With Digital Element Patents (Class 327/159)
  • Publication number: 20090189657
    Abstract: A delay locked loop circuit includes a phase-frequency detector, a sampler, a charge pump, a bias generator and a voltage-controlled element. The phase-frequency detector outputs at least one difference signal by detecting a phase difference between an input clock signal and a feedback clock signal. The sampler outputs at least one sampled signal by delaying the difference signal in accordance with the input clock signal. The charge pump generates a control voltage in accordance with the sampled signal. The bias generator generates at least one bias voltage in accordance with the control voltage. The voltage-controlled element is controlled with the bias voltage to output the feedback clock signal to the phase-frequency detector in accordance with the input clock signal. A method for eliminating jitter and offset between an input clock signal and an output clock signal in a delay locked loop circuit is also disclosed.
    Type: Application
    Filed: January 25, 2008
    Publication date: July 30, 2009
    Applicant: HIMAX TECHNOLOGIES LIMITED
    Inventor: Chih-Haur Huang
  • Patent number: 7567643
    Abstract: A phase lock loop device further includes a probability shaping device provided between a phase detection device and charge pump and loop filter (CPLF) device. The probability shaping device operates to reduce the frequency of outputting up-index or down-index; thereby shaping probability distribution to reduce degradation due to mismatching of the CPLF device.
    Type: Grant
    Filed: December 9, 2005
    Date of Patent: July 28, 2009
    Assignee: Via Technologies, Inc.
    Inventor: Tse-Hsien Yeh
  • Patent number: 7567106
    Abstract: A semiconductor device and method of generating clock signals where a phase lock loop (PLL), or a delay lock loop (DLL), comprises a duty cycle correction circuit (DCC) having a shared charge pump and a plurality of amplification parts. The plurality of amplification parts generate internal clock signals. The shared charge pump adjusts voltage level of control signal (VC) in response to the internal clock signals and provides the control signal VC to each of the amplification parts.
    Type: Grant
    Filed: August 1, 2006
    Date of Patent: July 28, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Moon-sook Park, Kyu-hyoun Kim
  • Patent number: 7564313
    Abstract: A PLL system for generating an output signal according to a first reference signal is disclosed. The PLL system includes a clock generator to generate the output signal according to a phase difference between the first reference signal and the frequency-divided signal; and a phase-shift detector for detecting a position difference between the physical address and an updated logical address of the recording data to generate a phase adjusting signal. The PLL system also includes an adder for updating a detected logical address with a random value to output the updated logical address to the position difference detector; and a phase-controllable frequency divider for generating the frequency-divided signal and for receiving the phase adjusting signal to adjust the phase of the frequency-divided signal.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: July 21, 2009
    Assignee: Mediatek Inc.
    Inventors: Chin-Ling Hung, Hong-Ching Chen, Chi-Ming Chang
  • Patent number: 7557663
    Abstract: A digital phase locked loop (DPLL) comprising a digitally implemented voltage controlled oscillator (VCO) for producing a VCO feedback signal, a phase error counter which includes a digital phase-frequency detector for producing a first phase error signal, a quadrature phase detector for producing a second phase error signal and an adder for adding the first and second phase error signals to obtain a combined phase error signal, and two programmable dividers used to cooperatively determine the VCO feedback signal and to provide a DPLL output line sync value synchronized with an input signal.
    Type: Grant
    Filed: June 17, 2007
    Date of Patent: July 7, 2009
    Assignee: Systel Development & Industries Ltd.
    Inventors: Daniel Rubin, Arie Lev, Eytan Rabinovitz, Rafael Mogilner
  • Publication number: 20090167389
    Abstract: The present invention discloses a calibration circuit for a voltage-controlled oscillator (10a-10c) and also a method for calibrating the voltage-controlled oscillator. The apparatus comprises a first counter (210) for counting the number of cycles of a reference signal (Fclk) and a second counter (220) for counting the number of cycles of a feedback signal (Fin) produced by the voltage-controlled oscillator (10a-10c). The second counter (220) is further adapted to produce a difference value (OUTVAL) representative of the difference between the phase of the reference signal (Fclk) and the phase of the feedback signal (Fin). A memory (240) has a plurality of memory locations storing the difference values (OUTVAL) and capacitor selections. The apparatus further comprises a capacitor bank (90) selectable by the capacitor selections in the memory (240) and connected to the voltage-controlled oscillator (10a-10c).
    Type: Application
    Filed: December 31, 2007
    Publication date: July 2, 2009
    Applicant: ChipIdea Microelectronica S.A.
