Patents by Inventor Theodore W. Houston

Theodore W. Houston 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: 8755239
    Abstract: A memory circuit includes a bit cell that receives a word line, complementary bit lines and an array supply voltage; a word line driver coupled to the word line, the word line driver receiving one of the array supply voltage and a periphery supply voltage; and a word line suppression circuit coupled to the word line. The word line suppression circuit includes a diode and a switch coupled in series. The switch is responsive to the array supply voltage. The word line suppression circuit limits a word line voltage to a value lower than the array supply voltage such that the static noise margin (SNM) of the bit cell is increased.
    Type: Grant
    Filed: November 17, 2011
    Date of Patent: June 17, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Lakshmikantha V. Holla, Vinod J. Menezes, Theodore W. Houston, Michael Patrick Clinton
  • Patent number: 8724375
    Abstract: A method for writing a low data bit value, writing a high data bit value, and reading a data bit value of an addressed SRAM cell. The method may include adjusting a bias level of the n-wells that contain the bit driver, bit-bar driver, bit passgate, and optional bit-bar passgate.
    Type: Grant
    Filed: February 4, 2013
    Date of Patent: May 13, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Anand Seshadri, Theodore W. Houston
  • Patent number: 8654569
    Abstract: An integrated circuit including an array of SRAM cells containing a write port with a write word line and two read buffers with read word lines. The write port includes passgate transistors connected to each data node of the SRAM cell. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are biased during a read operation. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are floated during a read operation. A process of operating the integrated circuit in which the write port and the read ports share data lines and the source nodes of read buffer driver transistors are floated during a write operation.
    Type: Grant
    Filed: April 5, 2011
    Date of Patent: February 18, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8654572
    Abstract: An integrated circuit including an array of SRAM cells containing a write port with a write word line and two read buffers with read word lines. The write port includes passgate transistors connected to each data node of the SRAM cell. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are biased during a read operation. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are floated during a read operation. A process of operating the integrated circuit in which the write port and the read ports share data lines and the source nodes of read buffer driver transistors are floated during a write operation.
    Type: Grant
    Filed: March 6, 2012
    Date of Patent: February 18, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8654568
    Abstract: An integrated circuit including a ram array with SRAM cells containing a write port with a write word line and two read buffers with read word lines. The write port includes passgate transistors connected to each data node of the SRAM cell. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are biased during a read operation. A process of operating the integrated circuit in which source nodes of read buffer driver transistors are floated during a read operation. A process of operating the integrated circuit in which the write port and the read ports share data lines and the source nodes of read buffer driver transistors are floated during a write operation.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: February 18, 2014
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8535990
    Abstract: An integrated circuit containing logic transistors and an array of SRAM cells in which the logic transistors are formed in semiconductor material with one crystal orientation and the SRAM cells are formed in a second semiconductor layer with another crystal orientation. A process of forming an integrated circuit containing logic transistors and an array of SRAM cells in which the logic transistors are formed in a top semiconductor layer with one crystal orientation and the SRAM cells are formed in an epitaxial semiconductor layer with another crystal orientation. A process of forming an integrated circuit containing logic transistors and an array of SRAM cells in which the SRAM cells are formed in a top semiconductor layer with one crystal orientation and the logic transistors are formed in an epitaxial semiconductor layer with another crystal orientation.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: September 17, 2013
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Publication number: 20130229859
    Abstract: An integrated circuit with SRAM cells containing dual passgate transistors and a read buffer, all connected to one word line is disclosed. The read buffer and one passgate transistor may be variously configured to a separate read data line and write data line, or a combined data line, in different embodiments. The read buffer in addressed SRAM cells may be biased during read operations. The read buffer in half-addressed SRAM cells may be biased or floated, depending on the configuration of the read data line and the write data line. The read buffer in addressed and half-addressed SRAM cells may be biased or floated, depending on the configuration of the read data line and the write data line.
    Type: Application
    Filed: April 19, 2013
    Publication date: September 5, 2013
    Applicant: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8492205
    Abstract: An array with cells that have adjacent similar structures that are displaced from each other across a common cell border in a direction that is not perpendicular to the cell border thus avoiding an across cell border design rule violation between the adjacent similar structures. A method of forming reduced area memory arrays by moving adjacent similar structures that is not perpendicular to a fully identical common cell border. A method of building arrays using conventional array building software by forming unit pairs with cells that are not identical and are not mirror images or rotated versions of each other.
