Phase Locking Patents (Class 375/373)
  • Patent number: 8638884
    Abstract: The data processing unit (15) for a receiver of signals carrying information (1) includes a clock and data recovery circuit (16) on the basis of a data signal (DOUT), and a processor circuit (17) connected to the clock and data recovery circuit. The clock and data recovery circuit is clocked by a local clock signal (CLK) and includes a numerical phase lock loop, in which a numerically controlled oscillator (25) is arranged. This numerically controlled oscillator generates an in-phase pulse signal (IP) and a quadrature pulse signal (QP) at output. The frequency and phase of the pulse signals IP and QP are adapted on the basis of the received data signal (DOUT). The processor circuit is arranged to calculate over time the mean and variance of the numerical input signal (NCOIN) of the numerically controlled oscillator (25), so as to determine the coherence of the data signal if the calculated mean and variance are below a predefined coherence threshold.
    Type: Grant
    Filed: October 19, 2011
    Date of Patent: January 28, 2014
    Assignee: The Swatch Group Research and Development Ltd
    Inventor: Arnaud Casagrande
  • Patent number: 8634512
    Abstract: A two point modulation digital phase locked loop circuit is disclosed. The circuit includes a sampling clock input that is switchable between a plurality of frequencies. The circuit also includes a sigma-delta modulator in a feedback path that receives low-pass modulation data. The circuit also includes a voltage-mode digital-to-analog converter (VDAC) that receives high-pass modulation data. The circuit also includes an analog voltage controlled oscillator coupled to the feedback path and the output of the VDAC. The circuit also includes a phase-to-digital converter (PDC) coupled to the feedback path, the sampling clock and a loop filter.
    Type: Grant
    Filed: February 8, 2011
    Date of Patent: January 21, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Lai Kan Leung, Chiewcharn Narathong
  • Patent number: 8634503
    Abstract: A clock-data recovery system and method promotes fast adjustment to large phase changes in the incoming data signal. The system can include phase alignment circuitry, clock generator circuitry, time-to-digital converter circuitry, and sampling circuitry. The phase alignment circuitry uses the incoming data signal and a feedback clock signal to generate an output clock signal. The clock generator circuitry uses the output clock signal to generate base phase clock signals of different phases or polarities. The time-to-digital converter circuitry uses the base phase clock signals and the incoming data signal to generate the feedback clock signal. The time-to-digital converter circuitry bases the feedback clock signal on the base phase clock signal that is aligned more closely in phase with the incoming data signal than the other base phase clock signals. The sampling circuitry re-times or recovers the data signal using one or more of the base phase clock signals.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: January 21, 2014
    Inventors: Brian J. Misek, Robert K. Barnes, Peter J. Meier
  • Patent number: 8625728
    Abstract: A communication system including a phase-locked loop, a signal division controller, a divider, and a transmitter. The phase-locked loop is configured to generate an output signal in response to a common reference clock signal. The output signal is in phase lock with the common reference clock signal. The signal division controller is configured to receive a select signal, select an edge of a rising edge of the output signal and a falling edge of the output signal in response to the select signal, and generate a divider reset signal in response to the selected edge. The divider is configured to generate a communication clock signal by performing frequency division of the output signal. The divider reset signal controls a start time of the frequency division. The transmitter is configured to operate in response to the communication clock signal.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: January 7, 2014
    Assignee: Marvell International Ltd.
    Inventor: Pierte Roo
  • Patent number: 8625730
    Abstract: In a phase locked loop, frequency-divided clocks each of which is given a phase difference of at least one cycle of a feedback clock are inputted to a first phase comparator and a second phase comparator, respectively, which are made to perform phase comparison with a reference clock. Then, outputs of the first and second phase comparators are weighted by a result of the phase comparison of a receive signal and the feedback clock, and phase adjustment of the feedback clock is phase adjusted using the weighted outputs. Thereby, it is possible to lower a frequency of the reference clock and consequently to suppress power consumption.
    Type: Grant
    Filed: July 12, 2011
    Date of Patent: January 7, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Tatsunori Usugi, Daisuke Hamano
  • Patent number: 8619755
    Abstract: Embodiments of a dual-master mode Ethernet node are provided herein. The dual-master mode Ethernet node includes a first multiplexer configured to select between a local oscillator signal and a primary reference source (PRS) signal to provide a reference clock signal, a digital phase-locked loop (DPLL) configured to generate a master clock signal based on the reference clock signal, a phase rotator configured to rotate a phase of the master clock signal based on a frequency error between the master clock signal and an extracted clock signal to generate a slave clock signal, and a second multiplexer configured to select between the master clock signal and the slave clock signal to provide a transmit clock signal. The dual-master mode Ethernet node can dynamically generate the transmit clock based on either the extracted clock or the PRS without re-performing the auto-negotiation process.
