Variable Or Adjustable Patents (Class 327/237)
  • Publication number: 20110267119
    Abstract: A phase shifter includes a low-pass filter, a high-pass filter, and an all-pass filter coupled in series between an RF input terminal and an RF output terminal of the phase shifter, at least one of the filters being tunable, controlling the phase of an input signal over a wide range of frequencies.
    Type: Application
    Filed: May 3, 2011
    Publication date: November 3, 2011
    Inventors: Michael Koechlin, Cemin Zhang
  • Publication number: 20110248761
    Abstract: Apparatus and methods are disclosed for adjusting phase of data signals to compensate for phase-offset variations between devices during normal operation. The phase of data signals are adjusted individually in each transmit data unit and receive data unit across multiple data slices with a common set of phase vector clock signals and a corresponding clock cycle count signal. The transmission of signal information between a first device (such as a memory controller) and a second device (such as a memory component) occurs without errors even when the accumulated delays between the first device and second device change by a half symbol time interval or more during operation of the system. The apparatus reduces the circuitry required, such as phase-lock-loops, for individually adjusting the phase of each transmit data unit and receive data unit across multiple data slices, which in turn results in reduction in complexity and cost of the system.
    Type: Application
    Filed: June 17, 2011
    Publication date: October 13, 2011
    Inventors: Craig E. Hampel, Richard E. Perego, Stefanos S. Sidiropoulos, Ely K. Tsern, Fredrick A. Ware
  • Patent number: 8035436
    Abstract: A phase-interpolator circuit is described. In the phase-interpolator circuit, an output signal, having a fundamental frequency and a phase, is generated based on a weighted summation of a first reference signal and a second reference signal, where the first reference signal has the fundamental frequency and a first phase, and the second reference signal has the same fundamental frequency and a second phase. Note that contributions of the first reference signal and the second reference signal, respectively, to the output signal are determined based on associated first and second impedance values in a weighting circuit in the phase-interpolator circuit. For example, a programmable capacitance ratio of two capacitors may be used to interpolate between the first reference signal and the second reference signal.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: October 11, 2011
    Assignee: Oracle America, Inc.
    Inventors: Tamer M. Ali, Robert J. Drost, Chih-Kong Ken Yang
  • Patent number: 8035437
    Abstract: A phase interpolator receiving a first signal having an oscillation frequency Fin and providing a second signal having said oscillation frequency and having a phase shift ?? with respect to the first signal which depends on a third signal. The interpolator includes a variable phase-shifter receiving the first signal and providing the second signal, the phase-shifter circuit includes an oscillator having a variable natural frequency Fo controlled by a fourth signal; a phase comparator capable of receiving the first and second signals and of providing a fifth signal representative of said phase shift; and a unit capable of providing the fourth signal which depends on the third and fifth signals.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: October 11, 2011
    Assignee: STMicroelectronics Maroc
    Inventors: Mohamed Benyahia, Lionel Vogt
  • Patent number: 8013652
    Abstract: In a case where two constant envelope signals corresponding to an input signal are generated through analog signal processing, variation in detection sensitivities of amplitudes of those signals is suppressed. At least one of a mixer (24) for detecting an amplitude of a first intermediate signal S1 and a mixer (26) for detecting an amplitude of a second intermediate signal S2 detects an amplitude of a given reference signal, and sampling hold circuits (36, 38) hold a voltage related to those amplitudes. Then, detection sensitivities of the mixer (24, 26) are corrected based on the held voltage.
    Type: Grant
    Filed: December 25, 2008
    Date of Patent: September 6, 2011
    Assignee: Kyocera Corporation
    Inventor: Akira Nagayama
  • Patent number: 8013650
    Abstract: A phase adjustment circuit includes first to nth two-phase adjustment circuits. Each two-phase adjustment circuit includes a first logic circuit for performing logical sum of two input signals, a second logic circuit for performing logical product of the two input signals, a first delay circuit having a signal delay equal to that of the second logic circuit and configured to delay a signal output from the first logic circuit, and a second delay circuit having a signal delay equal to that of the first logic circuit and configured to delay a signal output from the second logic circuit. Two signals output from two of the two-phase adjustment circuits in a certain stage are input into one of the two-phase adjustment circuits in the next stage.
