Patent ID: 7756664

Claim:
A test apparatus for testing a device under test, comprising: a gradient adjusting section that separately adjusts a gradient of a rising edge of a signal under measurement which is output from the device under test and a gradient of a falling edge of the signal under measurement; a sampling section that samples the signal under measurement whose edge gradients are adjusted by the gradient adjusting section; a judging section that judges whether the device under test passes or fails the test based on a result of the sampling performed by the sampling section; and a comparator that compares a level of a signal output from the device under test with a reference level to generate a comparison result signal, and outputs the comparison result signal as the signal under measurement, wherein the gradient adjusting section is positioned between the comparator and the sampling section, and adjusts the gradients of the edges of the signal under measurement which is output from the comparator and inputs the adjusted signal under measurement into the sampling section, the comparator outputs, as the signal under measurement, the comparison result signal which is a differential signal, the test apparatus further comprises a differential buffer that converts the signal under measurement which is output from the comparator and is a differential signal into a single-ended signal under measurement, and the gradient adjusting section adjusts the gradients of the edges of the signal under measurement which is output from the differential buffer, and inputs the adjusted signal under measurement into the sampling section.