Patents by Inventor Mehrdad Heshami
Mehrdad Heshami 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: 11528016Abstract: A low latency comparator circuit with a local clock circuit is disclosed. A comparator circuit configured to compare a first input signal to a second input signal. The comparator circuit includes at least one regenerative latch circuit having a first and second inputs configured to receive the first and second input signals, respectively. The comparator circuit further includes a clock circuit configured to generate and provide a clock signal exclusively to circuitry in the comparator circuit, including the at least one regenerative latch circuit. At least one output latch circuit coupled to the at least one regenerative latch circuit and configured to provide a first output signal indicative of a comparison of the first and second input signals.Type: GrantFiled: January 21, 2021Date of Patent: December 13, 2022Assignee: Apple Inc.Inventors: Mehrdad Heshami, Jafar Savoj
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Publication number: 20220231672Abstract: A low latency comparator circuit with a local clock circuit is disclosed. A comparator circuit configured to compare a first input signal to a second input signal. The comparator circuit includes at least one regenerative latch circuit having a first and second inputs configured to receive the first and second input signals, respectively. The comparator circuit further includes a clock circuit configured to generate and provide a clock signal exclusively to circuitry in the comparator circuit, including the at least one regenerative latch circuit. At least one output latch circuit coupled to the at least one regenerative latch circuit and configured to provide a first output signal indicative of a comparison of the first and second input signals.Type: ApplicationFiled: January 21, 2021Publication date: July 21, 2022Inventors: Mehrdad Heshami, Jafar Savoj
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Patent number: 8364433Abstract: A calibration system employed for use with a resistance capacitance (RC) filter having resistors and capacitors with parasitic capacitance associated therewith. The calibration system has a digital calibration circuit receiving a time constant signal and generating, based thereon, a control word of N digital bits. The calibration system includes an analog monitor circuit having monitor capacitance assembly having a particular equivalent resistor and capacitor configuration. The analog monitor circuit generates the time constant signal and includes N switches, where each switch is controlled by one of the N bits of the control word, each switch is configured to connect or disconnect one or more capacitors of the monitor capacitor assembly thereby generating a time constant signal that represents the time constant of the RC integrated filter.Type: GrantFiled: December 18, 2008Date of Patent: January 29, 2013Assignee: Integrated Device Technology, Inc.Inventors: Mansour Keramat, Syed S. Islam, Mehrdad Heshami
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Patent number: 7977762Abstract: An integrated circuit (IC) is disclosed to include a central area of the IC that is partitioned into a first section containing at least one digital circuit and a second section containing at least one analog circuit; and a guard strip (or shield) that is within the central area and that is positioned within between the digital circuit and the analog circuit. The shield or guard strip comprises of n-well and p-tap regions that separate digital and analog circuits.Type: GrantFiled: December 9, 2008Date of Patent: July 12, 2011Assignee: Alvand Technologies, Inc.Inventors: Mansour Keramat, Mehrdad Heshami, Syed S. Islam
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Patent number: 7898056Abstract: Disclosed is a seal-ring architecture that can minimize noise injection from noisy digital circuits to sensitive analog and/or radio frequency (RF) circuits in system-on-a-chip (SoC) applications. In order to improve the isolation, the seal-ring structure contains cuts and ground connections to the segment which is close to the analog circuits. The cuts are such that the architecture is fully compatible with standard design rules and that the mechanical strength of the seal rings is not significantly sacrificed. Some embodiments also include a grounded p-tap ring between the analog circuits and the inner seal ring in order to improve isolation. Some embodiments also include a guard strip between the analog circuits and the digital circuits to minimize the noise injection through the substrate.Type: GrantFiled: December 9, 2008Date of Patent: March 1, 2011Assignee: Alvand Technology, Inc.Inventors: Mansour Keramat, Syed S. Islam, Mehrdad Heshami
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Patent number: 7606546Abstract: A system, method and system are disclosed for using a variable frequency clock generator to synchronize an average data rate over intervals of time in a variable clock domain to make it equal to a fixed data rate in a fixed clock domain while reducing electromagnetic interference, among other things. In various embodiments, setting the data rates equal to each other minimizes storage used to transition data signals between clock domains. In one embodiment, a variable frequency clock generator includes a phase modulator configured to form a variable frequency clock. Also, the variable clock generator is configured to maintain an average frequency over specific periods of time for the range of discrete frequencies. The phase-offset controller sets an average clock having substantially no offset between a fixed data rate in the fixed clock domain and an average data rate in the variable clock domain.Type: GrantFiled: April 18, 2008Date of Patent: October 20, 2009Assignee: Nvidia CorporationInventors: Tao Liu, Mansour Keramat, Edward Wai Yeung Liu, Mehrdad Heshami, Timothy C. Kuo