    Type: Grant
    Filed: September 1, 2006
    Date of Patent: September 6, 2011
    Assignee: Panasonic Corporation
    Inventors: Shiro Dosho, Shiro Sakiyama, Yusuke Tokunaga, Seiji Watanabe, Hiroshi Koshida
  • Publication number: 20110193606
    Abstract: A radio frequency (RF) modulator includes: converting means for up-converting a first and second baseband signals into a first and second up-converted signals with a reference clock, wherein a phase difference between the first and second baseband signals substantially equals 180°/N; and combining means for combining the first and second up-converted signals to generate an output signal.
    Type: Application
    Filed: February 11, 2010
    Publication date: August 11, 2011
    Inventor: Chih-Hao Sun
  • Publication number: 20110187432
    Abstract: A semiconductor device including a common delay circuit configured to delay an input signal in response to a delay control code to output a first delayed input signal and a second delayed input signal; a first delay circuit configured to delay the first delayed input signal in response to the delay control code and to output a first output signal; and a second delay circuit configured to delay the second delayed input signal in response to the delay control code and to output a second output signal.
    Type: Application
    Filed: April 5, 2010
    Publication date: August 4, 2011
    Inventors: Yong-Hoon Kim, Hyun-Woo Lee
  • Patent number: 7990179
    Abstract: A layout design method in accordance with an exemplary aspect of the present invention is a layout design method for a clock tree circuit, including disposing a first clock distribution circuit in a clock tree circuit, wiring the clock tree circuit in which the first clock distribution circuit is disposed, verifying timing of the wired clock tree circuit, and replacing the first distribution element by a second clock distribution circuit based on a result of the timing verification, the second clock distribution circuit having roughly a same input load capacitance as the first clock distribution circuit and a different delay value from the first clock distribution circuit.
    Type: Grant
    Filed: May 12, 2010
    Date of Patent: August 2, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Toshiaki Nakahashi
  • Patent number: 7969219
    Abstract: A delay cell with a wider delay range is provided. The delay cell employs frequency dependent current source to generate the majority of the delay of the cell, while a control circuit (which is generally a current source that is controlled by a control voltage) provides additional delay. Thus, the delay cell provided here can be used to improve the performance of delay locked loops (DLLs) and other circuits.
    Type: Grant
    Filed: November 23, 2009
    Date of Patent: June 28, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Jagannathan Venkataraman, Vivesvaraya A. Pentakota, Samarth S. Modi
  • Publication number: 20110148498
    Abstract: Methods and systems to adjust a phase difference between signals, such as to perform quadrature phase correction. First and second signals are digitally compared, such as with exclusive OR circuitry, to provide a comparison signal having a duty cycle representative of a phase difference between the signals. A phase delay of one or both of the first and second signals is adjusted until the duty cycle of the comparison signal corresponds to a desired phase difference. In a clock and data recovery system, the signals may correspond to a zero degree phase of a first phase interpolator and a ninety degree phase of a second phase interpolator, and digital codes to the first and second phase interpolators may be adjusted to provide a fifty percent duty cycle in the comparison signal.
    Type: Application
    Filed: December 17, 2009
    Publication date: June 23, 2011
    Inventors: Praveen Mosalikanti, Nasser Kurd
  • Patent number: 7961025
    Abstract: In one illustrative embodiment, an apparatus for a current-mode phase rotator with partial input phase switching comprises a mixer, wherein the mixer is a four quadrant current-mode mixer comprised of four interpolation buffers, wherein each interpolation buffer receives as input a clock phase from a set of four equidistant clock phases, and a set of two-output current-steering digital to analog converters that supply tail currents to the mixer wherein a first digital to analog converter has additional switches to connect each of two outputs to one of two polarities of a given clock while each remaining digital to analog converter has no additional switches and has two outputs supplying current only to two different polarities of a same clock phase wherein steering the current during incremental rotation about a phase circle defines an octagonal shaped phase envelope.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: June 14, 2011
    Assignee: International Business Machines Corporation
    Inventor: Sergey Vladimirovich Rylov
  • Publication number: 20110133784
    Abstract: A circuit for detecting a phase imbalance of signals includes a conversion block and a comparator coupled to the conversion block. The conversion block generates generating a direct current (DC) signal based on a first signal and a second signal. The level of the DC signal is determined by a phase difference between the first signal and the second signal. The comparator compares the DC signal to a reference signal and generates an alert signal if a difference between the DC signal and the reference signal is greater than a predetermined threshold.
