Semiconductor device and IC label, IC tag, and IC card provided with the semiconductor device

• US 8,339,245 B2
• Filed: 10/07/2011
• Issued: 12/25/2012
• Est. Priority Date: 05/31/2007
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kawae, Daisuke, Ikeda, Takayuki, Kozuma, Munehiro
• Primary Examiner(s): Lee, Benjamin C
• Assistant Examiner(s): PHAM, QUANG
• Application Number:
  US13/267,936
• Publication Number:
  US 20120024965A1
• Time in Patent Office: 445 Days
• Field of Search: 340/10.1, 340/572.8, 340/572.1, 340/539.1, 340/10.34, 235/492, 363/60, 327/536, 455/269, 455/343.1, 323/282, 323/284, 323/265
• US Class Current: 340/10.1
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0723 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 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/248 provided with an AC/DC converting device, e.g. rectennas
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

A charge accumulation circuit having a structure in which a capacitor is divided into a plurality of pieces and the divided capacitors are connected in parallel through switches is provided. The charge accumulation circuit controls the switch provided between the capacitors and thus can dynamically vary electrostatic capacitance of the charge accumulation circuit which applies a voltage to a constant voltage circuit.

Claims

1. A semiconductor device comprising:

an antenna;

a rectifier circuit electrically connected to the antenna;

a first capacitor comprising a first electrode electrically connected to the rectifier circuit, and a second electrode electrically connected to a first ground line;

a first switch electrically connected to the first electrode,

a second capacitor comprising a third electrode electrically connected to the first switch, and a fourth electrode electrically connected to a second ground line;

a second switch electrically connected to the third electrode;

a third capacitor comprising a fifth electrode electrically connected to the second switch, and a sixth electrode electrically connected to a third ground line; and

a constant voltage circuit, wherein an input terminal of the constant voltage circuit is electrically connected to the rectifier circuit and the first electrode, and an output terminal of the constant voltage circuit is electrically connected to a logic circuit,

wherein the first switch and the second switch each comprises a first transistor and a first diode, and one terminal of the first diode is electrically connected to one of source and drain of the first transistor, and the other terminal of the first diode is electrically connected to the other of source and drain of the first transistor, and

wherein during charging, the first switch is configured to be turned on after the first capacitor is charged above a predetermined level to charge the second capacitor, and the second switch is configured to be turned on after the second capacitor is charged above a predetermined level to charge the third capacitor; and

wherein during discharging, the second switch is configured to be turned off after the third capacitor discharge below a predetermined level of charge, and the first switch is configured to be turned off after the second capacitor is below a predetermined level of charge.

2. The semiconductor device according to claim 1, wherein the first switch further comprises:

a first comparator electrically connected to a gate of the first transistor, and

a resistor electrically connected to one input terminal of the first comparator and the one of source and drain of the first transistor.

3. The semiconductor device according to claim 1,

wherein the constant voltage circuit comprises a second transistor and a second comparator,

wherein one of source and drain of the second transistor is electrically connected to the first capacitor and the first switch, and

wherein the second comparator is electrically connected to a gate of the second transistor.

4. The semiconductor device according to claim 3, wherein the logic circuit is electrically connected to the other of source and drain of the second transistor.

5. The semiconductor device according to claim 4, wherein the logic circuit includes a CPU, a ROM, a RAM, and a controller for controlling writing or reading of data from or to the CPU, the ROM, and the RAM.

6. The semiconductor device according to claim 1, wherein the first transistor is a thin film transistor.

7. An IC label, an IC tag, or an IC card comprising the semiconductor device described in claim 1.

8. A semiconductor device comprising:

an antenna;

a first diode comprising a first electrode electrically connected to the antenna, and a second electrode;

a first capacitor comprising a third electrode electrically connected to the second electrode, and a fourth electrode electrically connected to a first ground line;

a first switch electrically connected to the third electrode,

a second capacitor comprising a fifth electrode electrically connected to the first switch, and a sixth electrode electrically connected to a second ground line,

a second switch electrically connected to the fifth electrode;

a third capacitor comprising a seventh electrode electrically connected to the second switch, and an eighth electrode electrically connected to a third ground line; and

