Patents by Inventor Mohammad Hekmat

Mohammad Hekmat 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).

  • Patent number: 10389303
    Abstract: Circuitry capable of performing fractional clock multiplication by using an injection-locked oscillator is described. Some embodiments described herein perform fractional clock multiplication by periodically changing the injection location, from a set of injection locations, where the injection signal is injected and/or by periodically changing a phase, from a set of phases, of the injection signal that is injected into the ILO.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: August 20, 2019
    Assignee: Rambus Inc.
    Inventors: Masum Hossain, Farshid Aryanfar, Mohammad Hekmat, Reza Navid
  • Patent number: 10140912
    Abstract: A display interface for transmitting reverse data. The display interface includes a timing controller, a first plurality of driver integrated circuits, a first shared data lane connected to the timing controller and to each of the first plurality of driver integrated circuits, and a shared synchronization lane connected to the timing controller and to each of the first plurality of driver integrated circuits. Each of the first plurality of driver integrated circuits has a data input configured to receive reverse data from a display panel, and a buffer configured to store reverse data. The timing controller is configured to periodically send a synchronization pulse having a triggering edge. Each of the first plurality of driver integrated circuits is configured to periodically send, on the first shared data lane, reverse data to the timing controller in a respective time slot of a plurality of non-overlapping time slots, after each triggering edge.
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: November 27, 2018
    Assignee: Samsung Display Co., Ltd.
    Inventors: Mohammad Hekmat, Amir Amirkhany
  • Publication number: 20180278210
    Abstract: Circuitry capable of performing fractional clock multiplication by using an injection-locked oscillator is described. Some embodiments described herein perform fractional clock multiplication by periodically changing the injection location, from a set of injection locations, where the injection signal is injected and/or by periodically changing a phase, from a set of phases, of the injection signal that is injected into the ILO.
    Type: Application
    Filed: March 14, 2018
    Publication date: September 27, 2018
    Inventors: Masum Hossain, Farshid Aryanfar, Mohammad Hekmat, Reza Navid
  • Patent number: 9954489
    Abstract: Circuitry capable of performing fractional clock multiplication by using an injection-locked oscillator is described. Some embodiments described herein perform fractional clock multiplication by periodically changing the injection location, from a set of injection locations, where the injection signal is injected and/or by periodically changing a phase, from a set of phases, of the injection signal that is injected into the ILO.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: April 24, 2018
    Assignee: Rambus Inc.
    Inventors: Masum Hossain, Farshid Aryanfar, Mohammad Hekmat, Reza Navid
  • Publication number: 20180019706
    Abstract: Circuitry capable of performing fractional clock multiplication by using an injection-locked oscillator is described. Some embodiments described herein perform fractional clock multiplication by periodically changing the injection location, from a set of injection locations, where the injection signal is injected and/or by periodically changing a phase, from a set of phases, of the injection signal that is injected into the ILO.
    Type: Application
    Filed: June 23, 2017
    Publication date: January 18, 2018
    Inventors: Masum Hossain, Farshid Aryanfar, Mohammad Hekmat, Reza Navid
  • Publication number: 20170359027
    Abstract: A phase-locked loop circuit comprises a multi-phase oscillator having a plurality of coupled oscillators. A calibration module detects mismatches between frequency characteristics of the different oscillators in the phase-locked loop circuit during a calibration process. The calibration module then calibrates the various oscillators to compensate for the detected mismatch. Once calibrated, the phase-locked loop circuit can operate with little or no performance degradation despite the mismatch in frequency characteristics between the different oscillators.
    Type: Application
    Filed: June 29, 2017
    Publication date: December 14, 2017
    Inventors: Mohammad Hekmat, Reza Navid
  • Patent number: 9722539
    Abstract: A phase-locked loop circuit comprises a multi-phase oscillator having a plurality of coupled oscillators. A calibration module detects mismatches between frequency characteristics of the different oscillators in the phase-locked loop circuit during a calibration process. The calibration module then calibrates the various oscillators to compensate for the detected mismatch. Once calibrated, the phase-locked loop circuit can operate with little or no performance degradation despite the mismatch in frequency characteristics between the different oscillators.
    Type: Grant
    Filed: September 18, 2015
    Date of Patent: August 1, 2017
    Assignee: Rambus Inc.