    Inventor: Ricardo dos Santos REIS
  • Patent number: 7555073
    Abstract: Provided is a frequency control loop circuit changing division ratios of a frequency synthesizer to oscillate frequencies in a broadband with high precision. The circuit comprises a clock oscillator, a frequency synthesizer, and a demodulator.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: June 30, 2009
    Assignee: Integrant Technologies Inc.
    Inventor: Minsu Jeong
  • Patent number: 7548126
    Abstract: A phase locked loop circuit includes a voltage controlled oscillator having an oscillating characteristic value changed by a switching signal. A characteristic controller supplies the switching signal to the voltage controlled oscillator to increase the oscillating characteristic value according to elapse of time. The voltage controlled oscillator oscillates according to both of the oscillating characteristic value and a frequency control signal. Even if the frequency control signal is equal to a power source level at the beginning of supplying electric power, the phase locked loop can be locked in a target frequency.
    Type: Grant
    Filed: December 17, 2005
    Date of Patent: June 16, 2009
    Assignee: NEC Corporation
    Inventor: Tomohiro Hayashi
  • Patent number: 7541849
    Abstract: A phase locked circuit includes a locked loop circuit having a phase comparator, a voltage controlled oscillator, and a variable frequency divider which divides a clock signal fvco output from the voltage controlled oscillator by n and outputs it. Additionally, the phase locked circuit includes a band pass filter part which is coupled to an output side of the voltage controlled oscillator via a switching part. A frequency division ratio setting signal to be input into the variable frequency divider is input as a switching signal into the switching part so as to switch a frequency of the clock signal fvco output from the voltage controlled oscillator. As synchronizing with switching of the frequency, the switching part switches a plurality of band pass filters provided to the band pass filter part and couples to the voltage controlled oscillator.
    Type: Grant
    Filed: August 8, 2006
    Date of Patent: June 2, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Mikio Shigemori, Masataka Nomura
  • Patent number: 7538591
    Abstract: A fast locking phase locked loop includes a first phase frequency detector (PFD), a second PFD, a lock detector, an up-signal output unit, a down-signal output unit, a selective charge pump, a loop filter, and a voltage-controlled oscillator (VCO). The first PFD outputs a first up-signal and a first down-signal. The second PFD outputs a second up-signal and a second down-signal. The lock detector outputs an inverted lock signal. The selective charge pump outputs a pumping current. The loop filter generates a control voltage in response to the pumping current. The VCO generates the external clock signal having a frequency determined in accordance with the control voltage. The PLL has a faster locking time because the PFDs included in the PLL are capable of detecting a phase difference in a missing edge.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: May 26, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jung-Hoon Oh
  • Patent number: 7538583
    Abstract: A high voltage circuit driver includes high and low side driver cells to drive a high and a low side power MOSFET, a bootstrap circuit to energize the high side driver cell, a high voltage PMOS transistor (HVPMOS) between a voltage source and the bootstrap circuit, wherein the HVPMOS is embedded in an N-isolation layer and is integrated with the driver cells. A bootstrap control circuit, for controlling the HVPMOS, includes a high voltage level shift stage, which can also be embedded in an N-isolation layer. The circuit driver is operated by switching the high side drive signal from high to low, the low side drive signal from low to high with a first delay, and a bootstrap control signal from high to low with an additional second delay. Also, the bootstrap capacitor is first charged by switching on the HVPMOS, and then it energizes the high side driver cell.
    Type: Grant
    Filed: September 8, 2006
    Date of Patent: May 26, 2009
    Assignee: Fairchild Semiconductor Corporation
    Inventor: Stephen W. Bryson
  • Patent number: 7535275
    Abstract: A programmable memory interface circuit includes a programmable DLL delay chain, a phase offset control circuit and a programmable DQS delay chain. The DLL delay chain uses a set of serially connected delay cells, a programmable switch, a phase detector and a digital counter to generate a coarse phase shift control setting. The coarse phase shift control setting is then used to pre-compute a static residual phase shift control setting or generate a dynamic residual phase shift control setting, one of which is chosen by the phase offset control circuit to be added to or subtracted from the coarse phase shift control setting to generate a fine phase shift control setting. The coarse and fine phase shift control settings work in concert to generate a phase-delayed DQS signal that is center-aligned to its associated DQ signals.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: May 19, 2009
    Assignee: Altera Corporation
    Inventors: Joseph Huang, Chiakang Sung, Philip Pan, Yan Chong, Andy L. Lee, Brian D. Johnson
  • Patent number: 7532050
    Abstract: A delay locked loop includes initialization circuitry that ensures that a DLL is initialized to an operating point that is not to close to either end of a delay vs. control voltage characteristic. The initialization circuitry forces the DLL to initially search for a lock point starting from an initial delay, the delay is varied in one direction, forcing the DLL to skip the first lock point. The initialization circuitry only allows the DLL to vary the delay of the voltage controlled delay loop in the one direction from the initial delay until the operating point is reached.
