| 摘要 |
PURPOSE:To provide sufficient operating margin to power supply fluctuation and to operate a titled circuit on a low power supply voltage, by dividing the entire internal circuit into plural circuit groups and providing a circuit representing all gate currents in the circuit groups with one bias. CONSTITUTION:The internal circuit of an LSI chip is divided into plural gate circuit groups and one bias circuit is arranged for each gate circuit. The bias circuit is provided with circuits 15-18 representing all the gate currents with one bus in the concerned circuit group and the fluctuation of amplitude in the bus is fed back via an even number of stages of inverters 20 so as to keep the desired amplitude constant. The compensation of the power supply voltage by means of the current bus is done by feeding back a voltage drop across the resistor 15 to the transistor 17 via the inverter stage 20. Since the change in the current of each gate circuit against the fluctuation of the power supply voltage is almost made to zero, the sufficient operating margin is provided even with a small logical amplitude of the circuit. |
