| 摘要 |
PURPOSE:To disable to select the unnecessary operating mode even after packaging by fusing a fuse link by the irradiation of a laser beam or flowing of an overcurrent. CONSTITUTION:A series circuit comprising a MOS transistor (TR) array Q1 and a resistor R constitutes an input level detection circuit and the fuse link FL is inserted in this circuit. The fuse link FL is fused by the irradiation of the laser beam. When the fuse link FL is blown, the selection of the prescribed mode is disabled.
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