Patents by Inventor Ankur Agrawal

Ankur Agrawal 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).

  • Publication number: 20140125382
    Abstract: Circuits and methods are provided for generating clock signals and correcting duty cycle distortion in clock signals. A circuit for generating a clock signal includes a multiplexer circuit and an edge-triggered flip-flop circuit. The multiplexer circuit selectively outputs one of a plurality of input clock signals. The edge-triggered flip-flop detects a transitioning edge of the input clock signal that is selectively output from the multiplexer circuit, and in response to the detection, samples a logic level of a received data signal, and generates a transition of an output clock signal at an output port of the edge-triggered flip-flop. The multiplexer circuit selectively outputs one of the plurality of input clock signals to a clock signal port of the edge-triggered flip-flop, based on a logic level of the output clock signal at the output port of the edge-triggered flip-flop, which is input to a select control port of the multiplexer circuit.
    Type: Application
    Filed: January 10, 2014
    Publication date: May 8, 2014
    Applicant: International Business Machines Corporation
    Inventors: John F. Bulzacchelli, Ankur Agrawal
  • Patent number: 8686764
    Abstract: Circuits and methods are provided for generating clock signals and correcting duty cycle distortion in clock signals. A circuit for generating a clock signal includes a multiplexer circuit and an edge-triggered flip-flop circuit. The multiplexer circuit selectively outputs one of a plurality of input clock signals. The edge-triggered flip-flop detects a transitioning edge of the input clock signal that is selectively output from the multiplexer circuit, and in response to the detection, samples a logic level of a received data signal, and generates a transition of an output clock signal at an output port of the edge-triggered flip-flop. The multiplexer circuit selectively outputs one of the plurality of input clock signals to a clock signal port of the edge-triggered flip-flop, based on a logic level of the output clock signal at the output port of the edge-triggered flip-flop, which is input to a select control port of the multiplexer circuit.
    Type: Grant
    Filed: July 22, 2013
    Date of Patent: April 1, 2014
    Assignee: International Business Machines Corporation
    Inventors: John F. Bulzacchelli, Ankur Agrawal
  • Publication number: 20140020835
    Abstract: A plasma reactor has an overhead multiple coil inductive plasma source with symmetric RF feeds and a symmetrical chamber exhaust with plural struts through the exhaust region providing access to a confined workplace support. A grid may be included for masking spatial effects of the struts from the processing region.
    Type: Application
    Filed: November 1, 2012
    Publication date: January 23, 2014
    Applicant: APPLIED MATERIALS, INC.
    Inventors: Andrew Nguyen, Kenneth S. Collins, Kartik Ramaswamy, Shahid Rauf, James D. Carducci, Douglas A. Buchberger, JR., Ankur Agrawal, Jason A. Kenney, Leonid Dorf, Ajit Balakrishna, Richard Fovell
  • Patent number: 8633764
    Abstract: An apparatus comprises an amplifier circuit comprising at least one output node and a common-mode restoration circuit capacitively coupled to the at least one output node of the amplifier circuit. The common-mode restoration circuit is configured to introduce at least one common-mode restoring signal onto the output node, wherein the at least one common-mode restoring signal transitions in correspondence with an operation interval of the amplifier circuit and thereby compensates for a common-mode voltage drop on the at least one output node of the amplifier circuit. In one example, the amplifier circuit may comprise a current-integrating amplifier circuit, and the operation interval may comprise an integration interval.
    Type: Grant
    Filed: June 10, 2011
    Date of Patent: January 21, 2014
    Assignee: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Thomas H. Toifl
  • Publication number: 20130336378
    Abstract: Circuits and methods are provided for efficient feed-forward equalization when sample-and-hold circuitry is employed to generate n time-delayed versions of an input data signal to be equalized. To equalize the input data signal, m data signals are input to m feed-forward equalization (FFE) taps of a current-integrating summer circuit, wherein each of the m data signals corresponds to one of the n time-delayed versions of the input data signal. A capacitance is precharged to a precharge level during a reset period of the current-integrating summer circuit. An output current is generated by each of the m FFE taps during an integration period of the current-integrating summer circuit, wherein the output currents from the m FFE taps collectively charge or discharge the capacitance during the integration period. A gating control signal is applied to an FFE tap during the integration period to disable the FFE tap during a portion of the integration period in which the data signal input to the FFE tap is invalid.
