Analog Devices,inc.

Teradyne, Inc.

Stephen A Cohen

Jiann-Neng Chen

Timothy W Sheen

Thomas G O'Dwyer

Joseph Francis Wrinn

Richard R Muller, Jr

Michael A Baglino

An integrated circuit for automatic calibration control of pin electronics is disclosed. The integrated circuit includes a substrate, and both pin electronics and a calibration circuit integral with the substrate. The calibration circuit is dedicated to a single channel of automatic testing equipment for a single pin of a device under test. Each sub-circuit of the pin electronics may include a replica output. The replica output is electrically coupled to the calibration circuit. The calibration circuit may include a multiplexor for receiving each of the replica outputs from the sub-circuits, such as a comparator, load and a driver, and for selectively switching between the replica outputs to determine calibration parameters for one or more levels of the sub-circuit. The calibration circuit includes a state machine capable of determining calibration parameters including offset and gain. After determining the calibration parameters, the state machine can compensate the one or more levels for each sub-circuit of the pin electronics based upon the calibration parameters.

Calibration control for pin electronics of automatic testing equipment

A current mirror includes an output stage that responds to a change in mirror output voltage with a change in output stage current, and an output compensation stage that, in response to the change in output stage current, introduces an output compensation current to oppose a change in mirror output current resulting from the change in output stage current.

Current mirror apparatus and method for reduced early effect

Correction sensors and methods are provided for reduction of differential-heating signal errors along a differential signal path of an electronic circuit. An exemplary correction sensor includes first and second transistors which are coupled to different sides of the differential signal path and a differential error amplifier that couples a differential correction signal to the differential signal path in differential response to a differential error signal generated by like terminals of the first and second transistors. Bias generators are preferably included to bias at least one set of same terminals of the first and second transistors that differ from the like terminals.

Sensor structures and methods for reduction of differential-heating signal errors in integrated circuits

A shaped pulse generation circuit for applications such as automatic test equipment pin drivers employs an active feedback circuit that adds a pre-emphasis to the output pulses, thereby compensating for the effect of the transmission system between the pin driver and the device under test. Current pulses are applied to the pin driver output transistors in conjunction with the production of rising and falling output pulse edges to produce edge overshoots that are mitigated during pulse transit to the device under test. The driver circuit together with the pre-emphasis active feedback circuit can be integrated onto a single chip, with an additional programming circuit employed to control the amount of pre-emphasis.

Pulse generation circuit and method with transmission pre-emphasis

An apparatus and method are disclosed for testing connections between printed circuit boards and components mounted thereon. A conductive loop is formed by forward biasing a parasitic diode that is inherently present between an integrated circuit (IC) lead and the ground plane of the IC. A magnetic field is created by an antenna mounted above the component to be tested. When the antenna is energized by an RF source, a voltage is induced in the conductive loop if the loop is continuous, i.e., if all of the connections are properly made. The voltage in the loop is measured and compared to a selected threshold to produce a pass/fail indication. This tester may be implemented as an improvement to a standard type of 'bed-of-nails' printed circuit board tester. The antenna may be implemented as an array of spiral loop antennas, with adjacent antennas producing magnetic fields that are 90 degrees out of phase with each other.

Printed circuit board tester using magnetic induction

Apparatus for precisely and quickly measuring the length of a line under test to an electrical discontinuity of the line, the apparatus including an edge generator for providing an edge to one end of the line, a reflection detector for detecting the edge reflection returning from the discontinuity to the one end and triggering the edge generator to provide an edge at a fixed time after detecting the edge reflection so as to cause the edge generator to repeatedly provide the edges at a frequency related to the propagation delay in the length of line, and a frequency measurer connected to measure the frequency.

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Andover, MA, United States of America

Stephen A Cohen