| 摘要 |
PROBLEM TO BE SOLVED: To determine the precision of a bitline voltage distribution test in an FeRAM (ferroelectric random access memory) device. SOLUTION: In these method and circuit, a sense amplifier (130) is used to compare a bitline voltage (BL) with a series of reference voltages, and the upper and lower limits of a reference voltage range in which contradictory results are obtained by a detection operation is subsequently determined to thereby determine the measurement accuracy of a bitline voltage or an electric charge distribution read from an FeRAM cell 310. In one embodiment, an output signal (NT) of the sense amplifier (130) is used to control a pulldown transistor of an I/O line (165). In addition, by an alternate precharging method of the I/O line (165), a compression circuit (170) for processing a result value stream on the I/O line (165) is used to determine both the upper and lower limits. COPYRIGHT: (C)2004,JPO
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