US 2003/0189483 A1 · Contactless IC card

Abstract

A contactless IC card having an antenna, a transmit/receive circuit for recovering data (clock) and electric power from a carrier signal received by the antenna, a logic circuit operated with the electric power supplied thereto from the transmit/receive circuit, and a memory. The transmit/receive circuit has a rectifier circuit for outputting data (clock) and rectifier circuits for electric power in such a manner that the carrier signal is inputted to each of the rectifier circuit for outputting data (clock) and the rectifier circuit for electric power. With this configuration, high frequency matching can be optimized separately for the rectifier circuit for outputting data (clock) and the rectifier circuit for electric power. It is also possible to separately optimize adjustments to a voltage of recovered data (clock) and a recovered supply voltage.

Claims7

Dependent claims

A contactless IC card comprising:

an antenna;
a transmit/receive circuit for recovering a data signal and electric power from a carrier signal received by said antenna;
a logic circuit operated with said electric power supplied thereto from said transmit/receive circuit;
and
a memory,
wherein said transmit/receive circuit includes a first rectifier circuit for outputting a data signal, and a second rectifier circuit for outputting electric power;
and
said first rectifier circuit and said second rectifier circuit are respectively applied with said carrier signal.

5 more elements

A contactless IC card comprising:

an antenna;
a transmit/receive circuit for recovering a data signal and electric power from a carrier signal received by said antenna;
a logic circuit operated with said electric power supplied thereto from said transmit/receive circuit;
and
a memory,
wherein said transmit/receive circuit includes a plurality of impedance elements and a plurality of charge pump circuits;
said plurality of impedance elements include a first impedance element having one end connected to a ground, a second impedance element having one end connected to the other end of said first impedance element, a third impedance element having one end connected to the other end of said second impedance element, and a fourth impedance element having one end connected to the other end of said third impedance element, said first impedance element having the other end connected to an input terminal of said carrier signal;
each said charge pump circuit includes a first diode, a second diode, a flying condenser having one end connected to a cathode (anode) of said first diode and to an anode (cathode) of said second diode, and a capacitor arranged between a cathode (anode) of said second diode and the ground;
a first charge pump circuit comprises said first diode having an anode (cathode) connected to the ground, said flying condenser having the other end connected to the other end of said second impedance element, and said second diode having a cathode (anode) connected to an output terminal of said data signal;
a second charge pump circuit comprises said first diode having the anode (cathode) connected to the ground, and said flying condenser having the other end connected to the other end of said third impedance element;
and
a third charge pump circuit comprises said first diode having the anode (cathode) connected to the cathode (anode) of said second diode of said second charge pump circuit, said flying condenser having the other end connected to the other end of said fourth impedance element, and said second diode having the cathode (anode) connected to an output terminal of said electric power.

9 more elements

Dependencies are inferred from the claim text.

Contactless IC card

Life of this patent

Contactless IC card

Life of this patent

Abstract

Claims7