SMART CARD AND READER/WRITER FOR DETECTING AN OPERATING VOLTAGE OF THE SMART CARD

摘要

Many different types of smart card are available today and these operate at different operating voltages. This presents a problem in that if a particular type of smart card which operates at a given voltage is used with an incompatible reader/writer unit that operates at a different voltage, then damage to the smart card is sustained. It is difficult for the reader/writer unit to determine the correct operating voltage for a smart card without damaging the smart card. To address this problem, means for encoding information about a smart card's operating voltage is provided on the smart card. The encoding means is positioned on the smart card, relative to an interface to integrated circuits on the smart card, in such a way that the encoded information is accessible to a reader/writer unit before damage to the smart card can occur. The encoding means is positioned on the smart card such that it is more peripheral than the interface to integrated circuits supported by the smart card. The encoding means preferably comprises a row of electrically conducting pins positioned along a leading edge of the smart card. Some or all of these pins are electrically connected to a single pin with a ground potential. The number and position of the ground potential pins is used to encode information about the operating voltage of the smart card.