Duty Cycle Control Patents (Class 327/175)
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Publication number: 20100045353Abstract: Electronic apparatus, systems, and methods to implement selective edge phase mixing are disclosed. A selective edge phase mixing system includes a processor and memory device configured to perform operations in synchronization with transitions of an externally provided clock signal. A selective edge phase mixing unit for the memory device may include a first logic gate that receives the clock signal at an input port and receives first control signals, and pull-up circuits in communication with an output of the first logic gate and first control signals. A second logic gate receives the clock signal at the input port and receives second control signals. Pull-down circuits are coupled to the second logic gate and the second control signals, wherein the pull-up circuits and the pull-down circuits are coupled to the output port to provide a duty cycle corrected clock signal to the memory device. Additional apparatus, systems, and methods are disclosed.Type: ApplicationFiled: October 26, 2009Publication date: February 25, 2010Inventors: Eric R. Booth, Tyler J. Gomm
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Patent number: 7668698Abstract: Embodiments of the invention are generally directed to systems, methods, and apparatuses for the direct duty cycle calibration of a receiver clock. In some embodiments, an integrated circuit includes a receive (RX) data path, a RX clock path, and a control path. In some embodiments, the control path uses RX latches, a majority detector, and digital duty cycle control logic to calibrate the duty cycle of the clock signal. Other embodiments are described and claimed.Type: GrantFiled: December 6, 2007Date of Patent: February 23, 2010Assignee: Intel CorporationInventor: Yueming Jiang
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Patent number: 7667512Abstract: A duty cycle comparator is described for comparing the duty cycles of two digital signals. The duty cycle comparator comprises a first controllable current source, a second controllable current source and a charge accumulation device. The comparator provides an output signal that is representative of the difference between the duty cycles independent of the frequency of the two digital signals.Type: GrantFiled: March 29, 2007Date of Patent: February 23, 2010Assignee: Standard Microsystems CorporationInventors: Jade H. Alberkrack, Robert Alan Brannen
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Patent number: 7667513Abstract: A circuit and method of correcting the duty cycle of digital signals is disclosed. The duty cycle of an input digital signal is measured and compared to a desired duty cycle. The leading edge of the input digital signal is passed to an output. The circuit and method adjust the falling edges at the output to achieve the desired duty cycle. The falling edges occur in response to rising edges of a delayed version of the input digital signal.Type: GrantFiled: November 12, 2004Date of Patent: February 23, 2010Assignee: International Business Machines CorporationInventors: Gary D. Carpenter, Alan J. Drake, Fadi H. Gebara, Chandler T. McDowell, Hung C. Ngo
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Patent number: 7667520Abstract: The level shift device of the present invention comprises: a level shift circuit which converts a voltage level of a single input signal; and a duty correcting circuit which offsets a difference in the duty of an output signal of the level shift circuit with respect to the duty of the input signal.Type: GrantFiled: September 4, 2007Date of Patent: February 23, 2010Assignee: Panasonic CorporationInventors: Hiroshi Inoue, Yorimasa Funahashi, Satoshi Nakashima, Yasuyuki Okada
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Patent number: 7656113Abstract: A device of pulse width modulation type for load drive according to the present invention includes a first output unit (3) that applies a first output signal (e) to a load (5) in response to a first drive timing signal (c), a second output unit (4) that applies a second output signal (f) to the load (5) in response to a second drive timing signal (d), a signal converter (1) that converts a drive input signal (a) into a parallel signal (b), the drive input signal indicating time information allowing a potential difference to be generated across the load (5), and a drive timing generator (2) that generates the first and second drive timing signals (c, d) in response to the parallel signal (b), the load (5) being driven by increasing and reducing pulse widths of the first and second output signals (e, f).Type: GrantFiled: October 11, 2007Date of Patent: February 2, 2010Assignee: Panasonic CorporationInventors: Akihisa Ueno, Fumihisa Watanabe, Daijiro Arisawa
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Patent number: 7656213Abstract: Generating an output pulse signal (Y), which has an output signal period (Ty), which is divided by a magnitude transition into a leading part (LP) and a trailing part (TP). During each output signal period (Ty) altering means (27 to 36) determine in a coarse and fine way a duration (TLP, TTP) of one or both of said output signal period parts (LP, TP) by using a clock signal (Cx) of different clock cycle durations (TCx0, TCx1, TCx2), dependent on a value of a first digital number (D1) and a value of second, less significant digital number (D3, D5), respectively.Type: GrantFiled: September 12, 2006Date of Patent: February 2, 2010Assignee: Koninklijke Philips Electronics, N.V.Inventors: Carsten Deppe, Christian Hattrup
