Patents by Inventor Roger Kosaka

Roger Kosaka 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: 20050035892
    Abstract: A DAC (10) including an operational amplifier (12) having an input terminal; a plurality of current paths coupled to the input terminal; a plurality of current sources (I1/2-I4/2); and an arrangement (11) for switchably coupling current from at least two of the cells to a respective one of the paths in response to an input signal. In a specific embodiment, the inventive DAC (10) further includes a first resistive element (2R1-2R4) disposed in each of the current paths, a second resistive element (R1-R4) disposed between the current paths, and a feedback resistor (RF) disposed between an output terminal of the amplifier and the input terminal thereof. In the illustrative embodiment, the coupling arrangement includes a plurality of switches (SW1-SW4); each of the switches is adapted to switch half of the current from a first source and half of the current from a second source into a respective one of the paths.
    Type: Application
    Filed: December 18, 2003
    Publication date: February 17, 2005
    Inventors: Don Devendorf, Erick Hirata, Lloyd Linder, Christopher Langit, Roger Kosaka