Tektronix, Inc.

Advanced Energy Industries, Inc.

Aes Global Holdings Pte Ltd.

Donald F Murray

Steven K Sullivan

Lester L Larson

Roland E Andrews

William R Mark

Colin L Shepard

A Roy Kaufman

Collin L Shepard

This disclosure describes systems, methods, and apparatus for improving the signal-to-noise ratio, increasing sampling speed, and increasing the dynamic range of a pyrometer via improvements to the amplification section. In particular, single-stage non-differentiated amplifiers can be replaced with a differential amplifier circuit that increases gain without a proportional increase in noise. The differential amplifier circuit can comprise a pair of transimpedance amplifier circuits arranged in parallel that receive a differential current from a photo detector and generate a differential voltage output in response having a transconductance gain.

Fully-differential amplification for pyrometry

An instrument includes a probe providing a single signal path for conveying a signal from a circuit under test to the instrument. A receiver circuit within the instrument divides the path into an analog path and a digital path. The digital path includes a comparator for determining the logic state of the signal and producing a digital representation of the signal under test. The analog path includes a multiplexer to selectively couple one of a plurality of analog input signals to an output terminal for viewing on an oscilloscope. Preferably, the probe head includes a buffer amplifier to reduce loading on the circuit under test and to increase bandwidth of the signals conveyed along the test cable to the instrument. An electrically trimmable resistor is employed to terminate the transmission line of the test cable in its characteristic impedance in order to reduce reflections and maintain transmission bandwidth.

Capturing both digital and analog forms of a signal through the same probing path

In accordance with the present invention, a heater is included on an integrated circuit, together with a circuit for controlling the heater to selectively heat the integrated circuit and control the propagation delay time of signals passing through the integrated circuit. In a specific form of the invention, the propagation delay time of signals passing through at least a portion of an integrated circuit is measured and compared with a reference propagation delay time. The heater is controlled to increase the heat it produces when the measured propagation delay time is less than the reference propagation delay time. In addition, the heater is controlled to decrease the heat it provides when the measured propagation delay time is greater than the reference propagation delay time.

Digital integrated circuit propagation delay regulator

A calibrated automatic test system includes a test station for generating digital test function codes and a test head containing a plurality of I/O pins for connection to a device under test. Each I/O pin includes a pin electronics circuit responsive to the digital test function codes for providing test signals to the device under test. The pin electronics circuits are inexpensive CMOS IC's and lack the accuracy needed to test VLSI devices at the frequencies of interest. An external calibration unit is connected to each I/O pin and data measurements are taken which represent the performance of the CMOS IC's. The data measurements are converted to calibrated function codes representing desired data values which are then stored in correction memory circuits which respond to nominal digital test function codes and substitute in their places calibrated function codes which are then supplied to the pin electronics circuits.

Calibrated automatic test system

A cross bar multiplexer includes a plurality of small memory units addressable to indicate combinations of output conductors. The outputs of a plurality of memory units are ORed to provide the outputs for a full array.

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Beaverton, OR, United States of America

Donald F Murray