    Type: Grant
    Filed: October 4, 2007
    Date of Patent: May 12, 2009
    Assignee: MOSAID Technologies, Inc.
    Inventors: Dieter Haerle, Tony Mai, Peter Vlasenko
  • Patent number: 7528664
    Abstract: The signal-to-noise ratio for a digital conversion circuit is improved by taking a source signal and generating N signals that are each phase-shifted relative to each other, thereby generating N phase-shifted signals. Each of the N signals has a frequency that is a fraction of a frequency of the source signal. The source signal is input to a dividing circuit to generate the N signals. The source signal is generated by a signal source, such as an oscillator. Each of the N signals is hard-limited and processed through a detection circuit. The detection circuit can be a frequency detection circuit configured to determine the frequency of the source signal and to output a corresponding digital word, or a phase detection circuit configured to determine a phase of the source signal and to output a corresponding digital word.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: May 5, 2009
    Assignee: Panasonic Corporation
    Inventor: Paul Cheng-Po Liang
  • Patent number: 7528891
    Abstract: An AV signal transmission/reception apparatus and a digital signal transmission system and method. A reception apparatus and method that can reproduce an audio reference clock of a plurality of different frequencies from a video reference clock. A pixel clock is divided by a divider into a signal of a constant frequency for phase comparison by a phase comparator. A sample frequency (Fs) decoder determines division ratio information based on Fs information representing the frequency of an audio clock transmitted from a transmission unit. The division ratio information is supplied to a first variable divider and a second variable divider. As a result, even if the frequency of the audio clock changes, the oscillation frequency of the a VCO unit can be kept constant, and the second variable divider can output a signal of a constant frequency for keeping constant the frequency of the signal transmitted to the phase comparator.
    Type: Grant
    Filed: August 21, 2003
    Date of Patent: May 5, 2009
    Assignee: Sony Corporation
    Inventor: Masaru Miyamoto
  • Patent number: 7525354
    Abstract: Methods, circuits, devices, and systems are provided, including embodiments with local coarse delay units. One embodiment includes generating a first delayed signal, a second delayed signal, and a third delayed signal by delaying a clock reference signal with various time delays of a coarse delay line and local coarse delay units. This method embodiment also includes generating a clock output signal based on the first delayed signal, the second delayed signal, or the third delayed signal, depending on a phase difference between the clock reference signal and the clock output signal.
    Type: Grant
    Filed: June 9, 2006
    Date of Patent: April 28, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Tyler J. Gomm, Kang Y. Kim
  • Publication number: 20090102523
    Abstract: Provided are a digital phase interpolator, which performs linear phase interpolation irrelevantly to input order of two input signals, and a semi-digital delay locked loop (DLL), which includes and controls the same. The phase interpolator includes: a first clocked inverter controlled by a phase indicating signal and providing a first output signal to a common output terminal by inverting a first input signal, and a second clocked inverter controlled by the phase indicating signal and providing a second output signal to the common output terminal by inverting the second input signal. The second clocked inverter is clocked by the first input signal when the phase indicating signal is in a first logic state, and the first clocked inverter is clocked by the second input signal when the phase indicating signal is in a second logic state.
    Type: Application
    Filed: October 21, 2008
    Publication date: April 23, 2009
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Jin-gook KIM, Seung-jun BAE, Kwang-il PARK
  • Publication number: 20090102521
    Abstract: A circuit includes a logic circuit containing a first transistor and a second transistor which are connected in series to each other between a high power supply and a low power supply in such a manner that an emitter of one of the first and second transistors is connected to a collector of the other of the first and second transistors. The first transistor is positioned closer to the high power supply, and the second transistor is positioned closer to the low power supply. The logic circuit operates in accordance with voltages input into bases of the first and second transistors. The circuit further includes a current amplifying circuit containing a third transistor whose collector is connected to one of the high and low power supplies, whose emitter is connected to the other of the high and low power supplies, and whose base is connected to an output from the logic circuit.
