Memory card having improved data protection

Claim 1

A memory card having a shape similar to a credit card for storing information, said memory card being connectable to an external device which has a power source for supplying power at a given voltage, said memory card comprising: memory means for storing information and having two internal power terminals for supplying power to said memory means and a plurality of internal information terminals for receiving and outputting information signals; power supply means connected to said internal power terminals for supplying power to said memory means at a voltage different from the given voltage; a plurality of external information terminals connected to said internal information terminals for electrically connecting said memory means to the external device; two external power terminals; means connected said external power terminals to said internal power terminals for electrically connecting said internal power terminals to the power source of the external device, said means including a resistor connected in series between one of said external power terminals and one of said internal power terminals; a capacitor connected between said internal power terminals; and switching means connectable to the external device to be actuated by a signal from the external device and connected to said resistor for short-circuiting said resistor in response to such signal.