Semiconductor device

• US 8,160,636 B2
• Filed: 12/13/2007
• Issued: 04/17/2012
• 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
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US11/955,734
• Publication Number:
  US 20080143531A1
• Time in Patent Office: 1,587 Days
• Field of Search: 455 411- 413, 455/217, 455298-299, 4553431-3434, 455/572, 4551931-1933, 455269-2761, 455/550.1, 455/558, 455/333, 340/572.1
• US Class Current: 455/550.1
• 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,

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

the antenna circuit has a first terminal and a second terminal, and the variable resistance element is electrically connected to the first terminal and not connected to the second terminal.

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, wherein the variable resistance element has a higher resistance value as the power supplied from the antenna circuit being higher.

9. The semiconductor device according to claim 1, further comprising a battery.

10. 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 first 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,

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

the antenna circuit has a first terminal and a second terminal, and the variable resistance element is electrically connected to the first terminal and not connected to the second terminal.

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

12. The semiconductor device according to claim 10, 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.

13. The semiconductor device according to claim 10, 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.

14. The semiconductor device according to claim 10, 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.

15. The semiconductor device according to claim 10, 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.

16. The semiconductor device according to claim 10, 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.

17. The semiconductor device according to claim 10, wherein the variable resistance element has a higher resistance value when the output of the first portion is higher than the reference power comparing when the output of the first portion is lower than the reference power.

18. The semiconductor device according to claim 10, further comprising a battery.

19. 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 first 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,

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

the antenna circuit has a first terminal and a second terminal, and the variable resistance element is electrically connected to the first terminal and not connected to the second terminal.

20. The semiconductor device according to claim 19, wherein the variable resistance element includes a Schottky barrier diode.

21. The semiconductor device according to claim 19, 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.

22. The semiconductor device according to claim 19, 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.

23. The semiconductor device according to claim 19, 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.

24. The semiconductor device according to claim 19, 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.

25. The semiconductor device according to claim 19, 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.

26. The semiconductor device according to claim 19, wherein the variable resistance element has a higher resistance value when the third power is higher than the reference power comparing when the third power is lower than the reference power.

27. The semiconductor device according to claim 19, further comprising a battery.