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Publication number: 20100007393Abstract: Described herein are methods and apparatuses for achieving a desired duty cycle on an output of a PLL. According to one embodiment, a method is described, including generating a single ended clock signal from a differential common mode clock signal using a limiting differential amplifier, wherein the single ended clock signal has a duty cycle, generating a differential bias current signal in response to the duty cycle of the single ended clock signal, and correcting the duty cycle of the single ended clock signal to a desired duty cycle by applying the differential bias current signal to the limiting differential amplifier.Type: ApplicationFiled: July 11, 2008Publication date: January 14, 2010Applicant: HONEYWELL INTERNATIONAL INC.Inventor: James Douglas Seefeldt
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Patent number: 7642829Abstract: A duty detection circuit includes an integration circuit for receiving an RCLK signal and an FCLK signal that are internal clock signals generated by a DLL circuit, and generating voltage levels in accordance with the duty ratio of these internal clock signals; an amplifier for amplifying the output of the integration circuit; a latch circuit for latching the output of the amplifier; a control circuit for controlling the operation timings of each component; a bias circuit for feeding a BIAS signal to the integration circuit; and a frequency monitor circuit unit for monitoring the frequency of the clock signal. The frequency monitor circuit unit is a circuit component used when the power source is turned on, during resetting, and when other initial settings are performed, and detects the actual frequency of the clock signal and adjusts the amount of charging or discharging of the capacitors C1 through C4 in the integration circuit according to this actual frequency.Type: GrantFiled: January 29, 2008Date of Patent: January 5, 2010Assignee: Elpida Memory, Inc.Inventors: Atsuko Monma, Kanji Oishi
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Patent number: 7642767Abstract: Disclosed herein is a method and apparatus used to the measure duty cycle of a clocking waveform utilizing minimal hardware and achieving high accuracy. This invention utilizes digital sampling of the signal to be measured at a rate that can be significantly lower then the clocking frequency of the signal to be measured. It accomplishes broad-band, multi-frequency use by using a time-varying frequency for the sampling clock to make sure that the sampling clock is asynchronous with the frequency of the clocking signal to be measured. The average ratio of the sampled ones (or zeros) as compared to the total number of samples is then computed to derive the measurement of duty cycle.Type: GrantFiled: March 7, 2006Date of Patent: January 5, 2010Assignee: Synthesys Research, IncInventor: Andre Willis
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Patent number: 7642830Abstract: A delay locked loop includes a storage element coupled to a data bus and produces a data synchronization signal. A phase detector receives a data clock signal and the data synchronization signal and produces a delay control signal. A first delay circuit produces a signal which is delayed relative to the data clock signal according to the delay control signal. A second delay circuit receiving the delayed signal produces a control signal coupled to a control input of the storage element by delaying the delayed signal an amount which causes the control signal to have a predetermined duty cycle.Type: GrantFiled: October 30, 2008Date of Patent: January 5, 2010Assignee: Texas Instruments IncorporatedInventor: Robert L White
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Patent number: 7642828Abstract: A level conversion circuit includes an input section configured to receive a first signal of a first signal level and a correction signal and generates a second signal of a second signal level from the first signal and the correction signal. A level converting section converts the second signal into an output signal of a third signal level, and a duty correcting section generates the correction signal corresponding to a duty ratio of the output signal and outputs the correction signal to the input section.Type: GrantFiled: June 7, 2006Date of Patent: January 5, 2010Assignee: NEC Electronics CorporationInventor: Shingo Sakai
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Publication number: 20090322390Abstract: A duty cycle correction circuit and a delay locked loop circuit including the same are capable of reducing area and power consumption of a circuit. The delay locked loop circuit includes a delay locked loop unit, a delay controller, a duty cycle ratio correction circuit, and a duty cycle ratio detector. The delay locked loop unit outputs an internal clock by delaying an external clock in order to compensate a clock skew. The delay controller outputs a delay internal clock by delaying the internal clock in response to correction signals. The duty cycle ratio correction circuit outputs an internal correction clock by increasing or decreasing a high level section of the internal clock according to the correction signals. The duty cycle ratio detector outputs the correction signals in accordance with a duty cycle ratio of the internal correction clock.Type: ApplicationFiled: November 6, 2008Publication date: December 31, 2009Applicant: HYNIX SEMICONDUCTOR, INC.Inventor: Seok-Bo Shim
