| 摘要 |
In a semiconductor integrated circuit device, a MOS transistor has a relatively high built-in threshold, and in operation, a substrate bias is applied to the MOS transistor so as to cause the MOS transistor to forcibly have a reduced threshold, so that the MOS transistor operates at a high speed with the reduced threshold. When noise is detected, application of the substrate bias is stopped so that the MOS transistor restores the relatively high built-in threshold, and simultaneously, the MOS transistor is put in a standby condition, so that a malfunction can be prevented with the relatively high built-in threshold. <IMAGE> |
