Patents by Inventor Waseem Ahmad

Waseem Ahmad 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: 6397158
    Abstract: A method for determining the value of at least one capacitance required to be placed in a conductive path on a printed circuit board is disclosed. The method includes preparing a desired signal spectrum for the conductive path, preparing an actual signal spectrum for the conductive path, and then comparing the actual signal spectrum against the desired signal spectrum to determine where any out of tolerance conditions exist. If the actual signal spectrum is in amplitude versus time form, the method further includes performing, for each time having a voltage which is higher than the maximum voltage allowed on the conductive path, a fourier transform on the amplitude versus time data.
    Type: Grant
    Filed: April 29, 1999
    Date of Patent: May 28, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Waseem Ahmad, Kazi M. Hassan
  • Patent number: 6150843
    Abstract: A 5 volt tolerant I/O buffer circuit is coupled to a power supply terminal of a predetermined power supply voltage, for driving an I/O pad to a logic state depending on an input signal and an output enable signal. The I/O buffer circuit minimizes current flow into the power supply terminal when the pad is coupled to a voltage greater than the predetermined power supply voltage. A driver transistor of a first type is formed within a diffusion well and is coupled to the predetermined power supply voltage and to the pad. First and second terminals of a protection transistor are coupled to respective ones of the predetermined power supply voltage and the diffusion well. Circuitry is provided for, when the output enable signal is active, turning on the protection transistor so as to couple the predetermined power supply voltage to the diffusion well, regardless of a voltage level of the pad. A single protection transistor is sufficient to prevent current leakage through the parasitic PN diode.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: November 21, 2000
    Assignee: VLSI Technology, Inc.
    Inventors: James D. Shiffer, Waseem Ahmad
  • Patent number: 6018450
    Abstract: A output driving circuit having an output driving element, an overshoot protection mechanism, and an undershoot protection mechanism. When the overshoot protection mechanism senses an overshoot voltage at the output terminal of the output driving element, it raises the voltage at the control terminal of the output driving element. This serves to maintain the voltage between the output terminal and the control terminal of the output driving element within a safe range, thereby preventing overstress or damage to the element. When the undershoot protection mechanism senses an undershoot voltage at the output terminal of the output driving element, it lowers the voltage at the control terminal of the output driving element. This serves to maintain the voltage between the output terminal and the control terminal of the output driving element within a safe range, which in turn prevents overstress and damage to the element.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: January 25, 2000
    Assignee: Sun Microsystems, Inc.
    Inventors: Waseem Ahmad, Raoul B. Salem
  • Patent number: 5864243
    Abstract: A mixed voltage compatible buffer having reduced power consumption is provided. One embodiment of the buffer according to the present invention comprises: a data input configured to receive an output data signal; a data interface configured to couple with a pad interconnect; an output driver coupled with said data interface and being configured to apply the output data signal thereto; and a data controller intermediate said data input and said output driver, said data controller being configured to apply a plurality of control signals of substantially equal voltage to said output driver to control the operation thereof responsive to the output data signal received via said data input. The present invention also provides for a method of transferring data within the buffer.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: January 26, 1999
    Assignee: VLSI Technology, Inc.
    Inventors: Deng-Yuan David Chen, Waseem Ahmad