to provide the supply power signal received from the amplifier to its corresponding die responsive to a selection signal being asserted. Selector circuitries of the plurality of selector circuitries corresponding to unselected dies of the plurality of dies pull address supply power for the unselected dies to an input other than the supply power signal of the selector circuitries corresponding to the unselected die.
    Type: Grant
    Filed: November 14, 2019
    Date of Patent: June 22, 2021
    Assignee: XILINX, INC.
    Inventors: Sree R K C Saraswatula, Abhimanyu Kumar, Santosh Yachareni, Shidong Zhou
  • Patent number: 11032055
    Abstract: A clock data recovery circuit including a phase blender, a phase detector, a data sampling position detector and a data selector is provided. The phase blender generates a third clock signal and a fourth clock signal according to a first clock signal and a second clock signal. The phase detector samples a data signal according to the first and second clock signals to generate first sampled data, second sampled data and a phase state signal. The data sampling position detector samples the data signal according to the third and fourth clock signals to generate third sampled data, fourth sampled data and a control signal. The data selector generates output data according to the control signal and the phase state signal.
    Type: Grant
    Filed: August 31, 2020
    Date of Patent: June 8, 2021
    Assignee: Faraday Technology Corp.
    Inventor: Yu-Hsin Tseng
  • Patent number: 9166577
    Abstract: A clock modulator can include two configurable delay units and can receive a baseband signal and a clock signal. The two configurable delay units can generate two delayed clock signals, each with different delay amounts. The delay amounts can be based on the baseband signal. The delayed clock signals can be combined to generate a modulated clock signal. A quadrature modulated clock signal can be generated when a first clock modulator receives a first baseband signal and a first clock signal and a second clock modulator receives a second baseband signal and a second clock signal. The first clock signal can be a ninety-degree phase shifted version of the second clock signal. The modulated clock signal from the first clock modulator can be combined with the modulated clock signal from the second clock modulator to generate the quadrature modulated clock signal.
    Type: Grant
    Filed: January 29, 2014
    Date of Patent: October 20, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Niranjan Anand Talwalkar, Sanjay Kasturia
  • Publication number: 20150131706
    Abstract: There is proposed a method and system for determining a phase-alignment between first and second clock signals of differing frequency. The method comprise: sampling a value of the first clock signal at instants defined by an edge of the second clock signal; defining a sequence of the sampled values of the first clock signal, wherein consecutive sample values in the sequence are separated by N cycles of the second clock signal, and wherein N is an integer greater than 1; and detecting the occurrence of a predetermined pattern of values in the defined sequence.
    Type: Application
    Filed: November 6, 2014
    Publication date: May 14, 2015
    Inventor: Andrew Gough
  • Publication number: 20150116002
    Abstract: A method for comparing phases between first and second clock signal includes the first clock signals to a first precharge circuit coupled between a first node and a first terminal to which a first voltage is applied. The first clock signal is supplied to a second precharge circuit coupled between a second node and the first terminal. The second clock signal is supplied to a first discharge circuit coupled between the first node and a second terminal to which a second voltage different from the first voltage is applied. The second clock signal is supplied to a second discharge circuit coupled between the second node and the second terminal.
    Type: Application
    Filed: November 14, 2014
    Publication date: April 30, 2015
    Inventors: Koji KUROKI, Ryuji Takishita
  • Patent number: 8957705
    Abstract: Described is an apparatus comprising: a first phase frequency detector (PFD) to determine a coarse phase difference between a first clock signal and a second clock signal, the first PFD to generate a first output indicating the coarse phase difference; and a second PFD, coupled to the first PFD, to determine a fine phase difference between the first clock signal and the second clock signal, the second PFD to generate a second output indicating the fine phase difference.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: February 17, 2015
    Assignee: Intel Corporation
    Inventors: Wenyan Jia, Shenggao Li, Fulvio Spagna
  • Patent number: 8947167
    Abstract: Embodiments provide a reference-less frequency detector that overcomes the “dead zone” problem of conventional circuits. In particular, the frequency detector is able to accurately resolve the polarity of the frequency difference between the VCO clock signal and the data signal, irrespective of the magnitude of the frequency difference and the presence of VCO clock jitter and/or ISI on the data signal.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: February 3, 2015
    Assignee: Broadcom Corporation
    Inventors: Mahyar Kargar, Siavash Fallahi, Namik Kocaman, Mehdi Khanpour, Afshin Momtaz
  • Patent number: 8896348
    Abstract: In a semiconductor device, there are provided first to third pairs of nMOS transistors between a GND and two sense nodes and first to third pairs of pMOS transistors between the two sense nodes and the power supply. A first internal clock signal and its inverted signal are supplied to gates of the first pair of nMOS transistors and the second pair of nMOS transistors, respectively. Complementary external clock signals are supplied to the gates of the third pairs of nMOS transistors and the third pairs of pMOS transistors. An inverted version of a second internal clock signal and the second internal clock signal are supplied to gates of the first and second pairs of pMOS transistors. The two sense nodes are connected to inputs of a differential amplifier. The output of the differential amplifier is latched by a latch circuit. An equalizing circuit precharges/equalizes the two sense nodes.
