Frequency Division Patents (Class 327/115)
  • Patent number: 8598932
    Abstract: A clock divider is provided that is configured to divide a high speed input clock signal by an odd, even or fractional divide ratio. The input clock may have a clock cycle frequency of 1 GHz or higher, for example. The input clock signal is divided to produce an output clock signal by first receiving a divide factor value F representative of a divide ratio N, wherein the N may be an odd or an even integer. A fractional indicator indicates the divide ratio is N.5 when the fractional indicator is one and indicates the divide ratio is N when the fractional indicator is zero. F is set to 2(N.5)/2 for a fractional divide ratio and F is set to N/2 for an integer divide ratio. A count indicator is asserted every N/2 input clock cycles when N is even. The count indicator is asserted alternately N/2 input clock cycles and then 1+N/2 input clock cycles when N is odd.
    Type: Grant
    Filed: May 6, 2013
    Date of Patent: December 3, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Ramakrishnan Venkatasubramanian, Anthony Lell, Raguram Damodaran
  • Patent number: 8598923
    Abstract: A bias-shaping circuit for adjusting power consumption in a frequency divider to a temperature-dependent minimum includes a temperature-dependent bias source for producing a temperature-dependent bias. The bias is combined with an input signal to create an output bias. The output bias changes in response to a change in temperature to compensate for at least a portion of a temperature-induced change in the frequency divider, thereby adjusting power consumption in the frequency divider to a temperature-dependent minimum.
    Type: Grant
    Filed: September 24, 2012
    Date of Patent: December 3, 2013
    Assignee: Analog Devices, Inc.
    Inventor: Hyman Shanan
  • Patent number: 8593185
    Abstract: A clock divider circuit has a plurality of dividers for which dividing ratios are settable, a preset register group that stores the dividing ratios set for the plurality of dividers, and a selector that selects a single preset register within the preset register group, and imparts the dividing ratios stored in the selected preset register to the plurality of dividers.
    Type: Grant
    Filed: June 24, 2011
    Date of Patent: November 26, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventor: Takayuki Kume
  • Patent number: 8587349
    Abstract: A clock divider circuit. The clock divider receives m input clock signals each of the same frequency. Each input clock signal after the first has a phase offset of 2?/m from the previous input clock signal. The clock divider divides the frequency of the input clock signals by an integer of division K. The clock divider includes a counter that receives the first input clock signal and provides one or more count signals. The clock divider also includes m flip-flops, of which a first flip-flop receives the first input clock signal at its clock input and provides a first clock output signal. Each flip-flop after the first receives an input clock signal at its clock input and provides a clock output signal, each clock output signal after the first having a 2?K/m phase offset from the previous clock output signal.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: November 19, 2013
    Assignee: Texas Instruments Incorporated
    Inventor: Rajesh Velayuthan
  • Patent number: 8581640
    Abstract: A clock divider circuit. The clock divider receives m input clock signals each of the same frequency. Each input clock signal after the first has a phase offset of 2?/m from the previous input clock signal. The clock divider divides the frequency of the input clock signals by an integer of division K. The clock divider includes a counter that receives the first input clock signal and provides one or more count signals. The clock divider also includes m flip-flops, of which a first flip-flop receives the first input clock signal at its clock input and provides a first clock output signal. Each flip-flop after the first receives an input clock signal at its clock input and provides a clock output signal, each clock output signal after the first having a 2?K/m phase offset from the previous clock output signal.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: November 12, 2013
    Assignee: Texas Instruments Incorporated
    Inventor: Rajesh Velayuthan
  • Publication number: 20130293271
    Abstract: A semiconductor apparatus includes a clock frequency change block configured to output a plurality of internal clocks with different frequencies by dividing a frequency of an external clock in response to a mode register set signal and a setting command to enable the plurality of internal clocks to be outputted, and generate a flag signal to designate the completion of the output, and a command generation block configured to receive a command and generate the setting command in response to the flag signal and the mode register to set signal.
    Type: Application
    Filed: December 10, 2012
    Publication date: November 7, 2013
    Applicant: SK HYNIX INC.
