| 摘要 |
<p>PURPOSE:To adjust the time until a prescribed circuit operation of a semiconductor integrated circuit is completed after starting, by changing the gain constant and threshold voltage of an MOS transistor (TR) in the seiconductor integrated circuit even after manufacture. CONSTITUTION:In case of the adjusting mode, a drain of the MOS(TR)Q2 is connected to a node NH1, the source to a node NH2 and the gate to the node NH1 with a switch circuit 1, respectively. Further, a voltage difference VH larger than a power supply voltage VDD subtracted from a threshold value of the TRQ2 is applied between the drain and the source of the TRQ2, and the TRQ2 is conductive. In this case, the implantation of hot carrier to the gate oxide is caused in the TRQ2 and the characteristics of the TRQ2 is changed. The change is directed toward the reduced gain constant and the increased threshold voltage. Through this change, the discharge time constant of a capacitor C1 at the normal mode is increased and the input and output delay time is adjusted.</p> |
