Patents by Inventor Richard S. Lewison

Richard S. Lewison 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).

  • Delta-sigma pulse width modulator control circuit
    Patent number: 5933453
    Abstract: A delta sigma pulse width modulator control circuit uses a delta sigma modulator as a first stage to create a sequence of pulses representing an input control signal. A pulse width modulator accumulates the sequence of pulses and defines a pulse width modulated output signal from the accumulated pulses. The pulse width modulated signal is given a randomly generated offset to the time of pulse value transition and an adjacent pulse value matching technique is used to reduce harmonically related noise generation.
    Type: Grant
    Filed: April 29, 1997
    Date of Patent: August 3, 1999
    Assignee: Hewlett-Packard Company
    Inventor: Richard S. Lewison
  • Delta-sigma pulse width modulator control circuit
    Patent number: 5901176
    Abstract: A delta sigma pulse width modulator control circuit uses a delta sigma modulator as a first stage to create a sequence of pulses representing an input control signal. A pulse width modulator weighs each pulse, accumulates the sequence of weighted pulses and defines a pulse width modulated output signal from the accumulated pulses. The pulse width modulated signal is given a randomly generated offset to the time of pulse value transition and an adjacent pulse value matching technique is used to reduce harmonically related noise generation.
    Type: Grant
    Filed: October 16, 1997
    Date of Patent: May 4, 1999
    Assignee: Hewlett-Packard Company
    Inventor: Richard S. Lewison