    Type: Application
    Filed: August 16, 2013
    Publication date: December 19, 2013
    Applicant: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Daniel J. Friedman, Zeynep Toprak Deniz
  • Publication number: 20130300481
    Abstract: Circuits and methods are provided for generating clock signals and correcting duty cycle distortion in clock signals. A circuit for generating a clock signal includes a multiplexer circuit and an edge-triggered flip-flop circuit. The multiplexer circuit selectively outputs one of a plurality of input clock signals. The edge-triggered flip-flop detects a transitioning edge of the input clock signal that is selectively output from the multiplexer circuit, and in response to the detection, samples a logic level of a received data signal, and generates a transition of an output clock signal at an output port of the edge-triggered flip-flop. The multiplexer circuit selectively outputs one of the plurality of input clock signals to a clock signal port of the edge-triggered flip-flop, based on a logic level of the output clock signal at the output port of the edge-triggered flip-flop, which is input to a select control port of the multiplexer circuit.
    Type: Application
    Filed: July 22, 2013
    Publication date: November 14, 2013
    Applicant: International Business Machines Corporation
    Inventors: John F. Bulzacchelli, Ankur Agrawal
  • Patent number: 8564352
    Abstract: A phase interpolator circuit is provided that generates an output clock signal by interpolating between phases of first and second clock signals. Interpolation is performed by detecting an edge of the first clock signal and applying a first current to charge a capacitance of an output node to a voltage level which is less than or equal to a switching threshold of a voltage comparator, and detecting an edge of the second clock signal and applying a second current to charge the capacitance of the output node to a voltage level which exceeds the switching threshold of the voltage comparator. The magnitude of the first current is varied to adjust a timing at which the capacitance of the output node is charged to a voltage level that exceeds the switching threshold of the voltage comparator and to adjust a phase of the output clock signal output from the voltage comparator.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: October 22, 2013
    Assignee: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Sergey V. Rylov
  • Patent number: 8558597
    Abstract: A phase interpolator circuit is provided that generates an output clock signal by interpolating between phases of first and second clock signals. Interpolation is performed by detecting an edge of the first clock signal and applying a first current to charge a capacitance of an output node to a voltage level which is less than or equal to a switching threshold of a voltage comparator, and detecting an edge of the second clock signal and applying a second current to charge the capacitance of the output node to a voltage level which exceeds the switching threshold of the voltage comparator. The magnitude of the first current is varied to adjust a timing at which the capacitance of the output node is charged to a voltage level that exceeds the switching threshold of the voltage comparator and to adjust a phase of the output clock signal output from the voltage comparator.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: October 15, 2013
    Assignee: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Sergey V. Rylov
  • Publication number: 20130207703
    Abstract: Circuits and methods are provided for generating clock signals and correcting duty cycle distortion in clock signals. A circuit for generating a clock signal includes a multiplexer circuit and an edge-triggered flip-flop circuit. The multiplexer circuit selectively outputs one of a plurality of input clock signals. The edge-triggered flip-flop detects a transitioning edge of the input clock signal that is selectively output from the multiplexer circuit, and in response to the detection, samples a logic level of a received data signal, and generates a transition of an output clock signal at an output port of the edge-triggered flip-flop. The multiplexer circuit selectively outputs one of the plurality of input clock signals to a clock signal port of the edge-triggered flip-flop, based on a logic level of the output clock signal at the output port of the edge-triggered flip-flop, which is input to a select control port of the multiplexer circuit.
    Type: Application
    Filed: June 27, 2012
    Publication date: August 15, 2013
    Applicant: International Business Machines Corporation
    Inventors: John F. Bulzacchelli, Ankur Agrawal
  • Publication number: 20130207702
    Abstract: Circuits and methods are provided for generating clock signals and correcting duty cycle distortion in clock signals. A circuit for generating a clock signal includes a multiplexer circuit and an edge-triggered flip-flop circuit. The multiplexer circuit selectively outputs one of a plurality of input clock signals. The edge-triggered flip-flop detects a transitioning edge of the input clock signal that is selectively output from the multiplexer circuit, and in response to the detection, samples a logic level of a received data signal, and generates a transition of an output clock signal at an output port of the edge-triggered flip-flop. The multiplexer circuit selectively outputs one of the plurality of input clock signals to a clock signal port of the edge-triggered flip-flop, based on a logic level of the output clock signal at the output port of the edge-triggered flip-flop, which is input to a select control port of the multiplexer circuit.
