Patents by Inventor Stephen D. Wyatt
Stephen D. Wyatt has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7449942Abstract: Analog supply for an analog circuit and process for supplying an analog signal to an analog circuit. The analog supply includes a noise filter having a variable resistor, and a control device coupled to adjust the variable resistor. The control device is structured and arranged to set the resistance of the variable resistor to maximize noise filtering and optimize performance of the analog circuit.Type: GrantFiled: February 28, 2006Date of Patent: November 11, 2008Assignee: International Business Machines CorporationInventors: Anthony R. Bonaccio, Hayden C. Cranford, Jr., Joseph A. Iadanza, Sebastian T. Ventrone, Stephen D. Wyatt
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Publication number: 20080244479Abstract: A design structure for intrinsic RC power distribution for noise filtering of analog supplies. The design structure is embodied in a machine readable medium for designing, manufacturing, or testing an integrated circuit. The design structure includes a voltage regulator; a variable resistor coupled to the voltage regulator; and a performance monitor and control circuit providing a feedback loop to the variable resistor.Type: ApplicationFiled: March 24, 2008Publication date: October 2, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Anthony R. BONACCIO, Hayden C. Cranford, Joseph A. Iadanza, Sebastian T. Ventrone, Stephen D. Wyatt
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Patent number: 7403054Abstract: A circuit apparatus and method for generating multiphase clocks in a delay lock loop (DLL) at sub-picosecond granularity. The circuit and method of the invention involves locking a number of cycles M in an N stage DLL, e.g., M cycles, where M is an prime number, which results in clock edges in each cycle that are not located at the same phase locations in each of the M cycles. Any of the phase locations from any of the cycles can be used to generate a clock edge for all cycle in the system application. This requires a special technique to “lock” the DLL loop over a M cycle period instead of a one cycle period. The benefit is that it improves the clock placement granularity by a factor of M over the previous art.Type: GrantFiled: December 5, 2007Date of Patent: July 22, 2008Assignee: International Business Machines CorporationInventors: Anjali R. Malladi, Christopher Ro, Stephen D. Wyatt
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Patent number: 7339364Abstract: An improved built-in self-test (BIST) circuit and an associated method for measuring phase and/or cycle-to-cycle jitter of a clock signal, the BIST circuit implement a Variable Vernier Digital Delay Locked Line method. Specifically, the embodiments of the BIST circuit incorporate both a digital delay locked loop and a Vernier delay line, for respectively coarse tuning and fine tuning portions of the circuit. Additionally, the BIST circuit is variable, as the resolution of the circuit changes from chip to chip, and digital, as it is implemented with standard digital logic elements.Type: GrantFiled: June 19, 2006Date of Patent: March 4, 2008Assignee: International Business Machines CorporationInventors: Brandon R. Kam, Stephen D. Wyatt
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Publication number: 20080012549Abstract: Disclosed herein are embodiments of an improved built-in self-test (BIST) circuit and an associated method for measuring phase and/or cycle-to-cycle jitter of a clock signal. The embodiments of the BIST circuit implement a Variable Vernier Digital Delay Locked Line method. Specifically, the embodiments of the BIST circuit incorporate both a digital delay locked loop and a Vernier delay line, for respectively coarse tuning and fine tuning portions of the circuit. Additionally, the BIST circuit is variable, as the resolution of the circuit changes from chip to chip, and digital, as it is implemented with standard digital logic elements.Type: ApplicationFiled: June 19, 2006Publication date: January 17, 2008Inventors: Brandon R. Kam, Stephen D. Wyatt
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Patent number: 7268632Abstract: A loop filter for a phase-locked-loop is provided, comprising a set of capacitor banks coupled in parallel to form the loop filter, and a detection circuit for identifying and isolating defective capacitor banks. A method for providing a loop filter for a phase-locked-loop in accordance with an embodiment of the present invention includes the steps of forming the loop filter using a set of capacitor banks coupled in parallel, detecting any defective capacitor banks in the set of capacitor banks, isolating each defective capacitor bank, providing a set of redundant capacitor banks, and replacing each defective capacitor bank with a redundant capacitor bank from the set of redundant capacitor banks.Type: GrantFiled: September 30, 2005Date of Patent: September 11, 2007Assignee: International Business Machines CorporationInventors: Anthony R. Bonaccio, Hayden C. Cranford, Jr., Joseph A. Iadanza, Stephen D. Wyatt