    Inventor: Choung Ki SONG
  • Publication number: 20130294186
    Abstract: A phase-locked loop includes a phase detection unit configured to compare the phase of a feedback clock with the phase of an input clock, a clock generation unit configured to adjust the frequency of a first clock based on a result of the comparison of the phase detection unit, a first division unit configured to generate an output clock by dividing the first clock at a first division ratio in test mode and generate the output clock by dividing the first clock at a second division ratio that is lower than the first division ratio in normal mode, and a second division unit configured to generate the feedback clock by dividing the output clock.
    Type: Application
    Filed: December 13, 2012
    Publication date: November 7, 2013
    Applicant: SK HYNIX INC.
    Inventors: Hae-Rang CHOI, Joo-Hwan CHO, Kwang-Jin NA, Kwan-Dong KIM
  • Publication number: 20130293272
    Abstract: High-speed RF differential, Quadrature, divide-by-2 clock divider designs are based on inverters and clocking circuits connected in a serial ring formation. In one embodiment, only NMOS transistors are used in the inverters, and only PMOS transistors are used in the clocking circuits. This structure uses only 12 transistors. The input can be coupled directly to a VCO output, and provides minimum loading, as each VCO output is connected to only two transistors. Another embodiment comprises clocked inverter stages connected in a serial ring configuration with inverters between stages. The RF clock (or VCO signal) is used at the outer side of the inverters for speed improvement. In both circuits, positive and negative clock inputs are connected alternately at each stage of the ring.
    Type: Application
    Filed: June 5, 2013
    Publication date: November 7, 2013
    Inventors: Leonardus Hesen, Paul Mateman, Johannes Petrus Antonius Frambach
  • Patent number: 8577305
    Abstract: Embodiments of the present invention may be used to generate oscillating signals. One embodiment of the present invention includes a circuit that receives a differential signal to be divided. The circuit converts the differential signal into an injection signal. The injection signal is coupled to an oscillator, and the oscillator generates an output signal having a frequency that is a fraction of the frequency of the differential input signal. In another embodiment, the present invention includes a MIMO wireless communication system. The MIMO system may use the divider circuit to divide a local oscillator signal with reduced common mode distortion.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: November 5, 2013
    Assignee: Marvell International Ltd.
    Inventors: Paolo Rossi, Sang Won Son
  • Patent number: 8575976
    Abstract: At least one example embodiment provides for a frequency divider system including a delay unit configured to receive a first input clock signal having a first input clock frequency and a requirement and output a modified clock signal, and a frequency divider configured to receive the modified clock signal and output an output clock signal having an output clock frequency. The output clock frequency is an odd or even integer division of the first input clock frequency based on the requirement such as an input control word.
    Type: Grant
    Filed: September 15, 2010
    Date of Patent: November 5, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Vadim Gelfand, Aharon El-Bahar
  • Patent number: 8576967
    Abstract: It is possible to provide a highly reliable semiconductor device and a communication method in which communication can be performed between circuits with a large degree of freedom of clock frequency which can be set in each of the circuits, a decisive operation, and a small communication latency. The semiconductor device according to the present invention includes a first circuit that performs processing based on a first clock signal, the first clock signal having a frequency M/N times as large as a frequency of a second clock signal (N is a positive integer, and M is a positive integer larger than N); a second circuit that performs processing based on the second clock signal; and a communication timing control circuit that generates a communication timing signal to control a timing at which the first circuit performs communication with the second circuit.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: November 5, 2013
    Assignee: NEC Corporation
    Inventor: Atsufumi Shibayama
  • Publication number: 20130278302
    Abstract: Embodiments of the present invention provide a clock signal generator, and the clock signal generator is applied to a physical layer subsystem supporting data transmission at multiple baud rates. The clock signal generator includes: a source clock signal generator, and two or more processors connected to an output end of the source clock signal generator; where the source clock signal generator outputs multiple source clock signals with the same frequency according to a reference signal of a reference clock in the subsystem; the processors perform frequency dividing processing on the multiple source clock signals through a digital logic circuit according to an oversampling technology, to obtain a synchronous clock signal corresponding to a baud rate of data transmission in the subsystem, so as to implement timing and transceiving functions when data is transmitted at the baud rate.
    Type: Application
    Filed: January 30, 2013
    Publication date: October 24, 2013
    Applicant: Huawei Technologies Co., Ltd.
