Memory systems and power management apparatuses including secondary power devices, and related methods of operation

A power management apparatus comprising:

• a secondary power device comprising a plurality of capacitors that are connected in parallel;
• a direct current (DC)-DC converter comprising a field effect transistor (FET) as a switching device and configured to supply power to the secondary power device;
• a measuring circuit configured to measure a switching profile of the DC-DC converter, and to determine a state of the secondary power device by comparing at least one time period of the switching profile with a reference time;
• and
• a control circuit configured to control the DC-DC converter,
• wherein the power management apparatus is in a memory system comprising at least one memory chip, and
• wherein the power management apparatus is configured to monitor the state of the secondary power device in real time without a forced discharge of at least one of the plurality of capacitors or without changing an operation mode of the memory system.

A memory system comprising:

• a power loss protection (PLP) system comprising a secondary power device comprising a plurality of capacitors that are connected in parallel, and a direct current (DC)-DC converter configured to supply power to the secondary power device;
• a main system comprising a control circuit and at least one memory chip;
• and
• a power circuit between the PLP system and the main system, and configured to supply power to the main system,
• wherein one of the PLP system or the main system further comprises a measuring circuit configured to monitor the secondary power device, based on a switching profile of the DC-DC converter, and
• wherein the measuring circuit is further configured to monitor a state of the secondary power device in real time without a forced discharge of at least one of the plurality of capacitors or without changing an operation mode of the memory system.