    Type: Grant
    Filed: January 3, 2011
    Date of Patent: December 31, 2013
    Assignee: Broadcom Corporation
    Inventors: Peiqing Wang, Linghsiao Wang
  • Patent number: 8619839
    Abstract: An interface module (4) for a unit (1, 2) which is designed to transmit and/or amplify essential communication signals inside an antenna distribution system (29) is specified, said module comprising a first analog interface (6) for forwarding and receiving essential communication signals from mobile terminals (32), a second interface (7) for forwarding and receiving essential communication signals from the antenna distribution system (29), at least one signal path (9, 10) for forwarding the received communication signals between the two interfaces (6, 7), and a controllable digital unit (11) which incorporates the signal path (9, 10) and has means for digitizing incoming communication signals and for subjecting outgoing communication signals to analog conversion. In this case, the digital unit (11) is designed to identify essential communication signals in the digitized communication signals, to mask the remaining signals and to forward the essential communication signals.
    Type: Grant
    Filed: April 26, 2011
    Date of Patent: December 31, 2013
    Assignee: Andrew Wireless Systems GmbH
    Inventors: Oliver Braz, Jorg Stefanik, Jaroslav Hoffmann
  • Patent number: 8619934
    Abstract: A clock data recovery system is described. It includes a high pass filter for transmitting a filtered data signal in response to receiving an input data signal; an adder for summing the filtered data signal with a feedback signal, wherein the adder produces a summed input signal; a plurality of clocked data comparators for receiving the summed input signal, wherein the clocked data comparators determine an input data bit value; a plurality of clocked error comparators for receiving an error signal associated with clock recovery; an equalization and adaptation logic for selecting an error sample such that a phase associated with the error sample is locked at a second post cursor; and a phase mixer for transmitting a delay in response to receiving the phase and the delay is transmitted to the clocked-data comparators and the clocked-error comparators.
    Type: Grant
    Filed: August 11, 2010
    Date of Patent: December 31, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Hae-Chang Lee, Arnold Robert Feldman, Andrew Joy
  • Patent number: 8619938
    Abstract: A clock generation device provided for a transmitter is provided and comprises a clock generator, a calculator and a first phase locked loop (PLL) circuit. The clock generator generates a first clock signal. The calculator calculates a frequency difference between the first and second clock signals. The first PLL circuit generates an output clock signal according to a first reference clock signal related to the first clock signal, and a frequency of the output clock signal is changed according to the frequency difference. The transmitter transmits data according to the output clock signal.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: December 31, 2013
    Assignee: Mediatek Inc.
    Inventors: Kuan-Hua Chao, Chuan Liu, Tse-Hsiang Hsu
  • Patent number: 8619924
    Abstract: A circuit, use, and method for controlling a receiver circuit is provided, wherein a complex baseband signal is generated from a received signal, a phase difference between a phase of the complex baseband signal and a phase precalculated from previous sampled values is determined, the phase difference is compared with a first threshold, a number is determined by counting the exceedances of the first threshold by the phase difference, a number of the counted exceedances is compared with a second threshold, and the receiver circuit is turned off if the number of counted exceedances exceeds the second threshold within a time period.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: December 31, 2013
    Assignee: Atmel Corporation
    Inventors: Ulrich Grosskinsky, Werner Blatz
  • Patent number: 8619937
    Abstract: An integrated CMOS clock generator with a self-biased phase locked loop circuit comprises a phase-frequency detector with a reference signal input, a feedback signal input and an output. A first charge pump of the clock generator has an input connected to the output of the phase-frequency detector and an output that supplies a control voltage. A loop capacitor is connected to the output of the first charge pump. The clock generator further has a second charge pump with an input connected to the output of the phase-frequency detector and an output. In particular, the clock generator has two oscillator blocks.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: December 31, 2013
    Assignee: Texas Instruments Deutschland GmbH
    Inventor: Joern Naujokat
  • Patent number: 8611371
    Abstract: A device (D2) is dedicated to the reconstruction of clock signals, for example within communication equipment (EQ2) of an IP network. This device (D2) comprises i) a phase-locked loop (BY) having a cut-off frequency dependent, on the one hand, on a configuration value making it possible to reconstruct clock signals according to a chosen clock frequency, and on the other hand, a chosen sampling frequency, and ii) control means (MC2) responsible for forcing the phase-locked loop (BV) to present a variable cut-off frequency according to a received operating mode indication.