    Type: Grant
    Filed: November 22, 2013
    Date of Patent: November 25, 2014
    Assignee: PS4 Luxco S.a.r.l.
    Inventors: Koji Kuroki, Ryuji Takishita
  • Patent number: 8866517
    Abstract: A system comprising an interface configured to condition a signal associated with a power system; a clock module configured to generate a synchronization signal; and a module coupled to the interface and configured to digitize the signal from the interface; filter the digitized signal; and generate a time-shifted, digitized signal in response to the filtering and the synchronization signal.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: October 21, 2014
    Assignee: Mehta Tech, Inc.
    Inventor: Richard T. Dickens
  • Patent number: 8866511
    Abstract: A method and a system are provided for clock phase detection. A first set of delayed versions of a first clock signal is generated and a second set of delayed versions of a second clock signal is generated. The second set of delayed versions of the second clock signal is sampled using the first set of delayed versions of the first clock signal to produce an array of clock samples in a domain corresponding to the first clock signal. At least one edge indication is located within the array of clock samples.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: October 21, 2014
    Assignee: NVIDIA Corporation
    Inventor: William J. Dally
  • Publication number: 20140285238
    Abstract: A PLL circuit includes a divider configured to generate a divided signal having a cycle of T/M (where M is an integer greater than or equal to two) by dividing an oscillation signal; a phase comparator configured to generate a phase comparison result by calculating an exclusive logical OR of M reference signals and the divided signal, the M reference signals having the cycle of T and respective time intervals shifted sequentially by T/2M; a loop filter configured to generate a voltage signal using the phase comparison result as input; and a voltage-controlled oscillator configured to generate the oscillation signal by oscillating at a frequency depending on the voltage signal.
    Type: Application
    Filed: March 4, 2014
    Publication date: September 25, 2014
    Applicant: FUJITSU LIMITED
    Inventor: Hiroshi Matsumura
  • Patent number: 8823564
    Abstract: A sampling circuit includes a continuous section which is a circuit for transmitting a continuous signal; a digital section for transmitting a signal which is sampled and quantized; and a sampling and holding section for transmitting a signal which is sampled but not quantized between the continuous section and the digital section. The sampling and holding section includes capacitors for accumulating charge generated by an input signal and plural switches for accumulating the charge in the capacitors. The plural switches receive plural clock signals having different operation timings and perform an ON/OFF operation in response to the supplied clock signals.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: September 2, 2014
    Assignee: Asahi Kasei Microdevices Corporation
    Inventors: Junya Nakanishi, Yutaka Nakanishi
  • Publication number: 20140139266
    Abstract: A method for calibrating a clock and data recovery circuit may include configuring a phase detector as a bang-bang phase detector. The bang-bang phase detector may be used to determine a phase difference between a sampling clock provided by an interpolator and a calibration signal. The phase detector may also be configured as a linear phase detector. While using the linear phase detector, a linear phase detector parameter may be adjusted such that the phase difference between the calibration signal and the sampling clock is zero, while keeping the phase of the sampling clock fixed.
    Type: Application
    Filed: November 16, 2012
    Publication date: May 22, 2014
    Inventors: John KENNEY, Jeremy Z. WALKER
  • Patent number: 8610476
    Abstract: One embodiment relates to a lock detection circuit. The lock detection circuit includes at least a dither detection circuit and a lock filter. The dither detection circuit maintains a bi-directional count based on early and late signals from a sampler circuit and asserts a non-lock signal if the bi-directional count reaches either a positive non-lock assertion threshold or a negative non-lock assertion threshold. The lock filter increments a lock filter count for each sample and outputs a lock-initiated signal when the lock filter count reaches a pre-set maximum value. The maximum value of the lock filter count is greater than the non-lock assertion thresholds. Other embodiments and features are also disclosed.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: December 17, 2013
    Assignee: Altera Corporation
    Inventor: Lip Kai Soh
  • Patent number: 8604835
    Abstract: In a semiconductor device, there are provided first to third pairs of nMOS transistors between a GND and two sense nodes and first to third pairs of pMOS transistors between the two sense nodes and the power supply. A first internal clock signal and its inverted signal are supplied to gates of the first pair of nMOS transistors and the second pair of nMOS transistors, respectively. Complementary external clock signals are supplied to the gates of the third pairs of nMOS transistors and the third pairs of pMOS transistors. An inverted version of a second internal clock signal and the second internal clock signal are supplied to gates of the first and second pairs of pMOS transistors. The two sense nodes are connected to inputs of a differential amplifier. The output of the differential amplifier is latched by a latch circuit. Also provided an equalizing circuit precharging/equalizing the two sense nodes (FIG. 2).
