Patents Assigned to Alvand Technologies, Inc.
  • Patent number: 7977762
    Abstract: 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: Grant
    Filed: December 9, 2008
    Date of Patent: July 12, 2011
    Assignee: Alvand Technologies, Inc.
    Inventors: Mansour Keramat, Mehrdad Heshami, Syed S. Islam
  • Patent number: 7920006
    Abstract: In one embodiment of the present invention, a clock generator circuit receives a clock signal having a period. The clock signal is employed by a digital circuit that is resident on the same substrate as an analog circuit, the digital circuit generates disturbance climaxes at clock edges that propagate through the substrate to the analog circuit. A clock generator circuit generates a plurality of clock signals, with each clock signal having a unique rate, wherein during a temporal gap, defined by the time between a last disturbance climax and a next sampling time of the clock signal, clock edges of any of the plurality of clock signals are avoided.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: April 5, 2011
    Assignee: Alvand Technologies, Inc.
    Inventors: Mansour Keramat, Keivan Etessam Yazdani
  • Patent number: 7898056
    Abstract: 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: Grant
    Filed: December 9, 2008
    Date of Patent: March 1, 2011
    Assignee: Alvand Technology, Inc.
    Inventors: Mansour Keramat, Syed S. Islam, Mehrdad Heshami
  • Patent number: 7852248
    Abstract: In one embodiment of the present invention, at least at one stage of a Sigma-Delta analog-to-digital converter (ADC) is disclosed to include means for receiving a voltage at least one of the inputs of an operational amplifier, the operational amplifier having at least one output coupled to the at least one of the inputs via an at least one integration capacitor, means for transforming the voltage to a current and means for integrating the current on the at least one of the integration capacitors, during integration time and varying the resistance of at least one of a variable resistors coupled to the operational amplifier during integration time.
    Type: Grant
    Filed: December 9, 2008
    Date of Patent: December 14, 2010
    Assignee: Alvand Technology, Inc.
    Inventors: Mansour Keramat, Ali Agah, Ali Tabatabaei
  • Patent number: 7473955
    Abstract: 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: Grant
    Filed: March 7, 2006
    Date of Patent: January 6, 2009
    Assignee: Alvand Technologies, Inc.
    Inventors: Mehrdad Heshami, Mansour Keramat
  • Patent number: 7456462
    Abstract: 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: Grant
    Filed: March 7, 2006
    Date of Patent: November 25, 2008
    Assignee: Alvand Technologies, Inc.
    Inventors: Mehrdad Heshami, Mansour Keramat
  • Patent number: 7446365
    Abstract: 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: Grant
    Filed: March 7, 2006
    Date of Patent: November 4, 2008
    Assignee: Alvand Technologies, Inc.
    Inventors: Mehrdad Heshami, Mansour Keramat
  • Patent number: 7403150
    Abstract: 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: Grant
    Filed: September 20, 2006
    Date of Patent: July 22, 2008
    Assignee: Alvand Technologies, Inc.
    Inventors: Mehrdad Heshami, Mansour Keramat