Patents by Inventor Lonnie C. Au

Lonnie C. Au 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).

  • Statistical method of measuring the differential linearity of an analog/digital converter using a pseudo-random triangle wave stimulus
    Patent number: 4352160
    Abstract: The differential linearity of an analog-digital converter is measured by a test method that eliminates the need for precision calibrated test equipment. A triangle waveform with a pseudo random period is applied to the analog/digital converter input. The waveform has a uniform amplitude probability density function. Therefore, any analog/digital converter input voltage has an equal chance of being sampled by the analog/digital converter. The number of times each possible analog/digital converter output code word occurs is counted by a microprocessor. These numbers are a direct measure of differential linearity with an accuracy described by the theory of repeated random sampling.
    Type: Grant
    Filed: January 21, 1980
    Date of Patent: September 28, 1982
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: John W. Frech, Lonnie C. Au