Teradyne, Inc.

Marc Spehlmann

Marc Hutner

John J Keough

The systems determine the parasitic capacitance of a signal path. That parasitic capacitance is then used to determine a leakage characteristic of the signal path, such as leakage current or leakage resistance. The capability of ATE channels to force current accurately, and to measure time intervals at prescribed voltages, can be used to multiply the accuracy of the force current function. Using these resources, small leakage currents&#x2014;for example, on the order of 10 nA or less&#x2014;can be measured.

Measuring a leakage characteristic of a signal path

Example automatic test equipment (ATE) includes: a per-pin measurement unit (PPMU); logic configured to execute a state machine to control the PPMU; memory that is part of, or separate from, the logic; and a control system to command the logic; where, in response to a command from the control system, the state machine is configured to obtain, at a known interval or ATE event, data that is based on an output of a measurement by the PPMU and to store the data in the memory, or to output data to the PPMU from the memory at a known interval or synchronous to an event.

Controlling a per-pin measurement unit

An example process for determining electrical path lengths includes: injecting current into a transmission line having a known capacitance per unit of length; determining a rate of change in voltage on the transmission line in response to the current; determining a capacitance of the transmission line based on the change in voltage; and determining an electrical path length of the transmission line based on the determined capacitance of the transmission line and the known capacitance per unit of length.

Determining electrical path length

A system for measuring the time interval of a signal. The second signal has a frequency higher than a frequency of the first signal. According to one embodiment, the system includes an electronic circuit for determining an approximation of the time based on a period of the second signal and for determining an adjustment to the approximation based on the second signal and a third signal corresponding to the second signal and aligned with the first signal. The length of the adjustment is less than the period of the second signal.

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North Reading, MA, United States of America

Marc Spehlmann