Uniform Pulse Waveform Patents (Class 327/10)
  • Patent number: 11264903
    Abstract: A power converter circuit includes a power stage that includes a transformer and a switch. The switch can be controlled in response to a PWM signal to provide a primary current through a primary winding of the transformer to induce a secondary current in a secondary winding of the transformer to generate an output voltage. The power stage includes a switching node between the switch and the primary winding having a switching voltage. The circuit also includes a switching controller configured to generate the PWM signal in response to a ramp signal. The ramp signal can have an amplitude of a slope that is proportional to a decay rate of a magnetizing current of the transformer and generated in response to feedback from the power stage. The switch can be activated in response to the switching voltage having an amplitude of approximately zero volts based on the amplitude of the ramp signal.
    Type: Grant
    Filed: September 18, 2017
    Date of Patent: March 1, 2022
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Pei-Hsin Liu, James Michael Walden
  • Patent number: 10602577
    Abstract: A control circuit for generating a switching control signal to control switching operations of a power switch in a power stage circuit, can include: a first control loop configured to receive a first voltage feedback signal, and to generate a first compensation signal; a voltage regulating circuit configured to receive an output voltage signal of the power stage circuit, and to generate a second compensation signal according to a difference between an output voltage signal of the power stage circuit during different time periods; and control and driving circuit configured to receive the first and second compensation signals and a sense voltage signal that represents a current through an inductor of the power stage circuit, and to generate an OFF signal, and a switching control signal according to the OFF signal and an ON signal.
    Type: Grant
    Filed: November 29, 2018
    Date of Patent: March 24, 2020
    Assignee: Silergy Semiconductor Technology (Hangzhou) LTD
    Inventor: Xiaoping Chen
  • Patent number: 10534025
    Abstract: A phase frequency detector (PFD) isolates supply (e.g., voltage supply) to a reference path and a feedback path of a phase locked loop (PLL) such that the power supply to the reference path is independent of the power supply to the feedback path. This isolation improves linearity. In one instance, the PFD includes a supply voltage, one or more switches, a reference capacitor and a feedback capacitor. The reference capacitor is selectively coupled to the supply voltage via the one or more switches and the feedback capacitor is selectively coupled to the supply voltage via the one or more switches.
    Type: Grant
    Filed: September 20, 2017
    Date of Patent: January 14, 2020
    Assignee: QUALCOMM Incorporated
    Inventor: Jingcheng Zhuang
  • Patent number: 10374605
    Abstract: Techniques are disclosed for designing a reconfigurable fabric. The reconfigurable fabric is designed using logical elements, configurable connections between and among the logical elements, and rotating circular buffers. The circular buffers contain configuration instructions. The configuration instructions control connections between and among logical elements. The logical elements change operation based on the instructions that rotate through the circular buffers. Clusters of logical elements are interconnected by a switching fabric. Each cluster contains processing elements, storage elements, and switching elements. A circular buffer within a cluster contains multiple switching instructions to control the flow of data throughout the switching fabric. The circular buffer provides a pipelined execution of switching instructions for the implementation of multiple functions.
    Type: Grant
    Filed: October 31, 2018
    Date of Patent: August 6, 2019
    Assignee: Wave Computing, Inc.
    Inventor: Christopher John Nicol
  • Patent number: 10320376
    Abstract: A frequency divider system and method includes a split-divisor frequency divider module. The split-divisor frequency divider module receives a clock signal and generates an output signal based on a first divisor and a second divisor. The clock signal and output signal each have rectangular waveforms characterized by a respective frequency and pulse width. The frequency of the output signal is a selectable integer fraction of the frequency of the clock signal, the frequency of the output signal being selected based on a sum of the first and second divisors. The pulse width of the output signal is a selectable integer number of clock cycles, the pulse width of the output signal being selected based on at least one of the first divisor and the second divisor.
