Auxiliary power supply test methods and electronic apparatus using the same

An electronic apparatus comprising:

• an auxiliary power supply unit configured to store electric energy and to supply auxiliary power to a system power supply line in response to a loss of a main power supply voltage;
• and
• a processor configured to control operation of the auxiliary power supply unit and a memory unit using power supplied to the system power supply line,
• wherein the processor repeatedly applies a charging enable signal and a charging disable signal to the auxiliary power supply unit,
• determines whether a charging voltage of the auxiliary power supply unit is less than a predetermined threshold voltage during a time interval in which the charging disable signal is applied to the auxiliary power supply unit, and
• generates a signal indicating whether the auxiliary power supply unit is defective in response to determining whether the charging voltage of the auxiliary power supply unit falls below the predetermined threshold voltage during the time interval in which the charging disable signal is applied to the auxiliary power supply unit.

A method of operating an auxiliary power supply unit, the method comprising:

• transmitting a charging disable signal to the auxiliary power supply unit, the charging disable signal disabling a charging operation of the auxiliary power supply unit;
• starting a timer;
• monitoring a charging voltage generated by the auxiliary power supply unit;
• determining if a value of the timer is greater than a timer threshold value;
• in response to determining that the value of the timer is greater than the timer threshold value, applying a charging enable signal to the auxiliary power supply unit, the charging enable signal enabling the charging operation of the auxiliary power supply unit;
• in response to determining that the value of the timer is less than the timer threshold value, determining if the charging voltage of the auxiliary power supply unit has fallen below a predetermined threshold voltage;
• and
• in response to determining that the charging voltage of the auxiliary power supply unit has fallen below the predetermined threshold voltage, generating a backup fail signal BUP_FA that indicates that the auxiliary power supply unit is defective.