    Type: Application
    Filed: October 19, 2007
    Publication date: April 23, 2009
    Applicant: ADVANTEST CORPORATION
    Inventor: Hiroyuki SATOH
  • Patent number: 7518423
    Abstract: A digital DLL circuit includes: a register configured to hold a delay target value; an oscillator; a first counter configured to count an external reference clock or an oscillation output from the oscillator; a second counter configured to count the oscillation output from the oscillator or the external reference clock in every measurement cycle determined by the first counter; and a digitally-controlled variable delay circuit. The DLL circuit further includes a control circuit configured to control the reset and activation of the first counter and the second counter, and control the stop of the first and second counters according to need, based on a count value of the first counter, the control circuit subjecting a count value of the second counter and the delay target value of the register to a digital arithmetic operation, and supplying the variable delay circuit with a result of the arithmetic operation as a delay control value.
    Type: Grant
    Filed: February 9, 2007
    Date of Patent: April 14, 2009
    Assignee: Sony Corporation
    Inventor: Ichiro Kumata
  • Publication number: 20090085622
    Abstract: Implementations feature systems and techniques for phase-locked loops (PLLs). In some aspects, implementations feature a system that has a PLL circuit including an oscillator and programmable reference frequency divider circuit or a programmable feedback frequency divider circuit. The PLL includes a control circuit to reduce a time required for a PLL settling time by programming a division value into the programmable reference frequency divider circuit and/or the programmable feedback frequency divider circuit to target the oscillator to operate outside of a system operating frequency range of the oscillator during start-up of PLL operations. The control circuit can program another division value into the programmable reference frequency divider circuit and/or the programmable feedback frequency divider circuit after stabilization of the variable oscillator.
    Type: Application
    Filed: April 25, 2008
    Publication date: April 2, 2009
    Applicant: NANOAMP SOLUTIONS, INC. (CAYMAN)
    Inventors: David H. Shen, Ann P. Shen, Axel Schuur
  • Patent number: 7511581
    Abstract: A wide-band multimode frequency synthesizer using a Phase Locked Loop (PLL) is provided. The multiband frequency synthesizer includes a multimode prescaler, a phase detector/a charge pump, a swallow type frequency divider, and a switching bank LC tuning voltage-controlled oscillator having wide-band and low phase noise characteristics. The multimode prescaler operates in five modes and divides a signal up to 12 GHz. The wide-band frequency synthesizer can be used in various fields such as WLAN/HYPERLAN/DSRC/UWB systems that operate in the frequency range from 2 GHz to 9 GHz.
    Type: Grant
    Filed: December 5, 2006
    Date of Patent: March 31, 2009
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Ja Yol Lee, Kwi Dong Kim, Chong Ki Kwon, Jong Dae Kim, Sang Heung Lee
  • Patent number: 7511543
    Abstract: An instantaneous phase error detector (IPED) and method includes a first gate configured to logically OR output phase error signals as data to a first latch, and a second gate configured to logically combine the output phase error signals to clock the first latch. A delay element delays to the data to the first latch where the output of the first latch provides instantaneous phase error change information. A second latch is coupled to the output phase error signals to output a lead/lag signal to indicate which of the output phase error signals is leading. A phase-locked loop employing the output of the IPED is also disclosed along with static phase measurement and jitter optimization features.
    Type: Grant
    Filed: February 8, 2007
    Date of Patent: March 31, 2009
    Assignee: International Business Machines Corporation
    Inventors: Daniel J. Friedman, Yong Liu, Woogeun Rhee
  • Patent number: 7511544
    Abstract: A digital DLL circuit includes: a first register configured to hold a delay specifying value to specify a delay; a second register configured to specify a correction value for a gate delay inside an LSI; a digitally-controlled variable delay circuit; and a control circuit configured to produce a delay control value to implement control so that a delay by the variable delay circuit is kept at the delay specifying value of the first register. The digital DLL circuit further includes an adder circuit configured to add a gate delay correction value held by the second register to the delay control value output from the control circuit, and output a resultant value to a control input of the variable delay circuit.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: March 31, 2009
    Assignee: Sony Corporation
    Inventor: Ichiro Kumata
  • Patent number: 7501865
    Abstract: A method and systems for a digital frequency locked loop in a multi-core processor are provided. The method includes applying a dither modulation signal at a dither modulation frequency to modulate an output frequency to provide a clock signal to a core of the multi-core processor. The method further includes filtering a feedback signal of the output frequency with respect to a target frequency. The method additionally includes determining a frequency error in the filtered feedback signal as a function of alignment of the output frequency to the target frequency, and adjusting the output frequency in response to the frequency error.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: March 10, 2009
    Assignee: International Business Machines Corporation
    Inventors: Lawrence Jacobowitz, Daniel J. Stigliani, Jr.