    Inventors: Wei Cao, Jindi Zhang, Yingyan Shan
  • Patent number: 8564336
    Abstract: A clock frequency divider circuit 11 according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by masking (S-N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency divider circuit 11 includes a mask control circuit that generates a mask signal in which a non-mask timing is preferentially assigned to a clock pulse at a timing at which no clock pulse exists in a clock signal used in a circuit Ai other than a target circuit Bi using the output clock signal among S clock pulses of the input clock signal, and a mask circuit that generates the output clock signal by masking a clock pulse of the input clock signal according to the mask signal generated by the mask control circuit.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: October 22, 2013
    Assignee: NEC Corporation
    Inventor: Atsufumi Shibayama
  • Patent number: 8558588
    Abstract: A clock divider circuit has a plurality of dividers for which dividing ratios are settable, a preset register group that stores the dividing ratios set for the plurality of dividers, and a selector that selects a single preset register within the preset register group, and imparts the dividing ratios stored in the selected preset register to the plurality of dividers.
    Type: Grant
    Filed: June 24, 2011
    Date of Patent: October 15, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventor: Takayuki Kume
  • Patent number: 8558575
    Abstract: A system is provided for generating an output clock used for N.5 modulus division. An edge-slip circuit accepts a modulus count, a divisor select signal, and a clock signal having a frequency greater than a modulus count frequency. The edge-slip circuit also has an input to accept an output clock signal, and an output to supply a clock slip signal (NE). An exclusive-or (XOR) has an input to accept a buffered clock signal (NF) and the clock slip signal (NE). The XOR has an output to supply the output clock signal. The output clock signal has a frequency equal to a buffered clock signal frequency, with no skipped clock edges, when the clock slip signal does not change logic levels. Alternatively, the output clock signal frequency is equal to the buffered clock signal frequency, with a skipped clock edge, when the clock slip signal changes logic levels.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: October 15, 2013
    Assignee: APPLIED Micro Circuits Corporation
    Inventor: Brian Abernethy
  • Patent number: 8558589
    Abstract: The present disclosure provides circuitry and a method for digital clock generation including the generation of integer and non-integer sub clocks. The proposed method provides simplified constant signal propagation and low skew in the divided clock path independent of division factor. Also provided is a simplified mechanism for generating low power clock patterns divided down by factors which are non-integer, phase-shifted, repeated pulse trains, dynamically changing and glitch-free.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: October 15, 2013
    Assignee: Dialog Semiconductor GmbH
    Inventors: Nir Dahan, Kevin Graham Allen
  • Patent number: 8552770
    Abstract: A frequency divider based on a series of divide-by-2/3 cells and divide-by-1/2/3 cells using extended division range is disclosed. The frequency divider uses modified divide-by-1/2/3 cells and additional circuit elements to correctly divide an input frequency by a divisor on successive output cycles while the divisor transitions across an octave boundary. The frequency divider creates a divide-by-1 mode for unused divide-by-1/2/3 cells in the series of cells. The divide-by-1 mode passes the input clock in the unused latches of each unused divide-by-1/2/3 cell as opposed to having each unused divide-by-1/2/3 cell implement divide-by-3 mode.
    Type: Grant
    Filed: January 24, 2012
    Date of Patent: October 8, 2013
    Assignee: Coherent Logix, Incorporated
    Inventor: Mark S. Cavin
  • Publication number: 20130249719
    Abstract: A device that supports communication over parallel serial lanes may include an analog circuit domain, a digital circuit domain, a buffer between the analog domain and the digital domain, and an alignment circuit. The buffer may receive data from the digital domain according to a write clock and send out the received data to the analog domain according to a read clock. The alignment circuit may generate control signals to initiate reading from the buffer when the read clock and write clocks are aligned. In one embodiment, the device may be an analog-to-digital converter (ADC) integrated circuit (IC) chip and the buffer may be a FIFO.
    Type: Application
    Filed: November 27, 2012
    Publication date: September 26, 2013
    Inventor: Ivan R. Ryan
  • Patent number: 8542040
    Abstract: An integrated circuit includes a first variable divider circuit configured to receive a clock signal and to apply a lower range of integer division factors thereto responsive to a first control input to generate a first divided clock signal and a second variable divider circuit configured to receive the clock signal and to apply an upper range of integer division factors thereto responsive to a second control input to generate a second divided clock signal. The integrated circuit further includes a multiplexer circuit configured to selectively pass the first and second divided clock signals responsive to a third control input.
