Patents by Inventor Hipolk Lu

Hipolk Lu 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).

  • SYSTEM OF MULTI-CHANNEL SHARED RESISTOR-STRING DIGITAL-TO-ANALOG CONVERTERS AND METHOD OF THE SAME
    Publication number: 20050073453
    Abstract: System of multi-channel shared resistor-string digital-to-analog converters comprises a time-sharing interpolator converting the multi-channel digital audio input at low sample rate to the multi-channel digital audio output at high sample rate, a time-sharing sigma-delta modulator modulating the multi-channel digital audio input with a long sample wordlength from the interpolator to be a multi-channel digital audio output with a shorter sample wordlength, multi-channel shared resistor-string digital-to-analog converters converting the multi-channel digital audio input to be a multi-channel staircase analog signal output, and one low-order RC filter for each channel further attenuating the out-of-band noise in the analog staircase analog output, especially the high-frequency residue images.
    Type: Application
    Filed: October 1, 2003
    Publication date: April 7, 2005
    Inventors: Eric Cheng, Wen-Lung Shieh, Chih-Hung Tseng, Hipolk Lu
  • System of multi-channel shared resistor-string digital-to-analog converters and method of the same
    Patent number: 6870494
    Abstract: System of multi-channel shared resistor-string digital-to-analog converters comprises a time-sharing interpolator converting the multi-channel digital audio input at low sample rate to the multi-channel digital audio output at high sample rate, a time-sharing sigma-delta modulator modulating the multi-channel digital audio input with a long sample wordlength from the interpolator to be a multi-channel digital audio output with a shorter sample wordlength, multi-channel shared resistor-string digital-to-analog converters converting the multi-channel digital audio input to be a multi-channel staircase analog signal output, and one low-order RC filter for each channel further attenuating the out-of-band noise in the analog staircase analog output, especially the high-frequency residue images.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: March 22, 2005
    Assignee: C-Media Electronics Inc.
    Inventors: Eric Cheng, Wen-Lung Shieh, Chih-Hung Tseng, Hipolk Lu