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Patent number: 7084615Abstract: A method, system and program product to measure performance of a device dedicated to a phase locked loop (PLL). A resistor-inductor-capacitor (RLC) model is produced to simulate the PLL. The RLC model and the device to be measured are mapped together into a test circuit and the characteristics of the test circuit is analyzed to determine whether the device, if attached to the PLL represented by the RLC model, can meet the required standard of performance. This invention can be used to measure the performance of all kinds of devices attached to all kinds of PLLs.Type: GrantFiled: February 18, 2005Date of Patent: August 1, 2006Assignee: International Business Machines CorporationInventors: Faraydon Pakbaz, Stephen D. Wyatt
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Patent number: 6963240Abstract: A structure and method for damping LC (inductance-capacitance) ringing in integrated circuit (IC) power distribution systems. The structure comprises a resistance electrically connected in parallel with a plurality of electrical switches. The resistance and electrical switches are electrically connected in series with the package and on-chip power distribution circuit. When on-chip switching activity creates a sudden and appreciable change in IC power demand the electrical switches are opened to temporarily increase the resistance in series with the power supply. This serves to dampen the power-distribution LC ringing. Later, the electrical switches are closed to shunt the series resistance and reduce the level of steady-state voltage drop in the power structure.Type: GrantFiled: November 25, 2003Date of Patent: November 8, 2005Assignee: International Business Machines CorporationInventors: Anthony R. Bonaccio, Allen P. Haar, Michael A. Sorna, Ivan L. Wemple, Stephen D. Wyatt
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Patent number: 6956417Abstract: A circuit, including: a capacitor coupled between a first circuit node and a second circuit node and that leaks a leakage current from the first circuit node to the second circuit node; and a compensation circuit adapted to supply a compensatory current to compensate for the leakage current to the first circuit node.Type: GrantFiled: November 21, 2003Date of Patent: October 18, 2005Assignee: International Business Machines CorporationInventors: Kerry Bernstein, Anthony R. Bonaccio, John A. Fifield, Allen P. Haar, Shiu C. Ho, Terence B. Hook, Michael A. Soma, Stephen D. Wyatt
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Patent number: 6946923Abstract: A structure and associated method to allow an oscillator circuit to operate with a plurality of different crystals. The oscillator circuit comprises a semiconductor device and a crystal. The semiconductor device comprises a primary inverting amplifier and a crystal substitution damping resistor. The crystal is electrically coupled to the primary inverting amplifier. A resistance value of the crystal substitution resistor is adapted to vary in order to control an amount of current flow from the primary inverting amplifier to the crystal. The amount of the current flow to the crystal is dependent upon an electrical property of the crystal.Type: GrantFiled: November 21, 2003Date of Patent: September 20, 2005Assignee: International Business Machines CorporationInventors: Jerry P. Knickerbocker, Jr., Vishwanath A. Patil, Stephen D. Wyatt
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Patent number: 6927616Abstract: An integrated circuit designed to reduce on-chip noise coupling. In one embodiment, circuit (60) includes the following: a circuit transformer (62) capable of converting a noise sensitive input reference clock signal to an output signal having a voltage compatible with a predetermined sink voltage logic level; and a biased receiver network (64) having a PFET current mirror (74) coupled with a NFET current (72), the biased receiver transistor network designed to multiply the transformer signal to offset a mutual coupling loss of the transformer. In at least one alternative embodiment, the input reference clock signal originates at an off-chip clock generator circuit (42) and the output signal from receiver (64) is input to a PLL (44). In another alternative embodiment, the transformer is a monolithic integrated transformer. Another alternative embodiment of the present invention is a method of reducing on-chip noise coupling.Type: GrantFiled: October 31, 2003Date of Patent: August 9, 2005Assignee: International Business Machines CorporationInventors: Shiu Chung Ho, Ivan L. Wemple, Stephen D. Wyatt