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Publication number: 20090323374Abstract: The present invention relates to a switch control device and a converter including the same. According to an exemplary embodiment of the present invention, the switch control device includes a PWM controller for forcing a power switch to turn on when the power switch is turned off during a predetermined period, a current sensor for determining whether a current flows through the power switch, and a conditional counter for determining that an input voltage is input to a power transmission element by using a sense result of the current sensor and a number of times that the PWM controller turns on the power switch by force.Type: ApplicationFiled: June 17, 2009Publication date: December 31, 2009Applicant: Fairchild Korea Semiconductor Ltd.Inventors: Young-Bae Park, Hang-Seok Choi, Ki-Tae Kim
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Patent number: 7639055Abstract: After an output signal S4 is level-inverted, first and second shorting FETs 55, 56 as a level-inversion inhibiting circuit inhibit level-inversion so that the signal is maintained to the inverted state. Thereafter the inhibition of level-inversion is released, when the signal is subsequently level-inverted at a proper time according to a desired duty ratio of a PWM signal S1. Thus chattering can be prevented and thereby a PWM signal S1 of a stable duty ratio can be generated, even if the level of a reference signal S3 fluctuates due to a noise or the like during vehicle acceleration, for example.Type: GrantFiled: October 17, 2006Date of Patent: December 29, 2009Assignees: Autonetworks Technologies, Ltd., Sumitomo Wiring Systems, Ltd., Sumitomo Electric Industries, Ltd.Inventors: Masayuki Kato, Seiji Takahashi, Masahiko Furuichi, Isao Isshiki
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Patent number: 7633324Abstract: A data output strobe signal generating circuit includes a duty cycle correcting unit that corrects the duty ratio of an input clock in response to a control signal to generate a corrected clock. A data output strobe signal generating unit receives the corrected clock and generates a data output strobe signal. A duty cycle control unit receives the data output strobe signal and outputs the control signal.Type: GrantFiled: July 20, 2007Date of Patent: December 15, 2009Assignee: Hynix Semiconductor Inc.Inventors: Won-Joo Yun, Hyun-Woo Lee
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Publication number: 20090302912Abstract: A duty cycle correction circuit of a semiconductor memory apparatus includes a duty ratio correcting unit configured to correct a duty ratio of a clock signal according to levels of a first reference voltage and a second reference voltage, and to output the clock signal as a correction clock signal, a duty ratio detecting unit configured to count first and second counting signals in response to a duty ratio of the correction clock signal when a pump enable signal is enabled, a pump enable signal generating unit configured to generate the pump enable signal in response to the duty ratio of the correction clock signal, and a reference voltage generating unit configured to generate the first and second reference voltages in response to the first and second counting signals.Type: ApplicationFiled: December 30, 2008Publication date: December 10, 2009Applicant: HYNIX SEMICONDUCTOR INC.Inventor: Seong Jun Lee
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Patent number: 7629829Abstract: Disclosed is a duty cycle correction device for correcting a duty cycle of a clock signal output from a delay locked loop circuit. The duty cycle correction device includes a mixer for mixing phases of the first and second clock signals, thereby outputting a first signal, a phase splitter receiving the first signal and outputting a third clock signal, a duty detection unit receiving the third and fourth clock signals to detect a difference between duty cycles of the third and fourth clock signals, a combination unit for outputting a second signal, a shift register for outputting a first control signal, a phase detection unit receiving the first and second clock signals and outputting a second control signal representing a difference between duty cycles of the first and second clock signals. The mixer adjusts a mixing ratio by using the first and second control signals.Type: GrantFiled: August 13, 2007Date of Patent: December 8, 2009Assignee: Hynix Semiconductor Inc.Inventor: Hyun Woo Lee
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Patent number: 7629824Abstract: The present invention relates to a duty correction circuit that corrects a distorted duty of a clock signal using a delay unit and a delay controller, thereby reducing the layout area and current consumption.Type: GrantFiled: August 1, 2008Date of Patent: December 8, 2009Assignee: Hynix Semiconductor Inc.Inventor: Kwang Jun Cho
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Publication number: 20090295446Abstract: A duty cycle correcting circuit includes a duty ratio control unit configured to alternately change logical values of a plurality of bits of a pull-up control signal and a plurality of bits of a pull-down control signal in response to a duty ratio detection signal, a duty ratio correcting unit configured to adjust driving abilities of a first driver and a second driver in response to the plurality of bits of the pull-up control signal and the plurality of bits of the pull-down control signal to output a correction clock signal, and a duty ratio detecting unit configured to detect a duty ratio of the correction clock to generate the duty ratio detection signal.Type: ApplicationFiled: December 29, 2008Publication date: December 3, 2009Applicant: HYNIX SEMICONDUCTOR INC.Inventors: Won-Joo Yun, Hyun-Woo Lee