    Type: Grant
    Filed: August 30, 2010
    Date of Patent: December 10, 2013
    Assignee: Elpida Memory, Inc.
    Inventors: Koji Kuroki, Ryuji Takishita
  • Patent number: 8502609
    Abstract: Embodiments provide a reference-less frequency detector that overcomes the “dead zone” problem of conventional circuits. In particular, the frequency detector is able to accurately resolve the polarity of the frequency difference between the VCO clock signal and the data signal, irrespective of the magnitude of the frequency difference and the presence of VCO clock jitter and/or ISI on the data signal.
    Type: Grant
    Filed: June 10, 2011
    Date of Patent: August 6, 2013
    Assignee: Broadcom Corporation
    Inventors: Mahyar Kargar, Siavash Fallahi, Namik Kocaman, Mehdi Khanpour, Afshin Momtaz
  • Patent number: 8497708
    Abstract: A phase frequency detector detects the difference between the edges of a fractional-rate recovered clock signal and the edges within a serial data bit stream, where the edges within the serial data bit stream correspond with the edges of a full-rate clock signal that was used to clock the serial data bit stream.
    Type: Grant
    Filed: May 6, 2011
    Date of Patent: July 30, 2013
    Assignee: National Semiconductor Corporation
    Inventors: Tonmoy Shankar Mukherjee, Arlo James Aude
  • Patent number: 8302054
    Abstract: Methods and apparatuses for retiming of multirate system for clock period minimization with a polynomial time without sub-optimality. In an embodiment, a normalized factor vector for the nodes of multirate graph is introduced, allowing the formulation of the multirate graph retiming constraints to a form similar to a single rate graph. In an aspect, the retiming constraints are formulated to allowed the usage of linear programming methodology instead of integer linear programming, thus significantly reducing the complexity of the solving algorithm. The present methodology also uses multirate constraints, avoiding unfolding to single rate equivalent, thus avoiding graph size increase. In a preferred embodiment, the parameters of the multirate system are normalized to the normalized factor vector, providing efficient algorithm in term of computational time and memory usage, without any sub-optimality.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: October 30, 2012
    Assignee: Synopsys, Inc.
    Inventors: Mustafa Ispir, Levent Oktem
  • Publication number: 20120218001
    Abstract: A phase detection circuit can include two phase detectors that each generate a non-zero output in response to input signals being aligned in phase. The input signals are based on two periodic signals. The phase detection circuit subtracts the output signal of one phase detector from the output signal of the other phase detector to generate a signal having a zero value when the periodic signals are in phase. Alternatively, a phase detector generates a phase comparison signal indicative of a phase difference between periodic signals. The phase comparison signal has a non-zero value in response to input signals to the phase detector being aligned in phase. The input signals are based on the periodic signals. An output circuit receives the phase comparison signal and generates an output having a zero value in response to the periodic signals being aligned in phase.
    Type: Application
    Filed: October 31, 2010
    Publication date: August 30, 2012
    Applicant: RAMBUS INC.
    Inventors: Brian Leibowitz, Hae-Chang Lee, Farshid Aryanfar, Kun-Yung Chang, Jie Shen
  • Patent number: 8207770
    Abstract: An apparatus may comprise a time-to-digital circuit architecture. Other embodiments are described and claimed.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: June 26, 2012
    Assignee: Intel Corporation
    Inventors: Ashoke Ravi, Pin-En Su, Paolo Madoglio, Georgios Palaskas
  • Patent number: 8111106
    Abstract: Some embodiments of the present invention may include a DPLL circuit comprising a firmware. The firmware may comprise a re-sampled NCO phase detector capable of receiving a reference clock timing signal and a VCXO clock timing signal. The re-sampled NCO phase detector may comprise a resampler capable of receiving phase output and the VCXO clock timing signal and resampling the phase output; and a subtractor capable of receiving the resampled phase output and subtracting the resampled phase output from a calculated mean value of the phase output. The firmware may further comprise a frequency detector capable of receiving the reference clock timing signal and the VCXO clock timing signal; and a multiplexer capable of switching between the re-sampled NCO phase detector and the frequency detector dependent upon a frequency lock status.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: February 7, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Leo Montreuil, Larry Stephen McKinney, Jiening Ao, Joel Paul Jenkins
  • Publication number: 20110095786
    Abstract: In a phase comparator used for a sync clock extraction circuit for extracting a clock synchronizing with reproduction data, a zero cross detection section 701, receiving the reproduction data, outputs a rising cross detection signal, a falling cross detection signal and three phase error candidates that are three consecutive samples. Rising and falling reference value hold sections 703 and 704 respectively output rising and falling reference values. When receiving the rising or falling cross detection signal, a phase error calculation section 702 outputs a sample the difference of which from the rising or falling reference value is minimum in absolute value, out of the three samples including a zero cross sample, as a phase error. The phase error is held in the rising or falling reference value hold section 703 or 704 as the rising or falling reference value for the next phase error calculation.
