Patents by Inventor James R. Welch

James R. Welch 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: 8262286
    Abstract: A temperature sensor generates a digital output signal representative of the absolute temperature of the sensor. The sensor includes a first circuit configured to generate a complementary to absolute temperature (CTAT) voltage signal and a second circuit configured to generate a proportional to absolute temperature (PTAT) current signal. A comparator receives the CTAT and PTAT signals and generates a comparison signal based on a comparison between the signals. A converter circuit receives the comparison signal and generates a digital output signal based on the comparison signal. The digital output signal is representative of the temperature of the sensor.
    Type: Grant
    Filed: November 18, 2008
    Date of Patent: September 11, 2012
    Assignee: Toshiba America Electronic Components, Inc.
    Inventors: Luverne R. Peterson, James R. Welch
  • Publication number: 20100124251
    Abstract: A temperature sensor generates a digital output signal representative of the absolute temperature of the sensor. The sensor includes a first circuit configured to generate a complementary to absolute temperature (CTAT) voltage signal and a second circuit configured to generate a proportional to absolute temperature (PTAT) current signal. A comparator receives the CTAT and PTAT signals and generates a comparison signal based on a comparison between the signals. A converter circuit receives the comparison signal and generates a digital output signal based on the comparison signal. The digital output signal is representative of the temperature of the sensor.
    Type: Application
    Filed: November 18, 2008
    Publication date: May 20, 2010
    Inventors: Luverne R. Peterson, James R. Welch
  • Patent number: 6307906
    Abstract: The multiple-channel clock and data recovery scheme of the present invention derives a single clock signal from multiple mis-matched data streams. The single clock is phased to provide a clocking signal such that the data sampler of the clock and data recovery scheme performs bit center sampling of the data at the bit center average of all channels. The phase of the recovery clock is the average of all the data stream phases, and is the optimal sampling phase for minimum combined bit error rate of all the channels.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: October 23, 2001
    Assignee: Applied Micro Circuits Corporation
    Inventors: Todd M. Tanji, James R. Welch
  • Patent number: 6268777
    Abstract: The voltage controlled oscillator (VCO) of the present invention generally includes a energy storage circuit portion, an oscillator operably connected to the energy storage circuit portion, a varactor connected to the oscillator and energy storage circuit portion, and an amplitude controller that is operably connected to the energy storage circuit portion, oscillator, and varactor. The energy storage circuit portion includes an inductance and a capacitance. The oscillator provides an oscillating output signal having a frequency and an amplitude. The varactor has a capacitance and receives an input signal having a varying level. The capacitance of the varactor varies according to the level of the input signal. The amplitude controller sets the amplitude of the oscillating output signal. Meanwhile, the inductance of the energy storage circuit portion, the capacitance of the energy storage circuit portion, and the varying capacitance of the varactor are used to set the frequency of the oscillating output signal.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: July 31, 2001
    Assignee: Applied Micro Circuits Corporation
    Inventor: James R. Welch
  • Patent number: 5748020
    Abstract: A high speed capture latch includes differential data inputs, a latch clock input, a boost clock input, a current steering circuit, a switched current source, a latch element and first and second boost current sources. The current steering circuit has first and second differential control terminals which are coupled to the differential data inputs and control current through first and second current paths, respectively. The switched current source is coupled between the current steering circuit and a first voltage supply terminal and has a control terminal coupled to the latch clock input. The latch element is coupled between a second voltage supply terminal and the current steering circuit and provides a latch output. The first boost current source is coupled to the first current path between the latch element and the current steering circuit and has a control terminal coupled to the boost clock input.
    Type: Grant
    Filed: February 2, 1996
    Date of Patent: May 5, 1998
    Assignee: LSI Logic Corporation
    Inventors: Iain Ross Mactaggart, James R. Welch, Alan Fiedler
  • Patent number: 5694062
    Abstract: A self-timed phase detector for detecting the phase of an input signal, such as a high speed serial data stream. The self-timed phase detector includes a precharged latch, a phase detector circuit and a data valid gate. The precharged latch has a latch input, a sample clock input and first and second complementary latch outputs. The first and second complementary latch outputs have an active state and a precharged state. The phase detector circuit is coupled to the first latch output and generates a phase signal on a phase output as a function of the phase of the input signal. The data valid gate is coupled to the phase output for passing the phase signal when the latch outputs are in the active state and for blocking the phase signal when the latch outputs are in the precharged state.
    Type: Grant
    Filed: February 2, 1996
    Date of Patent: December 2, 1997
    Assignee: LSI Logic Corporation
    Inventors: James R. Welch, Iain Ross Mactaggart, Alan Fiedler
  • Patent number: 5633899
    Abstract: A phase locked loop locks on to the phase of a high speed serial data stream. The phase locked loop includes a multiple bit latch, a multiple-stage voltage controlled oscillator, a phase detection circuit and a feedback circuit. The multiple-bit latch has a plurality of data latch elements and boundary-detect latch elements. Each latch element includes a latch input for receiving the serial data stream, a sample clock input and a latch output. The multiple-stage voltage controlled oscillator has a voltage control input, a plurality of sample clock outputs and an adjustable delay between each sample clock output. Each sample clock output is coupled to a corresponding sample clock input. The phase detection circuit is coupled to the latch outputs of the data and boundary-detect latch elements and has a phase control output. A feedback circuit is coupled between the phase control output and the voltage control input.
    Type: Grant
    Filed: February 2, 1996
    Date of Patent: May 27, 1997
    Assignee: LSI Logic Corporation
    Inventors: Alan Fiedler, James R. Welch, Iain R. Mactaggart