    Type: Grant
    Filed: November 9, 2016
    Date of Patent: June 11, 2019
    Assignee: Integrated Device Technology, Inc.
    Inventor: Richard Geiss
  • Patent number: 10194497
    Abstract: A control circuit for generating a switching control signal to control switching operations of a power switch in a power stage circuit, can include: a first control loop configured to receive a first voltage feedback signal, and to generate a first compensation signal; a voltage regulating circuit configured to receive an output voltage signal of the power stage circuit, and to generate a second compensation signal according to a difference between an output voltage signal of the power stage circuit during different time periods; and control and driving circuit configured to receive the first and second compensation signals and a sense voltage signal that represents a current through an inductor of the power stage circuit, and to generate an OFF signal, and a switching control signal according to the OFF signal and an ON signal.
    Type: Grant
    Filed: May 4, 2017
    Date of Patent: January 29, 2019
    Assignee: Silergy Semiconductor Technology (Hangzhou) LTD
    Inventor: Xiaoping Chen
  • Patent number: 10054635
    Abstract: A built-in test circuit for testing a system timing margin of a processing device under-test is provided. The processing device includes a controller and first clock circuit, wherein the first clock circuit generates a first clock signal and the first clock signal is a main clock signal provided for operation of the processing device. The built-in test circuit includes a second clock circuit and a logic circuit, both of which are integrated with the processing device. The second clock circuit generates a second clock signal. The logic circuit processes the first and second clock signals and outputs a third clock signal. The third clock signal is used to determine system timing margin of the processing device.
    Type: Grant
    Filed: May 9, 2016
    Date of Patent: August 21, 2018
    Assignee: Hamilton Sunstrand Corporation
    Inventors: Kirk A. Lillestolen, Gary L. Hess
  • Patent number: 9899991
    Abstract: A circuit includes a first and second oscillator, a first and second phase comparator, and a control unit. The first and second oscillators are configured to respectively generate a first and second oscillating signal. The first and second phase comparators are connected between the first and second oscillators. The first phase comparator is configured to generate a first phase error signal according to a first signal associated with the first oscillating signal and a delayed version of a second signal associated with the second oscillating signal. The second phase comparator is configured to generate a second phase error signal according to the second signal and a delayed version of the first signal. The control unit is connected between the first and second phase comparators and configured to generate one of a tuning signal and a pulse signal based on the difference between the first and second phase error signals.
    Type: Grant
    Filed: May 22, 2017
    Date of Patent: February 20, 2018
    Assignee: Taiwan Semiconductor Manufacturing Company Limited
    Inventors: Chewn-Pu Jou, Huan-Neng Chen, Lan-Chou Cho
  • Patent number: 9762128
    Abstract: Controlling an isolated converter can include: controlling a first voltage signal across the secondary winding according to a wake-up signal to reflect change of an output voltage of the isolated converter; obtaining a second voltage signal representing the first voltage signal at the primary side; controlling the main power switch according to a detection result of the second voltage signal; generating the wake-up signal according to the output voltage and a first threshold voltage when the isolated converter is in a dynamic loading state of a normal operating mode; generating the wake-up signal according to the output voltage and a second threshold voltage when the isolated converter is in a load steady state of a standby operating mode; and generating the wake-up signal according to the output voltage and a third threshold voltage when the isolated converter is in a dynamic loading state of the standby operating mode.
    Type: Grant
    Filed: April 15, 2016
    Date of Patent: September 12, 2017
    Assignee: Silergy Semiconductor Technology (Hangzhou) LTD
    Inventors: Shaobin Zhang, Yongjiang Bai, Zhiliang Hu, Le Li, Jinping Dong
  • Patent number: 9459314
    Abstract: The present disclosure provides a monitoring system for monitoring the operation of an integrated circuit, the monitoring system comprising: a reference circuit comprising a reference signal delay path and an output for outputting a reference signal; a monitoring circuit, the monitoring circuit comprising: a programmable delay line for providing a controllably selectable delay path; and an output for outputting a delayed signal; a comparison circuit, for comparing the reference signal to the delayed signal and determining whether the error has occurred based on the comparison.