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Patent number: 6882230Abstract: A re-centering system (116) for re-centering the control parameter of a phase lock loop (PLL) (112). The re-centering system includes sources (140) for obtaining/storing operating parameters, such as environmental data (184), setup data (188), and other knowns data (192). At least one state machine (132) utilizes the operating parameters to adjust the topology of the PLL so as to achieve a desirable topology for each target output frequency (18) that substantially centers the performance envelope(s) (120, 124, 128) to a desired pre-selected value of the control parameter. The re-centering system also includes a comparator (136) for comparing measured values of the control parameter to a pre-selected value. The state machine utilizes the output of the comparator to substantially center the corresponding performance envelope at the pre-selected value.Type: GrantFiled: June 26, 2003Date of Patent: April 19, 2005Assignee: International Business Machines CorporationInventors: Joseph A. Iadanza, Ram Kelkar, Stephen D. Wyatt
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Publication number: 20040263259Abstract: A re-centering system (116) for re-centering the control parameter of a phase lock loop (PLL) (112). The re-centering system includes sources (140) for obtaining/storing operating parameters, such as environmental data (184), setup data (188), and other knowns data (192). At least one state machine (132) utilizes the operating parameters to adjust the topology of the PLL so as to achieve a desirable topology for each target output frequency (18) that substantially centers the performance envelope(s) (120, 124, 128) to a desired pre-selected value of the control parameter. The re-centering system also includes a comparator (136) for comparing measured values of the control parameter to a pre-selected value. The state machine utilizes the output of the comparator to substantially center the corresponding performance envelope at the pre-selected value.Type: ApplicationFiled: June 26, 2003Publication date: December 30, 2004Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Joseph A. Iadanza, Ram Kelkar, Stephen D. Wyatt
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Patent number: 6825490Abstract: A structure and associated method to determine an actual resistance value of a calibration resistor within a semiconductor device. The semiconductor device comprises a capacitor, a calibration resistor, and a calibration circuit. A voltage applied to the calibration resistor produces a current flow through the calibration resistor to charge the capacitor. The calibration circuit is adapted to measure an actual time required to charge the capacitor. The calibration circuit is further adapted calculate an actual resistance value of the calibration resistor based on the actual time required to charge the capacitor and a capacitance value of the capacitor.Type: GrantFiled: October 9, 2003Date of Patent: November 30, 2004Assignee: International Business Machines CorporationInventors: Terence B. Hook, Raminderpal Singh, Stephen D. Wyatt
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Patent number: 5923097Abstract: An integrated circuit such as an application specific integrated circuit (ASIC) which has operational power supplies provided for different respective analog cores and digital logic and/or macros may be tested using on-chip power supplies, preferably comprising operational amplifiers connected as voltage followers and controlled by a band-gap voltage source or a voltage divider, drawing power from a single power supply to the chip which is generally provided in a standardized pin-out location. Disablement of respective operational amplifiers also provides electrical isolation of the respective cores during testing. A reduced pin-count is involved in the testing procedure since operational power supply connections can be open circuited or "tri-stated". On-chip power supplies for testing provides power while avoiding a need to provide low-noise power supplies and/or complex switching in a test system or to utilize custom front-end boards or both to provide power to arbitrary chip or package connections.Type: GrantFiled: July 24, 1997Date of Patent: July 13, 1999Assignee: International Business Machines CorporationInventors: Michael P. Corriveau, Christopher Ro, Stephen D. Wyatt
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Patent number: 5546052Abstract: A phase locked loop circuit is provided which includes a phase/frequency detector which uses a divider circuit and feedback from a clock distribution tree to generate INC and DEC pulses which do not have "dead zones". A pair of charge pumps receives the INC and DEC pulses. One charge pump is a differential pump and has a voltage controlled common mode feedback circuit to maintain a common mode controlled voltage. A differential current is outputted to a loop filter capacitor by this charge pump. The other charge pump is a single-ended output pump which supplies current to a current controlled oscillator which also receives input from a voltage to current converter. The current controlled oscillator includes a variable resistance load which varies inversely with the magnitude of the input current. A jitter control circuit is also provided which reduces jitter in the current controlled oscillator output in the locked phase.Type: GrantFiled: November 10, 1994Date of Patent: August 13, 1996Assignee: International Business Machines CorporationInventors: John S. Austin, Ilya I. Novof, Donald E. Strayer, Stephen D. Wyatt
