US Patent 7139214 Semiconductor integrated circuit

An apparatus and method to reduce, during standby time, electric power caused by the leakage current flowing through a storage transistor in a 3-transistor dynamic cell. Source electrodes of storage transistors in a plurality of 3-transistor dynamic cells constituting a memory array are connected, and a switch is provided between the source electrode and a power supply terminal. The leakage current during the standby time is interrupted by bringing the switch into a conducting state during the active time, and by bringing the switch into a nonconducting state during the standby time.