Patents by Inventor Marcellus C. Harper

Marcellus C. Harper 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: 8542143
    Abstract: A pipelined Analog-to-Digital Converter (ADC) stage includes a main sampling path having a first filter in series with a first sample and hold circuit and a sub-ADC sampling path having a second filter in series with a second sample and hold circuit driving a sub-ADC connected to a sub-Digital-to-Analog Converter (DAC). The frequency response of the main sampling path is matched to a frequency response of the sub-ADC sampling path such that a residue signal of the pipelined ADC stage stays within range.
    Type: Grant
    Filed: March 6, 2012
    Date of Patent: September 24, 2013
    Assignee: Crest Semiconductors, Inc.
    Inventors: Yusuf Haque, Ryan James Kier, Rex K. Hales, Paul Talmage Watkins, Marcellus C. Harper
  • Publication number: 20130234870
    Abstract: A pipelined Analog-to-Digital Converter (ADC) stage includes a main sampling path having a first filter in series with a first sample and hold circuit and a sub-ADC sampling path having a second filter in series with a second sample and hold circuit driving a sub-ADC connected to a sub-Digital-to-Analog Converter (DAC). The frequency response of the main sampling path is matched to a frequency response of the sub-ADC sampling path such that a residue signal of the pipelined ADC stage stays within range.
    Type: Application
    Filed: March 6, 2012
    Publication date: September 12, 2013
    Applicant: CREST SEMICONDUCTORS, INC
    Inventors: Yusuf Haque, Ryan James Kier, Rex K. Hales, Paul Talmage Watkins, Marcellus C. Harper
  • Patent number: 8344722
    Abstract: A method for measuring electric current applied to a load includes: with a sensor element having an inaccuracy, measuring an electric current supplied to a load to produce a measurement of the electric current; with the sensor element, measuring the electric current with an added perturbation current; and using measurements of the electric current taken with and without the perturbation current to refine the measurement of the electric current.
    Type: Grant
    Filed: May 17, 2010
    Date of Patent: January 1, 2013
    Assignee: Crest Semiconductors, Inc.
    Inventors: Marcellus C. Harper, William Picken, Yusuf Haque
  • Publication number: 20110279133
    Abstract: A method for measuring electric current applied to a load includes: with a sensor element having an inaccuracy, measuring an electric current supplied to a load to produce a measurement of the electric current; with the sensor element, measuring the electric current with an added perturbation current; and using measurements of the electric current taken with and without the perturbation current to refine the measurement of the electric current.
    Type: Application
    Filed: May 17, 2010
    Publication date: November 17, 2011
    Applicant: SIFLARE, INC
    Inventors: Marcellus C. Harper, William Picken, Yusuf Haque
  • Patent number: 8026838
    Abstract: A current-mode analog-to-digital converter includes: a current input node; a current-mode sample and hold circuit configured to output a steady source of electrical current having an analog value proportional to a sampled analog value of an electrical current at the current input node; and at least one current comparator that compares the electrical current output by the current-mode sample and hold circuit to at least one reference current to produce a digital representation of the sampled analog value of the electrical current at the current input node.
    Type: Grant
    Filed: August 27, 2010
    Date of Patent: September 27, 2011
    Assignee: Siflare, Inc.
    Inventors: Rex K. Hales, Marcellus C. Harper, Tracy Johancsik, Yusuf Haque
  • Patent number: 7928884
    Abstract: An Analog-to-Digital Converter (ADC) includes analog to digital conversion circuitry configured to receive an analog signal and output a digital representation of the analog signal on a plurality of data lines; a balancing circuit configured to encode the digital representation of the analog signal on the data lines such that a total number of 1's and 0's transmitted on any given data line is the same.
    Type: Grant
    Filed: March 23, 2009
    Date of Patent: April 19, 2011
    Assignee: SiFlare, Inc.
    Inventor: Marcellus C. Harper
  • Publication number: 20100321227
    Abstract: A current-mode analog-to-digital converter includes: a current input node; a current-mode sample and hold circuit configured to output a steady source of electrical current having an analog value proportional to a sampled analog value of an electrical current at the current input node; and at least one current comparator that compares the electrical current output by the current-mode sample and hold circuit to at least one reference current to produce a digital representation of the sampled analog value of the electrical current at the current input node.
    Type: Application
    Filed: August 27, 2010
    Publication date: December 23, 2010
    Applicant: SIFLARE INC.
    Inventors: Rex K. Hales, Marcellus C. Harper, Tracy Johancsik, Yusuf Haque
  • Patent number: 7804436
    Abstract: A current measuring system has an electrical component configured to provide an electrical current representative of a parameter of interest at an output node; and an analog to digital converter having a current input node in electrical communication with the output node of the electrical component.