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Patent number: 7558348Abstract: A radio frequency antenna system and high-speed digital data link are disclosed to, among other things, reduce electromagnetic interference (“EMI”) at relatively high data rates while reducing the manufacturing complexities associated with conventional data links. In one embodiment, a radio frequency (“RF”) antenna system includes an antenna and an RF radio coupled to the antenna for receiving wireless RF signals. In particular, the RF radio is configured to digitize RF signals at a fixed data rate to form digitized data signals and to apply the digitized data signals at a variable data rate to a high-speed digital link. The variable data rate distributes the signal energy of the digitized data signals over one or more bands of frequencies, thereby beneficially altering an EMI spectral profile describing emissions that develop as the digitized data signals are transported through a channel.Type: GrantFiled: May 18, 2005Date of Patent: July 7, 2009Assignee: Nvidia CorporationInventors: Tao Liu, Mansour Keramat, Mehrdad Heshami, Feng Bao, Timothy C. Kuo, Douglas J. Hogberg, Bo Liang, Edward Wai Yeung Liu
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Patent number: 7548740Abstract: A system, method and system are disclosed for using a variable frequency clock generator to synchronize an average data rate over intervals of time in a variable clock domain to make it equal to a fixed data rate in a fixed clock domain while reducing electromagnetic interference, among other things. In various embodiments, setting the data rates equal to each other minimizes storage used to transition data signals between clock domains. In one embodiment, a variable frequency clock generator includes a phase modulator configured to form a variable frequency clock. Also, the variable clock generator is configured to maintain an average frequency over specific periods of time for the range of discrete frequencies. The phase-offset controller sets an average clock having substantially no offset between a fixed data rate in the fixed clock domain and an average data rate in the variable clock domain.Type: GrantFiled: December 12, 2007Date of Patent: June 16, 2009Assignee: Nvidia CorporationInventors: Tao Liu, Mansour Keramat, Edward Wai Yeung Liu, Mehrdad Heshami, Timothy C. Kuo
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Patent number: 7542749Abstract: A system, method and system are disclosed for using a variable frequency clock generator to synchronize an average data rate over intervals of time in a variable clock domain to make it equal to a fixed data rate in a fixed clock domain while reducing electromagnetic interference, among other things. In various embodiments, setting the data rates equal to each other minimizes storage used to transition data signals between clock domains. In one embodiment, a variable frequency clock generator includes a phase modulator configured to form a variable frequency clock. Also, the variable clock generator is configured to maintain an average frequency over specific periods of time for the range of discrete frequencies. The phase-offset controller sets an average clock having substantially no offset between a fixed data rate in the fixed clock domain and an average data rate in the variable clock domain.Type: GrantFiled: December 12, 2007Date of Patent: June 2, 2009Assignee: NVIDIA CorporationInventors: Tao Liu, Mansour Keramat, Edward Wai Yeung Liu, Mehrdad Heshami, Timothy C. Kuo
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Patent number: 7499690Abstract: A system, method and system are disclosed for using a variable frequency clock generator to synchronize an average data rate over intervals of time in a variable clock domain to make it equal to a fixed data rate in a fixed clock domain while reducing electromagnetic interference, among other things. In various embodiments, setting the data rates equal to each other minimizes storage used to transition data signals between clock domains. In one embodiment, a variable frequency clock generator includes a phase modulator configured to form a variable frequency clock. Also, the variable clock generator is configured to maintain an average frequency over specific periods of time for the range of discrete frequencies. The phase-offset controller sets an average clock having substantially no offset between a fixed data rate in the fixed clock domain and an average data rate in the variable clock domain.Type: GrantFiled: December 12, 2007Date of Patent: March 3, 2009Assignee: NVIDIA CorporationInventors: Tao Liu, Mansour Keramat, Edward Wai Yeung Liu, Mehrdad Heshami, Timothy C. Kuo
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Patent number: 7473955Abstract: A fabricated cylinder capacitor having two or more layers is provided, each layer having a bottom plate and top plate portions. A first set of vias connect the bottom plate portions and a second set of vias connect the top plate portions. The bottom plate portions and the first set of vias comprise a bottom plate and the top plate portions and the second set of vias comprise a top plate of the capacitor. The layers may comprise five metal layers and may be produced using semiconductor fabrication methods. Also provided is a capacitor array having two or more cylinder capacitors where a set of connectors connect all top plates of the capacitors. The capacitor array may be used in a capacitive DAC, the capacitors being connected according to the architecture of the DAC. The capacitive DAC may be used in a SAR ADC.Type: GrantFiled: March 7, 2006Date of Patent: January 6, 2009Assignee: Alvand Technologies, Inc.Inventors: Mehrdad Heshami, Mansour Keramat
