Memory card having improved data protection
First 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.
1 Assignment
0 Petitions
Accused Products
Abstract
A memory card for storing information having a shape similar to that of a credit card. The memory card includes a capacitor connected across power terminals of a RAM and a resistor connected between one power terminal of the RAM and an external terminal. A switch is connected in parallel with the resistor for short-circuiting the resistor. The switch is controlled in accordance with a signal from an external device. When the RAM is accessed by the external device, the switch is closed so that the impedance of the power supply line is decreased.
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Citations
3 Claims
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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:
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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. - View Dependent Claims (2, 3)
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Specification