EP0463261A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
IC card with improved power supply switching circuitry
Assignee: Mitsubishi Electric Corp
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Filing: 1990-12-28
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Granted: —
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Expires: 2010-12-28
Abstract
Abstract An IC card has its internal load divided into a plurality of load circuits 1, 2 through which substantially equal currents flow, and a power supply switching circuit 41, 42 is provided for each of the load circuits. The switching circuits switch the power supply for the IC card between an internal power supply 3 and an external power supply 7. The load currents flowing through the respective switching circuits are substantially equal.
Inventors
- 👤 Yoshikado C/O Mitsubishi Denki K. K. Sanemitsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 16:00
CPC Classifications
G; G06; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/0701; G06K7/00; G06K7/0008; G06K7/0013; G06K7/0086; G11; G11C; G11C5/00; G11C5/14; G11C5/141; G11C5/143; H; H02; H02J; H02J9/00; H02J9/04; H02J9/06; H02J9/061
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
173 words
An IC card comprising: a plurality of load circuits so arranged that substantially equal load currents flow therethrough; an internal power supply for providing operating voltages to said load circuits; a connector which is coupled to an external power supply when the IC card is connected to an external device; and power supply switching circuits, provided for respective ones of said load circuits, connected between said connector and said internal power supply, on one hand, and the respective ones of said load circuits, on the other hand, said power supply switching circuits performing such a switching operation that when said connector is coupled to the external device, an operating voltage is supplied from said external power supply to the respective ones of said load circuits through the associated ones of said power supply switching circuits, and when said connector is decoupled from the external device, an operating voltage is supplied from said internal power supply to the respective ones of said load circuits through the associated ones of said power supply switching circuits.
Claim 2
Dependent Claim
173 words
An IC card comprising: a plurality of load circuits so arranged that substantially equal load currents flow therethrough; an internal power supply for providing operating voltages to said load circuits; a connector which is coupled to an external power supply when the IC card is connected to an external device; and power supply switching circuits, provided for respective ones of said load circuits, connected between said connector and said internal power supply, on one hand, and the respective ones of said load circuits, on the other hand, said power supply switching circuits performing such a switching operation that when said connector is coupled to the external device, an operating voltage is supplied from said external power supply to the respective ones of said load circuits through the associated ones of said power supply switching circuits, and when said connector is decoupled from the external device, an operating voltage is supplied from said internal power supply to the respective ones of said load circuits through the associated ones of said power supply switching circuits.
Claim 3
Dependent Claim
60 words
An IC card according to Claim 1 wherein each of said power supply switching circuits comprises a pair of diodes having their one electrodes being connected to an associated load circuit, the other electrode of one of said diodes being connected to said connector, the other electrode of the other of said diodes being connected to said internal power supply.
Claim 4
Dependent Claim
22 words
An IC card according to Claim 2 wherein said one electrodes of said diodes are cathodes, and said other electrodes are anodes.
Claim 5
Dependent Claim
28 words
An IC card according to Claim 1 wherein each of said power supply switching circuits comprises a pair of transistors, such as bipolar transistors or field effect transistors.
Claim 6
Dependent Claim
74 words
An IC card according to Claim 1 wherein said power supply switching circuits comprise: diodes connected between said internal power supply and associated ones of said load circuits; transistors connected between said connector and the associated load circuits; and a voltage sensing circuit for sensing an external supply voltage supplied thereto from the external power supply through said connector when said connector is coupled to the external device, to turn on said respective transistors.
References Cited (Backward Citations)
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