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Patent number: 5541442Abstract: An improved configuration of a capacitor formed with FET technology and a resistor and/or conductor is provided. In this configuration a capacitor is formed in which the diffusion zone of the substrate is used as one plate of the capacitor and what would normally be the gate electrode of an FET is used as the other plate of the capacitor, with the two plates being separated by a conventional thin dielectric gate oxide layer. An insulator, such as silicon dioxide overlays the gate electrode, and electrical connections to the gate electrode and diffusion zone are made through the insulator to allow the two plates of the capacitor to be connected to various devices or components as required. The top surface of this insulation layer is also used to form metal resistors. Depending on the value of required resistance, a second insulating layer may be used and a second level of metal used to connect segments of the resistors formed on the first layer of metal to form a longer resistor.Type: GrantFiled: August 31, 1994Date of Patent: July 30, 1996Assignee: International Business Machines CorporationInventors: Richard F. Keil, Ram Kelkar, Ilya I. Novof, Jeffery H. Oppold, Kenneth D. Short, Stephen D. Wyatt
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Patent number: 5525932Abstract: A phase locked loop circuit which includes a phase/frequency detector which uses a divider circuit and feedback from a clock distribution tree to generate INC and DEC pulses which have no "dead zone" is provided. A pair of charge pumps receives the INC and DEC pulses. One charge pump is a differential pump and has a voltage controlled common mode feedback circuit to maintain a common mode controlled voltage. A differential current is outputted to a loop filter capacitor by this charge pump. The other charge pump is a single-ended output pump which supplies current to a current controlled oscillator which also receives input from a voltage to current converter. The current controlled oscillator includes a variable resistance load which varies inversely with the magnitude of the input current. A jitter control circuit is provided which reduces jitter in the current controlled oscillator output in the locked phase.Type: GrantFiled: August 31, 1994Date of Patent: June 11, 1996Assignee: International Business Machines CorporationInventors: Ram Kelkar, Iiya I. Novof, Stephen D. Wyatt
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Patent number: 5513225Abstract: A phase locked loop circuit includes a phase/frequency detector which uses a divider circuit and feedback from a clock distribution tree to generate INC and DEC pulses which have no "dead zone". A pair of charge pumps receives the INC and DEC pulses. One charge pump is a differential pump and has voltage controlled common mode feedback circuit to maintain a common mode controlled voltage. A differential current is outputted to a loop filter capacitor by this charge pump. The other charge pump is a single-ended output pump which supplies current to a current controlled oscillator which also receives input from a voltage to current converter. The current controlled oscillator includes a variable resistance load which varies inversely with the magnitude of the input current. A jitter control circuit is provided which reduces jitter in the current controlled oscillator output in the locked phase.Type: GrantFiled: August 31, 1994Date of Patent: April 30, 1996Assignee: International Business Machines CorporationInventors: Ram Kelkar, Ilya I. Novof, Donald E. Strayer, Stephen D. Wyatt
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Patent number: 5491439Abstract: A phase locked loop circuit includes a phase/frequency detector which uses a divider circuit and feedback from a clock distribution tree to generate INC and DEC pulses which have no "dead zone". A pair of charge pumps receives the INC and DEC pulses. One charge pump is a differential pump and has voltage controlled common mode feedback circuit to maintain a common mode controlled voltage. A differential current is outputted to a loop filter capacitor by this charge pump. The other charge pump is a single-ended output pump which supplies current to a current controlled oscillator which also receives input from a voltage to current converter. The current controlled oscillator includes a variable resistance load which varies inversely with the magnitude of the input current. A jitter control circuit is provided which reduces jitter in the current controlled oscillator output in the locked phase.Type: GrantFiled: August 31, 1994Date of Patent: February 13, 1996Assignee: International Business Machines CorporationInventors: Ram Kelkar, Ilya I Novof, Stephen D. Wyatt