Semiconductor integrated circuit

#1. Field of the Invention

#The present invention relates to a semiconductor integrated circuit, and in particular to a circuit having an input buffer, an internal circuit and an output buffer, in which a power supply voltage supplied to the internal circuit is different from power supply voltages supplied to the input and output buffers.

#2. Related Art

#FIG. 1 is a structural view of semiconductor integrated circuit according to a first embodiment of the present invention.

#FIG. 2 is a view showing a specific structural example of an output circuit of the semiconductor integrated circuit.

#FIG. 3 is a view showing an example of switching signal generating circuit using an inner lead connected to a pad.

#Hereinafter, embodiments of a semiconductor integrated circuit according to the present invention will be described in detail with reference to the attached drawings.

#First Embodiment.

#FIG. 1 shows a configuraiton of semiconductor integrated circuit according to the present invention. The semiconductor integrated circuit 100 includes an internal circuit 15 which carries out a predetermined function, an output circuit 10 which drives an output signal for a subsequent circuit, and a power supply switching circuit 20 which switches a power supply for the output circuit 10. A level shift circuit (not shown) is interposed between the internal circuit 15 and the output circuit 10. The level shift circuit shifts a level of an output signal from the internal circuit 15 into a high level corresponding to an input stage of the output circuit 10.