Patents by Inventor Gautam Gangasani
Gautam Gangasani 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: 9369263Abstract: Method and apparatus to calibrate sampling phases of a multi-phase sampling system. The method includes on-chip generating a pristine phase reference pattern signal for use in generating at least one reference output signal from a data path; sampling, responsive to a clock signal, the at least one reference output signal to obtain samples; and modifying a phase of the clock signal to align the obtained samples to pattern edges of at least one reference output signal. Both symmetric and asymmetric duty cycle distortion are removed from the pristine phase reference pattern signal input to the data path. The effects of asymmetric distortion in the data path output signal upon the phase calibration are cancelled by periodically inverting the at least one reference output signal.Type: GrantFiled: June 30, 2015Date of Patent: June 14, 2016Assignee: International Business Machines CorporationInventors: Matthew B. Baecher, John F. Bulzacchelli, John F. Ewen, Gautam Gangasani, Mounir Meghelli, I, Matthew J. Paschal, Trushil N. Shah
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Patent number: 8867668Abstract: A data receiver, a method of operating a data receiver, and an integrated coupling system in a data receiver are disclosed. In one embodiment, the data receiver comprises an input terminal for receiving an input data signal, an input amplifier for amplifying selected components of the input data signal, and an input signal path for transmitting specified high-frequency components and a baseline component of the input data signal from the input terminal to the input amplifier. The data receiver further comprises a feed-forward resistive network connected to the input terminal and to the input amplifier. This feed forward resistive network is used to forward a low-frequency drift compensation signal from the input terminal to the input amplifier, using a passive resistive network, to compensate for low frequency variations in the input data signal, and to develop a desired bias voltage at the input amplifier.Type: GrantFiled: November 8, 2013Date of Patent: October 21, 2014Assignee: International Business Machines CorporationInventors: Troy J. Beukema, Gautam Gangasani, Thomas H. Toifl
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Publication number: 20140133604Abstract: A data receiver, a method of operating a data receiver, and an integrated coupling system in a data receiver are disclosed. In one embodiment, the data receiver comprises an input terminal for receiving an input data signal, an input amplifier for amplifying selected components of the input data signal, and an input signal path for transmitting specified high-frequency components and a baseline component of the input data signal from the input terminal to the input amplifier. The data receiver further comprises a feed-forward resistive network connected to the input terminal and to the input amplifier. This feed forward resistive network is used to forward a low-frequency drift compensation signal from the input terminal to the input amplifier, using a passive resistive network, to compensate for low frequency variations in the input data signal, and to develop a desired bias voltage at the input amplifier.Type: ApplicationFiled: November 8, 2013Publication date: May 15, 2014Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Troy J. Beukema, Gautam Gangasani, Thomas H. Toifl
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Patent number: 8599966Abstract: A data receiver, a method of operating a data receiver, and an integrated coupling system in a data receiver are disclosed. In one embodiment, the data receiver comprises an input terminal for receiving an input data signal, an input amplifier for amplifying selected components of the input data signal, and an input signal path for transmitting specified high-frequency components and a baseline component of the input data signal from the input terminal to the input amplifier. The data receiver further comprises a feed-forward resistive network connected to the input terminal and to the input amplifier. This feed forward resistive network is used to forward a low-frequency drift compensation signal from the input terminal to the input amplifier, using a passive resistive network, to compensate for low frequency variations in the input data signal, and to develop a desired bias voltage at the input amplifier.Type: GrantFiled: June 30, 2011Date of Patent: December 3, 2013Assignee: International Business Machines CorporationInventors: Troy J. Beukema, Gautam Gangasani, Thomas H. Toifl
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Publication number: 20130002347Abstract: A data receiver, a method of operating a data receiver, and an integrated coupling system in a data receiver are disclosed. In one embodiment, the data receiver comprises an input terminal for receiving an input data signal, an input amplifier for amplifying selected components of the input data signal, and an input signal path for transmitting specified high-frequency components and a baseline component of the input data signal from the input terminal to the input amplifier. The data receiver further comprises a feed-forward resistive network connected to the input terminal and to the input amplifier. This feed forward resistive network is used to forward a low-frequency drift compensation signal from the input terminal to the input amplifier, using a passive resistive network, to compensate for low frequency variations in the input data signal, and to develop a desired bias voltage at the input amplifier.Type: ApplicationFiled: June 30, 2011Publication date: January 3, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Troy J. Beukema, Gautam Gangasani, Thomas H. Toifl
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Patent number: 8126045Abstract: A decision feedback equalizer (DFE) and method include summer circuits configured to add a dynamic feedback tap to a received input to provide a sum and to add a speculative static tap to the sum. Sense amplifiers are configured to receive outputs of the summer circuits and evaluate the outputs of the summer circuits in accordance with a clock signal. A passgate multiplexer is configured to receive outputs from sense amplifiers wherein the multiplexers is clock-gated for isolation of subsequent ciruitry from the outputs of the sense amplifiers during a precharged period. A gating circuit is configured to perform gating of a selected signal output from a second circuit portion with a clock signal and to enable the isolation of the subsequent circuitry by the multiplexer during the precharge period.Type: GrantFiled: August 29, 2008Date of Patent: February 28, 2012Assignee: International Business Machines CorporationInventors: John Francis Bulzacchelli, Gautam Gangasani, Mounir Meghelli, Sergey V. Rylov, Michael A. Sorna, Steven J. Zier
