| 摘要 |
PURPOSE:To control a variation in substrate current and to keep the fluctuation of bias voltage less by a method wherein a circuit on a chip of IC is divided into a plurality of circuit blocks having a different operation timings and the foregoing circuit is caused to perform the same operation as a capacitive element. CONSTITUTION:IC on a chip 10 is divided into two circuit blocks 11-A and 11-B and the circuit 11-A is operated when a clock to a terminal 12 is at a low level while the circuit 11-B is set at a precharge. On the other hand, when the clock is at a high level the circuit 11-B is operated and the circuit 11-A is at a precharge. Namely, the fluctuation of the substrate current when the circuit 11-A begins to operate is suppressed by the substrate current of the counter direction when the circuit 11-B begins to precharge. However, the circuit 11-B is controlled by the circuit 11-A. As a result, the substrate current of the chip 10 is controlled at the operation time of the circuit and at the precharging without mounting any capacitive element on the chip, thereby keeping the fluctuation in the substrate bias current at a low level. |