    Type: Application
    Filed: June 27, 2012
    Publication date: August 15, 2013
    Applicant: International Business Machines Corporation
    Inventors: John F. Bulzacchelli, Ankur Agrawal
  • Publication number: 20130207708
    Abstract: A phase interpolator circuit is provided that generates an output clock signal by interpolating between phases of first and second clock signals. Interpolation is performed by detecting an edge of the first clock signal and applying a first current to charge a capacitance of an output node to a voltage level which is less than or equal to a switching threshold of a voltage comparator, and detecting an edge of the second clock signal and applying a second current to charge the capacitance of the output node to a voltage level which exceeds the switching threshold of the voltage comparator. The magnitude of the first current is varied to adjust a timing at which the capacitance of the output node is charged to a voltage level that exceeds the switching threshold of the voltage comparator and to adjust a phase of the output clock signal output from the voltage comparator.
    Type: Application
    Filed: June 29, 2012
    Publication date: August 15, 2013
    Applicant: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Sergey V. Rylov
  • Publication number: 20130207707
    Abstract: A phase interpolator circuit is provided that generates an output clock signal by interpolating between phases of first and second clock signals. Interpolation is performed by detecting an edge of the first clock signal and applying a first current to charge a capacitance of an output node to a voltage level which is less than or equal to a switching threshold of a voltage comparator, and detecting an edge of the second clock signal and applying a second current to charge the capacitance of the output node to a voltage level which exceeds the switching threshold of the voltage comparator. The magnitude of the first current is varied to adjust a timing at which the capacitance of the output node is charged to a voltage level that exceeds the switching threshold of the voltage comparator and to adjust a phase of the output clock signal output from the voltage comparator.
    Type: Application
    Filed: June 29, 2012
    Publication date: August 15, 2013
    Applicant: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Sergey V. Rylov
  • Patent number: 8484417
    Abstract: Version indicators within an existing range can be associated with a data partition in a distributed data store. A partition reconfiguration can be associated with one of multiple partitions in the data store, and a new version indicator that is outside the existing range can be assigned to the reconfigured partition. Additionally, a broadcast message can be sent to multiple nodes, which can include storage nodes and/or client nodes that are configured to communicate with storage nodes to access data in a distributed data store. The broadcast message can include updated location information for data in the data store. In addition, a response message can be sent to a requesting node of the multiple nodes in response to receiving from that node a message that requests updated location information for the data. The response message can include the requested updated location information.
    Type: Grant
    Filed: December 24, 2011
    Date of Patent: July 9, 2013
    Assignee: Microsoft Corporation
    Inventors: Lu Xun, Hua-Jun Zeng, Muralidhar Krishnaprasad, Radhakrishnan Srikanth, Ankur Agrawal, Balachandar Pavadaisamy
  • Publication number: 20120313703
    Abstract: An apparatus comprises an amplifier circuit comprising at least one output node and a common-mode restoration circuit capacitively coupled to the at least one output node of the amplifier circuit. The common-mode restoration circuit is configured to introduce at least one common-mode restoring signal onto the output node, wherein the at least one common-mode restoring signal transitions in correspondence with an operation interval of the amplifier circuit and thereby compensates for a common-mode voltage drop on the at least one output node of the amplifier circuit. In one example, the amplifier circuit may comprise a current-integrating amplifier circuit, and the operation interval may comprise an integration interval.
