Patents by Inventor Todd Alan Christensen

Todd Alan Christensen 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).

  • Publication number: 20090108457
    Abstract: A first through via is electrically insulated from surrounding wafer substrate material. A second through via is not electrically insulated from the surrounding wafer substrate material. This configuration is advantageous when the non-insulated via serves as the path for either Vdd or GND. By not insulating the through via, a first supply voltage (Vdd or GND) is allowed to flow through the surrounding wafer substrate material thereby decreasing the resistance of the first supply voltage path.
    Type: Application
    Filed: October 31, 2007
    Publication date: April 30, 2009
    Inventors: Todd Alan Christensen, John Edward Sheets, II
  • Patent number: 7525367
    Abstract: A low power level shifter circuit includes an input inverter operating in a domain of a first voltage supply. The input inverter receives an input signal and provides a first inverted signal. An output inverter operating in a domain of a second voltage supply coupled to the input inverter and provides an output signal having a voltage level corresponding to the second voltage supply and a logic value corresponding to the input signal. The second voltage supply is higher than the first voltage supply. A leakage current control circuit includes a finisher transistor connected between the second voltage supply and the input to the output inverter and a path control transistor control a path between the first voltage supply and the input inverter.
    Type: Grant
    Filed: October 5, 2006
    Date of Patent: April 28, 2009
    Assignee: International Business Machines Corporation
    Inventors: Derick Gardner Behrends, Todd Alan Christensen, Travis Reynold Hebig
  • Publication number: 20090027945
    Abstract: A method and apparatus including a static random access memory (SRAM) cell implement an enhanced SRAM read performance sort ring oscillator (PSRO), and a design structure on which the subject circuit resides is provided. A pair of parallel reverse polarity connected inverters defines a static latch or cross-coupled memory cell. The SRAM cell includes independent left and right wordlines providing a respective gate input to a pair of access transistors used to access to the memory cell. The SRAM cell includes a voltage supply connection to one side of the static latch. For example, a complement side of the static latch is connected to the voltage supply. A plurality of the SRAM cells is assembled together to form a SRAM base block. A plurality of the SRAM base blocks is connected together to form the SRAM read PSRO.
    Type: Application
    Filed: October 17, 2007
    Publication date: January 29, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chad Allen Adams, Todd Alan Christensen, Travis Reynold Hebig, Kirk David Peterson
  • Publication number: 20090027946
    Abstract: A method and apparatus including a static random access memory (SRAM) cell implement an enhanced SRAM read performance sort ring oscillator (PSRO). A pair of parallel reverse polarity connected inverters defines a static latch or cross-coupled memory cell. The SRAM cell includes independent left and right wordlines providing a respective gate input to a pair of access transistors used to access to the memory cell. The SRAM cell includes a voltage supply connection to one side of the static latch. For example, a complement side of the static latch is connected to the voltage supply. A plurality of the SRAM cells is assembled together to form a SRAM base block. A plurality of the SRAM base blocks is connected together to form the SRAM read PSRO.
    Type: Application
    Filed: July 25, 2007
    Publication date: January 29, 2009
    Inventors: Chad Allen Adams, Todd Alan Christensen, Travis Reynold Hebig, Kirk David Peterson
  • Patent number: 7480170
    Abstract: A method and apparatus including a static random access memory (SRAM) cell implement an enhanced SRAM read performance sort ring oscillator (PSRO). A pair of parallel reverse polarity connected inverters defines a static latch or cross-coupled memory cell. The SRAM cell includes independent left and right wordlines providing a respective gate input to a pair of access transistors used to access to the memory cell. The SRAM cell includes a voltage supply connection to one side of the static latch. For example, a complement side of the static latch is connected to the voltage supply. A plurality of the SRAM cells is assembled together to form a SRAM base block. A plurality of the SRAM base blocks is connected together to form the SRAM read PSRO.
    Type: Grant
    Filed: July 25, 2007
    Date of Patent: January 20, 2009
    Assignee: International Business Machines Corporation
    Inventors: Chad Allen Adams, Todd Alan Christensen, Travis Reynold Hebig, Kirk David Peterson
  • Publication number: 20080273402
    Abstract: A method and apparatus implementing domino static random access memory (SRAM) leakage current reduction include a local evaluation circuit coupled to true and complement bit lines of a pair of local SRAM cell groups, receives precharge signals and provides an output connected to a global dot line. A sleep input is applied to SRAM sleep logic and a write driver including sleep control. Data true and data complement outputs of the write driver are forced to a respective selected level to discharge the bit lines and global dot lines when the sleep input transitions high. Discharging the bit lines and global dot lines is implemented through gating in the write driver without requiring any additional devices in the local evaluation circuit.
