Patent · US Expired

Signal processing circuit for electro-optic probe

US6087838A · kind A · utility

1Cited by
3References
8Claims
0Family size

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Inventors

Key dates

Filing dateNov 9, 1998
Grant dateJul 11, 2000
Priority date
Expiry dateNov 9, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R1/071
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A signal processing circuit is provided for an electro-optic probe, which is used to perform testing of a printed-circuit board of high-speed processing. When laser beams are incident on the electro-optic probe which is brought into contact with the printed-circuit board, they are changed in polarization and are then converted to electric signals. The electric signals are amplified and are then subjected to analog-to-digital conversion to produce digital data. The laser beams (or optical pulses) are generated based on sampling pulses used for sampling of the analog-to-digital conversion. Herein, the sampling pulses are created based on a sweep signal and a step-like signal. The sweep signal increases in level with a certain slope and then decreases suddenly in one period of a trigger pulse signal. The step-like signal increases in level in a step-like manner, wherein it is increased by a predetermined level in response to each of the sampling pulses. A comparator produces a pulse signal consisting of pulses, each of which appears when the sweep signal coincides with the step-like signal in levels. Then, a mask circuit allows output of only the necessary pulses of the comparator as …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.