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Publication number: 20090289680Abstract: A semiconductor device includes a first duty determining circuit (20) and a second duty determining circuit (30). The first duty determining circuit (20) determines a duty correction condition for an input signal in a first predetermined cycle longer than a cycle of the input signal to obtain a first determination result and updates the duty correction condition for the input signal on the basis of the first determination result. The second duty determining circuit (30) determines the duty correction condition for the input signal in a second predetermined cycle shorter than first predetermined cycle to obtain a second determination result and updates the duty correction condition for the input signal only when the second determination result is fixed during a predetermined period.Type: ApplicationFiled: May 19, 2009Publication date: November 26, 2009Applicant: ELPIDA MEMORY, INC.Inventor: Kazutaka MIYANO
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Publication number: 20090289679Abstract: A duty correction circuit is formed using at least one delay circuit, which is constituted of a first inverter including three transistors of different conduction types and a second inverter including three other transistors of different conduction types and which delays and adjusts an input clock signal at the leading-edge/trailing-edge timing so as to convert it into an output clock signal based on a first or second bias voltage produced by a bias circuit detecting the duty ratio of the output clock signal. The duty correction circuit decreases the high-level period of the output clock signal having a high duty ratio based on the first bias voltage. Alternatively, the duty correction circuit increases the high-level period of the output clock signal having a low duty ratio based on the second bias voltage.Type: ApplicationFiled: May 18, 2009Publication date: November 26, 2009Applicant: ELPIDA MEMORY, INC.Inventors: Koji Kuroki, Yasuhiro Takai
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Publication number: 20090284288Abstract: A high-speed low-power latch includes three sets of transistors. A first set of transistors selects a tracking mode or a holding mode for the latch based on a clock signal having non-rail-to-rail or rail-to-rail voltage swing. A second set of transistors captures a data value based on an input signal and provides an output signal during the tracking mode. A third set of transistors stores the data value and provides the output signal during the holding mode. The input and output signals have rail-to-rail voltage swing. In another aspect, a signal generator includes at least one latch and a control circuit. The latch(es) receive a clock signal and generate an output signal. The control circuit senses a duty cycle of a feedback signal derived from the output signal and generates a control signal to adjust operation of the latch(es) to obtain 50% duty cycle for the feedback signal.Type: ApplicationFiled: May 15, 2008Publication date: November 19, 2009Applicant: QUALCOMM INCORPORATEDInventors: Kun Zhang, Harish Muthali
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Publication number: 20090284290Abstract: A DLL circuit is designed to adjust the delay time and the duty applied to an input clock signal, thus producing a DLL clock signal. In a non-clocking state of the DLL clock signal in which pulses disappear temporarily, the DLL circuit stops updating the delay time and the duty of the DLL clock signal. That is, the DLL circuit is capable of preventing a phase difference between the input clock signal and the DLL clock signal from being erroneously detected in the non-clocking state of the DLL clock signal, thus preventing the delay time and the duty from being updated based on the erroneously detected phase difference. Thus, it is possible to reduce the number of cycles adapted to the delay-locked control and to thereby stabilize the operation of the DLL circuit.Type: ApplicationFiled: May 13, 2009Publication date: November 19, 2009Applicant: ELPIDA MEMORY, INC.Inventors: Koji Kuroki, Ryuuji Takishita
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Publication number: 20090284293Abstract: A duty correction circuit includes a duty ratio sensor for controlling a duty ratio sensing speed by a sensing speed control signal and outputting a correction signal by sensing a duty ratio of a clock, and a duty ratio corrector for controlling the duty ratio of the clock in response to the correction signal.Type: ApplicationFiled: December 24, 2008Publication date: November 19, 2009Inventors: Kyung-Hoon Kim, Bo-Kyeom Kim
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Publication number: 20090278581Abstract: The provided delay lock loop delaying an input signal includes a quadrature generator, a voltage controller and a delay cell. The input signal is inputted into the quadrature generator and the delay cell. A phase-changing signal from the quadrature generator and a delay signal respectively from the delay cell are inputted into the voltage controller at the same time so that a control voltage inputted into the delay cell to control a delay time of the delay signal is generated. Also, the provided phase angle generator generates an output signal in an arbitrary phase.Type: ApplicationFiled: July 16, 2009Publication date: November 12, 2009Applicant: HOLTEK SEMICONDUCTOR INC.Inventors: Chih-Wei Yang, Chien-Hsun Lee