    Type: Grant
    Filed: February 5, 2008
    Date of Patent: December 17, 2013
    Assignee: Thomson Licensing
    Inventors: Thierry Tapie, Serge Defrance, Luis Montalvo
  • Patent number: 8605848
    Abstract: An arrangement for synchronizing a transmission time of a digital data stream in individual high-frequency transmitters of a common-wave network operating according to an ATSC standard and transmitting identical data at an identical frequency. The stream generated in a master station is supplied to the transmitters as a periodic succession of data frames, and a setpoint transmission time is calculated in the transmitters from a synchronizing time stamp inserted into the data frames within the master station and from a time reference used in the master station and transmitters, while the transmission of the frames by the transmitter is determined by a system clock in the transmitters. The setpoint transmission time is compared with the actual transmission time determined by the clock, and the clock frequency is regulated by a regulating circuit so that the actual transmission time determined by the clock corresponds with the calculated setpoint transmission time.
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: December 10, 2013
    Assignee: Rohde & Schwarz GmbH & Co. KG
    Inventors: Cornelius Heinemann, Wolfgang Boehm
  • Patent number: 8605846
    Abstract: Various embodiments of the present invention relate to systems, devices and methods of oversampling electronic components where high frequency oversampling clock signals are generated internally. The generated oversampling clock is automatically synchronous with the input clock and the input serial data in a serial data link, and is adaptive to predetermined parameters, such as bit depth and oversampling rate.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: December 10, 2013
    Assignee: Maxim Integrated Products, Inc.
    Inventors: Matthew Felder, Mark Summers
  • Patent number: 8605847
    Abstract: In described embodiments, a transceiver includes a clock and data recovery module (CDR) with an eye monitor and a cycle slip monitor. The cycle slip detector monitors a CDR lock condition, which might be through detection of slips in sampling and/or transition timing detection. The cycle slip detector provides a check point to sense system divergence, allowing for a mechanism to recover CDR lock. In addition, when the CDR is out-of-lock, the various parameters that are adaptively set (e.g., equalizer parameters) might be invalid during system divergence. Consequently, these parameters might be declared invalid by the system and not used.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: December 10, 2013
    Assignee: LSI Corporation
    Inventors: Mohammad Mobin, Mark Trafford, Ye Liu, Vladimir Sindalovsky, Amaresh Malipatil
  • Patent number: 8599985
    Abstract: In accordance with an embodiment of the present disclosure a phase-locked loop comprises a voltage controlled oscillator (VCO) configured to generate an output signal based on an input reference signal. The phase-locked loop further comprises a first charge pump communicatively coupled to a control input of the VCO and configured to generate, for a duration of time following occurrence of an event, a first control signal. The first control signal is independent of the output signal and is for causing the output signal to have a first frequency based on a second frequency of the input reference signal. The phase-locked loop further comprises a second charge pump communicatively coupled to the control input of the VCO. The second charge pump is configured to generate, after the duration of time, a second control signal.
    Type: Grant
    Filed: April 5, 2011
    Date of Patent: December 3, 2013
    Assignee: Intel IP Corporation
    Inventor: Rizwan Ahmed
  • Patent number: 8599984
    Abstract: A delay locked loop operates over a wide range of frequencies and has high accuracy, small silicon area usage, low power consumption and a short lock time. The DLL combines an analog domain and a digital domain. The digital domain is responsible for initial lock and operational point stability and is frozen after the lock is reached. The analog domain is responsible for normal operation after lock is reached and provides high accuracy using smaller silicon area and low power.
    Type: Grant
    Filed: March 26, 2013
    Date of Patent: December 3, 2013
    Assignee: MOSAID Technologies Incorporated
    Inventors: Peter Vlasenko, Dieter Haerle
  • Patent number: 8594214
    Abstract: Disclosed is an input module of a programmable logic controller (PLC) capable of counting coefficient values of multiple channels. An input module of a PLC includes a plurality of detection units, a decision unit and a control unit. The plurality of detection units receives a pulse signal corresponding to each channel, applied from a load having a plurality of channels, detects rising and falling edges of the pulse signal, and transmits an output signal that is the detected result. The decision unit receives a plurality of output signals respectively transmitted from the plurality of detection units, detects edges of the plurality of channels, and transmits a detection signal that is the detected result. The control unit identifies the presence of occurrence of an interrupt using the detection signal transmitted from the decision unit and performs a counting process using the applied pulse signal when the interrupt occurs.
    Type: Grant
    Filed: April 4, 2011
    Date of Patent: November 26, 2013
    Assignee: LSIS Co., Ltd.
    Inventor: Sang Back Lee
  • Patent number: 8588281
    Abstract: A transceiver comprises a transmitter that converts a plurality of data components into serial data in response to a first clock signal and transmits the serial data, and a receiver that receives the serial data and converts the serial data into the plurality of data components in response to a second clock signal generated from the serial data. The transmitter adds at least one dummy bit to the serial data at predetermined intervals. The at least one dummy bit includes information regarding a data type of the plurality of data components.
