Teradyne, Inc.

Richard P Davis

Jiann-Neng Chen

Eric Lenhart Truebenbach

Tushar K Gohel

John Joseph Arena

David John Lind

Teresa P Lopes

A driver circuit suitable for use in automatic test equipment includes a driver input for receiving an input signal and a driver output for producing an output signal. The driver input is coupled to respective inputs of first and second amplifiers. The first amplifier has an output that can substantially source current only, and the second amplifier has an output that can substantially sink current only. The outputs of the first and second amplifiers are coupled to the driver output, for producing the driver output signal. The driver circuit further includes a disable circuit having an input for receiving a drive disable signal and at least one output coupled to the first and second amplifiers. The driver circuit is constructed and arranged so that the disable circuit drives the first amplifier low and the second amplifier high in response to an activation of the drive disable signal. These actions cut off output current and effectively tristate the driver circuit. In response to a deactivation of the drive disable signal, the first and second amplifiers are restored to their normal operating modes.

Driver circuit employing high-speed tri-state for automatic test equipment

Analog test instrument architecture for performing functional testing of electronic circuit assemblies is disclosed. The analog test instrument includes a plurality of identical channels, each channel including circuitry for driving test stimuli and measuring responses at one node of a circuit assembly under test. The driver and measurement circuitry in each channel implement functions that traditionally have been implemented in a test system using discrete instruments. The analog test instrument further includes a master clock reference, which is used for synchronizing the operation of the driver and measurement circuits. Each channel further includes triggering circuitry for distributing trigger events within the channel and to the other channels; and, an input buffer, which is shared by the measurement circuits in the channel. The synchronized operation, distributed trigger events, and shared input buffers are used to improve the correlation of measurements made during functional testing.

Integrated multi-channel analog test instrument architecture providing flexible triggering

A tester that is capable of performing voltage measurements on electronic circuits is disclosed. The tester includes voltage measurement circuitry with an input, a plurality of gain stages, and switching circuitry coupled between the input and the gain stages. The switching circuitry includes a plurality of diodes, and a portion of the gain stages includes current-to-voltage converters. Each diode is coupled to a respective current-to-voltage converter. By applying different bias voltages to the respective current-to-voltage converters, the diodes can be made to conduct current for different ranges of voltages at the input. The output of each current-to-voltage converter is proportional to a respective voltage range.

Relayless voltage measurement in automatic test equipment

Analyzing electrical circuit boards by providing a probe having at least two contact tips close enough to each other to simultaneously contact a lead of a mounted integrated circuit element, but spaced apart from each other sufficiently to permit measurement of electrical activity in the lead segment between the tips; and measuring the voltage drop between the tips resulting from the flow of test current through the resistance of the lead segment. In preferred embodiments the test current is injected directly into the lead through a third tip of the probe while the third tip is in contact with the lead at a point farther from the IC than the other two tips.

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Billerica, MA, United States of America

Richard P Davis