Internal voltage generator and contactless IC card including the same

A contactless integrated circuit (IC) card, comprising:

• a voltage generator configured to generate a first internal voltage and a second internal voltage based on an input voltage received through an antenna of the contactless IC card, the second internal voltage having a level that is less than a level of the first internal voltage;
• an internal circuit configured to receive the second internal voltage and operate according to the second internal voltage;
• and
• a detector configured to detect a current consumed in the internal circuit and send a mode signal to the voltage generator based on the detected current,
• wherein the voltage generator includes,
• a regulator configured to generate the first internal voltage based on the input voltage and a first reference voltage,
• an internal voltage generator configured to generate the second internal voltage based on the first internal voltage such that the second internal voltage is less than the first internal voltage,
• a reference voltage generator configured to generate a second reference voltage based on the first internal voltage, the second reference voltage being generated without regard to a fluctuation component of the first internal voltage, and
• a switching unit, connected to the regulator, the internal voltage generator, and the reference voltage generator, configured to apply one of the first internal voltage and the second reference voltage as the first reference voltage in response to first and second switching control signals, the first and second switching control signals being based on the mode signal, the mode signal indicating an operation mode of the internal circuit.