Keithley Instruments, Inc.

Martin J Rice

Wayne C Goeke

James A Niemann

Matthew Holtz

Gregory Sobolewski

William Knauer

Mark D Zimmerman

William F Merkel

Carl Scharrer

Dave Rose

Warren Kumley

A source measure unit has a voltage output stage to provide a voltage across first and second output terminals to connect to a load, and a current output stage to provide a voltage to a first sense resistor, the source measure unit to switchably employ both the voltage output stage and the current output stage for a first range of output current, to regulate a common point, and either output voltage or output current, or employ only one of either the voltage output stage or the current output stage to provide voltage to both the first and second output terminals and a second sense resistor for a second range of output current, and to regulate either output voltage or output current.

High current extension for a dual-stage source measure unit

A test and measurement device, including a first input structured to receive a first voltage from a first conductor of a first triaxial cable, a second input structured to receive a second voltage from a second conductor of the first triaxial cable or a second triaxial cable, circuitry configured to change modes based on the first voltage and the second voltage; and an output structured to output a signal.

Triaxial power and control systems and methods

A test and measurement instrument includes a current measurement device having an input to accept an electrical current for measurement, an output to pass an output current output from the current measurement device, a sense path through which the electrical current is measured, and an active bypass device to pass an amount of current from the input of the current measurement device to the output of the current measurement device without passing through the sense path. The active bypass device may be tuned to allow the current sense device to operate without bypass within a specific range of target current values. Some current measurement devices may include more than one active bypass circuits, each tuned for a different range of input current values.

Multi-stage current measurement architecture

Disclosed is a test and measurement switch matrix. The test and measurement switch matrix includes a solid state switch to couple a test signal from a Device Under Test (DUT) to a test system. The solid state switch has a dual tee guard arrangement providing low leakage when off. The solid state switch also includes an optically coupled drive, which further improves isolation and reduces undesirable charge injection when changing switch states.

Current leakage and charge injection mitigating solid state switch

A method for calibrating a test instrument having an initial output voltage level and an open output relay can include programming the test instrument for a certain current level, starting a timer, and stopping the timer (responsive to the test instrument entering compliance) to determine a time interval. The method can also include determining whether the time interval is within a desired range.

Method for self calibration of measurement nonlinearity

A device with low dielectric absorption includes a printed circuit board (PCB), a component connection area including a first conductor layered on a top surface of the component connection area and a second conductor layered on a bottom surface of the component connection area, an aperture surrounding the component connection area, a low-leakage component connecting the component connection area to the PCB across the aperture, and a guard composed of a third conductor at least substantially surrounding the aperture on a top surface of the PCB and a fourth conductor at least substantially surrounding the aperture on a bottom surface of the PCB.

Guarded printed circuit board islands

A power envelope controller configured for use with an amplification stage and method are disclosed. The power envelope controller includes voltage feedback input circuitry configured to receive a voltage feedback signal representing an internal voltage drop across the amplification stage and current feedback input circuitry configured to receive a current feedback signal representing an output current of the amplification stage. An analog multiplier is configured to generate an internal power dissipation signal representing the internal power dissipation of the amplification stage based on the voltage and current feedback signals. A comparator circuit is configured to compare the internal power dissipation signal to a power threshold and generate a power control error signal when the internal power dissipation of the amplification stage exceeds the threshold.

Power envelope controller and method

A range-changing circuit for a measurement device having a desirable range includes an array of graduated impedances. And amplifier supplies an electrical voltage to at least one of the impedances of the array. A voltage sensing and limiting switch is provided in a feedback path of the amplifier. The switch limits said electrical voltage supplied to said at least one of the impedances in response to a sensed voltage that is sensed by the switch. An electrical voltage in the desirable range is developed across a different one of the impedances of the array based on an operation of the switch.

Active autoranging current sensing circuit

A circuit for alternatively controlling a current through a device and permitting measurement of a voltage across the device or controlling a voltage across the device and permitting measurement of a current through the device includes a sense impedance in series combination with the device; a buffer communicating with a common point between the sense impedance and the device; a current output stage; and a voltage output stage. When the circuit is controlling the current through the device, the voltage output stage forces the common point to a virtual ground and the current output stage forces a desired current through the device in response to a signal from the buffer. When the circuit is controlling the voltage across the device, the current output stage forces the common point to a virtual ground and the voltage output stage forces a desired voltage across the device in response to the signal from the buffer.

Dual output stage source measure circuit

A measurement system with selectable feedback paths includes a DUT interface including a first and a second DUT sensor, the first sensor being connected to a first feedback path for providing a measure of a first DUT characteristic, the second sensor being connected to a second feedback path for providing a measure of a second DUT characteristic, the sensors having a shared reference path and each feedback path including a set point adjustment; a differential amplifier system including differential inputs and differential outputs, the differential outputs being applied to the DUT interface; and a multi-pole switcher for connecting the differential inputs to either the first feedback path and the reference path or to the reference path and the second feedback path, respectfully. The first feedback path is selected to produce a desired first DUT characteristic or the second feedback path is selected to produce a second desired DUT characteristic.

Low glitch multiple form C summing node switcher

A test head for testing a DUT includes a probe card having a plurality of DUT probes, the probes being in contact with the DUT during the testing; an instrument carrier, the instrument carrier being located above the DUT during the testing; and a SMU mounted on the carrier for each of the probes, each SMU being operably connectable to a respective probe, wherein the carrier is moved with respect to the probe card to permit replacement of the probe card.

Growing community of inventors

Sagamore Hills, OH, United States of America

Martin J Rice