Patents by Inventor James D. Quarfoot

James D. Quarfoot 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: 6518839
    Abstract: A programmable gain amplifier (10) has a differential input (12-13), a differential output (16-17), and a plurality of enable inputs (21, 31-34). The amplifier includes a plurality of transconductor sections (26-29), which each have input nodes coupled to the differential input, output nodes coupled to the differential output, and an enable node coupled to a respective enable signal. The transconductor sections have different gains, which are respective powers of two. Each transconductor section includes a transconductor circuit (51, 56) which is coupled in series with at least one current mirror circuit (52-53, 57-58). Each transconductor circuit has a transistor (121) with a class A quiescent current that is proportional to the corresponding gain, the transistor being sized to achieve an optimum current density for its quiescent current.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: February 11, 2003
    Assignee: Texas Instrumetns Incorporated
    Inventors: Neil Gibson, Marco Corsi, Philip Sean Stetson, James D. Quarfoot
  • Publication number: 20020011897
    Abstract: A programmable gain amplifier (10) has a differential input (12-13), a differential output (16-17), and a plurality of enable inputs (21, 31-34). The amplifier includes a plurality of transconductor sections (26-29), which each have input nodes coupled to the differential input, output nodes coupled to the differential output, and an enable node coupled to a respective enable signal. The transconductor sections have different gains, which are respective powers of two. Each transconductor section includes a transconductor circuit (51, 56) which is coupled in series with at least one current mirror circuit (52-53, 57-58). Each transconductor circuit has a transistor (121) with a class A quiescent current that is proportional to the corresponding gain, the transistor being sized to achieve an optimum current density for its quiescent current.
    Type: Application
    Filed: June 22, 2001
    Publication date: January 31, 2002
    Inventors: Neil Gibson, Marco Corsi, Philip Sean Stetson, James D. Quarfoot