    Type: Application
    Filed: September 22, 2008
    Publication date: April 28, 2011
    Inventors: Akira Yamamoto, Yoshinori Shirakawa, Kouji Okamoto, Hiroki Mouri
  • Patent number: 7795926
    Abstract: A phase detector, including a sampling device, a comparing device, and an output device, is provided. The sampling device samples a data signal according to a plurality of clock signals, so as to provide a plurality of corresponding sampling values. The clock signals have the same frequency and different phases. The comparing device is coupled to the sampling device, and provides a plurality of corresponding comparison values according to comparison results of each of the sampling values comparing with the next sampling value. The output device is coupled to the comparing device, and outputs two of the comparison values in response to edges of the clock signals. The two outputted comparison values serve as a first instruction signal and a second instruction signal respectively. The first and the second instruction signals are referred to in controlling the frequency and the phase of the foregoing clock signals.
    Type: Grant
    Filed: April 11, 2008
    Date of Patent: September 14, 2010
    Assignee: Faraday Technology Corp.
    Inventors: Yu-Hsin Tseng, Wen-Ching Hsiung
  • Patent number: 7764759
    Abstract: Linear sample and hold phase detectors are disclosed herein. An example phase detector is coupled to an input data signal and a recovered clock signal and includes a linear phase difference generator circuit and a sample and hold circuit. The linear phase difference generator includes a first input coupled to the input data signal and a second input coupled to the recovered clock signal and outputs a first phase difference signal indicative of the phase difference between the input data signal and the recovered clock signal relative to a rising edge of the input data signal and a second phase difference signal indicative of the phase difference between the input data signal and the recovered clock signal relative to a falling edge of the input data signal.
    Type: Grant
    Filed: June 22, 2006
    Date of Patent: July 27, 2010
    Assignee: Gennum Corporation
    Inventors: Atul K. Gupta, Wesley C. d'Haene, Rajiv K. Shukla
  • Patent number: 7764088
    Abstract: A frequency detection circuit and a detection method thereof suitable for a clock data recovery (CDR) circuit are provided. The frequency detection circuit includes a phase detector, a first delayer, a frequency detector, and a logic circuit. The phase detector samples a data signal according to a first clock signal provided by the CDR circuit and provides a phase instruction signal according to the sampling. The first delayer delays the first clock signal to obtain a second clock signal. The frequency detector samples the data signal according to the second clock signal and provides a frequency instruction signal according to the sampling. The logic circuit generates a clock instruction signal according to the phase instruction signal and the frequency instruction signal. The CDR circuit adjusts the frequency of the first clock signal according to the status of the clock instruction signal.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: July 27, 2010
    Assignee: Faraday Technology Corp.
    Inventors: Kuan-Yu Chen, Wen-Ching Hsiung, Cheng-Tao Chang, Chia-Liang Lai
  • Patent number: 7755397
    Abstract: Methods and apparatus are provided for digital phase detection with improved frequency locking. A phase detector is disclosed for evaluating a phase difference between a clock signal and a reference signal. The disclosed phase detector samples the clock signal and the reference signal on positive edges of one or more of the clock signal and the reference signal, samples the clock signal and the reference signal on negative edges of one or more of the clock signal and the reference signal, and generates one or more error signals indicating a phase difference between the clock signal and the reference signal. A clock signal that is phase aligned with a reference signal can be generated by generating an error signal indicating a phase difference between the clock signal and the reference signal and applying the error signal to an oscillator to produce the clock signal.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: July 13, 2010
    Assignee: Agere Systems Inc.