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Patent number: 7456462Abstract: A layered capacitor having top and bottom plates formed from multiple layers. The capacitor has a bottom layer comprising a bottom plate portion and at least one upper layer, each upper layer comprising top and bottom plate portions. A first set of vias connect the bottom plate portions and a second set of vias connect the top plate portions. The bottom plate portions and the first set of vias comprise a U-shaped bottom plate and the top plate portions and the second set of vias comprise a top plate of the capacitor device. The layers may comprise metal layers produced using semiconductor fabrication methods. Also provided is a capacitor array having two or more capacitors where connectors connect all top plate portions of the capacitors. The capacitor array may be used in a capacitive DAC, which may be used in a SAR ADC.Type: GrantFiled: March 7, 2006Date of Patent: November 25, 2008Assignee: Alvand Technologies, Inc.Inventors: Mehrdad Heshami, Mansour Keramat
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Patent number: 7446365Abstract: A fabricated layered capacitor having three layers is provided. The first bottom layer comprises a first bottom plate portion, the second middle layer comprises a first top plate portion, and the third top layer comprises a second bottom plate portion of the layered capacitor. A set of vias connects the first and second bottom plate portions. The top plate portion may extend past the bottom plate portions. The layered capacitor may have a different number of layers (e.g., five layers). The layers may comprise metal layers produced using semiconductor fabrication methods. Also provided is a capacitor array having two or more layered capacitors where connectors connect all top plate portions of the capacitors. The capacitor array may be used in a capacitive DAC, the capacitors being connected according to the architecture of the DAC. The capacitive DAC may be used in a SAR ADC.Type: GrantFiled: March 7, 2006Date of Patent: November 4, 2008Assignee: Alvand Technologies, Inc.Inventors: Mehrdad Heshami, Mansour Keramat
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Patent number: 7403150Abstract: An analog-to-digital converter architecture is described. An analog-to-digital converter circuit includes a switched capacitor circuit structure to receive an input voltage signal and one or more reference voltage signals. The analog-to-digital converter circuit also includes a comparator device array coupled to the switched capacitor circuit structure.Type: GrantFiled: September 20, 2006Date of Patent: July 22, 2008Assignee: Alvand Technologies, Inc.Inventors: Mehrdad Heshami, Mansour Keramat
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Patent number: 7389095Abstract: A system, method and system are disclosed for using a variable frequency clock generator to synchronize an average data rate over intervals of time in a variable clock domain to make it equal to a fixed data rate in a fixed clock domain while reducing electromagnetic interference, among other things. In various embodiments, setting the data rates equal to each other minimizes storage used to transition data signals between clock domains. In one embodiment, a variable frequency clock generator includes a phase modulator configured to form a variable frequency clock. Also, the variable clock generator is configured to maintain an average frequency over specific periods of time for the range of discrete frequencies. The phase-offset controller sets an average clock having substantially no offset between a fixed data rate in the fixed clock domain and an average data rate in the variable clock domain.Type: GrantFiled: May 18, 2005Date of Patent: June 17, 2008Assignee: Nvidia CorporationInventors: Tao Liu, Mansour Keramat, Edward Wai Yeung Liu, Mehrdad Heshami, Timothy C. Kuo
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Patent number: 6909310Abstract: A line driver fabricated from CMOS devices that provides a substantially constant output impedance over a significant range of a time-varying input voltage includes a time-varying current source, a pair of CMOS output loads, and a pair of biasing circuits. Each CMOS output load includes a NMOS transistor and a PMOS transistor connected in parallel and each biased into a linear range of operation. In response to a time-varying input voltage, the time-varying current source draws current from the pair of CMOS output loads in a manner that operates each CMOS output load to collectively establish a time-varying output voltage component at an associated output terminal.Type: GrantFiled: January 30, 2003Date of Patent: June 21, 2005Assignee: Agilent Technologies, Inc.Inventors: Kenneth D. Poulton, Robert M. R. Neff, Jorge A. Pernillo, Mehrdad Heshami
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Publication number: 20040150432Abstract: A line driver fabricated from CMOS devices that provides a substantially constant output impedance over a significant range of a time-varying input voltage includes a time-varying current source, a pair of CMOS output loads, and a pair of biasing circuits. Each CMOS output load includes a NMOS transistor and a PMOS transistor connected in parallel and each biased into a linear range of operation. In response to a time-varying input voltage, the time-varying current source draws current from the pair of CMOS output loads in a manner that operates each CMOS output load to collectively establish a time-varying output voltage component at an associated output terminal.Type: ApplicationFiled: January 30, 2003Publication date: August 5, 2004Inventors: Kenneth D. Poulton, Robert M. R. Neff, Jorge A. Pernillo, Mehrdad Heshami
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Patent number: 5821785Abstract: The invention relates to a clock signal frequency multiplier circuit. The circuit multiplies the speed of a clock signal of an integrated circuit (IC) by a factor N to generate a times-N clock signal. The circuit first receives a clock signal. Next, the circuit replicates the clock signal into a plurality of N component signals. Each Jth component signal is delayed from the (J-1)th component signal by 1/N cycles, where J equals 1 to N. The (J=1)th component signal is the clock signal. The N component signals are referred to as phase-shifted components. Finally, the circuit logically combines the phase-shifted components into a times-N clock signal.Type: GrantFiled: August 2, 1996Date of Patent: October 13, 1998Assignee: Rockwell Int'l Corp.Inventors: Kevin W. Glass, Mehrdad Heshami