  • Publication number: 20090052508
    Abstract: In the case where a frequency control word is changed from FCW0 to FCW2, a control sensitivity estimation section 12 firstly measures oscillatory frequencies f1L and f1H obtained, respectively, when frequency control words FCW1L and FCW1H being used as dummies are set, and then measures an oscillatory frequency f2 obtained when a frequency control word FCW2 is set. Thereafter, based on values of the oscillatory frequencies f1L, f1H and f2, the control sensitivity estimation section 12 calculates a control sensitivity KDCO2 obtained when the frequency control word FCW2 is set. Based on a value of the control sensitivity KDCO2, the loop filter 13 determines values of filter coefficients ?2 and ?2 so as to be equal to a natural frequency ?n and a damping factor ?, respectively, both of which have been previously designed.
    Type: Application
    Filed: July 11, 2008
    Publication date: February 26, 2009
    Inventor: Kenji TAKAHASHI
  • Patent number: 7495488
    Abstract: A phase-locked loop (PLL) circuit includes a phase/frequency detector (PFD), a charge pump, a loop filter, a control circuit, a VCO, and a feedback circuit. The control circuit generates a digital control signal in response to the up signal, the down signal, and the oscillation-control voltage. The VCO generates an output signal of which a frequency is changed in response to the oscillation-control voltage and the digital control signal. Accordingly, the PLL circuit can automatically tune the frequency of the output signal of a VCO using a digital circuit having a simple structure.
    Type: Grant
    Filed: February 28, 2007
    Date of Patent: February 24, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Woo-Seok Kim
  • Publication number: 20090045859
    Abstract: A method and apparatus are provided for minimizing output pulse jitters in a phase locked loop. The method includes pre-setting the digital phase locked loop to a desired frequency, locking the digital phase locked loop to the desired frequency to generate an output signal, and filtering the output signal of the digital phase locked loop to maintain undesirable jitter to an acceptable range. In one embodiment, the apparatus is a medical imaging device. In another embodiment, the apparatus is a baggage imaging device.
    Type: Application
    Filed: August 16, 2007
    Publication date: February 19, 2009
    Inventors: Nathanael Dale Huffman, Jason Stuart Katcha, Phil E. Pearson, JR.
  • Patent number: 7492850
    Abstract: The phase locked loop (PLL) with adjustable phase shift is described. The PLL includes a voltage controlled oscillator which is capable of generating multiple phase shifted output signals, and multiple phase detectors capable of determining the phase differences between the output signals and a reference clock. The PLL further includes a weighting device capable of weighting the phase differences and generating a control signal for the voltage controlled oscillator.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: February 17, 2009
    Assignee: International Business Machines Corporation
    Inventors: Christian Ivo Menolfi, Thomas Helmut Toifl
  • Patent number: 7489568
    Abstract: A methodology is disclosed that enables the delay stages of an analog delay locked loop (DLL) or phase locked loop (PLL) to be programmed according to the operating condition, which may depend on the frequency of the input reference clock. The resulting optimized delay stages allow for a broad frequency range of operation, fast locking time over a wide range of input clock frequencies, and a lower current consumption at high clock frequencies. Better performance is achieved by allowing the number of analog delay stages active during a given operation to be flexibly set. The deactivation or turning off of unused delay stages conserves power at higher frequencies. The high frequency range of operation is increased by using a flexible number of delay stages for various input clock frequencies. Because of the rules governing abstracts, this abstract should not be used to construe the claims.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: February 10, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Kang Yong Kim, Dong Myung Choi
  • Patent number: 7482880
    Abstract: A frequency modulated output of a Digital Locked Loop (DLL) is implemented with a Johnson Counter outputting a sample clock and a synchronized digital code at a multiple of the sample clock. The digital code drives a digital-to-analog converter to generate a frequency modulated control signal. The control signal is summed with the center frequency control from the digital locked loop digital filter to provide a frequency modulated center frequency control signal to the DLL oscillator.
    Type: Grant
    Filed: November 8, 2006
    Date of Patent: January 27, 2009
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Scott W. Herrin, Chris C. Dao, Patrick M. Falvey, Thomas J. Rodriguez, Jules D. Campbell, Jr.
