Patents by Inventor David W. Boerstler
David W. Boerstler 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: 8381143Abstract: A design structure for a Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: GrantFiled: January 27, 2011Date of Patent: February 19, 2013Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 8183920Abstract: A variable gain amplifier includes a first common mode (CM) node configured to receive a first differential signal of a pair of differential signals. A first regulator couples to the first CM node, the first regulator being configured to generate a first CM offset. A second CM node is configured to receive a second differential signal of the pair of differential signals. A second regulator couples to the second CM node, the second regulator being configured to generate a second CM offset. In one embodiment, the first CM offset and the second CM offset together comprise a net CM offset, the net CM offset being configured to replace a current source net offset.Type: GrantFiled: June 30, 2010Date of Patent: May 22, 2012Assignee: International Business Machines CorporationInventors: Jieming Qi, David W. Boerstler, Minhan Chen, Hayden C. Cranford, Jr.
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Patent number: 8108813Abstract: A design structure for a circuit for obtaining a desired phase locked loop (PLL) duty cycle without a pre-scaler is provided. The PLL circuit of the illustrative embodiments utilizes two separate loops that simultaneously operate on the VCO. One loop ensures the frequency and phase lock while the other loop ensures the duty cycle lock. The VCO is modified to have an additional control port to adjust the duty cycle. Thus, the VCO has one control port for performing frequency adjustment and one control port for duty cycle adjustment. As a result, both the duty cycle and the frequency may be controlled using the VCO of the PLL circuit of the illustrative embodiments so as to achieve any desired duty cycle output without requiring a VCO pre-scaler circuit or duty cycle correction circuit.Type: GrantFiled: May 30, 2008Date of Patent: January 31, 2012Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Masaaki Kaneko, Jieming Qi
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Publication number: 20120001691Abstract: A variable gain amplifier includes a first common mode (CM) node configured to receive a first differential signal of a pair of differential signals. A first regulator couples to the first CM node, the first regulator being configured to generate a first CM offset. A second CM node is configured to receive a second differential signal of the pair of differential signals. A second regulator couples to the second CM node, the second regulator being configured to generate a second CM offset. In one embodiment, the first CM offset and the second CM offset together comprise a net CM offset, the net CM offset being configured to replace a current source net offset.Type: ApplicationFiled: June 30, 2010Publication date: January 5, 2012Applicant: International Business Machines CorporationInventors: Jieming Qi, David W. Boerstler, Minhan Chen, Hayden C. Cranford, JR.
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Patent number: 8037431Abstract: A design structure embodied in a machine readable medium used in a design process includes an interleaved voltage-controlled oscillator, including a ring circuit of main logic inverter gates; a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates; wherein each delay element comprises a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages; and a proportional section for regulating signal transmission through at least one logic inverter gate; at least one temperature compensation circuit responsive to a compensating voltage input that is proportional to temperature; an electronic circuit in communication with the temperature compensation circuit and configured to provide a voltage signal responsive to temperature; an amplifier in connection with the electronic circuit to amplify the voltage signal; and a DC offset generator configured to adjust the voltage of theType: GrantFiled: May 23, 2008Date of Patent: October 11, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Patent number: 8032850Abstract: A design structure for a circuit for measuring the absolute duty cycle of a signal, is provided. A non-inverted path from a signal source is selected and various DCC circuit setting indices are cycled through until a divider, coupled to the output of the DCC circuit, fails. A first minimum pulse width at which the divider fails is then determined based on the index value of the DCC circuit at the time of the failure. An inverted path from the signal source is selected and the various DCC circuit setting indices are cycled through again until the divider fails. A second minimum pulse width at which the divider fails is then determined based on the index value of the DCC circuit at the time of this second failure. The duty cycle is then calculated based on a difference of the first and second minimum pulse width values.Type: GrantFiled: May 30, 2008Date of Patent: October 4, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Masaaki Kaneko, Jieming Qi, Bin Wan
