Patents by Inventor Virgil Ioan Gheorghiu

Virgil Ioan Gheorghiu 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: 20080106247
    Abstract: A circuit is used for providing an output current that is proportional to an applied input current with high accuracy. The circuit includes an input circuit, a trimmable coupling circuit and an output circuit. The input circuit receives the input current and generates a reference input current in response to the input current. The trimmable coupling circuit is coupled to the input circuit for receiving the reference input current from the input circuit and for generating a reference output current for the output circuit. The trimmable coupling circuit is operable to achieve a predetermined ratio of the reference input current to the reference output current by causing internal terminals of the trimmable coupling circuit to settle to a substantially equal value. The output circuit receives the reference output current and outputs the output current in response to the receipt of the reference output current.
    Type: Application
    Filed: March 23, 2007
    Publication date: May 8, 2008
    Inventor: Virgil Ioan Gheorghiu
  • Patent number: 7151394
    Abstract: The present invention provides an inverter controller comprising a drive circuit that generates a plurality of switch drive signals for inverter applications. In some exemplary embodiments, the drive circuit operates by reversing the command level of an error signal. In other embodiments, the drive circuit operates by using a half period of a sawtooth signal. In still other embodiments, the drive circuit operates by using a double period opposite shifting pulses method. The present invention also provides a PWM signal generator circuit that generates periodic PWM switch drive signals symmetrical to the minimum or maximum of a sawtooth waveform.
    Type: Grant
    Filed: May 16, 2005
    Date of Patent: December 19, 2006
    Assignee: O2Micro International Limited
    Inventors: Virgil Ioan Gheorghiu, Da Liu
  • Patent number: 7026860
    Abstract: A compensated current generator includes a first current source and a second current source coupled in series. The first and second current sources have temperature coefficients with opposite signs to produce a temperature compensated current. The first current source may be a peaking current source biased by a bias signal to operate a peak of its transfer characteristic curve to enhance power supply rejection. An associated method is also provided.
    Type: Grant
    Filed: May 8, 2003
    Date of Patent: April 11, 2006
    Assignee: O2Micro International Limited
    Inventors: Virgil ioan Gheorghiu, Thomas Yang
  • Patent number: 6897698
    Abstract: The present invention provides an inverter controller comprising a drive circuit that generates a plurality of switch drive signals for inverter applications. In some exemplary embodiments, the drive circuit operates by reversing the command level of an error signal. In other embodiments, the drive circuit operates by using a half period of a sawtooth signal. In still other embodiments, the drive circuit operates by using a double period opposite shifting pulses method. The present invention also provides a PWM signal generator circuit that generates periodic PWM switch drive signals symmetrical to the minimum or maximum of a sawtooth waveform.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: May 24, 2005
    Assignee: O2Micro International Limited
    Inventors: Virgil Ioan Gheorghiu, Da Liu