Semiconductor Device

• US 20080143531A1
• Filed: 12/13/2007
• Published: 06/19/2008
• Est. Priority Date: 12/18/2006
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tadokoro, Asami
• Granted Patent: US 8,160,636 B2
• Time in Patent Office: Days
• US Class Current: 340/572.1
• 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: G08B 13/2417 having a radio frequency identification chip

Abstract

A semiconductor device is provided, which comprises a first circuit including a variable resistance element, a second circuit electrically connected to the first circuit, and an antenna circuit configured to supply power to the first circuit. A resistance value of the variable resistance element is changed in accordance with the power supplied from the antenna circuit, and the variable resistance element is electrically connected in series between the second circuit and the antenna circuit.

Claims

1. A semiconductor device comprising:

a first circuit including a variable resistance element;

a second circuit electrically connected to the first circuit; and

an antenna circuit configured to supply power to the first circuit,

wherein;

a resistance value of the variable resistance element is changed in accordance with the power supplied from the antenna circuit, and

the variable resistance element is electrically connected in series between the second circuit and the antenna circuit.

2. The semiconductor device according to claim 1, wherein the variable resistance element includes a Schottky barrier diode.

3. The semiconductor device according to claim 1, wherein the variable resistance element includes a transistor, wherein one of a source and a drain of the transistor is electrically connected to the second circuit, and wherein the other of the source and the drain of the transistor is electrically connected to the antenna circuit.

4. The semiconductor device according to claim 1, wherein the variable resistance element includes at least a first transistor and a second transistor, wherein one of a source and a drain of the first transistor and one of a source and a drain of the second transistor are electrically connected to the second circuit, and wherein the other of the source and the drain of the first transistor and the other of the source and the drain of the second transistor are electrically connected to the antenna circuit.

5. The semiconductor device according to claim 1, wherein the variable resistance element includes a plurality of transistors electrically connected in series, and wherein gate electrodes of the plurality of transistors are electrically connected.

6. The semiconductor device according to claim 1, wherein the variable resistance element includes at least two resistors electrically connected in series and at least one switching element, and wherein the switching element is disposed between the two resistors.

7. The semiconductor device according to claim 1, wherein the first circuit is a protection circuit, and wherein the second circuit is one of a rectifier circuit, a demodulation circuit, and a modulation circuit.

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

9. A semiconductor device comprising:

a first circuit including a variable resistance element;

a second circuit electrically connected to the first circuit;

an antenna circuit configured to supply power to the first circuit; and

a third circuit including a first portion and a second portion,

wherein;

the first portion configured to detect an output of the protection circuit,

the second portion configured to make a comparison between an output of the first portion and reference power,

a resistance value of the variable resistance element is changed in accordance with a result of the comparison, and

the variable resistance element is electrically connected in series between the second circuit and the antenna circuit.

10. The semiconductor device according to claim 9, wherein the variable resistance element includes a Schottky barrier diode.

11. The semiconductor device according to claim 9, wherein the variable resistance element includes a transistor, wherein one of a source and a drain of the transistor is electrically connected to the second circuit, and wherein the other of the source and the drain of the transistor is electrically connected to the antenna circuit.

12. The semiconductor device according to claim 9, wherein the variable resistance element includes at least a first transistor and a second transistor, wherein one of a source and a drain of the first transistor and one of a source and a drain of the second transistor are electrically connected to the second circuit, and wherein the other of the source and the drain of the first transistor and the other of the source and the drain of the second transistor are electrically connected to the antenna circuit.

13. The semiconductor device according to claim 9, wherein the variable resistance element includes a plurality of transistors electrically connected in series, and wherein gate electrodes of the plurality of transistors are electrically connected.

14. The semiconductor device according to claim 9, wherein the variable resistance element includes at least two resistors electrically connected in series and at least one switching element, and wherein the switching element is disposed between the two resistors.

15. The semiconductor device according to claim 9, wherein the first circuit is a protection circuit, and wherein the second circuit is one of a rectifier circuit, a demodulation circuit, and a modulation circuit.

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

17. A semiconductor device comprising:

a first circuit including a variable resistance element;

a second circuit electrically connected to the first circuit;

an antenna circuit configured to supply power to the first circuit; and

a third circuit including a first portion and a second portion,

wherein;

the first portion configured to detect second power outputted from the protection circuit and convert the second power into third power to output,

the second portion configured to make a comparison between the third power and reference power and generate a signal in accordance with a result of the comparison,

a resistance value of the variable resistance element is changed in accordance with the signal, and

the variable resistance element is electrically connected in series between the second circuit and the antenna circuit.

18. The semiconductor device according to claim 17, wherein the variable resistance element includes a Schottky barrier diode.

19. The semiconductor device according to claim 17, wherein the variable resistance element includes a transistor, wherein one of a source and a drain of the transistor is electrically connected to the second circuit, and wherein the other of the source and the drain of the transistor is electrically connected to the antenna circuit.

20. The semiconductor device according to claim 17, wherein the variable resistance element includes at least a first transistor and a second transistor, wherein one of a source and a drain of the first transistor and one of a source and a drain of the second transistor are electrically connected to the second circuit, and wherein the other of the source and the drain of the first transistor and the other of the source and the drain of the second transistor are electrically connected to the antenna circuit.

21. The semiconductor device according to claim 17, wherein the variable resistance element includes a plurality of transistors electrically connected in series, and wherein gate electrodes of the plurality of transistors are electrically connected.

22. The semiconductor device according to claim 17, wherein the variable resistance element includes at least two resistors electrically connected in series and at least one switching element, and wherein the switching element is disposed between the two resistors.

23. The semiconductor device according to claim 17, wherein the first circuit is a protection circuit, and wherein the second circuit is one of a rectifier circuit, a demodulation circuit, and a modulation circuit.

24. The semiconductor device according to claim 17, further comprising a buttery.