  • Publication number: 20090015303
    Abstract: Provided is an analog/digital control delay locked loop (DLL). The DLL includes a phase detector for detecting a phase difference between an input clock signal and a feedback signal to provide an up detection signal or a down detection signal, a charge pump for generating an adjusted output current based on the up or down signals, a loop filter for low pass-filtering the output current to produce an analog control voltage, a voltage controlled delay Line (VCDL) for receiving the analog control voltage, the input clock signal and a digital code, and delaying the input clock signal based on the analog control voltage and the digital code to provide an output clock signal, a delay replica modeling unit formed by replica of delay factors for producing the feedback signal depending on the output clock signal, and a digital code generator for generating the digital code.
    Type: Application
    Filed: September 15, 2008
    Publication date: January 15, 2009
    Inventor: Yong-Ju Kim
  • Patent number: 7477083
    Abstract: A delay amount variable circuit (8) adapted to change a delay amount according to a ZQ calibration result is inserted in a path of a DQ replica system. The delay amount of the path of the DQ replica system is variable and is adjusted so as to make constant a timing skew difference between a DQ buffer system and the DQ replica system. The ZQ calibration result changes depending on variations in temperature, voltage, and manufacture. Therefore, by obtaining the delay amount corresponding to these variations, there are obtained a DLL circuit with high accuracy that can make the skew difference constant, and a semiconductor device incorporating such a DLL circuit.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: January 13, 2009
    Assignee: Elpida Memory, Inc.
    Inventors: Hiroki Fujisawa, Ryuji Takishita
  • Patent number: 7471157
    Abstract: A charge pump that generates a bias input to affect an output voltage of the charge pump is described herein. The charge pump may include a charge pump stage, a replica charge pump stage, and a self-biased differential amplifier. In some instances, the charge pump may be incorporated into a delay locked loop or a phase locked loop.
    Type: Grant
    Filed: June 20, 2006
    Date of Patent: December 30, 2008
    Assignee: Intel Corporation
    Inventor: Yongping Fan
  • Publication number: 20080315928
    Abstract: An embodiment of the present invention provides a phase locked loop that operates on clock signals derived from an RF clock signal generated by the phase locked loop. A frequency reference input provides a reference clock. A controllable oscillator generates the RF clock signal. A phase detection circuit operates on the reference clock to provide digital phase error samples indicative of a phase difference between the reference clock and the RF clock. A dithering circuit is coupled to the reference signal and injects a short sequence dither signal into the reference signal in order to overcome quantization noise and thereby improve RMS phase-error detection for integer channels.
    Type: Application
    Filed: May 2, 2008
    Publication date: December 25, 2008
    Inventors: Khurram WAHEED, Mahbuba Sheba, Robert Bogdan Staszewski, Socrates Vamvakos
  • Patent number: 7466207
    Abstract: A novel apparatus for and a method of estimating, calibrating and tracking in real-time the gain of a radio frequency (RF) digitally controlled oscillator (DCO) in an all-digital phase locked loop (ADPLL). Precise setting of the inverse DCO gain in the ADPLL modulating path allows direct wideband frequency modulation that is independent of the ADPLL loop bandwidth. The gain calibration technique is based on a steepest descent iterative algorithm wherein the phase ADPLL error is sampled and correlated with the modulating data to generate a gradient. The gradient is then scaled and added to the current value of the DCO gain multiplier.
    Type: Grant
    Filed: January 3, 2007
    Date of Patent: December 16, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Robert B. Staszewski, Gennady Feygin, Oren E. Eliezer, Dirk Leipold
  • Publication number: 20080297217
    Abstract: A method and apparatus is provided for reducing interference in circuits. A management strategy is provided to reduce reference spurs and interference in circuits. The management strategy uses a combination of one or more techniques which reduce the digital current, minimize mutual inductance, utilize field cancellation, prevent leakage current, and/or manage impedance. These techniques may be used alone, or preferably, used on combination with one another.
