Patents by Inventor Douglas J. W. MACFARLANE

Douglas J. W. MACFARLANE 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).

  • Publication number: 20250088186
    Abstract: A switching transducer driver operable in: a first mode in which first and second output stage switches are controlled to generate a two-level output signal, wherein an impedance of the first output stage switch is substantially the same as an impedance of the second output stage switch; and a second mode in which the first and second output stage switches and a third switch are controlled to generate a three-level output signal, wherein an impedance of the third switch is substantially greater than the impedance of the first output stage switch and the second output stage switch.
    Type: Application
    Filed: November 15, 2024
    Publication date: March 13, 2025
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: John P. LESSO, Douglas J.W. MACFARLANE
  • Publication number: 20250030387
    Abstract: This application relates to methods and apparatus for switching drivers. The switching driver has first and second switches for selectively connecting an output node to first and second switching voltages respectively to generate a first output voltage. A compensator is configured to receive a first monitor signal indicative of a sum of the first and second switching voltages and a second monitor signal indicative of a difference between the first and second switching voltages and to apply compensation to the input signal based on the first and second monitor signals so as to compensate for variations in the first and second switching voltages from defined nominal values of the first and second switching voltages. A modulator controls a duty cycle of the first and second switches based on the input signal after said compensation has been applied.
    Type: Application
    Filed: July 21, 2023
    Publication date: January 23, 2025
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: John P. LESSO, Douglas J.W. MACFARLANE, John L. MELANSON
  • Patent number: 12184272
    Abstract: A switching transducer driver operable in: a first mode in which first and second output stage switches are controlled to generate a two-level output signal, wherein an impedance of the first output stage switch is substantially the same as an impedance of the second output stage switch; and a second mode in which the first and second output stage switches and a third switch are controlled to generate a three-level output signal, wherein an impedance of the third switch is substantially greater than the impedance of the first output stage switch and the second output stage switch.
    Type: Grant
    Filed: April 27, 2023
    Date of Patent: December 31, 2024
    Assignee: Cirrus Logic Inc.
    Inventors: John P. Lesso, Douglas J. W. Macfarlane
  • Publication number: 20240364328
    Abstract: A switching transducer driver operable in: a first mode in which first and second output stage switches are controlled to generate a two-level output signal, wherein an impedance of the first output stage switch is substantially the same as an impedance of the second output stage switch; and a second mode in which the first and second output stage switches and a third switch are controlled to generate a three-level output signal, wherein an impedance of the third switch is substantially greater than the impedance of the first output stage switch and the second output stage switch.
    Type: Application
    Filed: April 27, 2023
    Publication date: October 31, 2024
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: John P. LESSO, Douglas J.W. MACFARLANE
  • Publication number: 20240048128
    Abstract: Methods and apparatus for controlling a switch transition in an inductive switching circuit are disclosed. A switch driver is configured to receive an indication of current through a diode associated with a first switch and dynamically control a switch transition of a second switch based on the indication of current, so as to reduce the switch transition time, when possible, whilst maintaining a voltage transient due to the switch transition within an acceptable range.
    Type: Application
    Filed: August 24, 2022
    Publication date: February 8, 2024
    Applicant: Cirrus Logic International Semiconductor Ltd.
    Inventors: Vikas VIJAY, Eduardo VELARDE, Bryan QUINONES, Douglas J. W. MACFARLANE, David SMITH, Saurabh K. SINGH