A contactless smart card with excess current demand detection

摘要

A smart card with an interface 12 for providing power to a microprocessor 22 having a shunt regulator 24 for controlling a voltage supply thereto, wherein the regulator 24 uses a comparator 32 to compare the voltage supply to a first reference voltage supply 34 to produce a control voltage 36 which is compared to a second reference voltage supply 42 to detect when the microprocessor 22 is drawing too much current from the interface.