Semiconductor Device

• US 20080094180A1
• Filed: 10/11/2007
• Published: 04/24/2008
• Est. Priority Date: 10/18/2006
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tadokoro, Asami, Kato, Kiyoshi
• Granted Patent: US 7,907,902 B2
• Time in Patent Office: Days
• US Class Current: 340/10.3
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0715 the arrangement including means to regulate power transfer to the integrated circuit
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 1/2283 mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package
• CPC Class Codes: H02H 9/02 responsive to excess current current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025

Abstract

Of a wireless communication system, an RF tag which can operate normally even when a communication distance is extremely short, like the case where the RF tag is in contact with a reader/writer, whereby the reliability is improved. The RF tag which communicates data by wireless communication includes a comparison circuit which compares electric power supplied from outside with reference electric power and a protection circuit portion which is operated when the electric power supplied from outside is higher than the reference electric power in the comparison circuit.

Claims

1. A semiconductor device comprising:

an antenna;

a comparison circuit configured to compare electric power supplied from the antenna with reference electric power; and

a protection circuit configured to operate when the electric power supplied from the antenna is higher than the reference electric power in the comparison circuit.

2. The semiconductor device according to claim 1, further comprising a rectifier circuit configured to convert alternating-current power source voltage supplied from the antenna to a direct-current power source voltage.

3. The semiconductor device according to claim 1, further comprising a logic circuit configured to process data.

4. The semiconductor device according to claim 1, further comprising a buttery.

5. A semiconductor device comprising:

an antenna;

a comparison circuit configured to compare electric power supplied from the antenna with reference electric power; and

a protection circuit disposed between one terminal of the antenna and the other terminal of the antenna,

wherein current flows in the protection circuit when the electric power supplied from the antenna is higher than the reference electric power in the comparison circuit.

6. The semiconductor device according to claim 5, further comprising a rectifier circuit configured to convert alternating-current power source voltage supplied from the antenna to a direct-current power source voltage.

7. The semiconductor device according to claim 5, further comprising a logic circuit configured to process data.

8. The semiconductor device according to claim 5, further comprising a buttery.

9. A semiconductor device comprising:

an antenna;

a comparison circuit configured to compare electric power supplied from the antenna with reference electric power; and

a protection circuit disposed between one terminal of the antenna and the other terminal of the antenna,

wherein;

the protection circuit includes at least a switch, and

the switch turns on, and current flows in the protection circuit when the electric power supplied from the antenna is higher than the reference electric power in the comparison circuit.

10. The semiconductor device according to claim 9, further comprising a rectifier circuit configured to convert alternating-current power source voltage supplied from the antenna to a direct-current power source voltage.

11. The semiconductor device according to claim 9, further comprising a logic circuit configured to process data.

12. The semiconductor device according to claim 9, further comprising a buttery.

13. The semiconductor device according to claim 9, wherein the switch is a transistor.

14. The semiconductor device according to claim 9,

wherein the one terminal of the antenna is electrically connected to one terminal of the switch, and

wherein the other terminal of the switch is electrically connected to the other terminal of the antenna.

15. A semiconductor device comprising:

an antenna;

a comparison circuit configured to compare electric power supplied from the antenna with reference electric power; and

a protection circuit disposed between one terminal of the antenna and the other terminal of the antenna,

wherein;

the protection circuit includes at least a switch and a load, and

the switch turns on, the load operates, and current flows in the protection circuit when the electric power supplied from the antenna is higher than the reference electric power in the comparison circuit.

16. The semiconductor device according to claim 15, further comprising a rectifier circuit configured to convert alternating-current power source voltage supplied from the antenna to a direct-current power source voltage.

17. The semiconductor device according to claim 15, further comprising a logic circuit configured to process data.

18. The semiconductor device according to claim 15, further comprising a buttery.

19. The semiconductor device according to claim 15, wherein the switch is a transistor.

20. The semiconductor device according to claim 15,

wherein the one terminal of the antenna is electrically connected to one terminal of the switch,

wherein the other terminal of the switch is electrically connected to one terminal of the load, and

wherein the other terminal of the load is electrically connected to the other terminal of the antenna.

21. The semiconductor device according to claim 15, wherein the load is at least one of a capacitor, a resistor, and an inductor.