Patents by Inventor Ken W. Marr

Ken W. Marr 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: 6934209
    Abstract: A T-RAM memory cell includes a temperature compensation device to adjust the gate-to-source voltage of an access transistor for the memory cell as a function of temperature so that the sub-threshold current of the transistor is insensitive to temperature variations. As a result, the sub-threshold current can be maintained slightly above the holding current of a thyristor used in the memory cell despite substantial temperature variations. In one embodiment, the temperature compensation device includes a current source directing a fixed current through a diode-connected transistor of the type used as the memory cell access transistor. Temperature induced changes in a reference voltage generated at the junction between the current source and the transistor therefore match the temperature induced changed in the sub-threshold current of the access transistor.
    Type: Grant
    Filed: March 31, 2003
    Date of Patent: August 23, 2005
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6829156
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: December 7, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6781907
    Abstract: A T-RAM memory cell includes a temperature compensation device to adjust the gate-to-source voltage of an access transistor for the memory cell as a function of temperature so that the sub-threshold current of the transistor is insensitive to temperature variations. As a result, the sub-threshold current can be maintained slightly above the holding current of a thyristor used in the memory cell despite substantial temperature variations. In one embodiment, the temperature compensation device includes a current source directing a fixed current through a diode-connected transistor of the type used as the memory cell access transistor. Temperature induced changes in a reference voltage generated at the junction between the current source and the transistor therefore match the temperature induced changed in the sub-threshold current of the access transistor.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: August 24, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6731546
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: May 4, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6717866
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: April 6, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6717867
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: April 6, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6707707
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: March 16, 2004
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Publication number: 20030227790
    Abstract: A T-RAM memory cell includes a temperature compensation device to adjust the gate-to-source voltage of an access transistor for the memory cell as a function of temperature so that the sub-threshold current of the transistor is insensitive to temperature variations. As a result, the sub-threshold current can be maintained slightly above the holding current of a thyristor used in the memory cell despite substantial temperature variations. In one embodiment, the temperature compensation device includes a current source directing a fixed current through a diode-connected transistor of the type used as the memory cell access transistor. Temperature induced changes in a reference voltage generated at the junction between the current source and the transistor therefore match the temperature induced changed in the sub-threshold current of the access transistor.
    Type: Application
    Filed: March 31, 2003
    Publication date: December 11, 2003
    Inventor: Ken W. Marr
  • Publication number: 20030227792
    Abstract: A T-RAM memory cell includes a temperature compensation device to adjust the gate-to-source voltage of an access transistor for the memory cell as a function of temperature so that the sub-threshold current of the transistor is insensitive to temperature variations. As a result, the sub-threshold current can be maintained slightly above the holding current of a thyristor used in the memory cell despite substantial temperature variations. In one embodiment, the temperature compensation device includes a current source directing a fixed current through a diode-connected transistor of the type used as the memory cell access transistor. Temperature induced changes in a reference voltage generated at the junction between the current source and the transistor therefore match the temperature induced changed in the sub-threshold current of the access transistor.
    Type: Application
    Filed: June 6, 2002
    Publication date: December 11, 2003
    Inventor: Ken W. Marr
  • Publication number: 20030133342
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Application
    Filed: January 21, 2003
    Publication date: July 17, 2003
    Inventor: Ken W. Marr
  • Publication number: 20030133343
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Application
    Filed: January 21, 2003
    Publication date: July 17, 2003
    Inventor: Ken W. Marr
  • Publication number: 20030133341
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Application
    Filed: January 21, 2003
    Publication date: July 17, 2003
    Inventor: Ken W. Marr
  • Publication number: 20030128595
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Application
    Filed: January 21, 2003
    Publication date: July 10, 2003
    Inventor: Ken W. Marr
  • Publication number: 20030117833
    Abstract: A power-up circuit for an SRAM, particularly a loadless 4-T SRAM cell having PMOS access transistors. The power-up circuit disables a current path to the digit lines in an array of SRAM cells during power-up of the SRAM. As a result, the SRAM cells cannot draw power from the digit lines during power-up if voltages on word lines in the array during power-up cause access transistors for the SRAM cells to become conductive.