    Type: Grant
    Filed: February 7, 2011
    Date of Patent: November 19, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Woon-taek Oh, Jae-youl Lee, Jin-ho Kim, Tae-jin Kim, Ju-hwan Yi, Jong-shin Shin
  • Patent number: 8588355
    Abstract: A timing recovery controller capable of performing timing recovery for a data sequence at twice a symbol rate includes a sampler, a timing base device, a timing error detector and a timing lock detector. The timing error detector includes a first delay unit and a second delay unit, for delaying a data sequence to output a first delay data sequence and a second delay data sequence, respectively, and a timing error calculating module, for generating a timing error value, to adjust a time base. The timing lock detector includes a third delay unit, for delaying the data sequence to output a third delay data sequence, and a timing lock determination module, for generating a timing lock determination result.
    Type: Grant
    Filed: August 6, 2010
    Date of Patent: November 19, 2013
    Assignee: NOVATEK Microelectronics Corp.
    Inventor: Kung-Piao Huang
  • Patent number: 8588356
    Abstract: A method for receiving a signal having a succession of symbols, transmitted by a digital modulation, each symbol transmitted having a phase and an amplitude belonging to a set of values in finite number, the method includes evaluating a phase error (PHE) on a received symbol (S), resulting from a signal transmission noise, correcting the phase of the received symbol according to the phase error evaluated, demodulating the symbol corrected in phase, and modeling the transmission noise by a Gaussian component not correlated with the signal received and defined by a power and an interference component defined by an amplitude and which phase is substantially uniformly distributed, the phase error of the received symbol evaluated on the basis of the power of Gaussian component and the amplitude of the interference component.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: November 19, 2013
    Assignee: STMicroelectronics (Grenoble 2) SAS
    Inventor: Jacques Meyer
  • Patent number: 8588329
    Abstract: A phase-locked loop having: an oscillator for forming an oscillating output signal; a frequency divider connected to receive the output of the oscillator and frequency divide it by a value dependent on a division control signal; and a phase comparator for comparing the phase of the divided signal and a reference signal to generate a control signal, the operation of the oscillator being dependent on the control signal; the output data to form a divided signal a division ratio controller configured to, when clocked by an input signal, generate a series of output data for forming the division control signal; the phase-locked loop having: a first mode of operation in which the frequency divider is operable to frequency divide the output of the oscillator by a value dependent on the output of the division ratio controller; and a second mode of operation in which the frequency divider is not operable to frequency divide the output of the oscillator by a value dependent on the output of the division ratio controller
    Type: Grant
    Filed: March 13, 2009
    Date of Patent: November 19, 2013
    Assignee: Cambridge Silicon Radio Limited
    Inventors: Pasquale Lamanna, Nicolas Somin
  • Patent number: 8588358
    Abstract: A clock and data recovery (CDR) circuit includes an inductor-capacitor voltage controlled oscillator (LCVCO) configured to generate a clock signal with a clock frequency. A delay locked loop (DLL) is configured to receive the clock signal from the LCVCO and generate multiple clock phases. A charge pump is configured to control the LCVCO. A phase detector is configured to receive a data input and the multiple clock phases from the DLL, and to control the first charge pump in order to align a data edge of the data input and the multiple clock phases.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: November 19, 2013
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Chan-Hong Chern, Chih-Chang Lin, Ming-Chieh Huang, Fu-Lung Hsueh
  • Patent number: 8582710
    Abstract: Embodiments allow for the use of the SS modulation technique (and thus for significant reduction of EMI due to clock transmission) in scenarios involving tight synchronization requirements between two devices. In particular, embodiments can be used in high-speed communication networks (e.g., high-speed Ethernet) where a clock signal embedded in the data stream at the transmitter and recovered from the data stream at the receiver is the only source for synchronization between the transmitter and the receiver (i.e., no other synchronization channel available). Embodiments are also especially useful in communication systems utilizing echo cancellers.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: November 12, 2013
    Assignee: Broadcom Corporation
    Inventors: Neven Pischl, Joseph Cordaro, Yongbum Kim
  • Patent number: 8582690
    Abstract: An apparatus for determining signal power comprise an oscillating circuit and a determining circuit. The oscillating circuit generates an oscillating signal. When a to-be-detected signal has signal power greater than a threshold, the oscillating signal has a first frequency; when the signal power is smaller than the threshold, the oscillating signal has a second frequency. The determining circuit determines whether the oscillating signal has either the first frequency or the second frequency, and generates a determination result accordingly.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: November 12, 2013
    Assignee: MStar Semiconductor, Inc.
