Patents by Inventor Jason Zhang

Jason Zhang 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: 20040240238
    Abstract: An improved active voltage positioning (AVP) implementation for a power supply for a microprocessor or the like includes an AVP circuit which is separated from the power supply error amplifier by a buffer amplifier having a parallel RC feedback circuit to controllably adjust the transient response. An AVP signal derived from an output load current sensing element provides an input to the buffer amplifier. A second input is provided by power supply reference voltage. A output of the buffer amplifier is connected as an input to the error amplifier to provide the AVP window. This permits separate adjustment of the transient behavior of the error loop and the AVP loop.
    Type: Application
    Filed: May 10, 2004
    Publication date: December 2, 2004
    Applicant: International Rectifier Corporation
    Inventors: David Jauregui, Jason Zhang
  • Publication number: 20040219069
    Abstract: A device and methods for the automated histotechnological processing of a specimen are disclosed. The device comprises a microwave unit and a specimen positioning device which transports the specimen into a tank within the microwave unit where automated heating takes place. Preferably the microwave unit is controlled by a real-time microwave processor that permits control of the temperature within the microwave tank. Automated methods of dewaxing, antigen retrieval, nucleic acid retrieval, and hematoxylin and eosin staining which can be used in conjunction with the device are also provided. In one embodiment, a method is provided for simultaneous dewaxing and antigen retrieval; solutions useful for this method are also provided.
    Type: Application
    Filed: January 22, 2004
    Publication date: November 4, 2004
    Inventors: Krishan L. Kalra, Jason Zhang, Mitchell Lok
  • Patent number: 6803750
    Abstract: A multi-phase synchronous buck converter manufacturable using MCM architecture having improved output current sharing capability. The device is constructed of a plurality of single phase buck converter stages, and a sensing circuit for each converter stage to generate an output signal representative of the output current provided by that converter stage. A master controller provides duty cycle control signals in a predetermined phase relationship for the switching transistors of the individual converter stages according to the difference between the output voltage from the multi-phase converter and a reference signal representing a desired voltage at the output node. A duty cycle trimming controller which may include individual duty cycle trimming circuits coupled between the master controller and the drive circuits for each converter stage, modifies the duty cycle control signals from the master controller to equalize as nearly as possible the currents provided by each stage.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: October 12, 2004
    Assignee: International Rectifier Corporation
    Inventor: Jason Zhang
  • Patent number: 6781354
    Abstract: A synchronous buck converter manufacturable as an MCM having an output current sensing circuit. The device employs MOSFETS as the switching transistors, and a sensing circuit including a sampling switch operated synchronously on and off with the shunt MOSFET, a variable gain amplifier, the sampling switch being coupled to provide a signal to the variable gain amplifier representing the voltage across the RDS-ON of the shunt MOSFET, and a circuit, e.g., an RC circuit, associated with the variable gain amplifier implementing a low pass filter whereby the output of the variable gain amplifier is substantially independent of the value of the inductor and the magnitude of any time varying component of the signal input to the sampling switch. When the device is packaged an MCM, the current sense circuit gain can be trimmed based on the RDS-ON value.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: August 24, 2004
    Assignee: International Rectifier Corporation
    Inventor: Jason Zhang
  • Patent number: 6753723
    Abstract: A synchronous buck converter having an improved transient response during output current stepdown. The device includes series and shunt MOSFETS, a first driver circuit to turn the series MOSFET on and off according to a variable duty cycle determined by an error signal representing the difference between the voltage output of the converter and a reference voltage, a sensing circuit operative to provide a control signal output when the duty cycle for the series MOSFET is zero; and a second drive circuit responsive to the control signal output of the sensing circuit to turn off the shunt MOSFET. The sensing circuit operates by detecting when the error signal is of a lower amplitude than the minimum value of the ramp waveform used to generate the duty cycle for the series MOSFET.
    Type: Grant
    Filed: April 3, 2003
    Date of Patent: June 22, 2004
    Assignee: International Rectifier Corporation
    Inventor: Jason Zhang
  • Publication number: 20040000894
    Abstract: A multi-phase synchronous buck converter having plural single phase synchronous buck converter stages, connected together to provide an output current to a load. A sensing circuit in each converter stage includes a variable gain current sense amplifier that determines the current through the shunt MOSFET to generate an output signal representative of the output current provided by that converter stage. The gains of the current sense amplifiers in each converter stage are preset such that the output signals from all the amplifiers are substantially equal, thereby balancing the power loss in all the converter stages by adjustment of the output currents using varying current sense gains to compensate for variations in the RDS-ON of the shunt MOSFETS.
    Type: Application
    Filed: April 3, 2003
    Publication date: January 1, 2004
    Applicant: International Rectifier Corporation
    Inventor: Jason Zhang
  • Publication number: 20030210020
    Abstract: A synchronous buck converter manufacturable as an MCM having an improved output current sensing circuit. The device employs MOSFETS as the switching transistors, and a sensing circuit including a sampling switch operated synchronously on and off with the shunt MOSFET, a variable gain amplifier, the sampling switch being coupled to provide a signal to the variable gain amplifier representing the voltage across the RDS-ON of the shunt MOSFET, and a circuit, e.g., an RC circuit, associated with the variable gain amplifier implementing a low pass filter whereby the output of the variable gain amplifier is substantially independent of the value of the inductor and the magnitude of any time varying component of the signal input to the sampling switch. When the device is packaged an MCM, the current sense circuit gain can be trimmed based on the RDS-ON value.