    Type: Application
    Filed: January 20, 2010
    Publication date: June 9, 2011
    Inventors: Yongbin YUAN, Jundong ZHU, Jingwei ZHANG
  • Patent number: 7944319
    Abstract: Clock spreading systems and methods are disclosed. In one embodiment of the invention, a clock spreading system is provided in an integrated transceiver system that comprises a base band control system and a transceiver coupled to the base band control system. The clock spreading system provides a spread clock output signal derived from a clock reference signal for clocking one of the base band control system and the transceiver. The clock spreading system is configured to provide a periodic phase modulated spread clock output signal during receiving of data in a receive mode and a pseudo-random phase modulated spread clock output signal during transmitting of data in a transmit mode.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: May 17, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Jeff Kerr, Gennady Feygin, Jose Fresquez
  • Patent number: 7932552
    Abstract: Disclosed are embodiments of a variable-delay field effect transistor (FET) having multiple source regions that can be individually and selectively biased to provide an electrical connection to a single drain region. Delay is a function of which of the multiple source regions is/are selectively biased as well as a function of gate resistance and capacitance. Such a variable-delay FET can be incorporated into a phase adjusting circuit, which uses gate propagation delays to selectively phase adjust an input signal. The phase adjusting circuit can be tuned by incorporating non-salicided resistances and additional capacitance at various positions on the gate structure. The phase adjusting circuit can further be modified into a phase adjusting mixer circuit that enables a phase adjusted signal to be combined with an additional signal.
    Type: Grant
    Filed: August 3, 2007
    Date of Patent: April 26, 2011
    Assignee: International Business Machines Corporation
    Inventors: Wagdi W. Abadeer, Anthony R. Bonaccio, Joseph A. Iadanza
  • Patent number: 7928789
    Abstract: Methods and apparatus are provided for improving phase switching and linearity in an analog phase interpolator. A phase interpolator in accordance with the present invention comprises (i) a plurality of tail current sources that are activated for substantially all times when the phase interpolator is operational; (ii) at least two pairs of input transistor devices, wherein one pair of the input transistor devices is associated with a minimum phase of the phase interpolator and another pair of the input transistor devices is associated with a maximum phase of the phase interpolator; and (iii) a plurality of current steering switches that provide currents generated by the plurality of tail current sources to one or more of the at least two pairs of input transistor devices, based on an applied interpolation control signal.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: April 19, 2011
    Assignee: Agere Systems Inc.
    Inventors: Ronald L. Freyman, Craig B. Ziemer
  • Publication number: 20110050312
    Abstract: A multi-phase clock generation circuit including a phase interpolation circuit that generates and outputs an interpolation signal based on first and second clock signals, the interpolation signal interpolating a phase between output clock signals corresponding to the first and the second clock signals, and a control circuit that generates a first control signal to adjust a phase of the interpolation signal and outputs the first control signal to the phase interpolation circuit, in which the control circuit includes a timing detection circuit that detects a timing of a change in a logic value of the interpolation signal, and a control signal generation circuit that generates the first control signal according to a detection result in the timing detection circuit.
    Type: Application
    Filed: June 22, 2010
    Publication date: March 3, 2011
    Inventor: Satoshi FUJINO
  • Patent number: 7898353
    Abstract: A circuit includes a clock conditioning circuit which receives an encoded clock signal, and provides first and second conditioned clock signals in response. The clock conditioning circuit adjusts a period of the first and second conditioned clock signals in response to an adjustment of a period of the encoded clock signal. The circuit includes a modulator which receives the first and second conditioned clock signals.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: March 1, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Merit Y. Hong, Bruce M. Newman
  • Patent number: 7893745
    Abstract: The wideband programmable phase shifting circuitry includes a charge pump, a comparator, and a voltage reference generator block. An input signal controls the charge pump which charges and discharges a capacitor connected to an output of the charge pump. The comparator continuously compares the voltage across the capacitor with a reference voltage, ratio of VREF, which is generated by the voltage reference generator block. The voltage VREF is generated to compensate for power supply and integration process variations. The voltage reference generator is comprised of a charge pump unit, a frequency divider unit, switches, and two capacitors. The adjusted VREF ratio controls the comparator threshold level and hence a programmable phase difference between the input signal of the charge pump and the output signal of the comparator.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: February 22, 2011
    Assignee: King Fahd University of Petroleum and Minerals
    Inventor: Saad Mohammad Al-Shahrani
  • Patent number: 7872515
    Abstract: A phase interpolation device and a slew rate control device thereof. The slew rate control device comprises a slew rate control circuit, source followers and a comparator. The slew rate control circuit receives clock signals and a control signal, and adjusts slew rate of the clock signals according to the control signal. The source followers each comprise an input terminal and an output terminal. The input terminals of the source followers are coupled to the slew rate control circuit to receive the adjusted clock signals, respectively. The output terminals of the source followers are connected together at a node. The comparator has a first input terminal coupled to the node, a second input terminal receiving a voltage reference, and an output terminal providing the control signal for the slew rate control circuit. The setting of the voltage reference is dependent on the desired slew rate of the adjusted clock signals.