    Inventors: Ming Yu Hsieh, Shih-Chieh Yen
  • Patent number: 8582708
    Abstract: A clock and data recovery circuit includes a multiphase clock generator circuit which generates a multiphase clock having a plurality of clocks, a sampling circuit which samples a received data signal transferring serial data in synchronism with each of the plurality of clocks, and generates a plurality of data signals, a data recovery unit which generates a selection signal indicating a data signal having an appropriate phase among the plurality of data signals, and a storage unit which stores the selection signal. The data recovery unit selects one of the plurality of data signals, based on the selection signal read from the storage unit, and a clock corresponding to the selected data signal.
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: November 12, 2013
    Assignee: Panasonic Corporation
    Inventors: Michiyo Yamamoto, Kenji Murata, Kazuya Hatooka
  • Patent number: 8582628
    Abstract: A data reception unit 21 of a reception device 20n receives calibration data to detect a data reception state or a clock reception state in the reception device 20n from a data transmission unit 11 of a transmission device 10. A decoder unit 24 causes a transmission unit 26 to send out calibration sample data that a sampler unit 23 obtained by sampling calibration data to the transmission device 10. A control unit 15 of the transmission device 10 detects a data reception state or a clock reception state in the reception device 20n based on calibration sample data received from the reception device 20n and controls the data transmission unit 11 and a clock transmission unit 12 based on the detection result.
    Type: Grant
    Filed: October 20, 2010
    Date of Patent: November 12, 2013
    Assignee: Thine Electronics, Inc.
    Inventors: Seiichi Ozawa, Hironobu Akita
  • Publication number: 20130294492
    Abstract: A system may include a clock and data recovery circuit that includes one or more analog components. The system may also include a digital control circuit configured to control the clock and data recovery circuit. The digital control circuit and the clock and data recovery circuit may be formed on a single substrate.
    Type: Application
    Filed: May 4, 2012
    Publication date: November 7, 2013
    Applicant: FINISAR CORPORATION
    Inventor: Jason Y. MIAO
  • Patent number: 8576970
    Abstract: A PLL circuit (1a, 1b) for generating a pixel-clock signal based on a hsync signal. The PLL circuit comprises a phase-frequency detector arranged to receive the hsync signal and a frequency divided pixel-clock signal, and generate up and down signals based on the hsync signal and the frequency-divided pixel-clock signal. A charge pump (20) is arranged to generate an output signal based on the up and down signals and a loop filter (30) is arranged to generate a frequency-control signal based on the output signal of the charge pump (20). Furthermore, a VCO (40a, 40b) is arranged to generate an oscillating signal and adjust the frequency of the oscillating signal in response to the frequency-control signal. The VCO (40a, 40b) is adapted to have a tuning range with a center frequency which is larger than or equal to 4 GHz.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: November 5, 2013
    Assignee: CSR Technology Inc.
    Inventors: Graham R. Leach, Gordon A. Wilson, Rolf Sundblad
  • Patent number: 8571158
    Abstract: A method and a data transceiving system for generating a reference clock signal are provided. The data transceiving system comprises a voltage controlled oscillator, a phase lock loop (PLL) unit, and a data receiver. The voltage controlled oscillator is used to generate a reference clock signal. The PLL unit is used to increase a clock frequency of the reference clock signal to generate a PLL clock signal. The data receiver is used to compare the PLL clock signal with a clock signal of an input data stream, so as to output a voltage adjusting signal to the voltage controlled oscillator. The voltage controlled oscillator adjusts the clock frequency of the reference clock signal to be generated according to the reference clock signal, so as to lock the clock frequency of the PLL clock signal to a base frequency of the clock signal of the input data stream.
    Type: Grant
    Filed: August 17, 2010
    Date of Patent: October 29, 2013
    Assignee: Phison Electronics Corp.
    Inventors: An-Chung Chen, Wen-Lung Cheng, Wei-Yung Chen
  • Patent number: 8565362
    Abstract: A clock recovery apparatus includes a mask generator configured to generate a plurality of time masks using a multi-phase clock signal and a clock recovery unit configured to select one of the time masks to recover a clock from a data stream.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: October 22, 2013
    Assignee: Dongbu HiTek Co., Ltd.
