A storage device includes a main system; a power loss protection integrated circuit (PLP IC) configured to provide output power to the main system based on external or internal power; and an auxiliary power supply configured to provide the internal power to the PLP IC. The main system may operate in a dump mode where data is backed up in response to at least one of a first condition or a second condition being satisfied. The PLP IC may provide the output power based on the internal power in response to a sudden power off (SPO) occurring. The first condition is satisfied when the SPO occurs and an SPO time is longer than a maximum filtering time. The second condition is satisfied when the SPO occurs and a voltage level of the internal power provided by the auxiliary power supply is lower than a voltage level of a threshold voltage.