    Type: Grant
    Filed: October 27, 2009
    Date of Patent: January 18, 2011
    Assignee: Himax Technologies Limited
    Inventor: Chun-Cheng Kuo
  • Publication number: 20110006825
    Abstract: This invention relates to a phase control circuit for an optical receiver (1). The phase control circuit (9, 19) comprises a non-linear element (22) and a power detector (24). The non-linear element (22) has a rectifying characteristic, inputs the received electrical signal (7, 17) and provides a rectified signal at its output. The power detector (24) provides an error signal which is used to obtain a phase control signal (5) which is output by the phase control circuit. The invention further relates to a corresponding method for phase control of an optical receiver (1).
    Type: Application
    Filed: March 3, 2009
    Publication date: January 13, 2011
    Applicant: CISCO TECHNOLOGY, INC.
    Inventor: Christopher Fludger
  • Publication number: 20100321001
    Abstract: Provided is a phase detecting apparatus that detects a phase difference between signals, comprising a phase comparing section that sequentially delays a second input signal relative to a first input signal, according to a set value, and that compares a phase of the second input signal to a phase of the first input signal each time a relative phase between the input signals changes; and a delay adjusting section that adjusts in advance a delay amount of a signal in the phase comparing section.
    Type: Application
    Filed: April 2, 2010
    Publication date: December 23, 2010
    Applicant: ADVANTEST CORPORATION
    Inventor: Kiyotaka ICHIYAMA
  • Publication number: 20100311375
    Abstract: There are provided a sampling mixer, quadrature demodulator, and a wireless device capable of suppressing receiving sensitivity degradation caused by alias components or second-order distortion components. In the sampling mixer (101), a sampling switch (5) and another sampling switch (36) sample a reception signal based on a local signal with a predetermined frequency. A control signal generator (15) generates a control signal for controlling a filter operation. An in-phase mixer (2) and a reverse-phase mixer (3) perform, based on the control signal, filter processing on the sample signal obtained by the sampling switch (5). A delay controller (117) controls the phase difference between the local signal and the control signal according to a reception-desired frequency.
    Type: Application
    Filed: December 10, 2008
    Publication date: December 9, 2010
    Applicant: Panasonic Corporation
    Inventors: Yoshifumi Hosokawa, Yoshito Shimizu, Tadashi Morita, Atsushi Maruyama
  • Patent number: 7847241
    Abstract: In various aspects, ion sources, mass spectrometer systems, and a power supply circuit coupled to a feedback circuit are provided. A power supply is provided that includes at least the power supply circuit and is operable to transfer charge to a load. The feedback circuit is responsive to a DC component of an output voltage supplied by the power supply in a first feedback loop and an AC component of the output voltage in a second feedback loop to produce a feedback signal representative of at least one of: a value of the output voltage before a charge transfer from a capacitor of the power supply to a load; the value of the output voltage during the charge transfer from the capacitor of the power supply to the load; or the value of the output voltage after the charge transfer from the capacitor of the power supply to the load.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: December 7, 2010
    Assignee: DH Technololgies Development PTE. Ltd.
    Inventor: Stephen C. Gabeler
  • Publication number: 20100301916
    Abstract: A layout design method in accordance with an exemplary aspect of the present invention is a layout design method for a clock tree circuit, including disposing a first clock distribution circuit in a clock tree circuit, wiring the clock tree circuit in which the first clock distribution circuit is disposed, verifying timing of the wired clock tree circuit, and replacing the first distribution element by a second clock distribution circuit based on a result of the timing verification, the second clock distribution circuit having roughly a same input load capacitance as the first clock distribution circuit and a different delay value from the first clock distribution circuit.