    Inventor: Sang Seob Kim
  • Patent number: 8564347
    Abstract: Embodiments include implementing a phase detector for a delay-locked loop (DLL) circuit that is operable to detect substantially 270 degree and substantially 540 degree phase differences between two clock signals. In an embodiment, a DLL circuit comprises a delay line receiving a system clock signal and generating phase shifted clock signals, a phase detector receiving the system clock signal and phase shifted clock signal, and configured to generate corresponding up and down signals upon detection of a phase shift of substantially 270 degrees between the system clock signal and the phase shifted clock signal, a charge pump coupled to the phase detector, and configured to receive the up and down signals and generate a control signal responsive to thereto, and a regulator circuit to receive the control signal from the charge pump and generate a voltage control signal to the delay chain to control delay of the system clock signal.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: October 22, 2013
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Min Xu, Ming-Ju E. Lee
  • Patent number: 8559582
    Abstract: A circuit includes a phase detection circuit, a phase adjustment circuit, and a sampler circuit. The phase detection circuit compares a phase of a first periodic signal to a phase of a second periodic signal to generate a control signal. The phase adjustment circuit causes the phase of the second periodic signal and a phase of a third periodic signal to vary based on a variation in the control signal. The sampler circuit samples a data signal to generate a sampled data signal in response to the third periodic signal. The circuit varies a frequency of the third periodic signal to correspond to changes in a data rate of the data signal between at least three different data rates that are based on at least three data transmission protocols.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: October 15, 2013
    Assignee: Altera Corporation
    Inventor: Tim Tri Hoang
  • Patent number: 8558592
    Abstract: A circuit containing a pair of charge pumps and an active filter receives outputs of a phase frequency detector used in a phase locked loop. The charge pump is implemented using switches and resistors to reduce performance variations due to component mismatches. The loop filter includes a resistor and a capacitor coupled in series, the resistor and the capacitor determining a zero of the transfer function of the loop filter. The charge pump circuit simultaneously injects a first current pulse at a first node of the loop filter and a second current pulse at a second node formed by a junction of the resistor and the capacitor. The polarity of the first current pulse is the opposite of the polarity of the second current pulse. Multiplication of the capacitance of the capacitor is thereby achieved, enabling implementation of the loop filter in integrated circuit form.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: October 15, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Samala Sreekiran, Ramesh Chettuvetty
  • Patent number: 8553827
    Abstract: A Phase-Locked Loop (PLL) includes a Phase-to-Digital Converter (PDC), a programmable digital loop filter, a Digitally-Controlled Oscillator (DCO), and a loop divider. Within the PDC, phase information is converted into a stream of digital values by a charge pump and an Analog-to-Digital Converter (ADC). The stream of digital values is supplied to the digital loop filter which in turn supplies digital tuning words to the DCO. A number of types of ADCs can be used for the ADC including a continuous-time delta-sigma oversampling Digital ADC and a Successive Approximation ADC. The voltage signal on the charge pump output is a small amplitude midrange voltage signal. The small voltage amplitude of the signal leads to numerous advantages including improved charge pump linearity, reduced charge pump noise, and lower supply voltage operation of the overall PLL.
    Type: Grant
    Filed: October 20, 2009
    Date of Patent: October 8, 2013
    Assignee: Qualcomm Incorporated
    Inventor: Gang Zhang
  • Patent number: 8548405
    Abstract: A method of controlling the phases of RF output signals from a number of radio transmitters. A given radio has at least one synthesizer as a source of its RF output signal, and the synthesizer produces an output the phase offset of which relative to a reference signal is controlled by a phase offset command. A path from an antenna port of the radio obtains a fed back RF output signal and a phase difference between the reference signal and the fed back RF output signal is measured. A value of a zero degree phase offset command for the synthesizer is determined such that the phase difference between the reference signal and the fed back RF signal is nominally zero, and the value is stored. A phase offset command for providing a desired phase offset for the RF output signal is then determined based the stored value of the zero degree phase offset command.
    Type: Grant
    Filed: April 25, 2012
    Date of Patent: October 1, 2013
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventor: Michael S. Vogas
  • Patent number: 8543068
    Abstract: A transceiver node includes a pulse coupled oscillator in an integrated circuit, which can synchronize with other nodes to generate a global clock subsequently used to facilitate synchronous communications between individual nodes. Known potential uses include a low power sensor node radio for an ad-hoc network for military applications and medical applications such as ingestible and implantable radios, self powered radios, and medical monitoring systems such as cardiac and neural monitoring patches.
    Type: Grant
    Filed: August 4, 2008
    Date of Patent: September 24, 2013
    Assignee: Cornell University
    Inventors: Xiao Y. Wang, Alyssa B. Apsel
  • Patent number: 8537953
    Abstract: A clock-data recovery (CDR) that employs a time-interleaved scheme is disclosed. The circuit comprises: a time-interleaved sampler/phase-detector circuit for receiving an input voltage signal and a plurality of clock signals and outputting N-bit data and N phase signals, wherein N is an integer greater than 1; a control circuit, coupled to the time-interleaved sampler/phase-detector circuit, for receiving the N phase signals and converting the N phase signals into a control signal; and a controlled oscillator, coupled to the control circuit, for generating the plurality of clock signals under the control of the control signal. The CDR is used to relax circuit speed requirement by time-interleaving phase detection by using a multi-phase lower speed circuit.