    Type: Grant
    Filed: October 8, 2014
    Date of Patent: October 4, 2016
    Assignee: Microsemi Storage Solutions (U.S.), Inc.
    Inventor: Howard Shih Hao Chang
  • Patent number: 9318163
    Abstract: In accordance with at least one embodiment, a clock counter on a system (for example, a system-on-a-chip (SOC) or other system) is utilized to count a number of a clock edges of a memory clock within a predefined time based on a predetermined system clock frequency and, therefore, to determine whether the memory clock for a memory array (for example, a non-volatile memory (NVM) array or other memory array) is correct or not. The system is directed to wait until the count is within an expected range before moving to the next step in a start-up procedure. If the maximum allowed start-up time is exceeded, an error signal is sent to the system such that the application can react to it.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: April 19, 2016
    Assignee: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Richard K. Eguchi, Craig D. Gunderson
  • Patent number: 8923444
    Abstract: A receiver for decoding a communication signal is disclosed. The receiver includes an input port and a filter. The input port receives the communication signal from a communication medium. The communication signal comprises a sequence of symbols. Each symbol of the symbol sequence is an analog pulse that has a leading edge of exponential shape. The exponential shape has an exponential growth parameter value that has been selected from values ?0 and ?1, which are distinct positive values. For each symbol of the symbol sequence, the exponential growth parameter value for the leading edge of the symbol has been selected based on a corresponding bit from a stream of information bits. The filter receives the communication signal from the input port and filters the communication signal to obtain an output signal. The transfer function of the filter has one or more zeros at ?0.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: December 30, 2014
    Assignee: Board of Regents, The University of Texas System
    Inventor: Robert H. Flake
  • Patent number: 8867657
    Abstract: A first transmitter transmits symbols. The leading edge of each symbol has the form Djexp{?jt}, where Dj is real, where ?j is selected from N possible values based on a current group of bits. The receiver has N filters whose transfer functions correspond respectively to the N possible values. The filter outputs are used to recover the group of bits. A second transmitter transmits an exponential symbol or a zero symbol depending on a current bit to be transmitted. The zero symbol has zero amplitude over the symbol period. The corresponding receiver applies threshold detection to estimate the transmitted bits. A third transmitter transmits a sequence of analog pulses with known interpulse time separation(s). The pulse sequence reflects from a moving object. A receiver captures the reflected pulse sequence. The interpulse separation(s) of the reflect pulse sequence is used to determine the radial velocity of the object.
    Type: Grant
    Filed: February 17, 2014
    Date of Patent: October 21, 2014
    Assignee: Board of Regents, The University of Texas System
    Inventor: Robert H. Flake
  • Patent number: 8786315
    Abstract: The present invention relates to a phase frequency detector (PFD) (100) for use as one of the blocks in a phase-locked loop. The PFD of the present invention has zero dead zone, has a simpler structure with a minimum number of transistors and requires a smaller area. The PFD of the present invention does not use any inverter or delay gate as found in the conventional PFD. Instead, the PFD of the present invention utilizes feedback transistors that save power and thus the PFD of the present invention is suitable to be used in low power applications.
    Type: Grant
    Filed: November 16, 2009
    Date of Patent: July 22, 2014
    Assignee: Mimos Berhad
    Inventors: Mahmoud Hammamm Ismail Nesreen, Shahiman Mohd. Sulaiman Mohd
  • Publication number: 20140070849
    Abstract: Methods and structure for on-chip self-test of clock jitter for an application clock signal generated within an integrated circuit (IC). Features and aspects hereof provide for acquisition of samples of an application clock signal within the IC and counting the number of samples having a predetermined value. The count is compared to acceptable limits range values to generate a pass/fail signal of the IC use by external automated. A sample clock is generated based on the reference clock used by a Phase Locked Loop (PLL) circuit. An incremental delay is added to the sample clock pulse such that the sequence of samples “walk” through an application clock pulse waveform to sense clock jitter at various points of the waveform based on the counts.
