Patents by Inventor David M. Thomas

David M. Thomas 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: 9287002
    Abstract: A sampling circuit may include a sampling capacitance, an electronic sampling switch, and a switch controller. The electronic sampling switch may have a control input that controls whether the electronic sampling switch is in a sample state or a hold state. The electronic sampling switch may connect the sampling capacitance to an input signal while in the sample state and disconnect the sampling capacitance from the input signal while in the hold state. The switch controller may control the control input to the electronic sampling switch so as to cause the electronic sampling switch to be in the sample state during one period and the hold state during another period. While in the sample state, the switch controller may cause the impedance of the electronic sampling switch that is seen by the input signal to be substantially independent of the voltage of the input signal.
    Type: Grant
    Filed: September 17, 2014
    Date of Patent: March 15, 2016
    Assignee: LINEAR TECHNOLOGY CORPORATION
    Inventor: David M. Thomas
  • Publication number: 20150270013
    Abstract: A sampling circuit may include a sampling capacitance, an electronic sampling switch, and a switch controller. The electronic sampling switch may have a control input that controls whether the electronic sampling switch is in a sample state or a hold state. The electronic sampling switch may connect the sampling capacitance to an input signal while in the sample state and disconnect the sampling capacitance from the input signal while in the hold state. The switch controller may control the control input to the electronic sampling switch so as to cause the electronic sampling switch to be in the sample state during one period and the hold state during another period. While in the sample state, the switch controller may cause the impedance of the electronic sampling switch that is seen by the input signal to be substantially independent of the voltage of the input signal.
    Type: Application
    Filed: September 17, 2014
    Publication date: September 24, 2015
    Applicant: LINEAR TECHNOLOGY CORPORATION
    Inventor: David M. Thomas
  • Patent number: 8786318
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: July 22, 2014
    Assignee: Linear Technology Corporation
    Inventor: David M. Thomas
  • Patent number: 8723556
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: May 13, 2014
    Assignee: Linear Technology Corporation
    Inventor: David M. Thomas
  • Patent number: 8698522
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: April 15, 2014
    Assignee: Linear Technology Corporation
    Inventor: David M. Thomas
  • Patent number: 8648741
    Abstract: Circuits and methods for converting a signal from analog to digital. A random number generator provides a random number to a memory. The memory is preconfigured to include codes of predetermined digital to analog (DAC) configurations that provide the maximum amount of DAC gradient suppression. At least one Flash reference generation DAC (FRGD) has an input coupled to the memory unit and an output providing a reference voltage level for its respective Flash comparator. The Flash comparators compare the analog input signal to their respective reference voltage and provide a digital output signal based on the comparison.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: February 11, 2014
    Assignee: Linear Technology Corporation
    Inventor: David M. Thomas
  • Patent number: 8482442
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: July 9, 2013
    Assignee: Linear Technology Corporation
    Inventor: David M. Thomas
  • Publication number: 20120313666
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Application
    Filed: June 8, 2011
    Publication date: December 13, 2012
    Inventor: David M. THOMAS
  • Publication number: 20120313800
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Application
    Filed: June 8, 2011
    Publication date: December 13, 2012
    Inventor: David M. THOMAS
  • Publication number: 20120313670
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Application
    Filed: June 8, 2011
    Publication date: December 13, 2012
    Inventor: David M. THOMAS
  • Publication number: 20120313667
    Abstract: Circuits and methods that improve the performance of electronic sampling systems are provided. Impedances associated with sampling semiconductor switches are maintained substantially constant during sample states, at least in part, by compensating for encountered input signal variations in order to reduce or minimize signal distortion associated with sampled signals that pass through the sampling switch.
    Type: Application
    Filed: June 8, 2011
    Publication date: December 13, 2012
    Inventor: David M. THOMAS
  • Publication number: 20120013389
    Abstract: In the preferred embodiment, a current source is switchable between two precisely defined output currents. A terminal of a coupling capacitor is coupled to the gate of an output MOSFET. The other terminal of the capacitor is switched between two reference voltages to toggle the MOSFET to output the selected one of the two currents. A switchable bias voltage source is coupled to the gate only during the on state of the MOSFET to set the gate voltage of the MOSFET. The current output of the current source is quickly and accurately changed. A reference MOSFET is not directly coupled to the output MOSFET, so there are no slow settling components coupled to the gate of the output MOSFET.
    Type: Application
    Filed: November 18, 2010
    Publication date: January 19, 2012
    Applicant: LINEAR TECHNOLOGY CORPORATION
    Inventors: David M. Thomas, Richard J. Reay
  • Patent number: 7907074
    Abstract: Circuits and methods that improve the performance of voltage reference driver circuits and associated analog to digital converters are provided. A voltage reference driver circuit that maintains a substantially constant output voltage when a load current is modulated by an input signal is provided. The voltage reference driver circuit synchronously decouples a voltage regulation circuit from the load circuit when modulating events such as pulses caused by the load circuit during a switching interval are generated, preventing disturbance of the regulation circuitry and keeping its output voltage substantially constant.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: March 15, 2011
    Assignee: Linear Technology Corporation
    Inventors: Alfio Zanchi, David M. Thomas, Joseph L. Sousa, Andrew J. Thomas, Jesper Steensgaard-Madsen
  • Patent number: 7683695
    Abstract: Systems and methods for reducing the magnitude of signal dependent capacitance are provided. Capacitance canceling circuitry is operative to generate cancellation capacitance in response to the magnitude of a signal, which may be the same signal that produces the undesired signal dependent capacitance, to at least partially cancel the signal dependent capacitance.
