Patents by Inventor Hio Leong Chao

Hio Leong Chao 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: 20090302822
    Abstract: A voltage regulator comprises first and second bipolar transistors operating at different current densities; a resistor is connected between their bases across which ?VBE appears. A third bipolar transistor is connected such that the voltages at the bases of the first and third transistors are equal or differ by a PTAT amount. A current mirror is arranged to balance the collector current of one of the second and third transistors with an image of the collector current of the first transistor when the output node is at a unique operating point. The operating point includes both PTAT and CTAT components, the ratio of which can be established such that the operating point has a desired temperature characteristic. A transistor connected to the output node and driven by the output of the current mirror regulates the output voltage by negative feedback.
    Type: Application
    Filed: June 10, 2008
    Publication date: December 10, 2009
    Inventors: Hio Leong Chao, A. Paul Brokaw
  • Publication number: 20090302823
    Abstract: A voltage regulator comprises first and second bipolar transistors operating at different current densities; a resistance is connected between their bases across which ?VBE appears. A third bipolar transistor is connected such that its base voltage is equal to that of the first transistor or differs by a PTAT amount. A current mirror balances the collector current of one of the second and third transistors with an image of the collector current of the first transistor when an output node is at a unique operating point. The operating point includes both PTAT and CTAT components, the ratio of which can be established to provide a desired temperature characteristic. A feedback transistor provides current to the bases of the bipolar transistors and to the output node and is driven by the current mirror output to regulate the voltage at the output node by negative feedback.
    Type: Application
    Filed: November 24, 2008
    Publication date: December 10, 2009
    Inventors: Hio Leong Chao, A. Paul Brokaw