| 摘要 |
PURPOSE: A test system for a semiconductor memory device is provided, which evaluates the performance of the device more accurately by varying the level of the power supply voltage applied to the memory device during a pump test. CONSTITUTION: If a pump test item is selected, a tester(4) applies a power supply voltage(A) to a load board(3) and applies a pulse signal(B) having a level variation. The applied pulse signal can be being applied by the tester, or by using an additional pulse generator. The power supply voltage and the pulse signal are applied at the same time so that the level of the power supply voltage applied during a write and a read operation oscillates with a level variation. At read and write operation, the power supply voltage applied to the semiconductor memory device is fixed at a certain level and the pulse signal oscillates with a predetermined level variation. So the power supply voltage periodically oscillates with a certain level variation.
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