    Type: Grant
    Filed: July 21, 2010
    Date of Patent: July 23, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Theodore W. Houston, Robert R. Garcia
  • Publication number: 20130128680
    Abstract: A memory circuit includes a bit cell that receives a word line, complementary bit lines and an array supply voltage; a word line driver coupled to the word line, the word line driver receiving one of the array supply voltage and a periphery supply voltage; and a word line suppression circuit coupled to the word line. The word line suppression circuit includes a diode and a switch coupled in series. The switch is responsive to the array supply voltage. The word line suppression circuit limits a word line voltage to a value lower than the array supply voltage such that the static noise margin (SNM) of the bit cell is increased.
    Type: Application
    Filed: November 17, 2011
    Publication date: May 23, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Lakshmikantha V. Holla, Vinod J. Menezes, Theodore W. Houston, Michael Patrick Clinton
  • Patent number: 8437214
    Abstract: A memory array has a memory cell that comprises a storage element storing a logical state at a reduced voltage during at least one functional operation and a write access circuit configured to connect the storage element to at least a first write bit line in response to a write signal on the write word line for writing the logical state to the memory cell. The memory cell further comprises a read access circuit including an input node connected to the storage element and an output node connected to a read bit line of the memory array. The read access circuit is enabled and configured to read the logic state of the storage element in response to a read signal on the read word line. The reduced voltage is reduced relative to an operating voltage of at least one peripheral circuit associated with reading and/or writing of the memory cell.
    Type: Grant
    Filed: July 17, 2012
    Date of Patent: May 7, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Donald Mikan, Hugh Mair, Theodore W. Houston, Michael Patrick Clinton
  • Patent number: 8437213
    Abstract: Embodiments of the present disclosure provide an integrated circuit including a functional memory and methods of characterizing a component or a defect of a memory cell in the functional memory. In one embodiment, the functional memory includes row and column periphery units having periphery sourcing and sinking voltage supply ports, an array of memory cells organized in rows and columns and a word line controlled by a word line driver that provides row access to a memory cell of the array. Additionally, the functional memory also includes a bit line controlled by a direct bit line access circuit that provides direct bit line access to the memory cell through a bit line analog access port and an independent voltage supply port.
    Type: Grant
    Filed: December 31, 2008
    Date of Patent: May 7, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Xiaowei Deng, Wah K. Loh, Theodore W. Houston
  • Patent number: 8379434
    Abstract: A first integrated circuit containing a single sided write SRAM cell array, each SRAM cell having a bit passgate and an auxiliary bit-bar driver transistor. A process of operating the first integrated circuit including a single sided read operation in which source nodes of the auxiliary drivers in both addressed cells and half-addressed cells are floated. A second integrated circuit containing an SRAM cell array, in which each SRAM cell includes a bit-side write passgate, a bit-bar-side read passgate and a bit-bar auxiliary driver transistor. A process of operating the second integrated circuit including a single sided read operation in which source nodes of the auxiliary drivers in both addressed cells and half-addressed cells are biased to a low bias voltage.
    Type: Grant
    Filed: May 19, 2010
    Date of Patent: February 19, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Theodore W. Houston, Anand Seshadri
  • Patent number: 8380478
    Abstract: Semiconductor fabrication using statistical analysis (400) to determine the robustness or reliability of a fabricated integrated circuit module given global and local variations of operating parameters of elements, such as transistors, of the module. Multiple sequences of statistical simulations (408, 414) are run to ascertain (416) the robustness of the module to local variations in an environment of global variations.
    Type: Grant
    Filed: June 7, 2004
    Date of Patent: February 19, 2013
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8379433
    Abstract: A 3T DRAM cell includes a first transistor having a first control element connected as a storage node and a second transistor connected between the first transistor and a read bit line having a second control element connected to a read word line. The 3T DRAM cell also includes a third transistor connected between the storage node and a write bit line having a third control element connected to a write word line. Additionally, the DRAM cell includes a supplemental capacitance connected to the storage node and configured to extend a refresh interval of the 3T DRAM cell. A method of operating an integrated circuit having a 3T DRAM cell includes providing a memory state on a storage node of the 3T DRAM cell and extending a refresh interval of the memory state with a supplemental capacitance added to the storage node.