    Type: Grant
    Filed: October 31, 2011
    Date of Patent: September 24, 2013
    Assignee: Integrated Device Technology, Inc.
    Inventor: Justin O'Day
  • Patent number: 8531213
    Abstract: The present invention provides a CMOS-inverter-type frequency divider circuit that can further reduce power consumption. The CMOS-inverter-type frequency divider circuit includes: a plurality of CMOS inverters that contribute to realizing a frequency division function; a frequency division control section for performing control such that some or all of the plurality of CMOS inverters are intermittently driven at the respective different timings in accordance with an input signal; and a drive power supplying section for supplying powers for driving the plurality of CMOS inverters, and for, based on state information indicating whether VCO sub band selection or normal transmission is performed, switching some or all of the powers for the plurality of CMOS inverters between the VCO sub band selection and the normal transmission.
    Type: Grant
    Filed: April 8, 2010
    Date of Patent: September 10, 2013
    Assignee: Panasonic Corporation
    Inventors: Masakatsu Maeda, Mikihiro Shimada
  • 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: 8532247
    Abstract: A clock divider divides a high speed input clock signal by an odd, even or fractional divide ratio. The clock divider receives a divide factor value F representative of a divide ratio N, wherein the N may be an odd or an even integer. A fractional indicator indicates a fractional divide ratio when one and an integral divide ratio when zero. A count indicator is asserted every N/2 input clock cycles when N is even. The count indicator is asserted alternately N/2 input clock cycles and then 1+N/2 input clock cycles when N is odd. The clock divider synthesizes one period of an output clock signal in response to each assertion of the count indicator for a fractional divide ratio and synthesizes one period of the output clock signal in response to two assertions of the count indicator for an integral divide ratio.
    Type: Grant
    Filed: September 28, 2011
    Date of Patent: September 10, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Ramakrishnan Venkatasubramanian, Anthony Lell, Raguram Damodaran
  • Patent number: 8525561
    Abstract: A phase lock loop (PLL) includes a PLL feedback circuit having a feedback divider. The feedback divider has a first dynamic latch, a first logic circuit, and a plurality of serially connected dynamic latches. Each of the serially connected dynamic latches receives and forwards additional data signals to subsequent ones of the serially connected dynamic latches in series. The second-to-last dynamic latch in the series outputs a fourth data signal to a last dynamic latch in the series. The last dynamic latch receives the fourth data signal and outputs a fifth data signal. A first feedback loop receives the fourth data signal from the second-to-last dynamic latch and the fifth data signal from the last dynamic latch. The first feedback loop comprises a NAND circuit that combines the fourth and fifth data signals and the first feedback loop outputs the first feedback signal.
    Type: Grant
    Filed: October 18, 2011
    Date of Patent: September 3, 2013
    Assignee: International Business Machines Corporation
    Inventors: John S. Austin, Kai D. Feng, Shiu Chung Ho, Zhenrong Jin
  • Publication number: 20130222016
    Abstract: A circuit according to the present invention includes: an oscillator; an divider; a time-to-digital converter comparing the phase and frequency of a reference clock signal REF from the divider with an internal clock signal and outputting digital data D1 based on the comparison results; a digital loop filter receiving the D1 and outputting digital data W1; a data holder holding the W1 from the filter in time series manner; a switch selecting either digital data W2 from the holder or the W1 and outputting the selected data as digital data W3; a digitally controlled oscillator with oscillation frequency controlled based on the W3; and a data controller switching input data of the switch, and starting/halting the operation of the oscillator, the divider, the converter and the filter. Current consumption by the digital PLL circuit can be reduced.
    Type: Application
    Filed: February 21, 2013
    Publication date: August 29, 2013
    Applicant: ASAHI KASEI MICRODEVICES CORPORATION
    Inventor: Asahi Kasei Microdevices Corporation
  • Publication number: 20130214826
    Abstract: The present disclosure provides circuitry and a method for digital clock generation including the generation of integer and non-integer sub clocks. The proposed method provides simplified constant signal propagation and low skew in the divided clock path independent of division factor. Also provided is a simplified mechanism for generating low power clock patterns divided down by factors which are non-integer, phase-shifted, repeated pulse trains, dynamically changing and glitch-free.
