Patents by Inventor Geoffrey T. Haigh

Geoffrey T. Haigh 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: 6291907
    Abstract: An isolator having a driver circuit which responsive to an input signal drives appropriate signals into one or more coils which are magnetically coupled to one or more corresponding MR or GMR elements whose resistance is variable in response to the magnetic field applied by the coil(s), and an output circuit that converts the resistance changes to an output signal corresponding to the input signal. A Faraday shield is interposed between the coil(s) and the MR or GMR elements. Common mode transients applied to the driver are capacitively coupled from the coil(s) into the Faraday shield and therethrough to ground, instead of into the MR elements. A second Faraday shield may be disposed in spaced relationship with the first Faraday shield and referenced to the potential of the MR elements for even greater common mode rejection. The entire structure may be formed monolithically as an integrated circuit on a single substrate, for low cost, small size, and low power consumption.
    Type: Grant
    Filed: April 25, 2000
    Date of Patent: September 18, 2001
    Assignee: Analog Devices, Inc.
    Inventors: Geoffrey T. Haigh, Paul R. Nickson
  • Patent number: 6275034
    Abstract: A semiconductor magnetic field sensor including a substrate; a semiconductor moveable element suspended above the substrate, the moveable element being configured to have a current passed therethrough and to deflect perpendicularly with respect to an applied magnetic field; and at least one fixed semiconductor element arranged adjacent to the moveable element, the moveable element being deflected to or away from the fixed element in response to an applied magnetic field.
    Type: Grant
    Filed: March 10, 1999
    Date of Patent: August 14, 2001
    Assignee: Analog Devices Inc.
    Inventors: Chau C. Tran, John A. Geen, A. Paul Brokaw, Geoffrey T. Haigh
  • Patent number: 6262600
    Abstract: A logic isolation circuit has a transmitter circuit for receiving a logic input signal and providing a periodic signal to an isolation barrier, and a receiving circuit for receiving the periodic signal from the isolation barrier and for providing an output signal that indicates the transitions in the logical input signal.
    Type: Grant
    Filed: February 14, 2000
    Date of Patent: July 17, 2001
    Assignee: Analog Devices, Inc.
    Inventors: Geoffrey T. Haigh, Baoxing Chen
  • Patent number: 6087882
    Abstract: An isolator having a driver circuit which is responsive to an input signal to drive signals into a magnetic-field generator such as at least one coil. The generator is magnetically coupled to a sensor that includes spin-valve resistors which have resistance characteristics that are variable in response to the magnetic field generated by the generator. A receiver circuit incorporating a strobe generator converts the resistance changes to an output signal corresponding to the input signal.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: July 11, 2000
    Assignee: Analog Devices, Inc.
    Inventors: Baoxing Chen, Geoffrey T. Haigh, Alberto G. Comaschi
  • Patent number: 6054780
    Abstract: An isolator having a driver circuit which responsive to an input signal drives appropriate signals into one or more coils which are magnetically coupled to one or more corresponding MR or GMR elements whose resistance is variable in response to the magnetic field applied by the coil(s), and an output circuit that converts the resistance changes to an output signal corresponding to the input signal. A Faraday shield is interposed between the coil(s) and the MR or GMR elements. Common mode transients applied to the driver are capacitively coupled from the coil(s) into the Faraday shield and therethrough to ground, instead of into the MR elements. A second Faraday shield may be disposed in spaced relationship with the first Faraday shield and referenced to the potential of the MR elements for even greater common mode rejection. The entire structure may be formed monolithically as an integrated circuit on a single substrate, for low cost, small size, and low power consumption.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: April 25, 2000
    Assignee: Analog Devices, Inc.
    Inventors: Geoffrey T. Haigh, Paul R. Nickson
  • Patent number: 5986450
    Abstract: A magnetic sensor has a first sensing element and a second sensing element surrounding the first sensing element so that the sensor is directionally independent in a plane perpendicular to a sensing axis. The sensor can be mounted in a housing that has an end with a threaded rod or a pin for connection to a support member.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: November 16, 1999
    Assignee: Analog Devices
    Inventors: Geoffrey T. Haigh, Paul R. Nickson
  • Patent number: 5952849
    Abstract: A logic isolation circuit with high transient immunity has a link-coupled transformer assembly for providing isolation. An input circuit provides pulses that indicate rising and falling edges, and an output circuit on the isolated side of the barrier converts the signal with pulses back into a digital logic signal with rising and falling edges. An interrogation feature allows the output to be updated frequently. The logic isolator can be provided in a single module for use in a process control board, or it can be provided as multiple parts for mounting on a circuit board.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: September 14, 1999
    Assignee: Analog Devices, Inc.
    Inventor: Geoffrey T. Haigh
  • Patent number: 5591996
    Abstract: A device for producing an output voltage which is proportional to an applied magnetic field. The device includes a plurality charge injection regions, a corresponding plurality of charge exit regions, and a charge transfer region. The charge transfer region includes gate electrodes which serve to propagate at least one isolated charge packet across the charge transfer region in a predetermined direction from the charge input region to the charge output region. The charge packet is subject to the applied magnetic field which is perpendicular to the charge transfer region so as to induce a resultant potential that is orthogonal to both the applied magnetic field and the predetermined direction. Furthermore, the resultant potential effects a lateral redistribution of charge carriers in the packet. A recirculation configuration allows for a recycling of the packet from the output region back to the input region in order to accommodate a continuation of the redistribution of charge carriers.
    Type: Grant
    Filed: March 24, 1995
    Date of Patent: January 7, 1997
    Assignee: Analog Devices, Inc.
    Inventors: Geoffrey T. Haigh, Scott C. Munroe