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Patent number: 7617059Abstract: The disclosed methodology and apparatus measures the duty cycle of a clock signal. A variable duty cycle circuit receives a clock signal from a clock signal generator. The variable duty cycle circuit adjusts the duty cycle of the clock signal by an amount dependent on a duty cycle index value that it receives. The variable duty cycle circuit supplies a duty-cycle adjusted clock signal to a divider circuit. The apparatus sweeps the frequency of the clock signal from a starting value up to a maximum frequency above which the divider circuit fails. The apparatus then determines the duty cycle of the duty-cycle adjusted clock signal from the maximum frequency.Type: GrantFiled: October 31, 2007Date of Patent: November 10, 2009Assignee: International Business Machines CorporationInventors: David William Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7616038Abstract: A clock modulation circuit includes a modulation block that receives a fixed clock generated from a reference clock and buffers the fixed clock so as to generate a modulated clock. A correction unit is provided in the modulation block to correct the duty ratio of the modulated clock.Type: GrantFiled: July 23, 2007Date of Patent: November 10, 2009Assignee: Hynix Semiconductor Inc.Inventor: Young-Hoon Oh
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Publication number: 20090273382Abstract: A circuit configured to correct a duty cycle includes a clock dividing unit configured to delay an input clock signal by a specified delay amount and to generate a plurality of delayed clock signals, a clock selection unit configured to output any one among the plurality of delayed clock signals as a selected delayed clock signal in response to duty ratio information of the input clock signal, an edge control unit configured to generate a falling clock signal by controlling a falling edge of the selected delayed clock signal and to generate a rising clock signal by controlling a falling edge of the input clock signal based on information regarding a difference between lengths of a high duration and a low duration of the input clock signal, and a phase mixing unit for mixing phases of the falling clock signal and the rising clock signal and generating an output clock signal.Type: ApplicationFiled: July 9, 2009Publication date: November 5, 2009Applicant: HYNIX SEMICONDUCTORR INC.Inventors: Dong Suk Shin, Hyun Woo Lee, Won Joo Yun
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Patent number: 7612592Abstract: A duty-cycle generator including, in one embodiment, a duty-cycle adjustment circuit and a delay processor. The duty-cycle adjustment circuit is adapted to receive an input clock signal having an input duty cycle, generate first and second versions of the input clock signal having different amounts of delay, and combine the first and second versions of the input clock signal to generate an output clock signal having an output duty cycle different from the input duty cycle. The delay processor is adapted to generate at least one control signal for controlling operations of the duty-cycle adjustment circuit based on a comparison of a characteristic of the output clock signal with a corresponding characteristic of a target output clock signal.Type: GrantFiled: December 22, 2005Date of Patent: November 3, 2009Assignee: Agere Systems, Inc.Inventor: Parag Parikh
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Patent number: 7612620Abstract: A system and method of conditioning differential clock signals iteratively adjusts the duty cycles and phases of the clock signals. The duty cycles of the clock signals are adjusted by comparing respective voltage corresponding to the duty cycles of respective clock signals in each of the differential pairs. The result of the comparison is used to adjust the duty cycles of the clock signal until the magnitudes of the voltages are substantially equal. The phases of the clock signals are adjusted by selecting two sets of two clock signals each that are assigned relative phases that differ from each other by the same amount. The selected sets of clock signals are processed so that the duty cycles of resulting signals correspond to the phases of the clock signals. The duty cycle of these signals is measured as described above and used to adjust the phases of the clock signals.Type: GrantFiled: June 29, 2007Date of Patent: November 3, 2009Assignee: Micron Technology, Inc.Inventors: Greg Rausch, Robert Rabe, Curtis Schnarr
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Patent number: 7612593Abstract: Semiconductor memory device with duty correction circuit includes a clock edge detector configured to generate first and second detection pulses in response to a transition timing of a common clock signal in an initial measurement operation; a duty detector configured to compare the first and second detection pulses to output comparison result signals; and a code counter configured to control the duty detector based on the comparison signals outputted from the duty detector in the initial measurement operation.Type: GrantFiled: December 28, 2007Date of Patent: November 3, 2009Assignee: Hynix Semiconductor Inc.Inventors: Kyung-Hoon Kim, Jun-Woo Lee, Dae-Kun Yoon, Taek-Sang Song
