LOGIC INTERFACE CIRCUIT AND SEMICONDUCTOR MEMORY DEVICE USING THEREOF

摘要

PURPOSE: A logic interface circuit is provided which can convert a level using logic gates such as an inverter, an NAND gate and an NOR gate of an output terminal of function blocks in a chip without adding a level shifter. CONSTITUTION: A logic interface circuit comprises: a logic gate comprising a pull-up transistor(P1) to pull up an output terminal in response to at least more than one input signal and a pull-down transistor(N1) to pull down the output terminal; a current counterflow preventing circuit(N2) to prevent the current counterflow from the pull-up transistor to the first power source voltage by being connected between the first power source voltage and the pull-up transistor; a precharge circuit(P2) which is to precharge a common point of the current counterflow preventing circuit and the pull-up transistor to the first power source voltage in response to a signal from the output terminal, being connected in parallel with the current counterflow preventing circuit; and a current counterflow preventing and boost circuit(P3) which is connected between the second power source voltage and the output terminal, and prevents the current counterflow from the output terminal to the second power source voltage by being off in response to the first power source voltage in case that the first power source voltage is higher than the second power source voltage, and boosts the output terminal to the second power source voltage by being on in response to at least more than one input signal in case that the first power source voltage is lower than the second power source voltage. Therefore, the circuit can shift level by adding a simple circuit to a logic gate such as an inverter(11), an NAND gate and an NOR gate.