US Patent 7499357 Semiconductor memory device

A semiconductor memory device includes a bit line precharge voltage generator, a bit line precharge circuit, a voltage drop circuit, and a voltage supply driver. The bit line precharge voltage generator generates a bit line precharge voltage. The bit line precharge circuit precharges a bit line. The voltage drop circuit drops a voltage level of the bit line precharge voltage in a standby mode to generate a low precharge voltage and provides the low precharge voltage to the bit line precharge circuit. The voltage supply driver provides the bit line precharge voltage to the bit line precharge circuit in an active mode.