Semiconductor device and power off method of a semiconductor device

A power-off method of a semiconductor device comprising a power sequence controller and a plurality of power sources, the power-off method comprising:

• starting, by the power sequence controller, a power-off operation of a first power source group including first and second power sources from among the plurality of power sources;
• starting, by the power sequence controller, a power-off operation of a second power source group including a third power source from among the plurality of power sources when a power voltage of the first power source group becomes a first reference voltage;
• and
• starting, by the power sequence controller, a power-off operation of a third power source group including a fourth power source from among the plurality of power sources when a power voltage of the second power source group becomes a second reference voltage, wherein magnitudes of the first reference voltage and the second reference voltage are different from each other.

A power-off method of a semiconductor device comprising a power sequence controller and a plurality of power sources, the power-off method comprising:

• starting, by the power sequence controller, a power-off operation of a first power source group at a first time, the first power source group including first and second power sources from among the plurality of power sources;
• starting, by the power sequence controller, a power-off operation of a second power source group at a second time when a first reference time has passed from the first time, the second power source group including a third power source from among the plurality of power sources;
• and
• starting, by the power sequence controller, a power-off operation of a third power source group at a third time when a second reference time has passed from the second time, the third power source group including a fourth power source from among the plurality of power sources,
• wherein lengths of the first reference time and the second reference time are different from each other.