    Type: Application
    Filed: February 22, 2012
    Publication date: August 22, 2013
    Applicant: Dialog Semiconductor GmbH
    Inventors: Nir Dahan, Kevin Graham Allen
  • Patent number: 8513987
    Abstract: In a high frequency mode a multiphase voltage-controlled oscillator (VCO) generates a first plurality of signals where each has the desired frequency and a different phase. A phase interpolator generates the signal at the desired frequency and the desired phase using a first plurality of signals. In a low frequency mode the VCO generates a second plurality of signals where each has a frequency which is a multiple of the desired frequency and a different phase. A multiphase frequency divider generates a third plurality of signals by dividing the frequency of the second plurality to the desired frequency while maintaining a phase relationship with the second plurality of signals. The phase interpolator generates the signal at the desired frequency and the desired phase using the third plurality.
    Type: Grant
    Filed: October 14, 2011
    Date of Patent: August 20, 2013
    Assignee: SK hynix memory solutions inc.
    Inventors: Heung S. Kim, Kenneth J. Evans
  • Patent number: 8502573
    Abstract: A frequency divider includes a plurality of logic circuit blocks. Each of the logic circuit blocks has a plurality of control terminals. At least one of the control terminals of one of the logic circuit blocks is arranged to receive an input clock signal having a first duty cycle. At least one of the remaining control terminals of the one of the logic circuit blocks is arranged to couple another one of the logic circuit blocks by a positive feedback. A clock signal at the at least one of the remaining control terminals has a second duty cycle different from the first duty cycle. Each of the logic circuit blocks includes a plurality of first transistors coupled in parallel between a first reference voltage and an output terminal, and a plurality of second transistors coupled in series between a second reference voltage and the output terminal.
    Type: Grant
    Filed: October 23, 2012
    Date of Patent: August 6, 2013
    Assignee: Mediatek Inc.
    Inventor: Ming-Da Tsai
  • Patent number: 8502588
    Abstract: A clock generation system for generating first and second clock signals at slightly different clock frequencies comprising a clock signal generator providing the first clock signal, frequency dividers dividing the clock frequencies by integers to produce auxiliary signals, a timer for measuring a first time lag between first signal edges of the auxiliary signals and a second time lag between second signal edges of the auxiliary signals, a comparator device for providing an error signal by comparing the difference between the measured time lags with a predetermined time value, and a voltage-controlled oscillator controlled in dependent on the error signal to generate the second clock signal.
    Type: Grant
    Filed: February 29, 2012
    Date of Patent: August 6, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventor: George Burcea
  • Publication number: 20130194008
    Abstract: To provide a clock frequency divider circuit that generates a clock signal enabling an expected proper communication in communication with a circuit operating by a clock having a different frequency. A clock frequency division circuit according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by subtracting (S?N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency division circuit generates a control signal used to preferentially subtract a clock pulse at a timing other than a communication timing of data communication performed by a target circuit using the output clock signal among S clock pulses of the input clock signal. Further, it generates the output clock signal by subtracting a clock pulse of the input clock signal according to the generated control signal.
    Type: Application
    Filed: March 13, 2013
    Publication date: August 1, 2013
    Inventor: Atsufumi SHIBAYAMA
  • Publication number: 20130187685
    Abstract: A dither control circuit includes a pseudo random number generator, which generates a pseudo random number sequence in response to a frequency-divided clock signal, and a dither circuit which dithers an input digital code by using at least one output bit of the pseudo random number sequence and outputs a dithered digital code corresponding to a result of the dithering. The dither circuit may output, as the dithered digital code, a digital code corresponding to a sum of or a difference between the input digital code and the input digital code based on the at least one output bit. The dithered digital code may be input to an accumulator which operates in-sync with the frequency-divided clock signal.
    Type: Application
    Filed: January 9, 2013
    Publication date: July 25, 2013
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: SAMSUNG ELECTRONICS CO., LTD.