    Type: Application
    Filed: May 12, 2010
    Publication date: December 2, 2010
    Applicant: NEC ELECTRONICS CORPORATION
    Inventor: Toshiaki NAKAHASHI
  • Patent number: 7839196
    Abstract: A multi-phase clock generation circuit having a low skew imprecision is presented. The circuit includes a phase clock generation block and a phase correction block. The phase clock generation block is configured to generate a plurality of phase clocks having phases different from each other with response to a pair of input clocks. The phase correction block is configured to generate final output interpolated phase clocks in which each has a center phase by adjusted by multiple phase clocks that have adjacent phases.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: November 23, 2010
    Assignee: Hynix Semiconductor Inc.
    Inventor: Dae Kun Yoon
  • Publication number: 20100289538
    Abstract: A circuit includes a clock conditioning circuit which receives an encoded clock signal, and provides first and second conditioned clock signals in response. The clock conditioning circuit adjusts a period of the first and second conditioned clock signals in response to an adjustment of a period of the encoded clock signal. The circuit includes a modulator which receives the first and second conditioned clock signals.
    Type: Application
    Filed: May 15, 2009
    Publication date: November 18, 2010
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Merit Y. Hong, Bruce M. Newman
  • Publication number: 20100283525
    Abstract: A phase control device that adjusts a phase of a clock receives a first clock, a second clock and a control code. The phase control device includes phase adjusters (PI-11, PI-12), PI-2 and PI-3 that output a clock of a phase corresponding to the control code. These phase adjusters are connected in a three-stages cascade. The control codes of these phase adjusters (PI-11, PI-12), PI-2 and PI-3 are varied in association with each other. Therefore, as compared with a case where a phase of a clock is adjusted by a phase adjuster alone, if a resolution (adjustment granularity) of each phase adjuster is defined as N, it is possible to reduce the adjustment granularity of a phase as small as N to the power of the number of the stages. Therefore, when the phase control device is used for a SSC, the peak power reduction value is improved.
    Type: Application
    Filed: October 28, 2008
    Publication date: November 11, 2010
    Inventor: Takefumi Yoshikawa
  • Patent number: 7830166
    Abstract: A method and apparatus is described herein for pulse shift modulation of output waveforms for reducing crosstalk on interconnects. Based on input pulses/bits, an output waveform is selectively delayed by a shift value to ensure transitions in a first direction occur in a first half of a period and transitions in a second direction occur in a second half of the period. When the same pulse shift modulation is implemented on surrounding traces, certain worst-case crosstalk scenarios are reduced; thus reducing crosstalk and increasing performance in power consumption and speed of data transfer.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: November 9, 2010
    Assignee: Intel Corporation
    Inventors: Welmin Sun, Karl Wyatt, Bo A. Zhang
  • Patent number: 7825712
    Abstract: A multi-phase clock signal generating circuit includes a phase correction block configured to receive multi-phase clock signals and produce a plurality of interpolated phase clock signal groups in which the phases of the multi-phase clock signals are differently controlled. The multi-phase clock signals are out of phase with each other. A clock control block is configured to produce output multi-clock signals by selectively outputting one among the interpolated phase clock signal groups using a digital control signal having a plurality of bits which are produced based on phase differences of the multi-phase clock signals.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: November 2, 2010
    Assignee: Hynix Semiconductor Inc.
    Inventor: Dae Kun Yoon
  • Patent number: 7813710
    Abstract: The present invention is a receiving circuit used for a cellular phone that is reduced in size and can realize low power consumption. In a signal reception circuit that is used in a cellular phone that perform transmission and reception of a plurality of band wireless signals and includes a low-pass filter for removing blockers unnecessary for signal reception, the low-pass filter 104 is composed of a plurality of filters composed of a plurality of different circuit configurations and having a plurality of different pole positions, switching between a filter for blocker removal and a filter configuration with reduced sensitivity degradation is performed by combining a plurality of filters for each signal reception band, and by performing power-off of an unnecessary filter portion in the filter configuration, power consumption is reduced.
    Type: Grant
    Filed: February 23, 2005
    Date of Patent: October 12, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Yusaku Katsube, Akio Yamamoto
  • Publication number: 20100244976
    Abstract: Clock spreading systems and methods are disclosed. In one embodiment of the invention, a clock spreading system is provided in an integrated transceiver system that comprises a base band control system and a transceiver coupled to the base band control system. The clock spreading system provides a spread clock output signal derived from a clock reference signal for clocking one of the base band control system and the transceiver. The clock spreading system is configured to provide a periodic phase modulated spread clock output signal during receiving of data in a receive mode and a pseudo-random phase modulated spread clock output signal during transmitting of data in a transmit mode.
