SEMICONDUCTOR DEVICE AND IC LABEL, IC TAG, AND IC CARD PROVIDED WITH THE SEMICONDUCTOR DEVICE

• US 20120024965A1
• Filed: 10/07/2011
• Published: 02/02/2012
• 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
• Granted Patent: US 8,339,245 B2
• Time in Patent Office: Days
• US Class Current: 235/492
• 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, and comprising a first transistor and a first diode, wherein 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;

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

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, further comprising 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, further comprising a logic circuit 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 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, and comprising a first transistor and a second diode, wherein 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;

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

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, further comprising 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, further comprising a logic circuit 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, and comprising a first transistor and a second diode, wherein 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;

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

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, further comprising 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, further comprising a logic circuit 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.