  • Patent number: 8493104
    Abstract: Memories, clock generators and methods for providing an output clock signal are disclosed. One such method includes delaying a buffered clock signal by a adjustable delay to provide an output clock signal, providing a feedback clock signal from the output clock signal, and adjusting a duty cycle of the buffered clock signal based at least in part on the feedback clock signal. An example clock generator includes a forward clock path configured to provide a delayed output clock signal from a clock driver circuit, and further includes a feedback clock path configured to provide a feedback clock signal based at least in part on the delayed output clock signal, for example, frequency dividing the delayed output clock signal. The feedback clock path further configured to control adjustment a duty cycle of the buffered input clock signal based at least in part on the feedback clock signal.
    Type: Grant
    Filed: July 3, 2012
    Date of Patent: July 23, 2013
    Assignee: Micron Technology, Inc.
    Inventors: Aaron Willey, Yantao Ma
  • Patent number: 8493105
    Abstract: An injection-locked frequency divider (ILFD) including a signal injector, an oscillator (OSC), and a buffer stage is provided. The signal injector is configured for receiving an injection signal. The OSC is configured for dividing the frequency of the injection signal, so as to generate a first divided frequency signal, where there is an integral-multiple relation between the frequency of the first divided frequency signal and that of the injection signal. The buffer stage is configured for receiving and boosting the first divided frequency signal, and performing a push-push process on the first divided frequency signal, so as to output a second divided frequency signal, where there is a fractional-multiple relation between the frequency of the second divided frequency signal and that of the injection signal.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: July 23, 2013
    Assignee: Industrial Technology Research Institute
    Inventors: Hong-Yeh Chang, Yen-Liang Yeh, Chia-Hung Chang, Chun-Jen Chen
  • Patent number: 8487669
    Abstract: High-speed RF differential, Quadrature, divide-by-2 clock divider designs are based on inverters and clocking circuits connected in a serial ring formation. In one embodiment, only NMOS transistors are used in the inverters, and only PMOS transistors are used in the clocking circuits. This structure uses only 12 transistors, The input can be coupled directly to a VCO output, and provides minimum loading, as each VCO output is connected to only two transistors. Another embodiment comprises clocked inverter stages connected in a serial ring configuration with inverters between stages. The RF clock (or VCO signal) is used at the outer side of the inverters for speed improvement. In both circuits, positive and negative clock inputs are connected alternately at each stage of the ring.
    Type: Grant
    Filed: September 29, 2011
    Date of Patent: July 16, 2013
    Assignee: ST-Ericsson SA
    Inventors: Leonardus Hesen, Paul Mateman, Johannes Petrus Antonius Frambach
  • Patent number: 8487670
    Abstract: A frequency divider involves a plurality of Injection-locked Ring Oscillators (ILRO). A first ILRO includes a pair of cross-coupled N-channel transistors, a pair of load resistors, an integrating capacitor, and a current injection circuit. The drain of each transistor is coupled to the gate of the other transistor. Each load resistor couples the drain of each transistor to a circuit voltage source. The integrating capacitor couples the sources of each transistor. The current injection circuit alternately opens and closes a path from the source of each transistor to circuit ground in response to an oscillatory input signal of a first frequency. In response, the voltage state at the drain of each transistor is alternately latched and toggled, generating a differential pair of oscillating signals frequency divided by two. A first and second ILRO driven in antiphase generate two differential output signals in phase quadrature.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: July 16, 2013
    Assignee: QUALCOMM, Incorporated
    Inventor: Russell J. Fagg
  • Publication number: 20130176060
    Abstract: This invention is a means to definitively establish the occurrence of various clock edges used in a design, balancing clock edges at various locations within an integrated circuit. Clocks entering from outside sources can be a source of on-chip-variations (OCV) resulting in unacceptable clock edge skewing. The present invention arranges placement of the various clock dividers on the chip at remote locations where these clocks are used. This minimizes the uncertainty of the edge occurrence.
    Type: Application
    Filed: September 2, 2010
    Publication date: July 11, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Raguram Modaran, Abhijeet Ashok Chachad, Ramakrishnan Venkatasubramanian
  • Patent number: 8471607
    Abstract: A high speed clock frequency divider circuit is provided that uses a first shift register loop-back circuit and a second shift-register loop-back circuit to shift a predetermined array of bits therethrough. The first shift register loop-back circuit is clocked on a rising clock edge of an input clock signal, while the second shift register loop-back signal is clocked on a negative edge of the input clock signal. The outputs of the first and second loop-back shift registers are ORed to provide a 50% duty cycle output clock signal.