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Patent number: 7609101Abstract: The present invention relates to a pulse width modulation switching direct voltage circuit. The PWM circuit comprises a first passive device, a second passive device and a third passive device connected in series between a power supply and a ground such that the first passive device is connected to the second passive device and the second passive device is connected to the third passive device, and a fourth passive device which is connected in-parallel between an output end and a point between the first passive device and the second passive device, wherein the rated value of the fourth passive device is at least three times more than the rated value of the first passive device. Herewith, the voltage-cycle relationship of the PWM circuit becomes linear. Under such a state, the PWM circuit is enabled with good work efficiency.Type: GrantFiled: October 11, 2007Date of Patent: October 27, 2009Assignees: Anpec Electronics CorporationInventor: Ching-Sheng Li
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Patent number: 7609583Abstract: Electronic apparatus, systems, and methods to implement selective edge phase mixing are disclosed. A selective edge phase mixing system includes a processor and memory device configured to perform operations in synchronization with transitions of an externally provided clock signal. A selective edge phase mixing unit for the memory device may include a first logic gate that receives the clock signal at an input port and receives first control signals, and pull-up circuits in communication with an output of the first logic gate and first control signals. A second logic gate receives the clock signal at the input port and receives second control signals. Pull-down circuits are coupled to the second logic gate and the second control signals, wherein the pull-up circuits and the pull-down circuits are coupled to the output port to provide a duty cycle corrected clock signal to the memory device. Additional apparatus, systems, and methods are disclosed.Type: GrantFiled: November 12, 2007Date of Patent: October 27, 2009Assignee: Micron Technology, Inc.Inventors: Eric R. Booth, Tyler J. Gomm
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Publication number: 20090261877Abstract: A duty cycle correction circuit with wide-frequency working range utilizes a pulse generator having adjustable pulse width function to adjust the width of the pulse and outputs a clock signal with the duty cycle of 50%. The pulse generator includes a NAND gate, a modulation device, and an inverter. The inverter is coupled between the second input end of the NAND gate and the modulation device. The modulation device modulates the low-level status of the input clock signal and accordingly outputs to the inverter. The first input end of the NAND gate receives the input clock signal. The NAND gate operates NAND calculation to the signals received on the input ends of the NAND gate and accordingly outputs a periodic low-level pulse signal.Type: ApplicationFiled: November 19, 2008Publication date: October 22, 2009Inventors: Hsien-Sheng Huang, Chun Shiah
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Patent number: 7605626Abstract: A clock duty cycle correction (DCC) circuit for correcting a clock duty cycle of an external clock includes a phase comparator for comparing a phase of a rising clock with that of a falling clock to thereby output comparing signal; a DCC controller for outputting a DCC enable signal and a weight selection signal in response to the comparing signal and a first and a second lock state signal; a DCC mixing block for blending the rising clock and the falling clock in response to the DCC enable signal and the weight selection signal to thereby generate a rising and a falling pre-clock signals; and a clock selector for selectively output the rising and the falling pre-clock signals in response to the weight selection signal.Type: GrantFiled: March 31, 2008Date of Patent: October 20, 2009Assignee: Hynix Semiconductor Inc.Inventor: Hwang Hur
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Patent number: 7602257Abstract: A signal generating circuit is provided. The signal generating circuit may include a plurality of delay circuits coupled to provide a plurality of control signals, a weighted-sum circuit to receive the plurality of control signals and to provide an output analog signal, and a comparator circuit to compare the output analog signal with a voltage and to provide a pulse width modulated (PWM) signal based on the comparison.Type: GrantFiled: December 19, 2006Date of Patent: October 13, 2009Assignee: Intel CorporationInventors: Gerhard Schrom, Dinesh Somasekhar, Fabrice Paillet, Peter Hazucha, Sung Tae Moon, Tanay Karnik
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Publication number: 20090251184Abstract: A duty cycle correction circuit apparatus includes a flip-flop, a feedback unit connected between an input node and an output node of the flip-flop to invert an output signal of the flip-flop and to output the inverted signal as an output signal of the feedback unit, and a selection unit to select and output one of a first clock signal and a second clock signal to the flip-flop in response to the output signal of the feedback unit, wherein the first clock signal has a half-period phase difference with respect to the second clock signal. Using clock signals with a half-period phase difference therebetween and a simple digital circuit, the duty cycle correction circuit can correct a duty ratio to 50:50 regardless of an initial condition.Type: ApplicationFiled: March 11, 2009Publication date: October 8, 2009Applicant: Samsung Electronics Co., LtdInventor: Dong-uk PARK
