Semiconductor device

• US 7,881,693 B2
• Filed: 10/05/2007
• Issued: 02/01/2011
• Est. Priority Date: 10/17/2006
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kurokawa, Yoshiyuki
• Primary Examiner(s): Dao; Minh D
• Application Number:
  US11/868,027
• Publication Number:
  US 20080214132A1
• Time in Patent Office: 1,215 Days
• Field of Search: 455/343.1, 455/127.1, 455/572, 455/571, 455/13.4, 340/572.8, 235/380
• US Class Current: 455/343.1
• 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: G06K 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• CPC Class Codes: G11C 5/142 Contactless power supplies, e.g. RF, induction, or IR
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/27 characterised by the type of receiving antennas, e.g. rectennas
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02M 7/103 Containing passive elements (capacitively coupled) which are ordered in cascade on one source

Abstract

In an RF tag, a mask ROM or a flash memory is used for storing data such as an ID number. Although the mask ROM can be realized at a low price, rewriting is not possible. In addition, in the flash memory, although electric rewriting is possible, production cost increases. Accordingly, it is difficult to provide an RF tag by which data rewriting is possible at a low price. An RF tag is provided with a power supply circuit having a function to generate a power supply voltage from a weak radio signal and a memory which can hold data stored in a data holding portion by the power supply voltage. With the above structure, a high-performance RF tag capable of rewriting data such as an ID number after production can be provided at a low price.

Claims

1. A semiconductor device comprising:

a first antenna circuit;

a second antenna circuit;

a first power supply circuit configured to generate a first direct voltage by converting a first radio signal received by the first antenna circuit into a direct voltage and boosting the direct voltage;

a second power supply circuit configured to generate a second direct voltage from a second radio signal received by the second antenna circuit; and

a memory circuit comprising a memory cell and a control circuit,

wherein the memory cell is configured to hold a signal by using the first direct voltage, and

wherein the control circuit is configured to control the memory cell by using the second direct voltage.

2. The semiconductor device according to claim 1, wherein the first radio signal and the second radio signal have different frequencies.

3. The semiconductor device according to claim 1, wherein the first radio signal and the second radio signal have different electric powers.

4. The semiconductor device according to claim 1, wherein the first power supply circuit includes a charge pump circuit.

5. The semiconductor device according to claim 1, wherein the memory cell includes a latch circuit.

6. The semiconductor device according to claim 1, wherein the memory cell includes a flip-flop circuit.

7. The semiconductor device according to claim 1, wherein the memory circuit is a static random access memory.

8. The semiconductor device according to claim 1, wherein any one of the first power supply circuit, the second power supply circuit, and the memory circuit uses a thin film transistor in which a semiconductor thin film formed over a substrate including an insulating surface serves as an active layer.

9. The semiconductor device according to claim 8, wherein the substrate including the insulating surface is any one of a glass substrate, a quartz substrate, a plastic substrate, and a silicon on insulator substrate.

10. A semiconductor device comprising:

a first antenna circuit;

a second antenna circuit;

a first power supply circuit configured to generate a first direct voltage by converting a radio signal received by the first antenna circuit into a direct voltage and boosting the direct voltage;

a second power supply circuit configured to generate a second direct voltage from the radio signal received by the second antenna circuit; and

a memory circuit comprising a memory cell and a control circuit,

wherein the memory cell is configured to hold a signal by using the first direct voltage, and

wherein the control circuit is configured to control the memory cell by using the second direct voltage.

11. The semiconductor device according to claim 10, wherein one of the first power supply circuit and the second power supply circuit includes a charge pump circuit.

12. The semiconductor device according to claim 10, wherein the memory cell includes a latch circuit.

13. The semiconductor device according to claim 10, wherein the memory cell includes a flip-flop circuit.

14. The semiconductor device according to claim 10, wherein the memory circuit is a static random access memory.

15. The semiconductor device according to claim 10, wherein any one of the first power supply circuit, the second power supply circuit, and the memory circuit uses a thin film transistor in which a semiconductor thin film formed over a substrate including an insulating surface serves as an active layer.

16. The semiconductor device according to claim 15, wherein the substrate including the insulating surface is any one of a glass substrate, a quartz substrate, a plastic substrate, and a silicon on insulator substrate.

17. A semiconductor device comprising:

a first antenna circuit;

a second antenna circuit;

a first power supply circuit;

a second power supply circuit; and

a memory circuit comprising a memory cell for holding a signal by using an output voltage from the first power supply circuit and a control circuit for controlling the memory cell by using an output voltage from the second power supply circuit,

wherein the first power supply circuit is configured to generate a first direct voltage from a first radio signal received by the first antenna circuit,

wherein the second power supply circuit is configured to generate a second direct voltage from a second radio signal received by the second antenna circuit, and

wherein when the output voltage from the second power supply circuit is larger than the output voltage from the first power supply circuit, the memory cell is configured to hold the signal by using the output voltage from the second power supply circuit.

18. The semiconductor device according to claim 17, wherein one of the first power supply circuit and the second power supply circuit includes a charge pump circuit.

19. The semiconductor device according to claim 17, wherein the memory circuit includes a latch circuit.

20. The semiconductor device according to claim 17, wherein the memory circuit includes a flip-flop circuit.

21. The semiconductor device according to claim 17, wherein the memory circuit is a static random access memory.

22. The semiconductor device according to claim 17, wherein any one of the first power supply circuit, the second power supply circuit, and the memory circuit uses a thin film transistor in which a semiconductor thin film formed over a substrate including an insulating surface serves as an active layer.

23. The semiconductor device according to claim 22, wherein the substrate including the insulating surface is any one of a glass substrate, a quartz substrate, a plastic substrate, and a silicon on insulator substrate.

24. A semiconductor device comprising:

a first antenna circuit;

a second antenna circuit;

a first power supply circuit;

a second power supply circuit; and

a memory circuit,

wherein the first power supply circuit is configured to generate a first direct voltage by converting a first radio signal received by the first antenna circuit into a direct voltage and boosting the direct voltage,

wherein the second power supply circuit is configured to generate a second direct voltage from a second radio signal received by the second antenna circuit, and

wherein the memory circuit is configured to operate by using the second direct voltage and to hold data by using the first direct voltage.

25. The semiconductor device according to claim 24, wherein one of the first power supply circuit and the second power supply circuit includes a charge pump circuit.

26. The semiconductor device according to claim 24, wherein the memory circuit includes a latch circuit.

27. The semiconductor device according to claim 24, wherein the memory circuit includes a flip-flop circuit.

28. The semiconductor device according to claim 24, wherein the memory circuit is a static random access memory.

29. The semiconductor device according to claim 24, wherein any one of the first power supply circuit, the second power supply circuit, and the memory circuit uses a thin film transistor in which a semiconductor thin film formed over a substrate including an insulating surface serves as an active layer.

30. The semiconductor device according to claim 29, wherein the substrate including the insulating surface is any one of a glass substrate, a quartz substrate, a plastic substrate, and a silicon on insulator substrate.