Patents Examined by Lisa Sievers
  • Patent number: 7164994
    Abstract: A differential termination and attenuator network having an internal common mode termination voltage generator includes first and second termination resistors coupled in parallel with corresponding resistive attenuator circuits. A monitoring circuit coupled to input nodes of the network generates an output signal representative of the combination of a DC common mode voltage on the input nodes and an internal termination voltage. A control circuit generates scaled termination and compensation voltages and associated drive currents using the internal termination voltage and the monitoring circuit output signal. The scaled termination voltage and the scaled compensation voltage operate on the differential termination and attenuation network to optimize the dynamic range of a differential amplifier connected to the first and second attenuator outputs and null the DC currents at the input of the network.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: January 16, 2007
    Assignee: Tektronix, Inc.
    Inventors: Richard A. Van Epps, Ira G. Pollock, Michael D. Stevens, Dale R. Daniels
  • Patent number: 7164995
    Abstract: A differential termination and attenuator network receives a differential input signal having a DC common mode voltage. The network circuit includes input termination resistors coupled in parallel with corresponding resistive attenuator circuits. A monitoring circuit coupled to input nodes of the network generates an output signal representative of the combination of a DC common mode voltage on the input nodes and an applied termination voltage. A control circuit receives the output signal from the monitoring circuit and the applied termination voltage and generates a scaled termination voltage and a scaled compensation voltage and drive currents. The scaled termination and compensation voltages and drive currents provide DC currents through the input termination resistances and the attenuators for nulling DC currents at the network input nodes and provides a DC common mode voltage output from the attenuators for optimizing the dynamic range of a differential measurement amplifier.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: January 16, 2007
    Assignee: Tektronix, Inc.
    Inventors: Ira G. Pollock, Richard A. Van Epps