Patents by Inventor Nagesh Challa

Nagesh Challa 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: 5323351
    Abstract: A method of controllably programming an electrically erasable programmable read only memory comprises the step of erasing a group of memory cells of the memory into a high threshold state. The group including data cells and monitor cells. The data cells of the group are programmed in accordance with data presented to the memory, and the monitor cells of the group are programmed to a low threshold state. The threshold voltage of the monitor cells is sampled, and the monitor cell programming step and the sampling step are repeated until an excessively low threshold voltage is sampled. If the sampling is done with a sampling voltage higher than the read voltage, the cell threshold voltage generally is not excessive. In any event, an excessively low threshold is raised by a controlled erasure.
    Type: Grant
    Filed: June 10, 1992
    Date of Patent: June 21, 1994
    Assignee: Nexcom Technology, Inc.
    Inventor: Nagesh Challa
  • Patent number: 5297081
    Abstract: A memory (1) operative in an erase mode, a program mode, or a read mode includes a memory cell array, word lines (30, 40, 50, 60), a row decoder (9) connected to the word lines, bit lines (2, 4, 6, 8), a precharge circuit (70, 72, 74, 76, 78, 80) connected to the bit lines, a load circuit (22, 23, 24, 25, 26, 27, 28, 29) connected to the bit lines, and a sense circuit (12, 14, 16, 18) connected to the bit lines. The memory array includes both floating gate MOSFET transistors and switch MOSFET transistors arranged in groups associated with respective subsets of word lines and bit lines.
    Type: Grant
    Filed: June 10, 1992
    Date of Patent: March 22, 1994
    Assignee: Nexcom Technology, Inc.
    Inventor: Nagesh Challa
  • Patent number: 5291584
    Abstract: A magnetic media hard disk is emulated in a solid state hard disk having a disk controller, a data buffer, a microcontroller, and a disk emulator section. The disk emulator section includes a disk emulator interface and a memory array. The architecture of the memory array includes a number of memory banks which typically correspond to respective sectors of the emulated hard disk, but could correspond to respective groups of sectors of the emulated hard disk. Each of the memory banks has its own serial data line and its own serial clock line, and include a number of serial memory devices that connect to the bank serial data line and bank clock line with respective serial data and clock lines. Each of the serial memory devices also has a static address corresponding to a head address of the emulated hard disk.
    Type: Grant
    Filed: July 23, 1991
    Date of Patent: March 1, 1994
    Assignee: Nexcom Technology, Inc.
    Inventors: Nagesh Challa, Michel E. Gannage
  • Patent number: 5222040
    Abstract: A single-transistor non-volatile memory cell MOS transistor with a floating gate and a control gate using two levels of polysilicon and a tunnel dielectric that overlaps the drain area wherein a tunneling of charge can take place between the drain and the floating gate by means of a system of applied voltages to the control gate and drain.
    Type: Grant
    Filed: December 11, 1990
    Date of Patent: June 22, 1993
    Assignee: Nexcom Technology, Inc.
    Inventor: Nagesh Challa
  • Patent number: 5197027
    Abstract: A single-transistor EEPROM device of the present invention comprises memory transistors in banks similar to NAND structures wherein the control gates of the memory transistors have negative voltages applied in various modes that allow reading, writing, and programming regardless of the V.sub.th of nonselected memory transistors in a bank. Programming and erasing results from various combinations of negative and positive voltages are used on the select gates together with positive voltages less than that alone which is necessary to induce Fowler-Nordheim tunneling are applied to the bit lines.
    Type: Grant
    Filed: January 24, 1991
    Date of Patent: March 23, 1993
    Assignee: Nexcom Technology, Inc.
    Inventor: Nagesh Challa