    Inventors: Mohammad Hekmat, Reza Navid
  • Patent number: 9722820
    Abstract: A method of calibrating coefficients of a calibrated decision feedback equalizer (DFE) across a process, voltage, and temperature (PVT) range, the calibrated DFE comprising a plurality of DFE taps for reducing distortions of an input signal, and a sampler for sampling the input signal, the method including applying a preset voltage to an input of the calibrated DFE, setting a DFE tap of the plurality of DFE taps to a maximum value, generating a source reference, via a source reference calibrator, to apply to the DFE tap, changing the source reference to a first level that causes an output of the sampler to transition from a first state to a second state, determining the first level as a calibrated source reference, and applying the calibrated source reference to the DFE tap during normal operation of the calibrated DFE.
    Type: Grant
    Filed: June 27, 2016
    Date of Patent: August 1, 2017
    Assignee: SAMSUNG DISPLAY CO., LTD.
    Inventors: Mohammad Hekmat, Amir Amirkhany
  • Patent number: 9716468
    Abstract: Circuitry capable of performing fractional clock multiplication by using an injection-locked oscillator is described. Some embodiments described herein perform fractional clock multiplication by periodically changing the injection location, from a set of injection locations, where the injection signal is injected and/or by periodically changing a phase, from a set of phases, of the injection signal that is injected into the ILO.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: July 25, 2017
    Assignee: RAMBUS INC.
    Inventors: Masum Hossain, Farshid Aryanfar, Mohammad Hekmat, Reza Navid
  • Patent number: 9712177
    Abstract: A phase-locked loop. The phase-locked loop includes a voltage-controlled oscillator having: a control input, and a clock output; and a phase frequency detector having: a reference clock input, a feedback clock input, an up output configured to be either in a set state or a reset state, and a down output configured to be either in a set state or a reset state. The up output and the down output are connected to the control input. The clock output is connected to the feedback clock input. The phase frequency detector includes an adjustable delay block configured to delay, by an adjustable delay time: a transition of the up output from the set state to the reset state, and a transition of the down output from the set state to the reset state.
    Type: Grant
    Filed: January 8, 2016
    Date of Patent: July 18, 2017
    Assignee: Samsung Display Co., Ltd.
    Inventors: Mohammad Hekmat, Jalil Kamali
  • Publication number: 20170201261
    Abstract: A phase-locked loop. The phase-locked loop includes a voltage-controlled oscillator having: a control input, and a clock output; and a phase frequency detector having: a reference clock input, a feedback clock input, an up output configured to be either in a set state or a reset state, and a down output configured to be either in a set state or a reset state. The up output and the down output are connected to the control input. The clock output is connected to the feedback clock input. The phase frequency detector includes an adjustable delay block configured to delay, by an adjustable delay time: a transition of the up output from the set state to the reset state, and a transition of the down output from the set state to the reset state.
    Type: Application
    Filed: January 8, 2016
    Publication date: July 13, 2017
    Inventors: Mohammad Hekmat, Jalil Kamali
  • Publication number: 20170178562
    Abstract: A display interface for transmitting reverse data. The display interface includes a timing controller, a first plurality of driver integrated circuits, a first shared data lane connected to the timing controller and to each of the first plurality of driver integrated circuits, and a shared synchronization lane connected to the timing controller and to each of the first plurality of driver integrated circuits. Each of the first plurality of driver integrated circuits has a data input configured to receive reverse data from a display panel, and a buffer configured to store reverse data. The timing controller is configured to periodically send a synchronization pulse having a triggering edge. Each of the first plurality of driver integrated circuits is configured to periodically send, on the first shared data lane, reverse data to the timing controller in a respective time slot of a plurality of non-overlapping time slots, after each triggering edge.
    Type: Application
    Filed: December 18, 2015
    Publication date: June 22, 2017
    Inventors: Mohammad Hekmat, Amir Amirkhany
  • Patent number: 9680430
    Abstract: A differential amplifier including: a first amplifier leg including a first transistor, and a second amplifier leg including a second transistor. Here, the first transistor is configured to have a bulk potential different from a bulk potential of the second transistor. The first amplifier leg and the second amplifier leg, together, may be configured to differentially amplify a received differential input signal. The differential amplifier may be configured to have an input offset voltage, which corresponds to the difference between the bulk potential of the first transistor and the bulk potential of the second transistor. The differential amplifier may be at an input stage of a comparator.
    Type: Grant
    Filed: October 23, 2013
    Date of Patent: June 13, 2017
    Assignee: Samsung Display Co., Ltd.
    Inventors: Mohammad Hekmat, Amir Amirkhany
  • Patent number: 9674008
    Abstract: A predictive decision feedback equalizer using body bias of one or more field effect transistors (FETs) to provide an offset for a predictive tap. In one embodiment, a predictive tap of the predictive decision feedback equalizer includes a differential amplifier composed of two FETs in a differential amplifier configuration, and the body bias of one or both FETs is controlled to provide an offset in the differential amplifier. In one embodiment a current DAC driving a DAC resistor is used to provide the body bias voltage, and a feedback circuit, including a replica circuit forming the maximum possible DAC output voltage, is used to control the bias of the current sources of the current DAC.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: June 6, 2017
    Assignee: Samsung Display Co., Ltd.