    Inventor: Tony S. El-Kik
  • Patent number: 7692501
    Abstract: A stream of data may flow over a fiber or other medium without any accompanying clock signal. The receiving device may then be required to process this data synchronously. Embodiments describe clock and data recovery (CDR) circuits which may sample a data signal at a plurality of sampling points to partition a clock cycle into four phase regions P1, P2, P3, and P4 which may be represented on a phase plane being divided into four quadrants. A relative phase between a data signal transition edge and a clock phase may be represented by a phasor on the phase plane. The clock phase and frequency may be adjusted by determining the instantaneous location of the phasor and the direction of phasor rotation in the phase plane.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: April 6, 2010
    Inventors: Yu-Li Hsueh, Miaobin Gao, Chien-Chang Liu
  • Patent number: 7671671
    Abstract: A demodulation device (1) in semiconductor technology is disclosed. The device (1) is capable of demodulating an injected modulated current. The device (1) comprises an input node (IN1), a sampling stage (DG1, IG1, GS1, IG2, DG2) and at least two output nodes (D1, D2). The sampling stage DG1, IG1, GS1, IG2, DG2) comprises transfer means (GL, GM, GR) for transferring a modulated charge-current signal from the input node (IN1) to one of the output nodes (D1, D2) allocated to the respective time interval within the modulation period. The small size and the ability to reproduce the device (1) in standard semiconductor technologies make possible a cost-efficient integration of the device (1).
    Type: Grant
    Filed: October 5, 2006
    Date of Patent: March 2, 2010
    Assignee: MESA Imaging AG
    Inventors: Bernhard Buettgen, Michael Lehmann, Simon Neukom, Thierry Oggier, Felix Lustenberger
  • Publication number: 20090315878
    Abstract: In a synchronous reproduction signal processor, when a phase error between reproduction data and a clock is repeatedly detected such that a clock synchronized with a reproduction signal is generated based on the phase error, a filtering process unit (34) performs a filtering process which performs a weighed addition with respect to a phase error series prior to the current time from a phase error calculation unit (33) using, e.g., a FIR filter with a plurality of taps so as to generate a reference value under reduced influence of noise mixed in the phase error series by feedback correction. A cross detection unit (32) detects the timing with which the sampled reproduction data crosses the reference value generated by the filtering process unit (34). This allows effective use of the dynamic range of the feedbacked reference value without limiting it, and simultaneously achieves the enhancement of noise immunity.
    Type: Application
    Filed: July 8, 2008
    Publication date: December 24, 2009
    Inventors: Kouji Okamoto, Kouhei Nakata
  • Patent number: 7586335
    Abstract: The present invention concerns a digital phase detector (PD) and also a method for digital phase detection, as can in particular be used e.g. in a so-called phase locked loop (PLL). According to the invention a digital phase detection signal (PD_OUT) is obtained, which specifies the phasing of an input clock signal (PD_IN) with reference to a higher frequency sampling clock signal (CK). In order hereby to overcome the limitation of the phase resolution as a result of a limited performance capability, in particular limited speed of the electronic components of a sampling device (14), a new kind of concept is used, in which the sampling clock signal (CK) is not immediately used for sampling (14), but is subjected beforehand to a digitally adjustable phase displacement (12). There originates an “auxiliary sampling clock signal” (CK<1:8>). The sampling (14) delivers a first, more significant digital component (OUT1<9:0>) of the phase detection signal (PD_OUT).
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: September 8, 2009
    Assignee: National Semiconductor Germany AG
    Inventors: Heinz Werker, Christian Ebner
  • Publication number: 20090212824
    Abstract: A system for determining an optimal sampling phase is provided. The system includes a plurality of analog to digital converters, each receiving an analog signal and a clock phase signal and generating an output. A clock generator receives a reference clock and generates a plurality of clock phase signals. A sampling phase system receives the plurality of outputs of the analog to digital converters and generates an optimal sampling phase.
    Type: Application
    Filed: February 26, 2008
    Publication date: August 27, 2009
    Inventor: Costantino Pala
  • Publication number: 20090184735
    Abstract: An automatic phase detection circuit for generating an internal synchronization signal when two clock input signals achieve a certain phase relationship. No external reference signal is required. The logic state of one clock is sampled on the active edge of the other clock and stored in a shift register. The content of the shift register is compared to a pre-defined signature and a sync signal is generated when the content matches the pre-defined signature. A mask register may be used to define which bits of the shift register and pre-defined signature are compared.
    Type: Application
    Filed: January 23, 2008
    Publication date: July 23, 2009
    Applicant: Sun Microsystems, Inc.
