US Patent 7705627 Semiconductor device using power gating

A semiconductor device using power gating includes a circuit unit and a current blocking unit. The circuit unit is connected between a first voltage node and a virtual voltage node. The current blocking unit is connected between the virtual voltage node and a second voltage node, and can block a leakage current of the circuit unit in a standby mode. Also, the current blocking unit controls whether or not to connect the virtual voltage node and the second voltage node in response to a plurality of random signals whose logic states are randomly transited when the standby mode is switched to an active mode. The semiconductor device can minimize ground bounce noise and can stably apply a voltage to a circuit storing data in a data retention mode.