a constant voltage circuit, wherein an input terminal of the constant voltage circuit is electrically connected to the second electrode and the third electrode, and an output terminal of the constant voltage circuit is electrically connected to a logic circuit,

wherein the first switch and the second switch each comprises a first transistor and a second diode, and one terminal of the second diode is electrically connected to one of source and drain of the first transistor, and the other terminal of the second diode is electrically connected to the other of source and drain of the first transistor, and

wherein during charging, the first switch is configured to be turned on after the first capacitor is charged above a predetermined level to charge the second capacitor, and the second switch is configured to be turned on after the second capacitor is charged above a predetermined level to charge the third capacitor; and

wherein during discharging, the second switch is configured to be turned off after the third capacitor discharge below a predetermined level of charge, and the first switch is configured to be turned off after the second capacitor is below a predetermined level of charge.

9. The semiconductor device according to claim 8, wherein the first switch further comprises:

a first comparator electrically connected to a gate of the first transistor, and

a resistor electrically connected to one input terminal of the first comparator and the one of source and drain of the first transistor.

10. The semiconductor device according to claim 8,

wherein the constant voltage circuit comprises a second transistor and a second comparator,

wherein one of source and drain of the second transistor is electrically connected to the first capacitor and the first switch, and

wherein the second comparator is electrically connected to a gate of the second transistor.

11. The semiconductor device according to claim 10, wherein the logic circuit is electrically connected to the other of source and drain of the second transistor.

12. The semiconductor device according to claim 11, wherein the logic circuit includes a CPU, a ROM, a RAM, and a controller for controlling writing or reading of data from or to the CPU, the ROM, and the RAM.

13. The semiconductor device according to claim 8, wherein the first transistor is a thin film transistor.

14. An IC label, an IC tag, or an IC card comprising the semiconductor device described in claim 8.

15. A semiconductor device comprising:

an antenna;

a first capacitor comprising a first electrode electrically connected to the antenna, and a second electrode;

a first diode comprising a third electrode electrically connected the second electrode, and a fourth electrode;

a second capacitor comprising a fifth electrode electrically connected to the fourth electrode, and a sixth electrode electrically connected to a first ground line;

a first switch electrically connected to the fifth electrode,

a third capacitor comprising a seventh electrode electrically connected to the first switch, and an eighth electrode electrically connected to a second ground line;

a second switch electrically connected to the seventh electrode,

a fourth capacitor comprising a ninth electrode electrically connected to the second switch, and a tenth electrode electrically connected to a third ground line;

a constant voltage circuit, wherein an input terminal of the constant voltage circuit is electrically connected to the fourth electrode and the fifth electrode, and an output terminal of the constant voltage circuit is electrically connected to a logic circuit,

wherein the first switch and the second switch each comprises a first transistor and a second diode, and one terminal of the second diode is electrically connected to one of source and drain of the first transistor, and the other terminal of the second diode is electrically connected to the other of source and drain of the first transistor, and

wherein during charging, the first switch is configured to be turned on after the second capacitor is charged above a predetermined level to charge the third capacitor, and the second switch is configured to be turned on after the third capacitor is charge above a predetermined level to charge the fourth capacitor; and

wherein during discharging, the second switch is configured to be turned off after the fourth capacitor discharge below a predetermined level of charge, and the first switch is configured to be turned off after the third capacitor is below a predetermined level of charge.

16. The semiconductor device according to claim 15, wherein the first switch further comprises:

a first comparator electrically connected to a gate of the first transistor, and

a resistor electrically connected to one input terminal of the first comparator and the one of source and drain of the first transistor.

17. The semiconductor device according to claim 15,

wherein the constant voltage circuit comprises a second transistor and a second comparator,

wherein one of source and drain of the second transistor is electrically connected to the first capacitor and the first switch, and

wherein the second comparator is electrically connected to a gate of the second transistor.

18. The semiconductor device according to claim 17, wherein the logic circuit is electrically connected to the other of source and drain of the second transistor.

19. The semiconductor device according to claim 18, wherein the logic circuit includes a CPU, a ROM, a RAM, and a controller for controlling writing or reading of data from or to the CPU, the ROM, and the RAM.

20. The semiconductor device according to claim 15, wherein the first transistor is a thin film transistor.

21. An IC label, an IC tag, or an IC card comprising the semiconductor device described in claim 15.