    Type: Application
    Filed: October 31, 2007
    Publication date: December 4, 2008
    Inventors: David R. Welland, Donald A. Kerth, Caiyi Wang
  • Patent number: 7457392
    Abstract: A delay locked loop includes a first delay device for obtaining a fine setting and a downstream-connected second delay device for obtaining a coarse setting of the delay time. The control signals for controlling the respective delay devices are provided by synchronization latches, which receive a clock obtained by the output signal of the first delay device for obtaining the fine setting. The delay locked loop enables a linear operating behavior at a high operating frequency and is particularly suitable when a differential embodiment of the two delay devices is used.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: November 25, 2008
    Assignee: Infineon Technologies AG
    Inventors: Christian Weis, Thomas Miller, Patrick Heyne
  • Patent number: 7453958
    Abstract: A device for extracting a clock frequency underlying a data stream includes means for controlling a controllable oscillator, coarse-tuning means and fine-tuning means, wherein coarse-tuning means responds to a second data pattern present in the data stream and sets the oscillator coarsely based on its length. Fine-tuning means responds to temporally consecutive first data patterns present in the data stream with a higher accuracy in order to perform a fine tuning of the oscillator on the basis of the temporal length between the two first data patterns and on the basis of the number of clock cycles of the controllable oscillator occurring in this temporal length.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: November 18, 2008
    Assignee: Infineon Technologies AG
    Inventors: Patrizia Greco, Andreas Steinschaden, Edwin Thaller, Gernot Zessar
  • Patent number: 7449928
    Abstract: According to the present invention, there is provided a semiconductor device including: a phase locked loop circuit having, a phase frequency detector which receives a reference signal and a frequency-divided signal, and outputs a phase difference detection signal by performing phase comparison, a charge pump which receives the phase difference detection signal and outputs a charge pump signal by converting a voltage change into a current change, a loop filter which receives the charge pump signal, and outputs a control voltage by passing components having frequencies not more than a predetermined frequency, a voltage controlled oscillator which outputs a frequency signal having a frequency based on the control voltage, and a frequency divider which receives the frequency signal, and outputs the frequency-divided signal by dividing the frequency; a mask signal generator which generates a mask signal masking a timing at which the phase frequency detector compares phases of the frequency-divided signal and the
    Type: Grant
    Filed: January 11, 2007
    Date of Patent: November 11, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroyuki Kobayashi
  • Patent number: 7449871
    Abstract: A system is disclosed for setting an electrical circuit parameter at a predetermined value. The system comprises a first electrical component having a first electrical parameter associated therewith. Sensing means generate a control signal indicative of the value of the first electrical parameter. A second electrical component has a second electrical parameter associated therewith, the value of which has a predetermined relation to the value of the first electrical parameter. Adjustment means receive the control signal generated by the sensing means; and, in response to the control signal being indicative that the electrical circuit parameter is not at the predetermined value, selectively connects or disconnects at least one further electrical component to or from the second electrical component thereby to provide said predetermined value.
    Type: Grant
    Filed: February 25, 2004
    Date of Patent: November 11, 2008
    Assignee: Intel Corporation
    Inventors: Andrew David Talbot, Keith Jones
  • Patent number: 7449927
    Abstract: A delay locked loop increases an operation margin of a delay locked loop by using an output clock having more advanced phase than a DLL output clock. A clock delay compensation block receives an external clock signal to thereby generate a first multi clock and a second multi clock. A phase control block compares the first multi clock with the second multi clock to generate phase control signal controlling a shifting operation. A multi-phase delay control block performs a shifting operation based on the phase control signal to control the clock delay compensation block.
    Type: Grant
    Filed: June 30, 2006
    Date of Patent: November 11, 2008
    Assignee: Hynix Semiconductor Inc.
    Inventor: Kyung-Hoon Kim
  • Patent number: 7447106
    Abstract: A methodology is disclosed that enables the delay stages of an analog delay locked loop (DLL) or phase locked loop (PLL) to be programmed according to the operating condition, which may depend on the frequency of the input reference clock. The resulting optimized delay stages allow for a broad frequency range of operation, fast locking time over a wide range of input clock frequencies, and a lower current consumption at high clock frequencies. Better performance is achieved by allowing the number of analog delay stages active during a given operation to be flexibly set. The deactivation or turning off of unused delay stages conserves power at higher frequencies. The high frequency range of operation is increased by using a flexible number of delay stages for various input clock frequencies. Because of the rules governing abstracts, this abstract should not be used to construe the claims.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: November 4, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Kang Yong Kim, Dong Myung Choi
  • Patent number: 7439812
    Abstract: A phase locked loop circuit includes an oscillator, a dividing circuit coupled to the oscillator having a controllable dividing factor, and a rangefinder circuit coupled to the dividing circuit. The rangefinder circuit is configured to control the dividing factor in response to an operating characteristic of the phase-locked loop circuit.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: October 21, 2008
    Assignee: Cypress Semiconductor Corporation
    Inventors: Carel J. Lombaard, Brendan O'Regan
  • Publication number: 20080246521
    Abstract: A system and a method for operating the same. The system includes a fractional-N phase-locked loop (PLL). The PLL includes a PLL input and a PLL output. The fractional-N PLL further includes a multiplexer. The multiplexer includes a multiplexer output electrically coupled to the PLL input. The multiplexer further includes M multiplexer inputs, M being an integer greater than 1. Two or more reference frequencies are applied to the inputs of the multiplexer, by the selection of one from the reference frequencies, the low spur can be reached.
