Patents by Inventor Randy T. Heilman

Randy T. Heilman 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).

  • Method of overtone selection and level control in an integrated circuit CMOS negative resistance oscillator to achieve low jitter
    Patent number: 6933793
    Abstract: A stable high-frequency clock pulse apparatus and method including frequency source, overtone crystal unit coupled with a negative resistance oscillator, a bandpass overtone filter and a drive level control is provided. The apparatus can include a frequency multiplier. The frequency source can be a micromechanical resonator.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: August 23, 2005
    Assignee: Vitesse Semiconductor Corporation
    Inventors: Raymond B. Patterson, III, Randy T. Heilman
  • Method of controlling the turn off characteristics of a VCSEL diode
    Patent number: 6683896
    Abstract: A drive circuitry that drives a vertical cavity surface emitting laser is provided. The drive circuitry includes a modulator, a negative peak timer and a limiter. The negative peak timer causes the modulator to rapidly decrease the magnitude of the output signal of the modulator to dissipate charge stored on the laser. Thus, the vertical cavity surface emitting laser quickly turns off.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: January 27, 2004
    Assignee: Vitesse Semiconductor Corporation
    Inventors: Randy T. Heilman, Taewon Jung, Raymond B. Patterson, III
  • Method of controlling the turn off characteristics of a VCSEL diode
    Publication number: 20020094000
    Abstract: A drive circuitry that drives a vertical cavity surface emitting laser is provided. The drive circuitry includes a modulator, a negative peak timer and a limiter. The negative peak timer causes the modulator to rapidly decrease the magnitude of the output signal of the modulator to dissipate charge stored on the laser. Thus, the vertical cavity surface emitting laser quickly turns off.
    Type: Application
    Filed: March 12, 2002
    Publication date: July 18, 2002
    Inventors: Randy T. Heilman, Taewon Jung, Raymond B. Patterson
  • Fast turn-off of thyristor structure
    Patent number: 5086242
    Abstract: A fast turn-off thyristor including a first active shunt region in the cathode gate region connected electrically to the anode terminal for shunting carriers around the anode gate region in response to the thyristor being on and a second shunt region in the anode gate region connected electrically to the cathode terminal for shunting carriers around the cathode gate region in response to the thyristor being on. These active shunts are inactive until the thyristor is turned on and are structured to remain active until after the thyristor is turned off. The active shunts are transistors in parallel with the pair of interconnected transistors which are for a PNPN thyristor.
    Type: Grant
    Filed: October 16, 1990
    Date of Patent: February 4, 1992
    Assignee: Harris Corporation
    Inventors: Randy T. Heilman, John S. Prentice