Patents by Inventor Mark J. W. Rodwell

Mark J. W. Rodwell 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: 8354885
    Abstract: An operational amplifier may include a transimpedance input stage. The operational amplifier is capable of self-biasing its input voltage(s) including a first stage, an input source connected to the first stage, an output stage connected to the first stage via feedback resistors, and feedback current sources connected to the first stage, wherein the feedback current sources are set to generate feedback currents flowing from the output stage back to the input stage via the feedback resistors, so as to self-bias the input voltage(s) at the input stage. A method for allowing for an op-amp to self-bias its input voltage(s), including generating feedback currents flowing from the output stage back to the input stage via feedback resistors, so as to self-bias the input voltage(s) at the input stage.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: January 15, 2013
    Assignees: The Regents of the University of California, Teledyne Scientific & Imaging, LLC
    Inventors: Zachary M. Griffith, Miguel E. Urteaga, Mark J. W. Rodwell
  • Publication number: 20120293263
    Abstract: An operational amplifier may include a transimpedance input stage. The operational amplifier is capable of self-biasing its input voltage(s) including a first stage, an input source connected to the first stage, an output stage connected to the first stage via feedback resistors, and feedback current sources connected to the first stage, wherein the feedback current sources are set to generate feedback currents flowing from the output stage back to the input stage via the feedback resistors, so as to self-bias the input voltage(s) at the input stage. A method for allowing for an op-amp to self-bias its input voltage(s), including generating feedback currents flowing from the output stage back to the input stage via feedback resistors, so as to self-bias the input voltage(s) at the input stage.
    Type: Application
    Filed: May 25, 2012
    Publication date: November 22, 2012
    Inventors: Zachary M. Griffith, Miguel E. Urteaga, Mark J.W. Rodwell
  • Patent number: 8222958
    Abstract: The present invention relates generally to an operational amplifier. In one embodiment, the present invention is an operational amplifier including a transimpedance input stage, the transimpedance input stage including a first stage connected to a first resistor and a second resistor, and an output stage connected to the transimpedance input stage.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: July 17, 2012
    Assignees: Teledyne Scientific & Imaging, LLC, The Regents of the University of California
    Inventors: Zachary M. Griffith, Miguel E. Urteaga, Mark J. W. Rodwell
  • Publication number: 20110169568
    Abstract: The present invention relates generally to an operational amplifier. In one embodiment, the present invention is an operational amplifier including a transimpedance input stage, the transimpedance input stage including a first stage connected to a first resistor and a second resistor, and an output stage connected to the transimpedance input stage.
    Type: Application
    Filed: February 3, 2011
    Publication date: July 14, 2011
    Inventors: Zachary M. Griffith, Miguel E. Urteaga, Mark J.W. Rodwell
  • Patent number: 7898333
    Abstract: The present invention relates generally to an operational amplifier. In one embodiment, the present invention is an operational amplifier including a transimpedance input stage, the transimpedance input stage including a first stage connected to a first resistor and a second resistor, and an output stage connected to the transimpedance input stage.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: March 1, 2011
    Assignees: Teledyne Scientific & Imaging, LLC, The Regents of the University of California
    Inventors: Zachary M. Griffith, Miguel E. Urteaga, Mark J. W. Rodwell
  • Publication number: 20090289714
    Abstract: The present invention relates generally to an operational amplifier. In one embodiment, the present invention is an operational amplifier including a transimpedance input stage, the transimpedance input stage including a first stage connected to a first resistor and a second resistor, and an output stage connected to the transimpedance input stage.
    Type: Application
    Filed: October 8, 2008
    Publication date: November 26, 2009
    Inventors: Zachary M. Griffith, Miguel E. Urteaga, Mark J.W. Rodwell
  • Patent number: 5256996
    Abstract: An integrated coplanar strip nonlinear transmission line comprising a substrate of gallium arsenide upon which a heavily doped buried layer and a lightly doped surface layer of epitaxially grown gallium arsenide are grown. Two parallel conductors are integThis work was funded by the United States Government's Office of Naval Research under contract No. N99914-85-K-0381. The United States Government has a paid up license in this technology.
    Type: Grant
    Filed: July 6, 1992
    Date of Patent: October 26, 1993
    Assignee: The Board of Trustees of the Leland Stanford, Junior University
    Inventors: Robert A. Marsland, Mark J. W. Rodwell, David M. Bloom
  • Patent number: 5014018
    Abstract: There is disclosed herein a non linear transmission line comprised of a 50 ohm coplanar monolithic waveguide formed on top of a gallium arsenide substrate having a layer of lightly doped epitaxial gallium arsenide with a heavily doped buried layer, said epitaxial layer having spaced, electrically isolated islands. A self aligned Schottky diode junction is formed at the intersection of each isolation island with the center conductor of the transmission line. The second conductor of the transmission line is coupled through a contact window and an ohmic contact to the buried layer in each isolation island.
    Type: Grant
    Filed: October 6, 1987
    Date of Patent: May 7, 1991
    Assignee: Stanford University
    Inventors: Mark J. W. Rodwell, David M. Bloom
  • Patent number: 4623786
    Abstract: The front end of an optical receiver circuit (10) is of the type having a field-effect device transimpedance amplifier (16,21) which receives at its input (14) the photocurrent of a photodiode (12). A field-effect device shunt impedance (26) to protect against amplifier overloading is connected between the input and ground through a decoupling capacitor (28). The shunt (26) is controlled by a controller (30), which has its input connected to the output (24) of the amplifier (16) and its output connected to the gate of the shunt (26). The controller (30) compares the output (24) of the amplifier (16) to a threshold reference voltage for determining whether to activate the shunt (26) and regulates the gate voltage of the shunt (26) by means of an AGC amplifier. A direct current feedback resistor (32) is connected between the output (24) of the amplifier (16) and the source of the shunt (26). This prevents the d.c.
    Type: Grant
    Filed: November 7, 1984
    Date of Patent: November 18, 1986
    Assignee: AT&T Bell Laboratories
    Inventor: Mark J. W. Rodwell