    Type: Application
    Filed: November 19, 2013
    Publication date: March 13, 2014
    Applicant: LSI CORPORATION
    Inventors: Douglas J. Feist, Tracy J. Feist
  • Patent number: 8660502
    Abstract: In a high frequency antenna switch module, an I/O interface generates various control signals for controlling a switch module on the basis of a system data signal and a system clock, a decoder generates a switch control signal SWCNT for controlling a switch in response to a control signal CNT in the control signals, a timing detector for switch-ports switching generates a switch-port switching detection signal t_sw in response to the switch control signal, a frequency control signal generator generates frequency control signals ICONT and CCONT in response to the signal t_sw, and a negative voltage generation circuit generates a negative voltage output signal NVG_OUT while switching the frequency of the clock signal generated in the negative voltage generation circuit to different frequencies in response to signals ICONT and CCONT. The switch switches the paths among the plural switch ports in response to the signals SWCNT and NVG_OUT.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: February 25, 2014
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yusuke Wachi, Takashi Kawamoto, Yuta Sugiyama
  • Patent number: 8179163
    Abstract: Efficient techniques improve the linearity of a charge pump in fractional-N PLLs. A feedback clock pulse several VCO clock periods wide is formed and supplied to a phase frequency detector (PFD). The down pulse generated by the PFD is fixed to eliminate the nonlinearity associated with up and down current source mismatch. The up pulse is made to fall when the down pulse falls, that is, when the feedback clock pulse falls.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: May 15, 2012
    Assignee: Silicon Laboratories Inc.
    Inventor: Qicheng Yu
  • Publication number: 20120098571
    Abstract: Methods and structure for on-chip self-test of clock jitter for an application clock signal generated within an integrated circuit (IC). Features and aspects hereof provide for acquisition of samples of an application clock signal within the IC and counting the number of samples having a predetermined value. The count is compared to acceptable limits range values to generate a pass/fail signal of the IC use by external automated. A sample clock is generated based on the reference clock used by a Phase Locked Loop (PLL) circuit. An incremental delay is added to the sample clock pulse such that the sequence of samples “walk” through an application clock pulse waveform to sense clock jitter at various points of the waveform based on the counts. Acceptable limits range for the count at each sampled point, the incremental delay, and the number of samples at each delayed value may be user programmed.
    Type: Application
    Filed: October 26, 2010
    Publication date: April 26, 2012
    Applicant: LSI CORPORATION
    Inventors: Douglas J. Feist, Tracy J. Feist
  • Patent number: 7847641
    Abstract: Disclosed are a digital phase-frequency detector and a method of operating a digital phase-frequency detector. The detector includes an input circuit, an output circuit and a reset circuit. In use, the input circuit receives first and second input signals during a plurality of cycles, and during a given one of the cycles, generates a first intermediate signal or a second intermediate signal depending on which of the first and second input signals was received first during that given one of said cycles. The output circuit receives these intermediate signals, and outputs, during said one cycle, a first output signal or a second output signal depending on which one of intermediate signals was received by the output circuit during said one cycle. The reset circuit applies a reset signal to the input circuit under defined conditions to begin a new one of said plurality of cycles.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: December 7, 2010
    Assignee: International Business Machines Corporation
    Inventors: Alexander V. Rylyakov, Jose A. Tierno
  • Patent number: 7839177
    Abstract: A phase detector includes transistors that generate first and second phase error signals. The phase detector resets the first phase error signal in response to at least one of the first and the second phase error signals through a first reset path having a maximum reset delay that is equal to or less than a sum of switching delays of three transistors in the first reset path. The phase detector resets the second phase error signal in response to at least one of the first and the second phase error signals through a second reset path having a maximum reset delay that is equal to or less than a sum of switching delays of three transistors in the second reset path.