    Type: Grant
    Filed: September 15, 2010
    Date of Patent: February 19, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Theodore W. Houston, Makarand R. Kulkarni, James (Hsu-Hsuan) Lan
  • Patent number: 8378405
    Abstract: A capacitor under bitline DRAM memory cell and method for its fabrication provides a high density memory cell with the capacitor formed in the PMD layer. The memory cell utilizes several variations of storage contact pillar structures as, for example, a storage plate of the memory cell capacitor formed within a trench in the PMD layer. This capacitor plate structure is overlaid with a capacitor dielectric layer which is overlaid with another conductive layer, for example, the M1 layer to form the other capacitor plate. An access transistor formed between substrate active regions and a word line, is in electrical communication with a bit line contact, the storage contact capacitor plate, and the word line respectively. The high density memory cell benefits from the simple standard processes common to logic processes, and in one embodiment requiring only one additional masking step.
    Type: Grant
    Filed: September 19, 2003
    Date of Patent: February 19, 2013
    Assignee: Texas Instruments Incorporated
    Inventor: Theodore W. Houston
  • Patent number: 8379467
    Abstract: Integrated circuit for performing test operation of static RAM bit and for measuring the read margin, write margin, and stability margin of SRAM bits with operational circuitry that includes effects of the SRAM array architecture and circuit design. In addition, the integrated circuit has a built-in self-test circuit for measuring the read margin, write margin, and stability margin of SRAM that excludes the effects of SRAM array architecture and circuit design.
    Type: Grant
    Filed: March 8, 2011
    Date of Patent: February 19, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Xiaowei Deng, Theodore W. Houston, Wah Kit Loh
  • Patent number: 8379435
    Abstract: An integrated circuit containing an array of SRAM cells with NMOS drivers and passgates, and an n-well bias control circuit which biases n-wells in each SRAM column independently. An integrated circuit containing an array of SRAM cells with PMOS drivers and passgates, and a p-well bias control circuit which biases p-wells in each SRAM column independently. A process of operating an integrated circuit containing an array of SRAM cells with NMOS drivers and passgates, and an n-well bias control circuit which biases n-wells in each SRAM column independently.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: February 19, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Russell C. McMullan, Theodore W. Houston
  • Publication number: 20130003471
    Abstract: A memory array has a memory cell that comprises a storage element storing a logical state at a reduced voltage during at least one functional operation and a write access circuit configured to connect the storage element to at least a first write bit line in response to a write signal on the write word line for writing the logical state to the memory cell. The memory cell further comprises a read access circuit including an input node connected to the storage element and an output node connected to a read bit line of the memory array. The read access circuit is enabled and configured to read the logic state of the storage element in response to a read signal on the read word line. The reduced voltage is reduced relative to an operating voltage of at least one peripheral circuit associated with reading and/or writing of the memory cell.
    Type: Application
    Filed: July 17, 2012
    Publication date: January 3, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Donald George Mikan, JR., Hugh Mair, Theodore W. Houston, Michael Patrick Clinton
  • Patent number: 8339839
    Abstract: A first integrated circuit containing a single sided write SRAM cell array, each SRAM cell having a bit passgate and an auxiliary bit-bar driver transistor. A process of operating the first integrated circuit including a single sided read operation in which source nodes of the auxiliary drivers in both addressed cells and half-addressed cells are floated. A second integrated circuit containing an SRAM cell array, in which each SRAM cell includes a bit-side write passgate, a bit-bar-side read passgate and a bit-bar auxiliary driver transistor. A process of operating the second integrated circuit including a single sided read operation in which source nodes of the auxiliary drivers in both addressed cells and half-addressed cells are biased to a low bias voltage.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: December 25, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Theodore W. Houston, Anand Seshadri
  • Patent number: 8331187
    Abstract: The present invention describes circuitry and a method of providing a low power WRITE mode of operation for an integrated circuit comprising an SRAM memory to provide a reduced IDDQ relative to the IDDQ of a full active mode. In one aspect, the circuitry includes an SRAM memory array, mode control circuitry coupled to the array and configured to alter a supply voltage level to the SRAM array based on a mode of operation. The circuitry also includes control inputs coupled to the mode control circuitry for selecting one of the low power write mode, the full active mode, and optionally a retention mode of operation. The mode control circuitry is configured to receive the control inputs to select one of the three modes of operation, and to alter one or more supply voltage levels to the array, for example, the Vss supply voltage using a Vss supply circuit and the Vdd supply voltage using a Vdd supply circuit, based on the selected mode of operation.
    Type: Grant
    Filed: February 12, 2009
    Date of Patent: December 11, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Theodore W. Houston, Michael P Clinton, Bryan D Sheffield