Semiconductor integrated circuit

Abstract

Abstract PURPOSE:To input a voltage of a power-supply or higher to an external input/ output terminal by a method wherein two transistors whose substrate is in a floating state are connected in series and are used as a P-channel transistor of an external output buffer, the transistor on one side is controlled by a control signal and the transistor on the other side is controlled by a voltage level of an external input/output terminal. CONSTITUTION:Two transistors whose substrate is in a floating state are connected in series and constitute a P-channel transistor of an external output transistor in such a way that the transistor on one side is controlled by a control signal and that the transistor on the other side is controlled by an input level from the outside. When an external input/output terminal 6 is used as an output terminal, a transistor 8 is turned off and a transistor 4 is turned on when a control signal 5b is set to an 'H' level; an electrode 2a of a transistor 2 is set to an 'L' level. Thereby, the transistor 2 is turned on and an electrode 1c of a transistor 1 is set to the '11' level. When the control signal 5a is set to the 'L' level, the transistor 2 is turned on; as a result, the external input/output terminal 6 becomes an output terminal at the 'H' level.

Inventors

• 👤 Yuji Osagawa
• 👤 長川　勇二

Bibliographic Details