Patents by Inventor Phi Thai

Phi Thai 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).

  • Patent number: 7049858
    Abstract: An isolation resistor is inserted in series between a current source and the emitters of bipolar switching transistors in a differential amplifier. The switching transistors may also be MOSFETs. The in-rush current through the resistor, due to a parasitic or added capacitance, creates a certain increased voltage drop across the resistor, reducing dv/dt and thus reducing the transient in-rush current into the capacitor. This results in reduced waveform distortion. Such an isolation resistor between a current carrying terminal of a switching bipolar transistor and a current source may be used in various applications, including an emitter follower.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: May 23, 2006
    Assignee: Micrel, Inc.
    Inventors: Thomas S. Wong, Benjamin Chan, Phi Thai
  • Patent number: 6933751
    Abstract: A logic gate is described that has an N-type region, which may be an N-well or N-tub, forming a cathode of one or more Schottky diodes and a collector of an NPN bipolar transistor. Accordingly, the Schottly diodes and transistor do not need to be isolated from one another, resulting in a very compact logic gate. The logic gate forms a portion of a NAND function in one embodiment. One or more Schottky diodes between the collector and base of the bipolar transistor act as a clamp to prevent the transistor from saturating. The clamp diodes can also be used to adjust the output voltage of the gate to ensure downstream transistors can be fully turned off.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: August 23, 2005
    Assignee: Micrel, Inc.
    Inventors: Thomas S. Wong, Robert W. Bechdolt, Phi Thai
  • Publication number: 20050062503
    Abstract: A logic gate is described that has an N-type region, which may be an N-well or N-tub, forming a cathode of one or more Schottky diodes and a collector of an NPN bipolar transistor. Accordingly, the Schottly diodes and transistor do not need to be isolated from one another, resulting in a very compact logic gate. The logic gate forms a portion of a NAND function in one embodiment. One or more Schottky diodes between the collector and base of the bipolar transistor act as a clamp to prevent the transistor from saturating. The clamp diodes can also be used to adjust the output voltage of the gate to ensure downstream transistors can be fully turned off.
    Type: Application
    Filed: September 18, 2003
    Publication date: March 24, 2005
    Inventors: Thomas Wong, Robert Bechdolt, Phi Thai
  • Publication number: 20050062517
    Abstract: An isolation resistor is inserted in series between a current source and the emitters of bipolar switching transistors in a differential amplifier. The switching transistors may also be MOSFETs. The in-rush current through the resistor, due to a parasitic or added capacitance, creates a certain increased voltage drop across the resistor, reducing dv/dt and thus reducing the transient in-rush current into the capacitor. This results in reduced waveform distortion. Such an isolation resistor between a current carrying terminal of a switching bipolar transistor and a current source may be used in various applications, including an emitter follower.
    Type: Application
    Filed: September 18, 2003
    Publication date: March 24, 2005
    Inventors: Thomas Wong, Banjamin Chan, Phi Thai
  • Patent number: 4722822
    Abstract: Current switches are used to control current into the columns during READ operations of a PROM. The circuit provides one such switch for each of the columns of the PROM and makes possible the use of a single current source which is connected to each of the switches but supplies current only to the column of the PROM that is currently selected for reading. A high voltage pre-bias is applied to the collectors of the NPN transistors used as current switches such that turn-on speed is improved because the collector parasitic capacitances are pre-charged to near the supply potential.
    Type: Grant
    Filed: November 27, 1985
    Date of Patent: February 2, 1988
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Phi Thai, Barry S. Cornell
  • Patent number: 4577294
    Abstract: A redundant memory circuit having a memory for storing information in a matrix of interconnected rows and columns, and a row and a column address decoder to access the rows and columns. The memory has a redundant row or rows to replace a defective row or rows in the matrix and a programmable decoder which is programmed with the row address of the defective row to access the redundant row. The row and column address decoders are used to access the defective row and to sequentially access the columns so as to entirely disconnect the defective row from the columns. The programmable decoder is then programmed with the defective row address, bit by bit, in response to the column addresses, to access the redundant row. After this procedure, a verification circuit can be used to verify that the redundant row can be accessed and that the programmable decoder is properly programmed to decode only one address to one row.
    Type: Grant
    Filed: April 18, 1983
    Date of Patent: March 18, 1986
    Assignee: Advanced Micro Devices, Inc.
    Inventors: George W. Brown, Phi Thai