    Type: Grant
    Filed: November 7, 2008
    Date of Patent: November 23, 2010
    Assignee: Altera Corporation
    Inventor: Lip Kai Soh
  • Patent number: 7769121
    Abstract: In one embodiment, a phase error signal generated by a phase detector is equalized to compensate for the distortion in the phase error signal due to finite circuit speeds. The equalization may be based on suppressing the low frequency components of the phase error signal. For example, the amplitude of the phase error signal may be reduced when the amplitude of the phase error signal is not changing.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: August 3, 2010
    Assignee: Realtek Semiconductor Corporation
    Inventor: Chia-Liang Lin
  • Patent number: 7755397
    Abstract: Methods and apparatus are provided for digital phase detection with improved frequency locking. A phase detector is disclosed for evaluating a phase difference between a clock signal and a reference signal. The disclosed phase detector samples the clock signal and the reference signal on positive edges of one or more of the clock signal and the reference signal, samples the clock signal and the reference signal on negative edges of one or more of the clock signal and the reference signal, and generates one or more error signals indicating a phase difference between the clock signal and the reference signal. A clock signal that is phase aligned with a reference signal can be generated by generating an error signal indicating a phase difference between the clock signal and the reference signal and applying the error signal to an oscillator to produce the clock signal.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: July 13, 2010
    Assignee: Agere Systems Inc.
    Inventor: Tony S. El-Kik
  • Publication number: 20090045848
    Abstract: A phase-frequency detection system and method for enhancing performance of the frequency detector in a phase-frequency detection system. Filtering of the frequency detector inputs makes operation of the frequency detector more robust in the presence of intersymbol interference within the incoming data signal and other non-ideal characteristics such as noise and crosstalk.
    Type: Application
    Filed: August 15, 2007
    Publication date: February 19, 2009
    Applicant: National Semiconductor Corporation
    Inventors: Ali Kiaei, Gerard G. Socci, Ali Djabbari, Ahmad Bahai
  • Patent number: 7443251
    Abstract: Disclosed are a digital phase-frequency detector and a method of operating a digital phase-frequency detector. The detector includes an input circuit, an output circuit and a reset circuit. In use, the input circuit receives first and second input signals during a plurality of cycles, and during a given one of the cycles, generates a first intermediate signal or a second intermediate signal depending on which of the first and second input signals was received first during that given one of said cycles. The output circuit receives these intermediate signals, and outputs, during said one cycle, a first output signal or a second output signal depending on which one of intermediate signals was received by the output circuit during said one cycle. The reset circuit applies a reset signal to the input circuit under defined conditions to begin a new one of said plurality of cycles.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: October 28, 2008
    Assignee: International Business Machines Corporation
    Inventors: Alexander V. Rylyakov, Jose A. Tierno
  • Patent number: 7298178
    Abstract: A programmable system-on-a-chip integrated circuit device comprises at least one of a crystal oscillator circuit, an RC oscillator circuit, and an external oscillator input. A clock conditioning circuit is selectively coupleable to one of the programmable logic block, the crystal oscillator circuit, the RC oscillator circuit, and the external oscillator input. A real-time clock is selectively coupleable to one of the programmable logic block, the crystal oscillator circuit, the RC oscillator circuit, and the external oscillator input. A programmable logic block is coupled to the clock conditioning circuit and the real-time clock.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: November 20, 2007
    Assignee: Actel Corporation
    Inventors: Shin-Nan Sun, Limin Zhu, Theodore Speers, Gregory Bakker
  • Patent number: 7102391
    Abstract: A programmable system-on-a-chip integrated circuit device comprises at least one of a crystal oscillator circuit, an RC oscillator circuit, and an external oscillator input. A clock conditioning circuit is selectively coupleable to one of the programmable logic block, the crystal oscillator circuit, the RC oscillator circuit, and the external oscillator input. A real-time clock is selectively coupleable to one of the programmable logic block, the crystal oscillator circuit, the RC oscillator circuit, and the external oscillator input. A programmable logic block is coupled to the clock conditioning circuit and the real-time clock.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: September 5, 2006
