Patents by Inventor Helmuth Robert Litfin

Helmuth Robert Litfin 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).

  • Digital to analog converter trim apparatus and method
    Patent number: 6307490
    Abstract: A digital to analog converter has a decoder configured to select weighted decoding elements in a decoding network. The decoded outputs increase in steps by a mathematical progression as a function of the value of the input to the decoder. A calibration circuit adjusts the value of the digital input code received by the decoder to achieve a calibration function. In a programmable resistor embodiment, the value of the resistance selected by subsequent digital codes increases by a constant ratio. An adder is used to add an offset value to the digital input, thereby shifting the value of the resistance selected by the decoder to compensate for fabrication variances.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: October 23, 2001
    Assignee: The Engineering Consortium, Inc.
    Inventors: Helmuth Robert Litfin, Anthony Joseph Becker, Clyde Manford Brown