    Type: Application
    Filed: March 31, 2009
    Publication date: September 30, 2010
    Inventors: Jeff Kerr, Gennady Feygin, Jose Fresquez
  • Patent number: 7805627
    Abstract: A technique includes providing transmitters that are each associated with a data bit line of a bus, and each transmitter is clocked by an associated transmit clock signal. The technique includes determining a baseline offset to apply to a base clock signal to synchronize the base clock signal to a source clock signal of a source that supplies data to the transmitters. For each transmitter, an associated phase offset is determined to compensate for an associated skew. The phase of each transmit clock signal is controlled based on the associated phase offset and the baseline offset.
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: September 28, 2010
    Assignee: Intel Corporation
    Inventors: Mamun Ur Rashid, Hing Y. To
  • Patent number: 7800025
    Abstract: The present invention provides a micro-control unit a RC oscillator for generating a reference clock, a plurality of touch switches for generating a transition signal indicating one of the touch switches being touched by human beings, a plurality of analog switches coupled to the touch switches for controlling transmission of the transition signal and a plurality of counters for counting time, all of the counters stop counting when one of the counters overflows and content of all counters being read, wherein ON/OFF of the analog switches controlled by a software.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: September 21, 2010
    Assignee: Holtek Semiconductor Inc.
    Inventors: Wen-Liang Liu, Chin-Hung Yang
  • Publication number: 20100231279
    Abstract: A phase shift generation circuit has an edge detector, which receives an input pulse signal and outputs a first and a second edge signal denoting the time of occurrence of the first and second edges of the input pulse signal. The circuit also has a divide by N circuit, which receives a first clock signal and a group of signals representing a number N, and outputs a second clock signal, said a second clock signal having a frequency equal to the frequency of said first clock signal divided by the number N. The circuit further comprises a pulse counter, which receives the first edge signal and the second clock signal, and outputs a group of signals representing the number of the second clock pulses between occurrences of the first edge signal. The circuit has a first recycling timer, which receives the number of second clock pulses, the first edge signal and the first clock signal, and outputs a group of pulses approximating a uniformly spaced group across the time duration of the period of the input pulse.
    Type: Application
    Filed: March 11, 2010
    Publication date: September 16, 2010
    Applicant: Supertex, Inc.
    Inventors: James T. Walker, Andrew Read
  • Patent number: 7795940
    Abstract: Disclosed herein are embodiments of a programmable phase adjusting circuit, a programmable phase adjusting mixer circuit and design structures for these circuits. These circuits comprise a variable delay device connected between input and output nodes. The device includes multiple FETs with input diffusion regions that are connected to a voltage rail via switches so that they can be selectively biased, gates that are connected in series to the input node so that a periodic input signal can be propagated sequentially through each of the gates and output diffusion regions that are connected in parallel to the output node. A current source is connected between the output node and another voltage rail for biasing the output node when the variable delay device is off. The variable delay device enables a circuit in which small increments of selectable phase adjustments can be made to the periodic input signal as a function of propagation delay.
    Type: Grant
    Filed: October 6, 2009
    Date of Patent: September 14, 2010
    Assignee: International Business Machines Corporation
    Inventors: Wagdi W. Abadeer, Anthony R. Bonaccio, Joseph A. Iadanza
  • Patent number: 7783251
    Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: August 24, 2010
    Assignee: Broadcom Corporation
    Inventors: Ahmadreza Rofougaran, Maryam Rofougaran, Meng-An Pan, Hung-Ming Chien, Shahla Khorram, William T. Colleran, Jacob Rael, Masood Syed, Brima Ibrahim, Stephen Wu, Shervin Moloudi
  • Publication number: 20100201421
    Abstract: A jitter generating circuit wherein a simple structure can be used to generate a pattern effect jitter. A jitter generating circuit 1 comprises a driver input circuit 20 that serves as a signal analyzing unit for analyzing the contents of the signal pattern of an input signal; a plurality of gain adjusting circuits 30; a plurality of lowpass filters 40; a plurality of adders 50; an adder 52; and a driver output circuit 60 that outputs a signal obtained by adjusting, in accordance with a signal analysis result, the phase of the input signal in such a direction in which the change timing deviates when the input signal is transmitted to the transmission line. Thus, the phase of an input signal is adjusted, thereby adding the jitter to the input signal.