    Assignee: Actel Corporation
    Inventors: Shin-Nan Sun, Limin Zhu, Theodore Speers, Gregory Bakker
  • Patent number: 7003065
    Abstract: A cycle slip detector interfaces with a phase/frequency detector (PFD), such as might be used in a phase-locked loop circuit (PLL), and indicates when cycle slips occur in the PFD. Typically, the PFD generates output control signals as a function of the phase difference between first and second input signals, with the first input signal usually serving as a reference signal against which the PLL adjusts the second input signal. The PFD provides linear phase comparison between its input signals, provided their relative phase difference does not exceed ±2? radians. If one of the two signals leads or lags the other by more than that amount, a cycle slip occurs, and the PFD responds nonlinearly. The cycle slip detector provides logic for detecting and indicating leading and lagging cycle slips as they occur in the PDF, and is typically implemented as a minimal arrangement of logic gates and flip-flops.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: February 21, 2006
    Assignee: Ericsson Inc.
    Inventors: David Homol, Theron Jones, Nikolaus Klemmer
  • Patent number: 6990597
    Abstract: A clock generation circuit capable of generating a high-frequency clock with a simple circuit configuration, together with a data transfer control device and an electronic instrument using the same. The clock generation circuit has: serially-connected inversion circuits IV0 to IV4 in which an output of IV4 is connected to an input of IV0 by a feedback line FL; and buffer circuits BF0 to BF4 which receives outputs from IV0 to IV4. The inversion circuits IV0 to IV4 are disposed along a line LN1 and the buffer circuits BF0 to BF4 are disposed along a line LN2 that is parallel to the feedback line FL but different from LN1. Dummy lines DL0 to DL3 each of which having parasitic capacitance that is equal to that of the feedback line FL are connected to the inversion circuits IV0 to IV3, to equalize the phase differences between clocks CK0 to CK4. The feedback line FL and the dummy lines DL0 to DL3 are disposed in a region between the inversion circuits IV0 to IV4 and the buffer circuits BF0 to BF4.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: January 24, 2006
    Assignee: Seiko Epson Corporation
    Inventors: Akira Abe, Yoshiyuki Kamihara, Shoichiro Kasahara
  • Patent number: 6838912
    Abstract: A digital fractional phase detector is shown that uses a phase error detector for generating a phase error signal based on the phase difference between a reference clock signal and a feedback clock signal. A quantizer directly measures the pulse width of a phase error signal and outputs the value in a digital form. By directly measuring the phase error signal, quantization accuracy is increased. In order to calibrate the digital fractional phase detector, a calibration pulse generator generates a calibration pulse of a known duration and passes it to the quantizer.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: January 4, 2005
    Assignee: Realtek Semiconductor Corp.
    Inventor: Yu-Pin Chou
  • Patent number: 6806742
    Abstract: A low-power phase detector with differential output may comprise a control signal generator. In one embodiment, two cyclic waveforms whose phase relationship is to be measured may be input to a control signal generator. The control signal generator may output a first control signal corresponding to the first cyclic waveform such that the control signal is de-asserted at a specific point with respect to the first cyclic waveform. For example, the control signal may be de-asserted corresponding to the rising edge of the first cyclic waveform. The control signal generator may also output a second control signal corresponding to the second cyclic waveform such that the control signal is asserted at a specific point with respect to the second cyclic waveform. For example, the control signal may be asserted corresponding to the falling edge of the second cyclic waveform.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: October 19, 2004
    Assignee: Standard Microsystems Corporation
    Inventors: Luis J. Briones, Klaas Wortel
  • Publication number: 20040150429
    Abstract: A single transistor device is configured of a plurality of transistor cells divided and arranged in a plurality of blocks. Corresponding to the blocks a plurality of bias current supply circuits are arranged, respectively, to supply the blocks with individual bias currents, respectively. The bias current supply circuits each have a transistor with a bias condition set to decrease its ability to drive current as the corresponding bias current increases. Thus a negative feedback can be given to an increase in bias current attributed to thermal unevenness.