    Type: Grant
    Filed: December 30, 2011
    Date of Patent: June 25, 2013
    Assignee: St-Ericsson SA
    Inventor: Ferdinando Pace
  • Patent number: 8466721
    Abstract: An injection locked frequency divider and a PLL circuit, having a wide operating frequency bandwidth and capable of reducing the influence of any parasitic capacitance, are provided. Injection locked frequency divider (100) includes ring oscillator 140 that cascade-connects first amplifier circuit (141) including N-channel MOS transistor (111) and P-channel MOS transistor (112), and second amplifier circuit 142 and third amplifier circuit (143) that have the same configuration as first amplifier circuit (141) in three stages in a ring; N-channel MOS transistor 150 in which the sources of N-channel MOS transistors (111, 121, 131) in the respective stages are connected to the drain thereof; and differential signal injection circuit (160) that injects injection signal I1 to the gates of P-channel MOS transistors (112, 122, 132) in the respective stages and injects a reverse phase signal of injection signal I1 as a differential signal to the gate of N-channel MOS transistor (150).
    Type: Grant
    Filed: January 21, 2011
    Date of Patent: June 18, 2013
    Assignee: Panasonic Corporation
    Inventors: Takahiro Shima, Junji Sato, Masashi Kobayashi
  • Patent number: 8466720
    Abstract: Circuitry and method for dividing the frequency of an input clock signal for use in a prescaler of a digital frequency synthesizer. A flip flop is clocked on a first type of edge of the input clock signal, and provides an output for use as a divided clock signal. Feedback circuitry is clocked on the first type of edge of the input clock signal and provides a signal to a data input of the flip flop based on the inverse of the output of the flip flop.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: June 18, 2013
    Assignee: STMicroelectronics International N.V.
    Inventor: Nitin Gupta
  • Publication number: 20130147526
    Abstract: A system-on-chip includes a clock controller configured to decrease an operating frequency of at least one function block based on a change in an operating state of the at least one function block from an active state to an idle state. In a method of operating a system-on-chip including at least one function block, an operating frequency of the at least one function block is decreased based on a change in an operating state of the at least one function block from an active state to an idle state. The decreased operating frequency is greater than zero.
    Type: Application
    Filed: November 28, 2012
    Publication date: June 13, 2013
    Inventors: Dong Keun KIM, Sun Cheol KWON, Si Young KIM, Jae Gon LEE, Jung Hun HEO
  • Patent number: 8461933
    Abstract: The frequency calibration device includes a logic unit for gating the clock signal according to a gating window signal to generate a gated clock signal, and a divider for dividing the gated clock signal by a divisor in frequency to generate a frequency indication signal, and output digits of the divider are set to the divisor in a calibration cycle, and the frequency indication signal is a most significant bit of the output digits.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: June 11, 2013
    Assignee: Mediatek Inc.
    Inventors: Yi-Hsien Cho, Yu-Li Hsueh
  • Patent number: 8456203
    Abstract: A multiphase clock generation circuit includes: a first frequency divider to generate a first intermediate clock and a second intermediate clock; a second frequency divider to generate output clocks of a first group including a first output clock and a second output clock; a third frequency divider to generate output clocks of a second group including a third output clock and a fourth output clock; a selector to supply one of the second intermediate clock and a value to the third frequency divider in response to a switching signal; an error detection circuit to detect an error in a phase relationship between the output clock of the first group and the output clock of the second group; and a re-reset circuit to output the switching signal to the selector based on the error.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: June 4, 2013
    Assignee: Fujitsu Limited
    Inventor: Masafumi Kondou
  • Patent number: 8456202
    Abstract: There are numerous types of dividers that have been employed at various frequency ranges. For many very high frequency ranges (i.e., above 30 GHz), dividers in CMOS have been developed. However, many of these designs use multiple stages. Here, however, a single stage divider has been provided that is adapted to operate at very high frequencies (i.e., 120 GHz). To accomplish this, it uses parasitic capacitances in conjunction with inductor(s) to form an LC tanks so as to take advantages of parasitics that normal degrade performance.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: June 4, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Richard Gu, Daquan Huang
  • Publication number: 20130127501
    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: Application
    Filed: January 18, 2013
    Publication date: May 23, 2013
    Applicant: MEDIATEK INC.
    Inventor: MediaTek Inc.