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Patent number: 7994830Abstract: Systems and methods for enabling the determination of voltage controlled oscillator (VCO) linearity, duty cycle determination and duty cycle correction in phase locked loop circuits (PLL's.) One embodiment comprises a method including the steps of determining the frequency response of a PLL's VCO as a function of duty cycle, applying a signal based on the VCO output to the VCO input, measuring the resulting frequency of the VCO output signal, determining the duty cycle corresponding to the measured frequency, and configuring a duty cycle correction unit correct the duty cycle of the VCO output signal to about 50%. Determining the frequency response of the VCO may include, for each of several different duty cycle values between 0% and 100%, applying the VCO input signal to the VCO and determining the corresponding frequency of the VCO output signal. This may also be done for duty cycles of 0% and 100%.Type: GrantFiled: November 24, 2009Date of Patent: August 9, 2011Assignees: Kabushiki Kaisha Toshiba, International Business Machines CorporationInventors: Masaaki Kaneko, David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7969250Abstract: A design structure for a programmable interpolative voltage controlled oscillator (VCO) with adjustable frequency range output is provided. Programmable delay cells whose size is modifiable based on control inputs to the programmable delay cells are utilized. A different set of control inputs may be provided to programmable delay cells of an inner sub-ring from the set of control inputs provided to programmable delay cells of a main ring of the VCO. The minimum frequency output of the VCO is governed by the main ring programmable delay cell strength with the maximum frequency output of the VCO being governed by a ratio of strengths of the main ring programmable delay cells to the inner sub-ring programmable delay cell. By modifying the control inputs to the inner sub-ring and main ring programmable delay cells, the minimum and maximum frequency outputs, and thus the range between these two frequency outputs, are made programmable.Type: GrantFiled: May 30, 2008Date of Patent: June 28, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Masaaki Kaneko, Jieming Qi
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Patent number: 7958469Abstract: A design structure for a hybrid phase locked loop (PLL) circuit that obtains stabilized dynamic response and independent adjustment of damping factor and loop bandwidth is provided. The hybrid PLL circuit of the illustrative embodiments includes the resistance/capacitance (RC) filter elements of a conventional RC PLL and the feed-forward path from the output of the phase frequency detector to the voltage controlled oscillator (VCO). The hybrid PLL essentially enhances the performance of the conventional feed-forward PLL by providing the RC filter whose components can be weighted to provide a dynamic response that is significantly less sensitive to parameter variation and which allows loop bandwidth optimization without sacrificing damping.Type: GrantFiled: May 29, 2008Date of Patent: June 7, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Publication number: 20110121874Abstract: Systems and methods for enabling the determination of voltage controlled oscillator (VCO) linearity, duty cycle determination and duty cycle correction in phase locked loop circuits (PLL's.) One embodiment comprises a method including the steps of determining the frequency response of a PLL's VCO as a function of duty cycle, applying a signal based on the VCO output to the VCO input, measuring the resulting frequency of the VCO output signal, determining the duty cycle corresponding to the measured frequency, and configuring a duty cycle correction unit correct the duty cycle of the VCO output signal to about 50%. Determining the frequency response of the VCO may include, for each of several different duty cycle values between 0% and 100%, applying the VCO input signal to the VCO and determining the corresponding frequency of the VCO output signal. This may also be done for duty cycles of 0% and 100%.Type: ApplicationFiled: November 24, 2009Publication date: May 26, 2011Inventors: Masaaki Kaneko, David W. Boerstler, Eskinder Hailu, Jieming Qi
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Publication number: 20110126162Abstract: A design structure for a Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: ApplicationFiled: January 27, 2011Publication date: May 26, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7917318Abstract: A design structure for a circuit for measuring the absolute duty cycle of a signal anywhere on an integrated circuit device is provided. The circuit has a plurality of substantially identical pulse shaper elements, each of which expand the pulse of an input signal whose duty cycle is to be measured by a same amount. The outputs of the pulse shaper elements may be coupled to substantially identical divider circuits whose outputs are coupled to a multiplexer that selects two inputs for output to a set of master/slave configured flip-flops, one input serving as a clock and the other as data to the flip-flops. The flip-flops sample the divider outputs selected by the multiplexer to detect if the dividers have failed or not. The outputs of the flip-flops are provided to an XOR gate which outputs a duty cycle signal indicative of the duty cycle of the input signal.Type: GrantFiled: May 30, 2008Date of Patent: March 29, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Masaaki Kaneko, Jieming Qi, Bin Wan
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Patent number: 7913199Abstract: A design structure for a Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: GrantFiled: May 29, 2008Date of Patent: March 22, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi
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Patent number: 7904264Abstract: A mechanism for measuring the absolute duty cycle of a signal is provided. A non-inverted path from a signal source is selected and various DCC circuit setting indices are cycled through until a divider, coupled to the output of the DCC circuit, fails. A first minimum pulse width at which the divider fails is then determined based on the index value of the DCC circuit at the time of the failure. An inverted path from the signal source is selected and the various DCC circuit setting indices are cycled through again until the divider fails. A second minimum pulse width at which the divider fails is then determined based on the index value of the DCC circuit at the time of this second failure. The duty cycle is then calculated based on a difference of the first and second minimum pulse width values.Type: GrantFiled: November 12, 2007Date of Patent: March 8, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Masaaki Kaneko, Jieming Qi, Bin Wan