    Inventors: Thomas Wicki, Bharat Daga
  • Patent number: 7501861
    Abstract: A phase-difference detecting method is for detecting phase difference between a first signal and a second signal of the same frequency. First, generate a detection signal. Next, sample the detection signal respectively according to the first signal and the second signal to obtain a first sample value and a second sample value. Then, determine whether a determination condition that the first and the second sample values are respectively equal to the previous first and second sample values is satisfied. When the determination condition is unsatisfied for the first time, record a delay time of the detection signal as a first time. When the determination condition is unsatisfied for the second time, record a delay time of the detection signal as a second time. Obtain the phase difference between the first signal and the second signal according to the first time and the second time.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: March 10, 2009
    Assignee: Prolific Technology Inc.
    Inventors: Ming-Hsien Yen, Hsin-Chuan Chen
  • Patent number: 7376201
    Abstract: A new system and method is developed for reducing the crest factor of a signal. The system includes a large signal extraction module for receiving the input signal and the magnitude of the input signal to extract a large signal greater than a predetermined threshold ?; a large signal transformation module for converting the extracted large signal to a monotonically increasing concave function; a large signal filtering module for filtering the large signal transformed by the large signal transformation module to pass a predetermined band of the large signal; a delay means for shifting the phase of the input signal; and a combiner means for combining the signal output from the large signal filtering module with the input signal whose phase has been shifted by the delay means to reduce the crest factor of the input signal.
    Type: Grant
    Filed: June 29, 2004
    Date of Patent: May 20, 2008
    Assignees: Danam Inc., Danam USA Inc.
    Inventor: Yongsub Kim
  • Publication number: 20080100280
    Abstract: The invention relates to electronic circuits for measuring, by synchronous detection, weak signals whose reference level is not well known and is subject to large fluctuations. A first correlated double sampling is performed between a time T1 situated just before the start of the measurement pulse and a time T2 situated just before the end of the measurement pulse; subsequently, a second correlated double sampling is performed between time T2 and a time T3 situated after the end of the measurement pulse. Finally, the difference between signal levels coming from the two measurements is taken, this difference being a representation of the signal value Vm considered with respect to a reference level that is intermediate between the reference levels at times T1 and T3.
    Type: Application
    Filed: April 20, 2005
    Publication date: May 1, 2008
    Inventors: Thierry Masson, Fabrice Salvi
  • Publication number: 20080048726
    Abstract: Signal-integrity measurement systems and methods utilizing unique time-base generation techniques for controlling the sampling of one or more signals under test. A time-base generator made in accordance with the present disclosure includes a phase filter and modulation circuitry that generates a rapidly varying phase signal as a function of the output of a sigma-delta modulator. The phase filter filters unwanted high-frequency phase components from the rapidly varying phase signal. The filtered signal is used to clock one or more samplers so as to create sampling instances of the signal(s) under test. The sampling instances are then analyze using any one or more of a variety of techniques suited to the type of signal(s) under test.
    Type: Application
    Filed: July 12, 2007
    Publication date: February 28, 2008
    Inventor: Mohamed M. Hafed
  • Patent number: 7325175
    Abstract: A system may adjust the times at which data is sampled by separate sampling mechanisms. Here, it may be desirable to ensure that one sampler samples data at substantially the same time as the other sampler. For example, output data from a high speed sampler that samples received data may be compared with an output of an analog to digital converter that samples the received data at a lower data rate. This difference or relative error may be accumulated over a period of time for given values of delay applied to the clock for the analog to digital converter. In this way, a delay value that minimizes the relative error may be selected as a desired delay value.
    Type: Grant
    Filed: May 4, 2005
    Date of Patent: January 29, 2008
    Assignee: Broadcom Corporation
    Inventor: Afshin Momtaz
  • Patent number: 7310397
    Abstract: In the data recovery circuit of the invention, a first group of sampling clock pulses is used for sampling approximately the central portions of the data bits in an incoming data stream to produce a first sampled data stream, while a second group of sampling clock pulses is used for sampling approximately the transition portions between every two adjacent data bits in the incoming data stream to produce a second sampled data stream. By detecting the resemblance of each bit in the second sampled data stream to the corresponding two adjacent bits in the first sampled data stream, a phase detection and correction circuit determines an early condition or a late condition for the phases of the sampling clocks and produces a signal to correct the phases of the sampling clocks by shifting the phases backwards or forwards. According to the invention, sampling clocks with lower frequencies can be used for sampling, and the phase error can be corrected to obtain the correct data recovery.
    Type: Grant
    Filed: November 3, 2003
    Date of Patent: December 18, 2007
    Assignee: MStar Semiconductor, Inc.