    Type: Application
    Filed: April 3, 2003
    Publication date: November 13, 2003
    Applicant: International Rectifier Corporation
    Inventor: Jason Zhang
  • Publication number: 20030206425
    Abstract: A synchronous buck converter having an improved transient response during output current stepdown. The device includes series and shunt MOSFETS, a first driver circuit to turn the series MOSFET on and off according to a variable duty cycle determined by an error signal representing the difference between the voltage output of the converter and a reference voltage, a sensing circuit operative to provide a control signal output when the duty cycle for the series MOSFET is zero; and a second drive circuit responsive to the control signal output of the sensing circuit to turn off the shunt MOSFET. The sensing circuit operates by detecting when the error signal is of a lower amplitude than the minimum valve of the ramp waveform used to generate the duty cycle for the series MOSFET.
    Type: Application
    Filed: April 3, 2003
    Publication date: November 6, 2003
    Applicant: International Rectifier Corporation
    Inventor: Jason Zhang
  • Publication number: 20030197245
    Abstract: A multi-phase synchronous buck converter manufacturable using MCM architecture having improved output current sharing capability. The device is constructed of a plurality of single phase buck converter stages, and a sensing circuit for each converter stage to generate an output signal representative of the output current provided by that converter stage. A master controller provides duty cycle control signals in a predetermined phase relationship for the switching transistors of the individual converter stages according to the difference between the output voltage from the multi-phase converter and a reference signal representing a desired voltage at the output node. A duty cycle trimming controller which may include individual duty cycle trimming circuits coupled between the master controller and the drive circuits for each converter stage, modifies the duty cycle control signals from the master controller to equalize as nearly as possible the currents provided by each stage.
    Type: Application
    Filed: April 3, 2003
    Publication date: October 23, 2003
    Applicant: International Rectifier Corporation
    Inventor: Jason Zhang
  • Publication number: 20030100043
    Abstract: A device and methods for the automated histotechnological processing of a specimen are disclosed. The device comprises a microwave unit and a specimen positioning device which transports the specimen into a tank within the microwave unit where automated heating takes place. Preferably the microwave unit is controlled by a real-time microwave processor that permits control of the temperature within the microwave tank. Automated methods of dewaxing, antigen retrieval, nucleic acid retrieval, and hematoxylin and eosin staining which can be used in conjunction with the device are also provided. In one embodiment, a method is provided for simultaneous dewaxing and antigen retrieval; solutions useful for this method are also provided.
    Type: Application
    Filed: March 23, 2001
    Publication date: May 29, 2003
    Applicant: BioGenex Laboratories, Inc.
    Inventors: Krishan L. Kalra, Jason Zhang, Mitchell Lok
  • Publication number: 20030092720
    Abstract: A medicament for preventive and/or therapeutic treatment of a microbial infection which comprises as an active ingredient a compound represented by the following general formula (I): 1
    Type: Application
    Filed: April 26, 2001
    Publication date: May 15, 2003
    Applicant: DAIICHI PHARMACEUTICAL CO., LTD
    Inventors: Kiyoshi Nakayama, Masami Ohtsuka, Haruko Kawato, William Watkins, Jason Zhang, Monica Palme, Aesop Cho
  • Publication number: 20030006655
    Abstract: The present invention provides methods for
    Type: Application
    Filed: May 8, 2002
    Publication date: January 9, 2003
    Inventor: Ming (Jason) Zhang
  • Publication number: 20020166740
    Abstract: The present invention provides methods and apparatus for efficiently cooling frictional brake components mounted on vehicle or heavy rotating machinery, including frictional lining, brake discs, vehicle wheels served as frictional brake components etc, by inducing intensive forced convective heat transfers on the surfaces of the said frictional brake components.
    Type: Application
    Filed: May 8, 2002
    Publication date: November 14, 2002
    Inventor: Ming Jason Zhang
  • Patent number: 6143156
    Abstract: The present invention provides an improved method for electroplating metallic ions onto a conductive substrate. In one embodiment, the method comprises at least partially covering a selected surface of the conductive substrate with an electrode wrap that includes a pad having an abrasive surface.The metallic ions are electrically depositing onto the selected surface through the electrode wrap while the conductive substrate is moved (e.g., rotated) relative to the electrode wrap. A substantially constant frictional force is controllably applied from the abrasive surface onto the selected surface while the metallic ions are being deposited. In this manner, a substantially constant abrasive force is applied to the selected surface as the thickness of the deposited metallic coating increases to create a relatively smooth, uniform, thick deposition that is substantially free of defects.
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: November 7, 2000
    Assignee: CAE Vanguard, Inc.
    Inventor: Ming Jason Zhang