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Patent number: 7895005Abstract: A mechanism is provided for measuring the absolute duty cycle of a signal anywhere on an integrated circuit device. The mechanism employs a circuit having a plurality of substantially identical pulse shaper elements, each of which expand the pulse of an input signal whose duty cycle is to be measured by a same amount. The outputs of the pulse shaper elements may be coupled to substantially identical divider circuits whose outputs are coupled to a multiplexer that selects two inputs for output to a set of master/slave configured flip-flops, one input serving as a clock and the other as data to the flip-flops. The flip-flops sample the divider outputs selected by the multiplexer to detect if the dividers have failed or not. The outputs of the flip-flops are provided to an XOR gate which outputs a duty cycle signal indicative of the duty cycle of the input signal.Type: GrantFiled: November 20, 2007Date of Patent: February 22, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Masaaki Kaneko, Jieming Qi, Bin Wan
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Patent number: 7877222Abstract: A design structure for an apparatus for utilizing a single set of one or more thermal sensors, e.g., thermal diodes, provided on the integrated circuit device, chip, etc., to control the operation of the integrated circuit device, associated cooling system, and high-frequency PLLs, is provided. By utilizing a single set of thermal sensors to provide multiple functions, e.g., controlling the operation of the integrated circuit device, the cooling system, and the PLLs, silicon real-estate usage is reduced through combining circuitry functionality. Moreover, the integrated circuit device yield is improved by reducing circuitry complexity and increasing PLL robustness to temperature. Furthermore, the PLL circuitry operating range is improved by compensating for temperature.Type: GrantFiled: May 29, 2008Date of Patent: January 25, 2011Assignee: International Business Machines CorporationInventors: David W. Boerstler, Nathaniel R. Chadwick, Eskinder Hailu, Kirk D. Peterson, Jieming Qi
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Patent number: 7786813Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.Type: GrantFiled: April 7, 2008Date of Patent: August 31, 2010Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Patent number: 7782146Abstract: An interleaved voltage-controlled oscillator (VCO) is disclosed. The VCO includes a ring circuit comprising a series connection of main logic inverter gates, a plurality of delay elements connected in parallel with a selected sequence of the main logic inverter gates, at least one temperature compensation circuit comprising a logic inverter gate in series connection with one or more field effect transistors, the field effect transistor responsive to a compensating voltage input that is proportional to temperature, and an electronic circuit in signal communication with the at least one temperature compensation circuit and configured to provide a voltage signal responsive to temperature. Each delay element includes a feedforward section, comprising controls for regulating signal transmission through feedforward elements responsive to one or more control voltages, and a proportional section, comprising controls for regulating signal transmission through at least one logic inverter gate.Type: GrantFiled: April 7, 2008Date of Patent: August 24, 2010Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi, Mike Shen
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Patent number: 7737794Abstract: Mechanisms are provided for compensating for process and temperature variations in a circuit. The mechanisms may select at least one resistor in a plurality of resistors in the circuit to provide a resistance value for generating a calibration voltage input to the circuit to compensate for variations in process. A reference signal may be compared to a feedback signal generated by the circuit based on the calibration signal. A determination is made as to whether the feedback signal is within a tolerance of the reference signal and, if so, an identifier of the selected at least one resistor is stored in a memory device coupled to the circuit. The circuit may be operated using the selected at least one resistor based on the identifier stored in the memory device. An apparatus and integrated circuit device utilizing these mechanisms are also provided.Type: GrantFiled: May 14, 2008Date of Patent: June 15, 2010Assignee: International Business Machines CorporationInventors: David W. Boerstler, Masaaki Kaneko, Toshiyuki Ogata, Jieming Qi
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Patent number: 7675338Abstract: A Duty Cycle Correction (DCC) circuit is provide in which pairs of field effect transistors (FETs) in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. The linear resistors are more tolerant of process, voltage and temperature (PVT) fluctuations than FETs and thus, the resulting DCC circuit provides a relatively smaller change in DCC correction range with PVT fluctuations than the known DCC circuit topology that employs FETs. The linear resistors may be provided in parallel with the switches and in series with a pair of FETs having relatively large resistance values. The linear resistors provide resistance that pulls-up or pulls-down the pulse width of the input signal so as to provide correction to the duty cycle of the input signal.Type: GrantFiled: June 17, 2008Date of Patent: March 9, 2010Assignee: International Business Machines CorporationInventors: David W. Boerstler, Eskinder Hailu, Jieming Qi