    Inventors: Sterling Smith, Sheng-Yao Liu, Huimin Tsai
  • Patent number: 7227919
    Abstract: A digital circuit and method for forming number streams for frequency and/or phase comparison of digital or digitized signals, referred to herein as clock signals, where typically one of the clock signals is a known clock signal and another of the clock signal is an unknown clock signal. The unknown clock signal may be derived, for example, from a communications signal. The rate of the unknown clock signal may exceed the rate of the known clock signal. In an exemplary embodiment, an “alias” value (e.g., an integer 1, 2, 3, etc.) is applied to the circuit as an indication of the expected frequency range of the unknown clock signal. The number stream is formed accordingly.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: June 5, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Brian Sander
  • Patent number: 7119582
    Abstract: A phase detector and phase detection method for a sync pulse generator operable in a clock synchronizer that effectuates data transfer between first circuitry disposed in a first clock domain and second circuitry disposed in a second clock domain. The first clock domain is operable with a first clock signal and the second clock domain is operable with a second clock signal. At least one first flip flop is operable to sample the first clock signal with a rising edge of the second clock signal and at least one second flip flop is operable to sample the first clock signal with a falling edge of the second clock signal. The sampling produces transitions indicative of the coincident rising edges between the first and second signals.
    Type: Grant
    Filed: July 23, 2004
    Date of Patent: October 10, 2006
    Assignee: Hewlett-Packard Development Company, LP.
    Inventor: Richard W. Adkisson
  • Patent number: 7034723
    Abstract: A data sampling apparatus includes plural stages of first variable delay elements for sequentially delaying a data signal by a first delay amount, plural stages of second variable delay elements for sequentially delaying a strobe signal by a second delay amount which is larger than the first delay amount, and a plurality of timing comparators for sampling a plurality of data signals delayed by the plural stages of first variable delay elements by the strobe signal delayed by the second variable delay element of the same stage, wherein the timing comparator includes a dynamic D-FF circuit for latching and outputting the data signal by its parasitic capacitance based on the strobe signal, a buffer for delaying the strobe signal, and a positive feed-back D-FF circuit for latching and outputting the output signal outputted by the dynamic D-FF circuit by its positive feed-back circuit based on the strobe signal delayed.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: April 25, 2006
    Assignee: Advantest Corporation
    Inventors: Masakatsu Suda, Satoshi Sudou, Toshiyuki Okayasu
  • Patent number: 7027545
    Abstract: The present invention, generally speaking, provides a digital circuit and method for forming number streams for frequency and/or phase comparison of digital or digitized signals, referred to herein as clock signals, where typically one of the clock signals is a known clock signal and another of the clock signal is an unknown clock signal. The unknown clock signal may be derived from a communications signal, for example. The rate of the unknown clock signal may exceed the rate of the known clock signal. In an exemplary embodiment, an “alias” value (e.g., an integer 1, 2, 3, etc.) is applied to the circuit as an indication of the expected frequency range of the unknown clock signal. The number stream is formed accordingly.
    Type: Grant
    Filed: May 9, 2001
    Date of Patent: April 11, 2006
    Assignee: Tropian, Inc.
    Inventor: Brian Sander
  • Patent number: 6952138
    Abstract: The present invention helps to mitigate and reduce the amount of interfering signals (e.g. RF leakage) that enter the phase detector of a phase locked loop by acting as a less than perfect sampler. This is accomplished by introducing a time jitter to the signal edges that enter the phase detector input. A phase detector can also be made to act as a less than perfect sampler by intentionally introducing an interfering signal. For example, a small interfering analog signal can be introduced with a different frequency from the reference frequency already present in the PLL. The interfering signal will cause the stable internal signal to vary slightly in time at the rate of the interfering signal frequency. It is this signal variation and jitter introduced on the signal edges entering the phase detector input that induces the phase detector to act as a less than perfect sampler.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: October 4, 2005
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Hans Hagberg, Magnus Nilsson
  • Patent number: 6950956
    Abstract: An integrated circuit device includes a receiver, a register and a clock circuit. The receiver samples data from an external signal line in response to an internal clock signal. The register stores a value that represents a timing offset to adjust the time at which the data is sampled. The clock circuit generates the internal clock signal such that the internal clock signal maintains a controlled timing relationship with respect to an external clock signal. The clock circuit includes an interpolator that phase mixes a set of reference clock signals such that the internal clock signal is phase offset in accordance with the value.
    Type: Grant
    Filed: November 3, 2003
    Date of Patent: September 27, 2005
    Assignee: Rambus Inc.
