Patent ID: 6275023
Filing Date: 2001-08-14
Classification: G01R

Abstract:
A semiconductor device tester for judging a state of a semiconductor device under test by supplying a predetermined test waveform from a driver circuit provided in a pin electronics circuit to said semiconductor device under test through a transmission line, receiving the response waveform from said semiconductor device through said transmission line after a predetermined time from the supply of the predetermined test waveform to said semiconductor device and comparing a state of the response waveform with a predetermined voltage level by an analog comparator, said semiconductor device tester comprising:a first switch circuit connected between said transmission line and an input terminal of said analog comparator, said first switch circuit being adapted to be turned ON according to a change of the response waveform from High level to Low level to connect an impedance substantially equal to a characteristic impedance of said transmission line to said transmission line;a second switch circuit connected between said transmission line and said input terminal of said analog comparator, said second switch circuit being adapted to be turned ON according to a change of the response waveform from Low level to High level to connect an impedance substantially equal to the characteristic impedance of said transmission line to said transmission line;a first voltage generator circuit connected to said first switch circuit for generating a voltage for clamping the level of the response waveform at a certain Low level; anda second voltage generator circuit connected to said second switch circuit for generating a voltage for clamping the level of the response waveform at a certain High level.