    Type: Grant
    Filed: August 18, 2006
    Date of Patent: March 23, 2010
    Assignee: Linear Technology Corporation
    Inventors: Joseph L. Sousa, David M. Thomas
  • Publication number: 20090121912
    Abstract: Circuits and methods that improve the performance of voltage reference driver circuits and associated analog to digital converters are provided. A voltage reference driver circuit that maintains a substantially constant output voltage when a load current is modulated by an input signal is provided. The voltage reference driver circuit synchronously decouples a voltage regulation circuit from the load circuit when modulating events such as pulses caused by the load circuit during a switching interval are generated, preventing disturbance of the regulation circuitry and keeping its output voltage substantially constant.
    Type: Application
    Filed: October 9, 2008
    Publication date: May 14, 2009
    Inventors: Alfio Zanchi, David M. Thomas, Joseph L. Sousa, Andrew J. Thomas, Jesper Steensgaard-Madsen
  • Patent number: 7255948
    Abstract: Fuel cells equipped with a self-contained gas- or air-lift which circulates fuel through the channels of the separator plate of the fuel cell via gaseous carbon dioxide produced by the reaction of the membrane electrode assembly and the fuel are provided. Also provided are exemplary self-contained gas-or air-lifts useful for production of these fuel cells.
    Type: Grant
    Filed: November 24, 2004
    Date of Patent: August 14, 2007
    Assignee: IRD Fuel Cells A/S
    Inventors: Jorgen Schjerning Lundsgaard, John Kaas, Madeleine Odgaard, David M. Thomas
  • Patent number: 6281717
    Abstract: Circuits and methods are provided that compensate for dynamic errors caused by voltage drops across a switch coupled in series with a capacitor in an electrical circuit such as a track-and-hold circuit. In such circuits, the capacitor should provide the same voltage as a signal coupled to the switch, but does not because of the switch voltage drop. The switch can be, for example, a MOSFET or more particularly a CMOS device. Dynamic errors are compensated for by measuring the voltage drop across the switch and then effectively adding the measured voltage drop to a voltage provided by the capacitor.
    Type: Grant
    Filed: December 8, 1999
    Date of Patent: August 28, 2001
    Assignee: Linear Technology Corporation
    Inventors: David M. Thomas, Richard J. Reay
  • Patent number: 6124818
    Abstract: Improved pipelined successive approximation analog-to-digital converter circuits are provided. Some embodiments of the present invention comprises two stages in which a first portion of the total bits are evaluated in the first stage of the circuit and then the residue is passed to the second stage of the circuit that evaluates the remaining portion. By operating both stages simultaneously, the throughput is increased. These embodiments utilize two matched buffers to isolate the first and second stages from switching errors of a sampling circuit and the loading effects of comparators associated with the two stages. In another embodiment, upon completion of the conversion of the MSBs, the remaining input signal or residue signal is amplified by a preamp and the output is subsequently sampled by a residue sample and hold circuit (S/H). After the residue is sampled by the residue S/H, the second stage begins to solve the least significant bits (LSBs). The second stage is a matched copy of the first stage.
    Type: Grant
    Filed: October 21, 1998
    Date of Patent: September 26, 2000
    Assignee: Linear Technology Corporation
    Inventors: David M. Thomas, Richard J. Reay
  • Patent number: 5948195
    Abstract: A method for rapid manufacturing multi-pane insulating glass windows where cooling gas is used to cool temperature activated adhesive or sealant on pane spacers thereby reducing the assembly time for windows used to replace broken windows in emergency conditions
    Type: Grant
    Filed: March 11, 1997
    Date of Patent: September 7, 1999
    Assignee: Artic Window, Inc.
    Inventor: David M. Thomas
  • Patent number: RE45798
    Abstract: Circuits and methods for converting a signal from analog to digital. A random number generator provides a random number to a memory. The memory is preconfigured to include codes of predetermined digital to analog (DAC) configurations that provide the maximum amount of DAC gradient suppression. At least one Flash reference generation DAC (FRGD) has an input coupled to the memory unit and an output providing a reference voltage level for its respective Flash comparator. The Flash comparators compare the analog input signal to their respective reference voltage and provide a digital output signal based on the comparison.
    Type: Grant
    Filed: August 29, 2014
    Date of Patent: November 10, 2015
    Assignee: LINEAR TECHNOLOGY CORPORATION
    Inventors: David M. Thomas, Alfio Zanchi