    Type: Application
    Filed: December 21, 2001
    Publication date: June 26, 2003
    Inventor: Ken W. Marr
  • Patent number: 6496422
    Abstract: The present invention is a current-mirror-based bias generator for a load less four transistor SRAM as well as associated methods of controlling or modifying the current conducted by the access transistors of such an SRAM. The present invention may be thought of as an adjustable temperature coefficient, bias generator that references, via a current mirror, a reference bank of SRAM cells. The bank of reference cells provides an indication of the necessary conduction characteristics (e.g., gate to source voltage) of the access transistors under various conditions. By applying a bias voltage to the word line the desired current is sourced from the digit line. The bank of reference SRAM cells inherently compensates for process variations. The adjustable temperature coefficient bias generator allows the current sourced by the digit lines to vary greatly as a result of temperature variations. Thus, the present invention compensates for both process variations and temperature variations.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: December 17, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6388933
    Abstract: The present invention is a current-mirror-based bias generator for a load less four transistor SRAM as well as associated methods of controlling or modifying the current conducted by the access transistors of such an SRAM. The present invention may be thought of as an adjustable temperature coefficient, bias generator that references, via a current mirror, a reference bank of SRAM cells. The bank of reference cells provides an indication of the necessary conduction characteristics (e.g., gate to source voltage) of the access transistors under various conditions. By applying a bias voltage to the word line the desired current is sourced from the digit line. The bank of reference SRAM cells inherently compensates for process variations. The adjustable temperature coefficient bias generator allows the current sourced by the digit lines to vary greatly as a result of temperature variations. Thus, the present invention compensates for both process variations and temperature variations.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: May 14, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6373756
    Abstract: The present invention is a current-mirror-based bias generator for a load less four transistor SRAM as well as associated methods of controlling or modifying the current conducted by the access transistors of such an SRAM. The present invention may be thought of as an adjustable temperature coefficient, bias generator that references, via a current mirror, a reference bank of SRAM cells. The bank of reference cells provides an indication of the necessary conduction characteristics (e.g., gate to source voltage) of the access transistors under various conditions. By applying a bias voltage to the word line the desired current is sourced from the digit line. The bank of reference SRAM cells inherently compensates for process variations. The adjustable temperature coefficient bias generator allows the current sourced by the digit lines to vary greatly as a result of temperature variations. Thus, the present invention compensates for both process variations and temperature variations.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: April 16, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6337813
    Abstract: The present invention is a current-mirror-based bias generator for a load less four transistor SRAM as well as associated methods of controlling or modifying the current conducted by the access transistors of such an SRAM. The present invention may be thought of as an adjustable temperature coefficient, bias generator that references, via a current mirror, a reference bank of SRAM cells. The bank of reference cells provides an indication of the necessary conduction characteristics (e.g., gate to source voltage) of the access transistors under various conditions. By applying a bias voltage to the word line the desired current is sourced from the digit line. The bank of reference SRAM cells inherently compensates for process variations. The adjustable temperature coefficient bias generator allows the current sourced by the digit lines to vary greatly as a result of temperature variations. Thus, the present invention compensates for both process variations and temperature variations.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: January 8, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Publication number: 20010054740
    Abstract: An apparatus includes a first doped region, a first doped well, a first doped plug, a second doped plug, and an isolation structure. The first doped well is disposed within the first doped region. The first doped plug is disposed within the first doped well. The second doped plug is disposed within the first doped region. The isolation structure is disposed between the first and second doped plugs. A method includes providing a first doped region. A first doped well is formed within the first doped region, and a first doped plug is formed within the first doped well. A second doped plug is formed within the first doped region, and an isolation structure is formed between the first and second doped plugs.
    Type: Application
    Filed: August 20, 2001
    Publication date: December 27, 2001
    Applicant: Micron Technology, Inc.
    Inventor: Ken W. Marr
  • Patent number: 6330195
    Abstract: The present invention is a current-mirror-based bias generator for a load less four transistor SRAM as well as associated methods of controlling or modifying the current conducted by the access transistors of such an SRAM. The present invention may be thought of as an adjustable temperature coefficient, bias generator that references, via a current mirror, a reference bank of SRAM cells. The bank of reference cells provides an indication of the necessary conduction characteristics (e.g., gate to source voltage) of the access transistors under various conditions. By applying a bias voltage to the word line the desired current is sourced from the digit line. The bank of reference SRAM cells inherently compensates for process variations. The adjustable temperature coefficient bias generator allows the current sourced by the digit lines to vary greatly as a result of temperature variations. Thus, the present invention compensates for both process variations and temperature variations.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: December 11, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Ken W. Marr