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).
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Patent number: 8755239Abstract: 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: GrantFiled: November 17, 2011Date of Patent: June 17, 2014Assignee: Texas Instruments IncorporatedInventors: Lakshmikantha V. Holla, Vinod J. Menezes, Theodore W. Houston, Michael Patrick Clinton
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Patent number: 8724375Abstract: 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: GrantFiled: February 4, 2013Date of Patent: May 13, 2014Assignee: Texas Instruments IncorporatedInventors: Anand Seshadri, Theodore W. Houston
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Patent number: 8654569Abstract: 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: GrantFiled: April 5, 2011Date of Patent: February 18, 2014Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8654572Abstract: 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: GrantFiled: March 6, 2012Date of Patent: February 18, 2014Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8654568Abstract: 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: GrantFiled: August 24, 2009Date of Patent: February 18, 2014Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8535990Abstract: 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: GrantFiled: December 21, 2010Date of Patent: September 17, 2013Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Publication number: 20130229859Abstract: 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: ApplicationFiled: April 19, 2013Publication date: September 5, 2013Applicant: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8492205Abstract: 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: GrantFiled: July 21, 2010Date of Patent: July 23, 2013Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Robert R. Garcia
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Publication number: 20130128680Abstract: 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: ApplicationFiled: November 17, 2011Publication date: May 23, 2013Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Lakshmikantha V. Holla, Vinod J. Menezes, Theodore W. Houston, Michael Patrick Clinton
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Patent number: 8437214Abstract: 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: GrantFiled: July 17, 2012Date of Patent: May 7, 2013Assignee: Texas Instruments IncorporatedInventors: Donald Mikan, Hugh Mair, Theodore W. Houston, Michael Patrick Clinton
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Patent number: 8437213Abstract: 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: GrantFiled: December 31, 2008Date of Patent: May 7, 2013Assignee: Texas Instruments IncorporatedInventors: Xiaowei Deng, Wah K. Loh, Theodore W. Houston
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Patent number: 8379434Abstract: 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: GrantFiled: May 19, 2010Date of Patent: February 19, 2013Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Anand Seshadri
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Patent number: 8380478Abstract: 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: GrantFiled: June 7, 2004Date of Patent: February 19, 2013Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8379433Abstract: 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: GrantFiled: September 15, 2010Date of Patent: February 19, 2013Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Makarand R. Kulkarni, James (Hsu-Hsuan) Lan
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Patent number: 8378405Abstract: 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: GrantFiled: September 19, 2003Date of Patent: February 19, 2013Assignee: Texas Instruments IncorporatedInventor: Theodore W. Houston
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Patent number: 8379467Abstract: 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: GrantFiled: March 8, 2011Date of Patent: February 19, 2013Assignee: Texas Instruments IncorporatedInventors: Xiaowei Deng, Theodore W. Houston, Wah Kit Loh
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Patent number: 8379435Abstract: 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: GrantFiled: July 22, 2009Date of Patent: February 19, 2013Assignee: Texas Instruments IncorporatedInventors: Russell C. McMullan, Theodore W. Houston
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Publication number: 20130003471Abstract: 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: ApplicationFiled: July 17, 2012Publication date: January 3, 2013Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Donald George Mikan, JR., Hugh Mair, Theodore W. Houston, Michael Patrick Clinton
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Patent number: 8339839Abstract: 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: GrantFiled: January 31, 2012Date of Patent: December 25, 2012Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Anand Seshadri
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Patent number: 8331187Abstract: 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: GrantFiled: February 12, 2009Date of Patent: December 11, 2012Assignee: Texas Instruments IncorporatedInventors: Theodore W. Houston, Michael P Clinton, Bryan D Sheffield