    Type: Application
    Filed: June 23, 2008
    Publication date: November 6, 2008
    Applicant: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Elizabeth Lair Gerhard, Omer Heymann, Amira Rozenfeld
  • Patent number: 7414878
    Abstract: A method and apparatus implementing domino static random access memory (SRAM) leakage current reduction include a local evaluation circuit coupled to true and complement bit lines of a pair of local SRAM cell groups, receives precharge signals and provides an output connected to a global dot line. A sleep input is applied to SRAM sleep logic and a write driver including sleep control. Data true and data complement outputs of the write driver are forced to a respective selected level to discharge the bit lines and global dot lines when the sleep input transitions high. Discharging the bit lines and global dot lines is implemented through gating in the write driver without requiring any additional devices in the local evaluation circuit.
    Type: Grant
    Filed: May 4, 2007
    Date of Patent: August 19, 2008
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Elizabeth Lair Gerhard, Omer Heymann, Amira Rozenfeld
  • Publication number: 20080084231
    Abstract: A low power level shifter circuit for integrated circuits, and a design structure on which the subject circuit resides are provided. The low power level shifter circuit includes an input inverter operating in a domain of a first voltage supply. The input inverter receives an input signal and provides a first inverted signal. An output inverter operating in a domain of a second voltage supply coupled to the input inverter and provides an output signal having a voltage level corresponding to the second voltage supply and a logic value corresponding to the input signal. The second voltage supply is higher than the first voltage supply. A leakage current control circuit includes a finisher transistor connected between the second voltage supply and the input to the output inverter and a path control transistor control a path between the first voltage supply and the input inverter.
    Type: Application
    Filed: October 4, 2007
    Publication date: April 10, 2008
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Derick Gardner Behrends, Todd Alan Christensen, Travis Reynold Hebig
  • Publication number: 20080084237
    Abstract: A low power level shifter circuit includes an input inverter operating in a domain of a first voltage supply. The input inverter receives an input signal and provides a first inverted signal. An output inverter operating in a domain of a second voltage supply coupled to the input inverter and provides an output signal having a voltage level corresponding to the second voltage supply and a logic value corresponding to the input signal. The second voltage supply is higher than the first voltage supply. A leakage current control circuit includes a finisher transistor connected between the second voltage supply and the input to the output inverter and a path control transistor control a path between the first voltage supply and the input inverter.
    Type: Application
    Filed: October 5, 2006
    Publication date: April 10, 2008
    Inventors: Derick Gardner Behrends, Todd Alan Christensen, Travis Reynold Hebig
  • Patent number: 7317217
    Abstract: An apparatus and method are disclosed for an improved semiconductor interconnect scheme using a simplified process. In an embodiment of the apparatus, a polysilicon shape is formed on a silicon area. The polysilicon shape is created having a bridging vertex. When a spacer is created on the polysilicon shape, the spacer width is formed to be small enough near the bridging vertex to allow a silicide bridge to form that creates an electrical coupling between the silicon area and the bridging vertex. Semiconductor devices and circuits are created using the improved semiconductor interconnect scheme using the simplified process.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: January 8, 2008
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Richard Lee Donze, William Paul Hovis, Terrance Wayne Kueper, John Edward Sheets, II
  • Patent number: 7218543
    Abstract: An apparatus and method to improve a cycle time of a Read Only Memory (ROM). Loading of each bit line is controlled such that no bit line has less than a specified loading fraction of a loading of a maximally loaded bit line. No additional space or additional circuitry is required. Four NFET pair arrangements are personalizable by via placement by a designer or design automation program. One of the NFET pair arrangements is usable to pad load on a bit line without altering a logical personalization of the bit line. Proper selection from the four NFET pair arrangements ensure that no bit line has less than the specified loading fraction of the loading of the maximally loaded bit line, as well as providing proper logical personality of the bit line.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: May 15, 2007
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Ryan O'Neal Miller, Phil Paone
  • Patent number: 7206236
    Abstract: Arrays such as SRAMs, DRAMs, CAMs & Programmable ROMs having multiple independent failures are repaired using redundant bit lines. A first embodiment provides redundant bit lines on one side of the array. During a write, data is shifted towards the redundant bit lines on the one side of the array, bypassing failed bit lines. A second embodiment provides a spare bit line on each side of the array. During a write, a first failing bit line is replaced by a first spare bit line on a first side of the array, and a second failing bit line is replaced by a second spare bit line on a second side of the array.
    Type: Grant
    Filed: January 12, 2006
    Date of Patent: April 17, 2007
    Assignee: International Business Machines Corporation
    Inventors: Anthony Gus Aipperspach, Todd Alan Christensen, Elizabeth Lair Gerhard, George Francis Paulik
  • Publication number: 20060087873
    Abstract: A method and a sum addressed content-addressable memory (CAM) compare are provided for implementing an enhanced sum address compare function. True and compliment bit signals applied to the CAM compare are encoded by combining respective ones of the applied true and compliment bit signals. Then the encoded true and compliment bit signals are applied to a critical path dynamic compare circuit. An encoder apparatus encodes true and compliment bit signals that then are applied to the dynamic compare circuit in the critical path.