    Type: Application
    Filed: April 4, 2007
    Publication date: October 9, 2008
    Inventor: Kai Di Feng
  • Publication number: 20080246522
    Abstract: A phase locked loop (PLL) which includes a phase frequency detector coupled with a time to digital converter capable of comparing a reference signal with an oscillator signal and generating a digital value representing the phase difference between the reference signal and the oscillator signal. The PLL further includes a state machine for phase acquisition that is capable of generating a control value depending on the digital value, and a controllable oscillator that is capable of generating the oscillator signal depending on the control value.
    Type: Application
    Filed: June 4, 2008
    Publication date: October 9, 2008
    Inventors: Marcel A. Kossel, Thomas E. Morf, Martin L. Schmatz, Silvan Wehrli
  • Publication number: 20080238498
    Abstract: A clock generator includes a delta sigma modulator, a counter and a first phase lock loop. The delta sigma modulator sequentially generates a plurality of variable parameters according to a predetermined value and a first input clock signal. The counter, which is connected to the delta sigma modulator, is used to generate an output clock signal in accordance with a counting value and a second input clock signal. The counting value is relevant to the variable parameters. The first phase lock loop, which is connected to the output of the counter, is used to generate an objective clock signal in accordance with the output clock signal.
    Type: Application
    Filed: March 12, 2008
    Publication date: October 2, 2008
    Applicant: MSTAR SEMICONDUCTOR, INC.
    Inventors: Christopher Tin Sing Lam, Fucheng Wang, Shoufang Chen
  • Publication number: 20080238508
    Abstract: An apparatus is provided for detecting the loss of an input clock signal for a phase-locked loop (PLL). The apparatus includes a time delay circuit, a first frequency divider and a digital logic circuit. The time delay circuit receives the input clock signal and outputs a first time-delayed clock signal. The first frequency divider receives an input signal from an internal clock of the PLL and outputs a clock signal having the same frequency or a lower frequency than that of the time-delayed clock signal. The digital logic circuit that receives the first frequency divider output signal and the first time-delayed clock signal and outputs a signal indicating the loss of the input clock signal if there is no first time-delayed clock signal for a cycle of the first frequency divider output signal.
    Type: Application
    Filed: March 30, 2007
    Publication date: October 2, 2008
    Applicant: INTEGRATED DEVICE TECHNOLOGY, INC.
    Inventor: Tao Jing
  • Patent number: 7423463
    Abstract: Clock capturing synchronization circuitry first generates a synchronized clock signal from a reference clock signal, then captures the synchronized clock signal, and continues to output a synchronized clock signal after the reference clock signal is removed. The clock capturing synchronization circuitry also reduces input referred jitter in the synchronized clock signal.
    Type: Grant
    Filed: July 18, 2006
    Date of Patent: September 9, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Adrian J Drexler, Debra M Bell, Tyler J Gomm, Seong-hoon Lee
  • Patent number: 7420426
    Abstract: A frequency modulated output of a digital locked loop (DLL) is implemented with a Johnson Counter outputting a sample clock and a synchronized digital code at a multiple of the sample clock. The digital code drives a digital-to-analog converter to generate a frequency modulated control signal. The control signal is summed with the center frequency control from the digital locked loop digital filter to provide a frequency modulated center frequency control signal to the DLL oscillator.
    Type: Grant
    Filed: December 30, 2005
    Date of Patent: September 2, 2008
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Scott W. Herrin, Chris C. Dao, Patrick M. Falvey, Thomas J. Rodriguez, Jules D. Campbell, Jr.
  • Patent number: 7421048
    Abstract: A multimedia processing system and method thereof are provided. The system and method provide for synchronizing a first clock of a multimedia decoder of a first multimedia processing device to a second clock of a multimedia encoder of a second multimedia processing device, synchronizing a first timing reference of the multimedia decoder to a second timing reference of the multimedia encoder, receiving, at a network interface of the first multimedia processing device, an encoded multimedia data stream from a network interface of the second multimedia processing device, wherein the encoded multimedia data stream is encoded by the multimedia encoder based on the second clock and the second timing reference, and decoding the encoded multimedia data stream at the multimedia decoder based on the first clock and the first timing reference.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: September 2, 2008
    Assignee: ViXS Systems, Inc.
    Inventors: Paul Ducharme, James Girardeau, Jr., Adeline Chiu, James Doyle