    Inventors: Jared LeVan Zerbe, Kevin S. Donnelly, Stefanos Sidiropoulos, Donald C. Stark, Mark A. Horowitz, Leung Yu, Roxanne Vu, Jun Kim, Bruno W. Garlepp, Tsyr-Chyang Ho, Benedict Chung-Kwong Lau
  • Patent number: 6806742
    Abstract: A low-power phase detector with differential output may comprise a control signal generator. In one embodiment, two cyclic waveforms whose phase relationship is to be measured may be input to a control signal generator. The control signal generator may output a first control signal corresponding to the first cyclic waveform such that the control signal is de-asserted at a specific point with respect to the first cyclic waveform. For example, the control signal may be de-asserted corresponding to the rising edge of the first cyclic waveform. The control signal generator may also output a second control signal corresponding to the second cyclic waveform such that the control signal is asserted at a specific point with respect to the second cyclic waveform. For example, the control signal may be asserted corresponding to the falling edge of the second cyclic waveform.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: October 19, 2004
    Assignee: Standard Microsystems Corporation
    Inventors: Luis J. Briones, Klaas Wortel
  • Patent number: 6806741
    Abstract: A phase comparator includes a phase comparison unit performing a phase comparison. The phase comparison unit carries out a switching operation according to the exclusive OR between two signals to be compared and passes or receives a current to or from an output node according to a resultant phase difference. The exclusive OR is associated with the switching operation of two transistors. Namely, when one of the two transistors is turned on, the result of the exclusive OR is L level. Accordingly, the charging/discharging time for an output signal of a logic circuit is shortened and a stable phase comparison can be performed.
    Type: Grant
    Filed: July 28, 2003
    Date of Patent: October 19, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toshihide Oka
  • Patent number: 6753704
    Abstract: The invention proposes a sampling phase detector in which a first sampling transistor with a very high sensitivity determines the phase of a signal to be sampled. A signal representative of the phase is supplied to a second sampling stage. The second sampling stage retains the phase value determined in this way. The invention provides a phase signal that is more stable and more sensitive. The invention also provides a method and an oscillator employing the method.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: June 22, 2004
    Assignee: Alcatel
    Inventors: Simon Desgrez, Dominique Langrez
  • Patent number: 6674309
    Abstract: A method and apparatus for measuring and controlling the phase difference or time difference between two signals is presented. In some embodiments two sample and hold (S/H) circuits are arranged as a cooperating system that alternately samples a first signal using the second as a reference. Chopping may be used at the input or output of the S/H circuits. In some embodiments, accurate measurement of digital signal phase differences, such as between two square waves, is obtained without the problems associated with traditional pulse-generation techniques that fail at high frequencies and short pulse lengths.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: January 6, 2004
    Assignee: Analog Devices, Inc.
    Inventors: Douglas A. Mercer, Michael P. Timko
  • Patent number: 6671755
    Abstract: A data capture system (1) has modular amplifier circuits (10) connected to modular capture circuits (11) within a rotor 2. Each capture circuit (11) has an FPGA (26) operation according to low-frequency and high-frequency state machines (M1, M2) to control ADCs (25) and upload from memories (30) to a host (15) During sampling, each FPGA (26) runs through a ready mode, a sampling mode, and again a ready mode according to a host command.
    Type: Grant
    Filed: May 23, 2000
    Date of Patent: December 30, 2003
    Assignee: Forfàs
    Inventors: Martin J Leahy, Catherine Byrne, Stephen Clothier, Gerard O'Regan, Philip Samways, Jeffrey Punch, Mark Davies
  • Publication number: 20030190001
    Abstract: A converting circuit which converts RZ data into intermeidate NRZ data. The intermediate NRZ data is then sampled to detect a phase of the intermediate NRZ data, which corresponds to the phase of the RZ data. In a preferred embodiment, the converting circuit is incorporated in a modified Hogge NRZ phase detector. A toggle flip-flop is placed in front of the Hogge phase detector. Since the toggle flip-flop is triggered by the leading edge of the RZ pulse, it essentially converts the RZ data into intermediate NRZ data. An exclusive-OR gate samples two different output stages of the Hogge NRZ phase detector, with the output stages being separated by an interim stage to provide a clock delay. The output of the exclusive-OR gate is an intermediate NRZ signal that corresponds to the input RZ data stream, which can then be sampled. The exclusive-OR gates inside the Hogge phase detector are used, as in the Hogge phase detector, to produce the up and down signals provided to a charge pump that is part of a PLL.
    Type: Application
    Filed: April 8, 2002
    Publication date: October 9, 2003
    Applicant: Exar Corporation
    Inventors: Roubik Gregorian, Mir Bahram Ghaderi, James Ban Ho, Vincent Sing Tso