    Inventors: Mohammad Hekmat, Amir Amirkhany
  • Publication number: 20170097905
    Abstract: A semiconductor memory system includes a first semiconductor memory die and a second semiconductor memory die. The first semiconductor memory die includes a primary data interface to receive an input data stream during write operations and to deserialize the input data stream into a first plurality of data streams, and also includes a secondary data interface, coupled to the primary data interface, to transmit the first plurality of data streams. The second semiconductor memory die includes a secondary data interface, coupled to the secondary data interface of the first semiconductor memory die, to receive the first plurality of data streams.
    Type: Application
    Filed: October 24, 2016
    Publication date: April 6, 2017
    Inventors: Frederick A. Ware, Amir Amirkhany, Suresh Rajan, Mohammad Hekmat, Dinesh Patil
  • Patent number: 9571034
    Abstract: Coupled multi-inductors and their applications. An apparatus includes several circuit stages. Each circuit stage includes an inductive element that overlaps with the inductive elements of its adjacent circuit stages, forming a loop of coupled circuit stages. The apparatus may be, for example, a multi-phase oscillator with multiple oscillators that are magnetically coupled to each other for generating oscillation signals at different phases. The apparatus may also be, for example, a phase interpolator for combining input signals.
    Type: Grant
    Filed: February 22, 2016
    Date of Patent: February 14, 2017
    Assignee: Rambus Inc.
    Inventors: Mohammad Hekmat, Farshid Aryanfar, Kambiz Kaviani
  • Patent number: 9531570
    Abstract: A system for reduced-rate predictive DFE. In one embodiment a plurality of sampler-multiplexer blocks, each including two samplers and a multiplexer-latch, controlled by a multi-phase clock, sample the received analog signal one at a time, and the output of each multiplexer-latch, which may represent the value of the last received bit, is used to control the select input of another multiplexer-latch, so that the other multiplexer-latch selects the appropriate one of two samplers, each applying a different correction to the received analog signal before sampling. Each multiplexer-latch is a clocked element that tracks the data input when the signal at its clock input has a first logic level and retains its output state when its clock input has another (i.e., a second) logic level.
    Type: Grant
    Filed: April 27, 2015
    Date of Patent: December 27, 2016
    Assignee: Samsung Display Co., Ltd
    Inventors: Mohammad Hekmat, Amir Amirkhany
  • Patent number: 9501433
    Abstract: A semiconductor memory system includes a first semiconductor memory die and a second semiconductor memory die. The first semiconductor memory die includes a primary data interface to receive an input data stream during write operations and to deserialize the input data stream into a first plurality of data streams, and also includes a secondary data interface, coupled to the primary data interface, to transmit the first plurality of data streams. The second semiconductor memory die includes a secondary data interface, coupled to the secondary data interface of the first semiconductor memory die, to receive the first plurality of data streams.
    Type: Grant
    Filed: April 9, 2015
    Date of Patent: November 22, 2016
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, Amir Amirkhany, Suresh Rajan, Mohammad Hekmat, Dinesh Patil
  • Publication number: 20160241191
    Abstract: Coupled multi-inductors and their applications. An apparatus includes several circuit stages. Each circuit stage includes an inductive element that overlaps with the inductive elements of its adjacent circuit stages, forming a loop of coupled circuit stages. The apparatus may be, for example, a multi-phase oscillator with multiple oscillators that are magnetically coupled to each other for generating oscillation signals at different phases. The apparatus may also be, for example, a phase interpolator for combining input signals.
    Type: Application
    Filed: February 22, 2016
    Publication date: August 18, 2016
    Inventors: Mohammad Hekmat, Farshid Aryanfar, Kambiz Kaviani
  • Patent number: 9417807
    Abstract: A data buffer with a strobe-based primary interface and a strobe-less secondary interface used on a memory module is described. One memory module includes an address buffer, the data buffer and multiple dynamic random-access memory (DRAM) devices. The address buffer provides a timing reference to the data buffer and to the DRAM devices for one or more transactions between the data buffer and the DRAM devices via the strobe-less secondary interface.
    Type: Grant
    Filed: August 6, 2015
    Date of Patent: August 16, 2016
    Assignee: RAMBUS INC.
    Inventors: Kambiz Kaviani, Amir Amirkhany, Dinesh Patil, Mohammad Hekmat