Regulator and power management integrated circuit including the same

A regulator comprising:

• a reference voltage generation circuit configured to generate a second reference voltage varied from a first reference voltage according to a dynamic control signal;
• an error amplifier configured to generate an error voltage based on the second reference voltage and a regulation voltage at an output node;
• a power transistor comprising a gate terminal connected to the error amplifier and configured to receive an input voltage to output the regulation voltage to the output node based on the error voltage;
• a dynamic voltage scaling (DVS) circuit connected to the reference voltage generation circuit and the output node and configured to drop the regulation voltage to the second reference voltage;
• and
• a control circuit configured to receive a power-off signal from a processor and further configured to turn off the power transistor when the regulation voltage drops to the second reference voltage by the DVS circuit.