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Patent number: 7598786Abstract: A duty cycle correction circuit comprises a frequency divider, a duty cycle detector and a delay circuit. The frequency divider receives a first clock signal and divides the frequency of the first clock signal to generate a second clock signal. The duty cycle detector receives the second clock signal and a correction clock signal and generates a control signal according to the second clock signal and the correction clock signal. The delay circuit receives the first clock signal and the control signal and adjusts a delay time of a falling edge of the first clock signal according to the control signal to generate the correction clock.Type: GrantFiled: October 26, 2007Date of Patent: October 6, 2009Assignee: Nanya Technology CorporationInventor: Wen-Chang Cheng
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Patent number: 7598783Abstract: A DLL circuit includes a duty ratio detection unit that detects a duty ratio of a rising clock and a duty ratio of a falling clock, thereby outputting a duty ratio detection signal. A correction control unit generates a correction control signal in response to the duty ratio detection signal. A duty ratio correction unit corrects a duty ratio of an internal. clock in response to the correction control signal, thereby outputting a reference clock.Type: GrantFiled: July 16, 2007Date of Patent: October 6, 2009Assignee: Hynix Semiconductor Inc.Inventors: Dong-Suk Shin, Hyun-Woo Lee, Won-Joo Yun
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Publication number: 20090243684Abstract: In an embodiment, the present invention relates to an integrated circuit comprising at least one data signal input (data1, data2), at least one clock signal input (Clock), at least one control signal input (Cnt_del1, Cnt_del2) and a data signal output (Data_out). According to the invention, the integrated circuit is configured to provide a digital data signal having a variable symbol duration at its output (Data_out), the symbol duration being controllable by means of the control signal (Cnt_del1, Cnt_del2). A further embodiment of the invention relates to a method for generating a digital data signal having a variable symbol duration in which an output signal is generated by at least one first data signal, at least one first clock signal and at least one control signal. For this purpose, at least one second clock signal is generated from the first clock signal, the second clock signal having a variable delay and the delay being set depending on the value of the at least one control signal.Type: ApplicationFiled: March 29, 2008Publication date: October 1, 2009Inventors: Dirk Scheideler, Otto Schumacher, Karthik Gopalakrishnan
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Publication number: 20090243677Abstract: Closed-loop duty-cycle correctors (DCCs), clock generators, memory devices, systems, and methods for generating an output clock signal having a particular duty cycle are provided, such as clock generators configured to generate an output clock signal synchronized with a received input clock signal having a predetermined duty cycle. Embodiments of clock generators include closed-loop duty cycle correctors that receive an already-controlled and corrected output signal. For example, DLL control circuitry and DCC control circuitry may each adjust a delay of a variable delay line. The DLL control circuitry adjusts the delay such that an output clock signal is synchronized with an input clock signal. The DCC control circuitry detects a duty cycle error in the output clock signal and adjusts the delay of the variable delay line to achieve a duty cycle corrected output signal.Type: ApplicationFiled: March 25, 2008Publication date: October 1, 2009Applicant: Micron Technology, Inc.Inventors: Eric Becker, Eric Booth, Tyler Gomm
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Publication number: 20090243685Abstract: A signal processing device includes a correction circuit configured to correct the distortion of the duty cycle in a data signal having different occurrence probabilities of 0 and 1.Type: ApplicationFiled: March 23, 2009Publication date: October 1, 2009Applicant: Sony CorporationInventors: Satoru OOSHIMA, Tatsuo SHIMIZU, Azuma KAWABE, Hidenobu KAKIOKA
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Patent number: 7595675Abstract: The disclosed methodology and apparatus measure the duty cycle of a reference clock signal that a clock circuit supplies to a duty cycle measurement (DCM) circuit. In one embodiment, the DCM circuit includes a capacitor driven by a charge pump. The reference clock signal drives the charge pump. The clock circuit varies the duty cycle of the reference clock signal among a number of known duty cycle values. The DCM circuit stores resultant capacitor voltage values corresponding to each of the known duty cycle values in a data store. The DCM circuit applies a test clock signal having an unknown duty cycle to the capacitor via the charge pump, thus charging the capacitor to a new voltage value that corresponds to the duty cycle of the test clock signal. Control software accesses the data store to determine the duty cycle to which the test clock signal corresponds.Type: GrantFiled: May 1, 2006Date of Patent: September 29, 2009Assignee: International Business Machines CorporationInventors: David William Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7592843Abstract: A clock input filter uses a first programmable low-pass delay element to filter during a low period of an input clock signal and to output a SET signal. The clock input filter uses a second programmable low-pass delay element to filter during a high period of the input clock signal and to output a RESET signal. A latch is set and reset by the SET and RESET signals. The latch outputs a filtered version of the input signal that has the same approximate duty cycle as the input signal. A pair of gates generates a corresponding pair of duty cycle adjusted versions of the input signal. Output multiplexing circuitry is provided to output either the output of the latch, or an increased duty cycle version of the input signal, or a decreased duty cycle version of the input signal, or an unfiltered version of the input signal.Type: GrantFiled: August 5, 2008Date of Patent: September 22, 2009Assignee: ZiLOG, Inc.Inventor: Steven K. Fong