  • Patent number: 8447008
    Abstract: A shift frequency demultiplier with automatic reset function is N-frequency demultiplication (N>2) and includes N-1 registers connected with each other and defined from a first register to an (N-1)th register. Each of the registers has an input end, an output end, a reset end and a clock end. For the registers from the first register to the (N-2)th register, the output end of every register is connected with the input end of a next register adjacent thereto, the output end of the (N-1)th register is connected with the input end of the first register by a reverser. The reset end of the (N-1)th register is connected with a system reset signal end. The system reset signal end logically multiplied by the output end of the (N-1)th register is connected with the reset ends of the registers from the first register to the (N-2)th register.
    Type: Grant
    Filed: June 2, 2011
    Date of Patent: May 21, 2013
    Assignee: IPGoal Microelectronics (SiChuan) Co., Ltd.
    Inventor: Xiu Yang
  • Publication number: 20130106472
    Abstract: An integrated circuit includes a clock control unit configured to selectively output an external clock or a delayed clock acquired by delaying the external clock as an input clock in response to a divided clock generated by dividing the external clock, when a test mode is entered; and an internal circuit operating in response to the input clock.
    Type: Application
    Filed: March 3, 2012
    Publication date: May 2, 2013
    Applicant: HYNIX SEMICONDUCTOR INC.
    Inventor: Hoon CHOI
  • Publication number: 20130099833
    Abstract: An integrated circuit chip includes: an internal circuit; a data output circuit configured to output a data packet of the internal circuit in response to a strobe signal; an oscillator configured to generate a first clock signal; a divider configured to divide the first clock signal and generate a second clock signal; and a strobe signal supply unit configured to supply the second clock signal as the strobe signal during an initial period of transmission of the data packet and supply the first clock signal as the strobe signal after the initial period.
    Type: Application
    Filed: September 11, 2012
    Publication date: April 25, 2013
    Inventor: Seung-Min OH
  • Publication number: 20130093468
    Abstract: Frequency synthesizers for use with oscillators that generate an arbitrary frequency are described, as well as related devices and methods. Divider information can be generated or otherwise accessed for use in configuring a phase lock loop device that is adapted for coupling with the oscillator, where the phase lock loop device can include a plurality of integer dividers without utilizing a fractional divider, where the divider information can include frequency deviations corresponding to groups of integer divider settings for the phase lock loop device, and where each deviation of the frequency deviations can be based on a frequency differential between a standard operating frequency and an output frequency for the phase lock loop utilizing one group of integer divider settings from the groups of integer divider settings.
    Type: Application
    Filed: October 13, 2011
    Publication date: April 18, 2013
    Applicant: Sand 9, Inc.
    Inventors: REIMUND REBEL, Klaus Juergen Schoepf
  • Patent number: 8422619
    Abstract: To provide a clock frequency divider circuit that generates a clock signal enabling an expected proper communication in communication with a circuit operating by a clock having a different frequency. A clock frequency division circuit according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by subtracting (S?N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency division circuit generates a control signal used to preferentially subtract a clock pulse at a timing other than a communication timing of data communication performed by a target circuit using the output clock signal among S clock pulses of the input clock signal. Further, it generates the output clock signal by subtracting a clock pulse of the input clock signal according to the generated control signal.
    Type: Grant
    Filed: July 30, 2009
    Date of Patent: April 16, 2013
    Assignee: NEC Corporation
    Inventor: Atsufumi Shibayama
  • Publication number: 20130082748
    Abstract: A technique includes controlling a modulus of a programmable divider, including selectively activating and deactivating cells of the divider. The activation for at least one of the cells includes configuring an output signal of the cell to exhibit a predetermined signal state when the cell transitions from a deactivated state to an activated state.
    Type: Application
    Filed: September 30, 2011
    Publication date: April 4, 2013
    Inventor: Tufan Coskun Karalar
  • Patent number: 8410831
    Abstract: A low-voltage high-speed frequency divider substantially reduces the power required to generate a half-rate in-phase clock signal and a half-rate quadrature-phase clock signal by reducing the number of pairs of transistors that respond to a full-rate clock signal and a full-rate inverse clock signal.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: April 2, 2013
    Assignee: National Semiconductor Corporation
    Inventor: Tonmoy Shankar Mukherjee