Semiconductor memory device enabling selective production of different semiconductor memory devices operating at different external power-supply voltages

摘要

Common circuit includes inactivation/activation circuits. Exclusive circuits include inverters IV3, IV4, IV5 and IV6 at the input portions thereof. When an SDR-SDRM is to be produced, inactivation/activation circuit outputs an inactivation signal DASL fixed to a ground voltage to exclusive circuit, while inactivation/activation circuit outputs a signal /OE inverted from an output enable signal OE to exclusive circuit. Inverters IV5 and IV6 in exclusive circuit then output a signal based on the signal /OE. Further, an N-channel MOS transistor and a P-channel MOS transistor in exclusive circuit are completely turned off, so that no through current flows from a power-supply node to a ground terminal in exclusive circuit. As a result, generation of the through current is prevented in an inactivated circuit.