Patents by Inventor Randall J. Pflueger

Randall J. Pflueger 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: 5422563
    Abstract: A bootstrap current reference circuit having an n-type negative resistance network, and a biasing device responsive to operating current of the n-type negative resistance network for biasing the network to operate as a current source at an operating point substantially in a region of a predetermined current peak associated with the n-type negative resistance network. In one embodiment the circuit includes a depletion-mode FET (DFET) and a stable trimmed n-type negative resistance device (ST-NNRD) connected in series with the source of the DFET. The gate of the DFET is feedback coupled to the output of the ST-NNRD so as to bias it in a region of operation in which it exhibits a large incremental resistance, thus bootstrapping the circuit to operate in a state substantially independent of fluctuations associated with supply voltage source. In an alternate embodiment, the circuit includes a ST-NNRD connected in series with the source terminal of a DFET.
    Type: Grant
    Filed: July 22, 1993
    Date of Patent: June 6, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: Randall J. Pflueger
  • Patent number: 5384530
    Abstract: A bootstrap voltage reference circuit having an amplifier with a positive feedback network including a non-linear device which operates as a current source. The non-linear device may be an n-type negative resistance device such as a tunnel diode. The circuit is operable for generating a predetermined reference voltage as the difference between the signal applied to the positive input and a signal generated by the negative feedback network and applied to the negative input approaches zero.
    Type: Grant
    Filed: August 6, 1992
    Date of Patent: January 24, 1995
    Assignee: Massachusetts Institute of Technology
    Inventor: Randall J. Pflueger
  • Patent number: 5099191
    Abstract: A tunnel diode voltage reference circuit includes a tunnel diode; bias voltage circuit for biasing the tunnel diode to operate in the region of the peak current where the tunnel diode output current variation is a fraction of the bias voltage variation; and circuits responsive to the tunnel diode output current, for isolating the tunnel diode output from load variations and converting the tunnel diode output to a reference voltage. A resistance may be placed in parallel with the tunnel diode for raising the negative resistance region to the levels of the peak region to flatten the slope of the negative resistance region between the peak and the valley regions, reducing the reference voltage variation at bias points greater than the peak voltage of the tunnel diode characteristic.
    Type: Grant
    Filed: November 5, 1990
    Date of Patent: March 24, 1992
    Assignee: The Charles Stark Draper Laboratory, Inc.
    Inventors: Francis A. Galler, Randall J. Pflueger