Semiconductor integrated circuit device and power control method thereof

A semiconductor IC comprising:

• a logic block;
• and
• a voltage control circuit controlling an operating voltage supplied to the logic block,
• wherein the voltage control circuit controls the operating voltage to increase in a stepwise fashion during each transient mode from a sleep mode to an active mode of the logic block,
• wherein the voltage control circuit comprises:
• a power gating circuit controllably supplying the operating voltage to the logic block;
• and
• a control block configured to control the power gating circuit in response to the operating voltage and an externally input command,
• wherein the control block controls the power gating circuit to increase the operating voltage in the stepwise fashion,
• wherein the power gating circuit comprises:
• first and third transistors connected to an external power voltage and controlled by the control block;
• a second transistor connected between the first and third transistors and controlled by the control block;
• and
• a capacitor having one electrode connected to the second and third transistors and the other electrode connected to the ground,
• wherein a voltage of a node between the first and second transistors is supplied to the logic block as the operating voltage,
• wherein the control block comprises:
• a voltage detector detecting the operating voltage;
• and
• a controller controlling the power gating circuit in response to a detection result of the operating voltage and the command,
• wherein when the operating voltage reaches a reference voltage, the controller turns the first transistor on to directly supply the external power voltage to the logic block.