    Type: Application
    Filed: June 18, 2006
    Publication date: August 12, 2010
    Applicant: ADVANTEST CORPORATION
    Inventors: Takayuki Nakamura, Takashi Sekino
  • Publication number: 20100188127
    Abstract: A signal adjusting system includes: a signal generating device for generating a plurality of output signals according to a plurality of pre-output signals, a plurality of signal transmitting paths being coupled to the signal generating device for transmitting the plurality of output signals; and a controlling device coupled to the plurality of signal transmitting paths for receiving a first transmitted signal corresponding to a first output signal and a second transmitted signal corresponding to a second output signal, and detecting a phase different between the first transmitted signal and the second transmitted signal to generate a detected result to the signal generating device, wherein the signal generating device adjusts the phase difference between the first output signal and the second output signal according to the detected result.
    Type: Application
    Filed: March 19, 2009
    Publication date: July 29, 2010
    Inventors: Wen-Chang Cheng, Chuan-Jen Chang
  • Patent number: 7764731
    Abstract: The present invention provides an equalizer and a semiconductor device, that can suppress a decrease in S/N ratio of a reception signal, can facilitate a disconnection test by a direct current signal, and are excellent in reproducibility of a transmission signal. A low-pass filter receives a reception signal supplied from a reception end to output a signal obtained by removing a high frequency component from the reception signal. A subtraction unit subtracts an output signal from the low-pass filter from the reception signal. An addition unit adds the reception signal from the reception end to an output signal from the subtraction unit. Thus, an output signal from the addition unit has a frequency characteristic of emphasizing the high frequency component. Then, an amplifier amplifies the output signal from the addition unit to transmit it to an output end.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: July 27, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Hideki Uchiki, Atsuhiko Ishibashi
  • Patent number: 7756472
    Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: July 13, 2010
    Assignee: Broadcom Corporation
    Inventors: Hooman Darabi, Ahmadreza Rofougaran, Shahla Khorram, Brima Ibrahim
  • Patent number: 7750707
    Abstract: High-resolution low-interconnect phase rotator. A signal may be generated having any desired phase (as determined by the step size employed). First and second control signals select a sector (e.g., the range from 0° to 360° is divided into a number of sectors) and a particular phase within that sector. Generally, this range from 0° to 360° is uniformly divided so that each sector is the same. However, if desired, there can alternatively be differences in the sizes of each of the sectors. The use of these two sets of controls signals (one for selecting the sector and one for selecting the particular phase within the sector) allows for very few control signals. N-channel metal oxide semiconductor field-effect transistor (N-MOSFET) based switches and differential pairs of transistors or alternatively p-channel metal oxide semiconductor field-effect transistor (P-MOSFET) based switches and differential pairs of transistors can be employed.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: July 6, 2010
    Assignee: Broadcom Corporation
    Inventor: Afshin Momtaz
  • Publication number: 20100148838
    Abstract: A delay cell with a wider delay range is provided. The delay cell employs frequency dependent current source to generate the majority of the delay of the cell, while a control circuit (which is generally a current source that is controlled by a control voltage) provides additional delay. Thus, the delay cell provided here can be used to improve the performance of delay locked loops (DLLs) and other circuits.
    Type: Application
    Filed: November 23, 2009
    Publication date: June 17, 2010
    Applicant: Texas Instruments Incorporated
    Inventors: Jagannathan Venkataraman, Vivesvaraya A. Pentakota, Samarth S. Modi
  • Patent number: 7724857
    Abstract: Disclosed is a system and method for improving the linearity of a clock and data recovery (CDR) circuit. In one embodiment, a data stream is received, and the phase of a clock signal is adjusted using two interpolators. The phase of the output signal of the second interpolator is adjusted simultaneously with, and complementary to, adjusting the phase of the first interpolator. The first interpolator's output signal is injected into a first delay cell in a delay loop having a plurality of delay cells, and the output of the second interpolator is inactivated. When the maximum phase of the first interpolator's output signal is reached, the second interpolator's output signal is injected into another one of the delay cells, and the first interpolator's output signal is inactivated. The data stream is then recovered using the output of the delay loop as a clock signal.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: May 25, 2010
    Assignee: Agere Systems Inc.
