Auxiliary power supply device and nonvolatile memory system including the same

Auxiliary power unit according to the present invention includes a first power storage unit; A first charging circuit to receive an input power to charge a first electric power storage; A second power storage unit having a longer time than the power supply has a slower rate than the power supplied to first power storage unit, a first power storage unit; A second charging circuit to receive an input power to charge the second power storage unit; And a sudden power to the first charging electric power electric power storage unit for a predetermined time during off supply to the external device, the switching part of the second power storage unit charging power after a predetermined time has elapsed supplied to an external device .