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Publication number: 20090231006Abstract: A duty cycle correction circuit includes a phase splitter configured to control a phase of a DLL clock signal to generate a rising clock signal and a falling clock signal, a clock delay unit configured to delay the rising clock signal and the falling clock signal in response to control signals to generate a delayed rising clock signal and a delayed falling clock signal, a duty ratio correction unit configured to generate a correction rising clock signal and a correction falling clock signal that toggle in response to an edge timing of the delayed rising clock signal and the delayed falling clock signal, and a delay control unit configured to detect duty cycles of the correction rising clock signal and the correction falling clock signal to generate the control signals.Type: ApplicationFiled: December 9, 2008Publication date: September 17, 2009Applicant: HYNIX SEMICONDUCTOR, INC.Inventors: Jae Min Jang, Yong Ju Kim, Sung Woo Han, Hee Woong Song, Ic Su Oh, Hyung Soo Kim, Tae Jin Hwang, Hae Rang Choi, Ji Wang Lee, Chang Kun Park
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Patent number: 7586349Abstract: A CMOS integrated circuit (12) for correction of the duty cycle of a clock signal has a correction amplifier (16) to which a clock signal (14) is applied. The output of correction amplifier (16) is connected to an output buffer (18) and to an input of a duty cycle detector (20), the output of which is fed back to a control input (VC) of correction amplifier (16), thus forming a control loop. The duty cycle detector (20) comprises a buffer amplifier (22), an RC low pass circuit and a second inverter (24). A deviation of the duty cycle of the clock signal is detected in the duty cycle detector 20 and used to correct the duty cycle in the correction amplifier 16.Type: GrantFiled: June 19, 2006Date of Patent: September 8, 2009Assignee: Texas Instruments Deutschland GmbHInventor: Sotirios Tambouris
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Patent number: 7579890Abstract: A duty detector may include a first amplifier and/or an integrator. The first amplifier may be configured to receive a first signal and a complementary first signal, differential-amplify the first signal and the complementary first signal, and/or output the differential-amplified first signal to an output terminal and the differential-amplified complementary first signal to a complementary output terminal. The integrator may be connected to the output terminal and the complementary output terminal of the first amplifier, configured to integrate the differential-amplified first signal and the differential-amplified complementary first signal, and/or configured to output a duty detection signal.Type: GrantFiled: October 17, 2007Date of Patent: August 25, 2009Assignee: Samsung Electronics Co., Ltd.Inventor: Young-soo Sohn
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Publication number: 20090206900Abstract: A duty cycle correction circuit capable of reducing current consumption and that includes a back-bias voltage supply circuit for supplying back-bias voltages, wherein a duty cycle of an input clock is reflected on the back-bias voltages; and a buffer for adjusting the duty cycle of the input clock and configured to receive the back-bias voltages.Type: ApplicationFiled: July 7, 2008Publication date: August 20, 2009Applicant: HYNIX SEMICONDUCTOR, INC.Inventors: Hee Woong Song, Yong Ju Kim, Sung Woo Han, Jae Min Jang, Hyung Soo Kim, Ji Wang Lee, Chang Kun Park, Ic Su Oh, Hae Rang Choi, Tae Jin Hwang
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Publication number: 20090206901Abstract: A duty cycle correction circuit includes a signal generating unit including a first signal generating unit coupled to a power supply voltage terminal and configured to output a complementary output signal of an output signal in response to a clock signal, and a second signal generating unit coupled to the power supply voltage terminal and configured to output the output signal in response to a complementary clock signal of the clock signal; a variable resistor unit coupled between the first and second signal generating units configured to vary an amount of current flowing into the signal generating unit according to a duty correction control signal, the duty correction control signal having a voltage level determined based on a voltage level of the output signal; and a current source coupled between the variable resistor unit and a ground voltage terminal configured to supply current to the signal generating unit.Type: ApplicationFiled: December 11, 2008Publication date: August 20, 2009Applicant: HYNIX SEMICONDUCTOR, INC.Inventors: Hee Woong Song, Yong Ju Kim, Sung Woo Han, Jae Min Jang, Hyung Soo Kim, Ji Wang Lee, Chang Kun Park, Ic Su Oh, Hae Rang Choi, Tae Jin Hwang