    Inventors: Christopher Abel, Joseph Anidjar, Vladimir Sindalovsky, Craig Ziemer
  • Publication number: 20100123502
    Abstract: A system for providing at least two output signals to produce a substantially uniform potential profile includes a signal generator adapted to emit a frequency at least about 30 megahertz, a splitter in communication with the signal generator, and a signal manipulator in communication with the splitter. The splitter is adapted to split the signal of the signal generator into the two output signals, and the signal manipulator is adapted to manipulate a phase, a gain, or an impedance of the two output signals. The signal manipulator manipulates the two output signals so that the two output signals produce the substantially uniform potential profile.
    Type: Application
    Filed: July 9, 2009
    Publication date: May 20, 2010
    Inventors: Imran A. Bhutta, Scott D. Ivins
  • Publication number: 20100109734
    Abstract: In one illustrative embodiment, an apparatus for a current-mode phase rotator with partial input phase switching comprises a mixer, wherein the mixer is a four quadrant current-mode mixer comprised of four interpolation buffers, wherein each interpolation buffer receives as input a clock phase from a set of four equidistant clock phases, and a set of two-output current-steering digital to analog converters that supply tail currents to the mixer wherein a first digital to analog converter has additional switches to connect each of two outputs to one of two polarities of a given clock while each remaining digital to analog converter has no additional switches and has two outputs supplying current only to two different polarities of a same clock phase wherein steering the current during incremental rotation about a phase circle defines an octagonal shaped phase envelope.
    Type: Application
    Filed: August 4, 2009
    Publication date: May 6, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Sergey Vladimirovich Rylov
  • Publication number: 20100066424
    Abstract: According to an aspect of the embodiment, a skew detecting unit includes at least one over delay path or racing path for detecting skew. A clock adjusting unit sets a set value of delay based on the skew detected by the skew detecting unit. A clock cell adjusts delay in a first clock according to the set value of the delay, and outputs the result as a second clock.
    Type: Application
    Filed: September 15, 2009
    Publication date: March 18, 2010
    Applicant: FUJITSU LIMITED
    Inventor: Keigo NAKATANI
  • Publication number: 20100060294
    Abstract: A variable delay circuit has a simple configuration for being incorporated in a timing generator to control a delay time in real time and assure a timing margin. The variable delay circuit of the timing generator includes a delay circuit having a plurality of cascaded clock buffers; a plurality of cascaded data buffers; and data holding circuits for outputting data to the data buffers in accordance with the clock from the delay circuit. The delay amount added to the data by the data buffers is made identical to the delay amount added to the clock by the clock buffers.
    Type: Application
    Filed: July 28, 2006
    Publication date: March 11, 2010
    Inventor: Masakatsu Suda
  • Patent number: 7671654
    Abstract: A method for generating a clock signal and a device having clock generating capabilities, the device includes: (i) a first divider, adapted to receive an input clock signal and divide the input clock signal to provide a first clock signal; (ii) a second divider, adapted to receive an input clock signal and divide the input clock signal to provide a second clock signal; wherein the first clock signal is phase shifted in relation to the second clock signal by half an input clock cycle; wherein a delay period of the first divider substantially equals a delay period of the second divider over a large range of delay affecting parameter values; (iii) a reconstruction circuit, connected to the first and second divider circuits, adapted to receive the first and second clock signals and apply a logical operation on the first and second clock signals to provide a reconstructed clock signal; and (iv) a selection circuit, connected to the first divider, second divider and reconstruction circuit, adapted to output an outp
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: March 2, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Anton Rozen, Michael Priel, Amir Zaltzman
  • Publication number: 20100019816
    Abstract: Disclosed herein are embodiments of a programmable phase adjusting circuit, a programmable phase adjusting mixer circuit and design structures for these circuits. These circuits comprise a variable delay device connected between input and output nodes. The device includes multiple FETs with input diffusion regions that are connected to a voltage rail via switches so that they can be selectively biased, gates that are connected in series to the input node so that a periodic input signal can be propagated sequentially through each of the gates and output diffusion regions that are connected in parallel to the output node. A current source is connected between the output node and another voltage rail for biasing the output node when the variable delay device is off. The variable delay device enables a circuit in which small increments of selectable phase adjustments can be made to the periodic input signal as a function of propagation delay.
    Type: Application
    Filed: October 6, 2009
    Publication date: January 28, 2010
    Applicant: International Business Machines Corporation
    Inventors: Wagdi W. Abadeer, Anthony R. Bonaccio, Joseph A. Iadanza