Tektronix, Inc.

Richard A Van Epps

Ira G Pollock

Michael Duane Stevens

Kenneth P Dobyns

Michael J Mende

Dale R Daniels

An accessory device voltage management system includes an accessory device selectively coupled to a host. The host provides a bulk power supply and a low power supply voltage to the accessory device. The host receives accessory device parameters from the device and determines if the accessory device is a valid and supported device and, if so, sends commands to the accessory device to couple the bulk power supply voltage to a power supply circuit in the accessory device. The power supply circuit in the accessory device generates at least a first regulated voltage output.

Host controlled voltage input system for an accessory device

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.

Differential termination and attenuator network for a measurement probe

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. The internal termination voltage generator receives termination voltage parameters from a measurement instrument for generating the internal termination voltage.

Differential termination attenuator network for a measurement probe having an internal termination voltage generator

A differential termination and attenuator network having an automated 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 adjustable termination voltage. A control circuit generates scaled termination and compensation voltages and associated drive currents using the adjustable 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. An automated termination voltage generator automatically adjusts the adjustable termination voltage to match the DC common mode input voltage, which nulls the DC currents at the input nodes.

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Vancouver, WA, United States of America

Richard A Van Epps