| 摘要 |
<p>PURPOSE:To carry out trimming after predicting the positions and bits to be trimmed by a method wherein the potential of a test terminal, provided in addition to a trimming terminal, is controlled in several steps before trimming operation. CONSTITUTION:In a reference voltage generating circuit, the potential of a test terminal 19 is controlled before trimming operation and the output potentials of an output terminal 8 corresponding to the respectively controlled potentials of the output terminal 19 are measured and positions, bits and so forth which are to be trimmed are predicted in accordance with those measured values and then trimming is carried out. With this constitution, defects of trimming failures caused by errors of positions, bits and so forth which are to be trimmed induced by discrepancies from originally designed values owing to misjudgement, element variation and production deviation at the time of integrated circuits or the like are significantly reduced and can be suppressed to the minimum level.</p> |