    Type: Application
    Filed: June 10, 2011
    Publication date: December 13, 2012
    Applicant: International Business Machines Corporation
    Inventors: Ankur Agrawal, John F. Bulzacchelli, Thomas H. Toifl
  • Publication number: 20120096103
    Abstract: Version indicators within an existing range can be associated with a data partition in a distributed data store. A partition reconfiguration can be associated with one of multiple partitions in the data store, and a new version indicator that is outside the existing range can be assigned to the reconfigured partition. Additionally, a broadcast message can be sent to multiple nodes, which can include storage nodes and/or client nodes that are configured to communicate with storage nodes to access data in a distributed data store. The broadcast message can include updated location information for data in the data store. In addition, a response message can be sent to a requesting node of the multiple nodes in response to receiving from that node a message that requests updated location information for the data. The response message can include the requested updated location information.
    Type: Application
    Filed: December 24, 2011
    Publication date: April 19, 2012
    Applicant: MICROSOFT CORPORATION
    Inventors: Lu Xun, Hua-Jun Zeng, Muralidhar Krishnaprasad, Radhakrishnan Srikanth, Ankur Agrawal, Balachandar Pavadaisamy
  • Patent number: 8108623
    Abstract: Systems and methods that supply poll based notification system in a distributed cache, for tracking changes to cache items. Local caches on the client can employ the notification system to keep the local objects in sync with the backend cache service; and can further dynamically adjust the “scope” of notifications required based on the number and distribution of keys in the local cache. The server can maintain the changes in an efficient fashion (in blocks) and returns the changes to clients that perform the appropriate filtering. Notifications can be associated with a session and/or an application.
    Type: Grant
    Filed: May 11, 2009
    Date of Patent: January 31, 2012
    Assignee: Microsoft Corporation
    Inventors: Muralidhar Krishnaprasad, Gopal Krishan, Lakshmi Suresh Goduguluru, Ankur Agrawal, Balachandar Pavadaisamy
  • Patent number: 8108612
    Abstract: Version indicators within an existing range can be associated with a data partition in a distributed data store. A partition reconfiguration can be associated with one of multiple partitions in the data store, and a new version indicator that is outside the existing range can be assigned to the reconfigured partition. Additionally, a broadcast message can be sent to multiple nodes, which can include storage nodes and/or client nodes that are configured to communicate with storage nodes to access data in a distributed data store. The broadcast message can include updated location information for data in the data store. In addition, a response message can be sent to a requesting node of the multiple nodes in response to receiving from that node a message that requests updated location information for the data. The response message can include the requested updated location information.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: January 31, 2012
    Assignee: Microsoft Corporation
    Inventors: Lu Xun, Hua-Jun Zeng, Muralidhar Krishnaprasad, Radhakrishnan Srikanth, Ankur Agrawal, Balachandar Pavadaisamy
  • Publication number: 20100293334
    Abstract: Version indicators within an existing range can be associated with a data partition in a distributed data store. A partition reconfiguration can be associated with one of multiple partitions in the data store, and a new version indicator that is outside the existing range can be assigned to the reconfigured partition. Additionally, a broadcast message can be sent to multiple nodes, which can include storage nodes and/or client nodes that are configured to communicate with storage nodes to access data in a distributed data store. The broadcast message can include updated location information for data in the data store. In addition, a response message can be sent to a requesting node of the multiple nodes in response to receiving from that node a message that requests updated location information for the data. The response message can include the requested updated location information.
    Type: Application
    Filed: May 15, 2009
    Publication date: November 18, 2010
    Applicant: Microsoft Corporation
    Inventors: Lu Xun, Hua-Jun Zeng, Muralidhar Krishnaprasad, Radhakrishnan Srikanth, Ankur Agrawal, Balachandar Pavadaisamy
  • Publication number: 20100106915
    Abstract: Systems and methods that supply poll based notification system in a distributed cache, for tracking changes to cache items. Local caches on the client can employ the notification system to keep the local objects in sync with the backend cache service; and can further dynamically adjust the “scope” of notifications required based on the number and distribution of keys in the local cache. The server can maintain the changes in an efficient fashion (in blocks) and returns the changes to clients that perform the appropriate filtering. Notifications can be associated with a session and/or an application.
    Type: Application
    Filed: May 11, 2009
    Publication date: April 29, 2010
    Applicant: MICROSOFT CORPORATION
    Inventors: Muralidhar Krishnaprasad, Gopal Krishan, Lakshmi Suresh Goduguluru, Ankur Agrawal, Balachandar Pavadaisamy