Hitachi, Ltd.

Renesas Technology Corp.

Takehiro Ookawa

Hiroshi Yoshigi

Tadashi Oonishi

Kazuki Watanabe

Ryouzou Yoshino

Shin Kanno

Koji Tsuru

Hisanobu Dobashi

Shigeru Date

Kimiaki Andou

Masahiro Sugiura

For obtaining an IC card low in both power consumption and manufacturing cost, operating conditions in case of going through a contact point, which conditions are associated with supply voltage and signal level in an internal circuit, are to lie within operating conditions in case of going through an antenna. To this end, an IC chip of the IC card is provided with a voltage conversion circuit for lowering a supply voltage supplied through the contact point and a level conversion circuit for lowering the level of a signal fed from the contact point to the internal circuit and raising the level of a signal fed from the internal circuit to the contact point.

Dual interface IC card

Composite IC card

An IC card capable of preventing the occurrence of an abnormal state of coupling and thereby preventing malfunction of IC is provided. The IC card is provided with a coupling detecting means for detecting a contact coupling and a non-contact coupling and is also provided with a communication cut-off means which, when there are supplied electric power and a signal for inducing the other coupling during communication by one coupling, cuts off communication so that communication is performed by neither of the couplings.

IC card

Growing community of inventors

Tachikawa, Japan

Takehiro Ookawa