    Type: Application
    Filed: January 22, 2004
    Publication date: August 5, 2004
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventors: Kazuya Yamamoto, Satoshi Suzuki
  • Patent number: 6415422
    Abstract: A method for performing capacitance estimations on an integrated circuit design routed by a global routing tool is disclosed. Routing areas and pin locations of a net within an integrated circuit design are initially obtained from a global routing tool. Common boundaries among the routing areas are then defined. Before the performance of a detailed routing step, congestion information furnished by the global routing tool is utilized to perform probabilistic capacitance calculations for an interconnect that can be routed within the routing areas via the defined common boundaries to connect the pin locations.
    Type: Grant
    Filed: September 17, 1999
    Date of Patent: July 2, 2002
    Assignee: International Business Machines Corporation
    Inventors: Sharad Mehrotra, Parsotam Trikam Patel
  • Patent number: 6351153
    Abstract: A phase detector is disclosed that detects the phase of two inputs with precision. A method and apparatus of phase detecting that subtracts out common errors due to temperature variations and supply voltage fluctuations. The phase detector and method preferably utilize digital circuitry such as exclusive OR gates and differential amplifiers to perform the accurate phase detection. The inputs and outputs may be attenuated or filtered to produce the desired results.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: February 26, 2002
    Assignee: Hewlett-Packard Company
    Inventor: Michael C. Fischer
  • Patent number: 6064235
    Abstract: A shared path phase detector circuit for receiving a reference clock and an oscillator clock, the phase detector circuit providing an output signal for indicating a magnitude difference between a phase of the reference and oscillator clocks. The output signal is independently derived from the leading or lagging edge relationship of the reference and oscillator clocks. The output signal does not describe which signal leads, but only the width magnitude difference. The design provides a single path over which the output signal travels, without feedback, such that the circuit dependencies are greatly reduced.
    Type: Grant
    Filed: March 18, 1998
    Date of Patent: May 16, 2000
    Assignee: International Business Machines Corporation
    Inventors: Masayuki Hayashi, Robert J. Savaglio
  • Patent number: 5818265
    Abstract: The digital phase detector detects a phase shift between a comparison clock pulse signal (VT) and a reference clock pulse signal (RT). It includes logic gates (STO,STA) for generating start and stop pulses from respective successive pulses of the comparison and reference clock pulse signals (RT,VT). A counter (ZG,Z) counts the pulses of a counter clock pulse signal (ZT) of a higher frequency in a time window between the start signal and the subsequent stop signal. The counter value of the counter is a measure of the phase shift between the comparison and reference clock pulse signals (VT,RT). Quantization errors in the phase shift signal are considerably reduced by providing a logical gate (VZ) for determining the sign of the phase shift and a device (.mu.P) for adding a constant, advantageously 0.5, to the counter value.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: October 6, 1998
    Assignee: Robert Bosch GmbH
    Inventors: Wolfgang Meller, Fritz Widmann
  • Patent number: 5663666
    Abstract: In the present embodiment, digital phase detection of digital telecommunications signals is based on heterodyning. The frequency of two signals are scaled to different nominal values that are separated by a typically small but finite difference. The two frequencies are then mixed to generate a finite beat frequency. In mixing, phase is preserved and the finite beat frequency phase is in one-to-one correspondence with the signal phase. Phase detection is performed indirectly at the lower finite beat frequency with high resolution and greater ease than direct phase detection.