    Type: Grant
    Filed: July 25, 2007
    Date of Patent: September 28, 2010
    Assignee: SiFlare, Inc
    Inventors: Rex K. Hales, Marcellus C. Harper
  • Patent number: 7705756
    Abstract: A system for multi-channel analog-to-digital conversion has a plurality of sampling modules, wherein each of the modules includes an input node and an output node; multiplexing circuitry configured to selectively route at least one of a plurality of electrical signals present on the output nodes to an analog-to-digital converter; and control circuitry in communication with the multiplexing circuitry, wherein the control circuitry is programmatically configured to control a sequence in which the electrical signals are routed to the analog-to-digital converter.
    Type: Grant
    Filed: November 1, 2007
    Date of Patent: April 27, 2010
    Assignee: Slicex, Inc.
    Inventor: Marcellus C. Harper
  • Publication number: 20090179788
    Abstract: An Analog-to-Digital Converter (ADC) includes analog to digital conversion circuitry configured to receive an analog signal and output a digital representation of the analog signal on a plurality of data lines; a balancing circuit configured to encode the digital representation of the analog signal on the data lines such that a total number of 1's and 0's transmitted on any given data line is the same.
    Type: Application
    Filed: March 23, 2009
    Publication date: July 16, 2009
    Applicant: SLICEX, INC.
    Inventor: Marcellus C. Harper
  • Publication number: 20080174319
    Abstract: A load board based test circuit includes a control module which receives user input over a user interface; a testing interface which makes a connection said load board based test circuit and a device under test; a memory which holds calibration values, test parameters, or test results; and a means for manipulating a test signal.
    Type: Application
    Filed: January 11, 2008
    Publication date: July 24, 2008
    Inventor: Marcellus C. Harper
  • Publication number: 20080170649
    Abstract: A digital signal synchronizer integrated circuit includes an input port which receives digital signals, programmable delay modules which synchronize the digital signals, and an output port which outputs the synchronized digital signals. A method of synchronizing a plurality of digital signals includes arranging synchronizer chips in a cascade and interconnecting the chips so that timing and control data may be communicated between the chips, connecting digital buses to the chips, synchronizing the digital signals carried by the digitals buses and outputting the synchronized signals.
    Type: Application
    Filed: January 11, 2008
    Publication date: July 17, 2008
    Inventor: Marcellus C. Harper
  • Publication number: 20080169947
    Abstract: A method of serializing parallel output from an analog-to-digital converter includes receiving a parallel output from an analog-to-digital converter; serializing the parallel output; and encoding the serialized output such that it is DC balanced. A system for serializing and DC balancing an analog-to-digital converter output includes an analog-to-digital converter that outputs digital data over a parallel bus; a serializer configured to receive said digital data from said parallel bus, said serializer serializing said digital data into serial output; and a means for encoding the serial output such that it is DC balanced.
    Type: Application
    Filed: January 11, 2008
    Publication date: July 17, 2008
    Inventor: Marcellus C. Harper
  • Publication number: 20080170610
    Abstract: A high speed serial testing circuit includes an input port that receives a serial signal; a means for altering the temporal characteristics of the serial signal; a means for altering the amplitude of the serial signal; a high speed analog-to-digital converter configured to receive the serial signal and output digital data representing the serial signal; and a memory module configured to receive and store the digital data. A method of testing high speed serial devices includes connecting an upstream host, a device under test, and a control device to a USB tester; altering the signals provided by the upstream host to test robustness of the device under test; sampling the signals using a analog-to-digital converter and storing the digital data in a memory.
    Type: Application
    Filed: January 11, 2008
    Publication date: July 17, 2008
    Inventor: Marcellus C. Harper
  • Publication number: 20080106448
    Abstract: A system for multi-channel analog-to-digital conversion has a plurality of sampling modules, wherein each of the modules includes an input node and an output node; multiplexing circuitry configured to selectively route at least one of a plurality of electrical signals present on the output nodes to an analog-to-digital converter; and control circuitry in communication with the multiplexing circuitry, wherein the control circuitry is programmatically configured to control a sequence in which the electrical signals are routed to the analog-to-digital converter.
    Type: Application
    Filed: November 1, 2007
    Publication date: May 8, 2008
    Inventor: Marcellus C. Harper
  • Publication number: 20080048644
    Abstract: A current measuring system has an electrical component configured to provide an electrical current representative of a parameter of interest at an output node; and an analog to digital converter having a current input node in electrical communication with the output node of the electrical component.
    Type: Application
    Filed: July 25, 2007
    Publication date: February 28, 2008
    Inventors: Rex K. Hales, Marcellus C. Harper