US Patent 7756664 Test apparatus and measurement circuit

There is provided a test apparatus for testing a device under test. The test apparatus includes 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, and 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.