PURPOSE: To start at high speed level, and to improve a write recovery characteristic by providing an nMOS transistor at the source side of an nMOS transistor for driving.

CONSTITUTION: nMOS transistors 1 and 2 are arranged between the source side of nMOS transistors 3 and 4 for driving in push-pull constitution and grounded lines. That is, the drain of the nMOS transistor 1 is connected to the source of the nMOS transistor 3, and the drain of the nMOS transistor 2 is connected to the source of the nMOS transistor 4. And the sources of the nMOS transistors 1 and 2 are connected to the grounded lines, and a ground voltage GND is supplied from the grounded line. A power supply voltage Vcc is supplied to each gate of these nMOS transistors 1 and 2. Thus, the write recovery characteristic is improved, and it is possible to operate at high speed.