    Type: Grant
    Filed: February 21, 1996
    Date of Patent: September 2, 1997
    Assignee: Hewlett-Packard Company
    Inventors: David C. Chu, Jeremy S. Sommer
  • Patent number: 5619148
    Abstract: A novel method and apparatus providing an all digital phase comparator of two binary signals which employs a type of cross correlation of two binary signals and provides a 2bit binary word uniquely representative of phase alignment. The method can be carried out using a pair of flip-flop (FF) circuits, each FF having a docking input and a data input, and where each FF has a delay in series with its data input.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: April 8, 1997
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Bin Guo
  • Patent number: 5578947
    Abstract: Within the differential detection demodulator, the received signal is first quantized by a limiter amplifier 10 and then subjected to frequency conversion by a frequency converter 50 including: an exclusive OR element 51; a running average generator 52 consisting of a shift register 53 and an adder 54; and a comparator 55. In response to the output of the frequency converter 50, the phase comparator 60 outputs a relative phase signal representing the phase shift of the received signal after frequency conversion relative to the phase reference signal. The phase comparator 60 includes: an exclusive OR element 61; an absolute phase shift measurement means 62 consisting of an adder 63 and D flip-flop arrays 64 and 65; and a D flip-flop 66 serving as a phase shift polarity decision means.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: November 26, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toshiharu Kojima
  • Patent number: 5566129
    Abstract: A semiconductor memory device with an address transition detector comprises a flip-flop circuit (FF) having set and reset input terminals and a delay circuit (3). A pulse signal is input to a set input terminal (S) of the flip-flop circuit (FF) and an output signal (P) of the flip-flop circuit (FF) is input through the delay circuit (3) to a reset terminal (R) of the flip-flop circuit (FF), whereby a constant width signal which is independent of a waveform of an address signal and which responds only to the change of address can be obtained as an address transition signal of a SRAM (static random access memory). An internal circuit of the SRAM is initialized by the constant width signal, thereby preventing a malfunction caused by the fact that an initialization time depends on the waveform of the address signal.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: October 15, 1996
    Assignee: Sony Corporation
    Inventors: Katsuya Nakashima, Shumpei Kohri, Akira Nakagawara
  • Patent number: 5530382
    Abstract: Within the differential detection demodulator, the received signal is first quantized by a limiter amplifier 10 and then subjected to frequency conversion by a frequency converter 50 including: an exclusive OR element 51; a running average generator 52 consisting of a shift register 53 and an adder 54; and a comparator 55. In response to the output of the frequency converter 50, the phase comparator 60 outputs a relative phase signal representing the phase shift of the received signal after frequency conversion relative to the phase reference signal. The phase comparator 60 includes: an exclusive OR element 61; an absolute phase shift measurement means 62 consisting of an adder 63 and D flip-flop arrays 64 and 65; and a D flip-flop 66 serving as a phase shift polarity decision means.
    Type: Grant
    Filed: March 28, 1994
    Date of Patent: June 25, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toshiharu Kojima
  • Patent number: 5410195
    Abstract: A phase detector comprises a ramp voltage generator for receiving a reference pulse of a constant frequency and an input pulse and producing a ramp voltage proportional to the phase difference between these pulses. A first sample-and-hold circuit samples the ramp voltage in response to a sampling pulse and holds the sampled voltage. To eliminate ripple component, a second sample-and-hold circuit is provided, which is also responsive to the sampling pulse for sampling a voltage from a constant voltage source and holding the sampled voltage. The voltages sampled by the first and second sample-and-hold circuits are input to a subtractor where the voltage difference between the two input voltages is detected. Ripple components generated by the two sample-and-hold circuits are cancelled out by the subtractor.
    Type: Grant
    Filed: October 29, 1992
    Date of Patent: April 25, 1995
    Assignee: NEC Corporation
    Inventor: Masaki Ichihara