    Type: Grant
    Filed: September 13, 2008
    Date of Patent: September 17, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventor: Chia-Liang Lin
  • Patent number: 8537945
    Abstract: An apparatus includes Radio Frequency (RF) circuitry and baseband circuitry. The RF circuitry is configured to receive strobe messages that are based on a system clock over a digital interface, and to communicate synchronously with the system clock based on the received strobe messages in accordance with a Radio Access Technology (RAT) that is selected from among multiple different RATs. The baseband circuitry is configured to generate the strobe messages, to delay the strobe messages by a delay that depends on the selected RAT, and to send the delayed strobe messages to the RF circuitry over the digital interface.
    Type: Grant
    Filed: November 21, 2010
    Date of Patent: September 17, 2013
    Assignee: Marvell International Ltd.
    Inventors: Daniel Ben-Ari, Avner Epstein
  • Patent number: 8537952
    Abstract: A fractional-N PLL uses separate charge pumps under the control of separate frequency and phase detectors. Phase jitter from an N divider is linearized by the use of a circuit that generates pulses from the output of the N divider. After frequency lock, the frequency detector turns off the frequency charge pump. After phase lock, activity in the phase detector down charge pump is minimized, reducing the overall noise produced by respective phase and frequency detector charge pumps.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: September 17, 2013
    Assignee: Marvell International Ltd.
    Inventor: Himanshu Arora
  • Patent number: 8537957
    Abstract: A clock synchronizer for generating a local clock signal synchronized to a received clock signal. The clock synchronizer incorporates a reference oscillator providing a reference signal, and a synthesizer circuit arranged to synthesize a local clock signal from the reference signal. The synthesizer circuit comprises a phase-locked-loop circuit, including a phase detector receiving the reference signal, and a controllable divider arranged in a feedback path from a controlled oscillator to the phase detector, the divider being controllable to set a frequency division value N along the path to determine a ratio of the local clock frequency to the reference frequency. The clock synchronizer also incorporates a clock comparison circuit adapted to generate a digital signal indicative of an asynchronism between the local and received clock signals. A control link is arranged to link the clock comparison circuit to the divider.
    Type: Grant
    Filed: May 23, 2011
    Date of Patent: September 17, 2013
    Assignee: Wolfson Microelectronics plc
    Inventor: Paul Lesso
  • Patent number: 8537935
    Abstract: A change-point detection circuit 16 extracts a clock signal from serial data, input data. A variable delay circuit provides a delay in accordance with a delay control signal to a reference signal having a predetermined frequency, so that the phase of the reference signal is shifted on the basis of an initial delay. An input latch circuit latches internal serial data by using an output signal of the variable delay circuit as a strobe signal. A phase comparator matches the frequencies of the clock signal and the strobe signal with each other, and generates phase difference data in accordance with a phase difference between the two signals. A loop filter integrates the phase difference data generated by the phase comparator and outputs it as the delay control signal. The phase shift amount acquisition unit acquires a phase shift amount based on the delay control signal, the phase shift amount being based on the initial delay provided to the reference signal by the variable delay circuit.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: September 17, 2013
    Assignee: Advantest Corporation
    Inventors: Daisuke Watanabe, Toshiyuki Okayasu
  • Patent number: 8537956
    Abstract: A demultiplexer circuit separates input data having different data rates into output data. A phase-locked loop circuit generates first clock signals having average frequencies that are based on a frequency of a second clock signal times a fractional, non-integer number. A serializer circuit serializes a set of the output data to generate serial data signals in response to one of the first clock signals generated by the phase-locked loop circuit.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: September 17, 2013
    Assignee: Altera Corporation
    Inventors: Tien Duc Pham, Leon Zheng, Sergey Shumarayev, Zhi Y. Wong, Paul B. Ekas
  • Patent number: 8532243
    Abstract: A technique that is readily implemented in monolithic integrated circuits includes a method including generating an output clock signal during a presence of a reference clock signal based, at least in part, on a digital control value indicating a phase difference between a feedback signal of a PLL and a reference clock signal. The method includes generating the output clock signal during an absence of the reference clock signal and based, at least in part, on an average digital control word indicating an average value of a number of samples of the digital control value during the presence of the reference clock signal, the number of samples preceding the absence of the reference clock signal by a delay period. The number of samples is selected from a plurality of numbers of samples and the delay period is selected from a plurality of delay periods.
    Type: Grant
    Filed: February 12, 2007
    Date of Patent: September 10, 2013
    Assignee: Silicon Laboratories Inc.