    Type: Application
    Filed: October 21, 2004
    Publication date: April 27, 2006
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Chad Allen Adams, Derick Gardner Behrends, Todd Alan Christensen, Peter Thomas Freiburger, Ryan Charles Kivimagi
  • Patent number: 7035127
    Abstract: A method and a sum addressed content-addressable memory (CAM) compare are provided for implementing an enhanced sum address compare function. True and compliment bit signals applied to the CAM compare are encoded by combining respective ones of the applied true and compliment bit signals. Then the encoded true and compliment bit signals are applied to a critical path dynamic compare circuit. An encoder apparatus encodes true and compliment bit signals that then are applied to the dynamic compare circuit in the critical path.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: April 25, 2006
    Assignee: International Business Machines Corporation
    Inventors: Chad Allen Adams, Derick Gardner Behrends, Todd Alan Christensen, Peter Thomas Freiburger, Ryan Charles Kivimagi
  • Patent number: 7015600
    Abstract: A pulse generator circuit is disclosed including a delay element coupled to a logic circuit. The delay element receives a clock signal CLK and a signal X and produces a signal XN dependent upon the clock signal CLK and the signal X. The logic circuit receives the clock signal CLK and the signal XN and produces a signal ACLK such that ACLK=CLK·XN?. The signal ACLK may include a series of positive pulses. The delay element may be, for example, one of multiple delay elements coupled in series, and signal X may be an output of a preceding one of the delay elements. A semiconductor device is described including the above pulse generator circuit and a self-resetting logic circuit. The self-resetting logic circuit receives the signal ACLK and one or more input signals and performs a logic operation using the one or more input signals during the positive pulses.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: March 21, 2006
    Assignee: International Business Machines Corporation
    Inventors: Chad Allen Adams, Todd Alan Christensen, Peter Thomas Freiburger
  • Patent number: 6901003
    Abstract: A method, an apparatus, and a computer program are provided to reading indicia from an SRAM cell. A low value is generated on a write true line. A high value is generated on a continuous bit_line. The true node of the SRAM cell is evaluated through use of a floating voltage coupled to the true node of the SRAM cell. If the floating voltage stays substantially constant, the value read from the SRAM cell is a high. If the floating voltage is drained to ground, the value read from the SRAM cell is a low.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: May 31, 2005
    Assignee: International Business Machines Corporation
    Inventors: Chad Allen Adams, Anthony Gus Aipperspach, Todd Alan Christensen, Peter Thomas Freiburger
  • Patent number: 6774734
    Abstract: Circuitry and methods are disclosed for quantitatively characterizing the delay of Embedded Dynamic Random Access Memory (EDRAM) and Dynamic Random Access Memory (DRAM). The performance critical portion of the memory is placed in a ring oscillator designed such that the delay through the portion, from a rising input to the memory to a rising output, can be accurately determined. Recently, such memory elements have begun to be implemented on chips along with high-speed logic circuitry. However, the performance characteristics of the memory elements do not track the performance characteristics of the logic circuitry. The current invention allows the memory performance to be characterized along with, or separately from, characterization of the logic circuitry.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: August 10, 2004
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Terrance Wayne Kueper, John Edward Sheets, II
  • Publication number: 20040100336
    Abstract: Circuitry and methods are disclosed for quantitatively characterizing the delay of Embedded Dynamic Random Access Memory (EDRAM) and Dynamic Random Access Memory (DRAM). The performance critical portion of the memory is placed in a ring oscillator designed such that the delay through the portion, from a rising input to the memory to a rising output, can be accurately determined. Recently, such memory elements have begun to be implemented on chips along with high-speed logic circuitry. However, the performance characteristics of the memory elements do not track the performance characteristics of the logic circuitry. The current invention allows the memory performance to be characterized along with, or separately from, characterization of the logic circuitry.
    Type: Application
    Filed: November 27, 2002
    Publication date: May 27, 2004
    Applicant: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Terrance Wayne Kueper, John Edward Sheets
  • Patent number: 6741493
    Abstract: An improved memory device has a reduced number of wires for carrying local write signals. The improved memory device includes an array of memory cells. A plurality of local true bitlines is coupled to the array of memory cells. A plurality of continuous complement bitlines is coupled to the array of memory cells. The memory device also includes a plurality of write circuits. At least one write circuit is coupled to at least one continuous complement bitline and at least one local true bitline, receives information on a data input from the continuous complement bitline, and controls the local true bitline. At least one local write line is coupled to at least two of the write circuits for providing a write enable signal to the two write circuits.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: May 25, 2004
    Assignee: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Peter Thomas Freiburger
  • Publication number: 20040090817
    Abstract: An improved memory device has a reduced number of wires for carrying local write signals. The improved memory device includes an array of memory cells. A plurality of local true bitlines is coupled to the array of memory cells. A plurality of continuous complement bitlines is coupled to the array of memory cells. The memory device also includes a plurality of write circuits. At least one write circuit is coupled to at least one continuous complement bitline and at least one local true bitline, receives information on a data input from the continuous complement bitline, and controls the local true bitline. At least one local write line is coupled to at least two of the write circuits for providing a write enable signal to the two write circuits.
    Type: Application
    Filed: November 7, 2002
    Publication date: May 13, 2004
    Applicant: International Business Machines Corporation
    Inventors: Todd Alan Christensen, Peter Thomas Freiburger