| 摘要 |
PURPOSE:To reduce leak current of the titled device provided with a substrate bias generating circuit by a method wherein a depletion type transistor is placed in an OFF state by a potential generated at the time of power ON with a polarity same as that of the substrate potential. CONSTITUTION:A substrate bias generating circuit 20 and a gate potential generating circuit 21 are provided in a MOS IC provided with an input gate protecting circuit consisting of a depletion type transistor. The substrate bias generating circuit 20 contains an oscillating circuit 22 whose output is supplied to the substrate 33 through a parallel circuit inculding a capacitor 29, diode 31, and a transistor 32. The gate potential generating circuit 21 is provided with an oscillating circuit 22' whose output is supplied to the gate of a transistor of the input gate protecting circuit through a capacitor 34 and transistor 36. When the power is made, a potential with a higher changing speed than the potential supplied to the substrate is supplied to the protecting circuit, thereby reducing transistor leak current. |