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Publication number: 20100054324Abstract: A decision feedback equalizer (DFE) and method include summer circuits configured to add a dynamic feedback tap to a received input to provide a sum and to add a speculative static tap to the sum. Sense amplifiers are configured to receive outputs of the summer circuits and evaluate the outputs of the summer circuits in accordance with a clock signal. A passgate multiplexer is configured to receive outputs from sense amplifiers wherein the multiplexer is clock-gated for isolation of subsequent circuitry from the outputs of the sense amplifiers during a precharge period. A gating circuit is configured to perform gating of a select signal output from a second circuit portion with a clock signal and to enable the isolation of the subsequent circuitry by the multiplexer during the precharge period.Type: ApplicationFiled: August 29, 2008Publication date: March 4, 2010Inventors: John Francis Bulzacchelli, Gautam Gangasani, Mounir Meghelli, Sergey V. Rylov, Michael A. Sorna, Steven J. Zier
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Patent number: 7394283Abstract: A signal regenerator is provided which includes a common mode reference generator and a signal converter circuit. A common mode reference voltage level is generated which is variable in relation to at least one of a process used to fabricate the common mode reference generator, a level of a power supply voltage provided to the common mode reference generator or a temperature at which the common mode reference generator is operated. A signal converter circuit receives a differentially transmitted signal pair including a first input signal and a second input signal and outputs a single-ended output signal representing information carried by the differentially transmitted signal pair. Using a feedback signal from the common mode reference generator, a feedback control block controls a common mode level of the single-ended output signal in accordance with the common mode reference voltage level.Type: GrantFiled: August 25, 2006Date of Patent: July 1, 2008Assignee: International Business Machines CorporationInventors: Louis L. Hsu, Gautam Gangasani, Michael A. Sorna, Steven J. Zier
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Publication number: 20080061825Abstract: A signal regenerator is provided which includes a common mode reference generator and a signal converter circuit. A common mode reference voltage level is generated which is variable in relation to at least one of a process used to fabricate the common mode reference generator, a level of a power supply voltage provided to the common mode reference generator or a temperature at which the common mode reference generator is operated. A signal converter circuit receives a differentially transmitted signal pair including a first input signal and a second input signal and outputs a single-ended output signal representing information carried by the differentially transmitted signal pair. Using a feedback signal from the common mode reference generator, a feedback control block controls a common mode level of the single-ended output signal in accordance with the common mode reference voltage level.Type: ApplicationFiled: August 25, 2006Publication date: March 13, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Louis L. Hsu, Gautam Gangasani, Michael A. Sorna, Steven J. Zier
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Patent number: 7205830Abstract: Circuits and methods are provided for reducing the voltage stress applied to the drain to source conduction path of an FET and/or to reduce the stress to the gate oxide of an FET which may have a thin gate oxide. Thus, in a current mirror circuit disclosed herein, a first field effect transistor (FET) has a first gate and a first drain, in which the first drain is conductively connected to a current source for conducting a first current. The current mirror circuit also includes at least one second FET having a second gate conductively connected to the first gate, in which the second FET is operable to output a second current in fixed proportion to the first current. A switching element having a first conductive terminal is connected to the first gate and to the second gate, the second conductive terminal being connected to the first drain of the first FET.Type: GrantFiled: January 4, 2005Date of Patent: April 17, 2007Assignee: International Business Machines CorporationInventors: Gautam Gangasani, Louis L. Hsu, Karl D. Selander, Steven J. Zier
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Patent number: 7205816Abstract: An apparatus and method for generating high-speed clock signals using a voltage-controlled-oscillator (VCO) device. The apparatus implements a linear variable gain amplifier rather than a non-linear hard limiter to remove unwanted signal modulation in VCO output signals. Implementation of the linear variable gain amplifier leads to the generation of amplitude modulation-free oscillation leading to the generation of jitter free high frequency clock signals.Type: GrantFiled: June 17, 2005Date of Patent: April 17, 2007Assignee: International Business Machines CorporationInventors: Herschel A. Ainspan, Gautam Gangasani, Louis C. Hsu, Jack A. Mandelman
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Publication number: 20070001736Abstract: An apparatus and method for generating high-speed clock signals using a voltage-controlled-oscillator (VCO) device. The apparatus implements a linear variable gain amplifier rather than a non-linear hard limiter to remove unwanted signal modulation in VCO output signals. Implementation of the linear variable gain amplifier leads to the generation of amplitude modulation-free oscillation leading to the generation of jitter free high frequency clock signals.Type: ApplicationFiled: June 17, 2005Publication date: January 4, 2007Applicant: International Business Machines CorporationInventors: Herschel Ainspan, Gautam Gangasani, Louis Hsu, Jack Mandelman
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Publication number: 20060145751Abstract: Circuits and methods are provided for reducing the voltage stress applied to the drain to source conduction path of an FET and/or to reduce the stress to the gate oxide of an FET which may have a thin gate oxide. Thus, in a current mirror circuit disclosed herein, a first field effect transistor (FET) has a first gate and a first drain, in which the first drain is conductively connected to a current source for conducting a first current. The current mirror circuit also includes at least one second FET having a second gate conductively connected to the first gate, in which the second FET is operable to output a second current in fixed proportion to the first current. A switching element having a first conductive terminal is connected to the first gate and to the second gate, the second conductive terminal being connected to the first drain of the first FET.Type: ApplicationFiled: January 4, 2005Publication date: July 6, 2006Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Gautam Gangasani, Louis Hsu, Karl Selander, Steven Zier