    Inventors: Srisai R. Seethamraju, Jerrell P. Hein, Kenneth Kin Wai Wong, Qicheng Yu
  • Patent number: 8532163
    Abstract: A transceiver system is disclosed that includes a plurality of transceiver chips. Each transceiver chip includes one or more SERDES cores. Each SERDES core includes one or more SERDES lanes. Each SERDES lane includes a receive channel and a transmit channel. The transmit channel of each SERDES lane is phase-locked with a corresponding receive channel. The transceiver system has the capability of phase-locking a transmit clock signal phase of a transmitting component with a receive clock signal phase of a receiving component that is a part of a different SERDES lane, a different SERDES core, a different substrate, or even a different board. Each SERDES core receives and transmits data to and from external components connected to the SERDES core, such as hard disk drives. A method of transferring data from a first external component coupled to a receive channel to a second external component coupled to a transmit channel is also disclosed.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: September 10, 2013
    Assignee: Broadcom Corporation
    Inventors: Abbas Amirichimeh, Howard Baumer, John Louie, Vasudevan Parthasarathy, Linda Ying
  • Patent number: 8531214
    Abstract: Spread spectrum generators and methods are disclosed. In one implementation, a spread spectrum clock generator includes a phase locked loop generating an output clock according to a first clock and a second clock; a delay line coupled between the first clock and the phase locked loop; a modulation unit providing a modulation signal to control the delay line thereby modulating phase of the first clock, such that frequency of the output clock generated by the phase locked loop varies periodically; a scaling unit scaling the modulation signal from the modulation unit according to a scaling ratio, and outputting to the delay line; and a calibration unit generating an output signal for controlling the scaling ratio.
    Type: Grant
    Filed: January 18, 2013
    Date of Patent: September 10, 2013
    Assignee: MediaTek Inc.
    Inventors: Shang-Ping Chen, Ping-Ying Wang
  • Patent number: 8520793
    Abstract: A phase detector includes a first sampling unit, a sampling module and a phase determining module. The first sampling unit is arranged for sampling a first data input signal to generate a first data signal according to a first clock signal. The sampling module includes a second sampling unit and a third sampling unit. The second sampling unit is arranged for sampling a second data input signal to generate a second data signal according to a second clock signal. The third sampling unit is arranged for sampling the second data signal to generate a third data signal according to the first clock signal. The phase determining module is arranged for generating a phase detecting result according to the first data signal and the third data signal.
    Type: Grant
    Filed: April 20, 2011
    Date of Patent: August 27, 2013
    Assignee: Faraday Technology Corp.
    Inventors: Chun-Cheng Lin, Ming-Shih Yu
  • Patent number: 8520725
    Abstract: A data equalizing circuit includes an equalizer configured to control a gain of data according to a value of a control code and output a controller gain; and a detection unit configured to divide n cycles of the data into N periods, count data transition frequencies for n/N periods while changing the value of the control code, calculate dispersion values of data transition frequencies for 1/N periods of the data from the data transition frequencies for the n/N periods, and finally output the value of the control code corresponding to a largest dispersion value, wherein n is equal to or greater than 2 and is set such that boundaries of the respective n/N periods of the data have different positions in the 1 UI data.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: August 27, 2013
    Assignee: SK Hynix Inc.
    Inventors: Chun Seok Jeong, Jae Jin Lee, Chang Sik Yoo, Jang Woo Lee, Seok Joon Kang
  • Patent number: 8514922
    Abstract: This invention relates to an apparatus and a method for controlling a filter coefficient. The filter coefficient control apparatus controls a coefficient of a filter of a phase recovering apparatus, and comprises a phase offset obtaining means, for obtaining a phase offset between a carrier and a local oscillation; an autocorrelation calculating means, for calculating an autocorrelation and related statistics of the phase offset; and a filter coefficient determining means, for determining the coefficient of the filter in accordance with the autocorrelation and related statistics.
    Type: Grant
    Filed: July 13, 2010
    Date of Patent: August 20, 2013
    Assignee: Fujitsu Limited
    Inventors: Lei Li, Zhenning Tao, Ling Liu, Shoichiro Oda
  • Patent number: 8514995
    Abstract: A circuit includes a receiver circuit, a data valid monitor circuit, a clock signal generation circuit, and a phase shift circuit. The receiver circuit is operable to generate a first periodic signal, a sampled data signal based on an input data signal, and a data valid signal based on a predefined number of bits in the sampled data signal. The data valid monitor circuit is operable to generate a count value by counting periods of the first periodic signal. The data valid monitor circuit is operable to generate a phase error signal based on the data valid signal and the count value. The clock signal generation circuit is operable to generate a second periodic signal. The phase shift circuit is operable to generate a third periodic signal based on the second periodic signal and to adjust a phase of the third periodic signal based on the phase error signal.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: August 20, 2013
    Assignee: Altera Corporation
    Inventors: Boon Hong Oh, Peter Schepers, Da Hai Tang