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

• US 8,035,484 B2
• Filed: 05/29/2008
• Issued: 10/11/2011
• Est. Priority Date: 05/31/2007
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kozuma, Munehiro, Ikeda, Takayuki, Kawae, Daisuke
• Primary Examiner(s): Lee; Benjamin C
• Assistant Examiner(s): PHAM, QUANG
• Application Number:
  US12/155,056
• Publication Number:
  US 20080297320A1
• Time in Patent Office: 1,230 Days
• Field of Search: 455/269, 327/536, 327/537, 320137-140, 320/162, 320/164, 320166-167
• 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 charge accumulation circuit electrically connected to the rectifier circuit; and

a voltage circuit electrically connected to the charge accumulation circuit, wherein the charge accumulation circuit includes switches and capacitors,

wherein all of the capacitors in the charge accumulation circuit are configured to be connected in parallel to one another through the switches,

wherein all of the capacitors in the charge accumulation circuit are directly connected to ground lines,

wherein each of the switches comprises a transistor and a diode,

wherein one of source and drain of the transistor is electrically connected to one terminal of the diode, and the other one of source and drain of the transistor is electrically connected to the other terminal of the diode such that when a charge accumulated in a capacitor is determined to reach a predetermined threshold level, the transistor is switched on to allow charge accumulation of the next capacitor,

wherein accumulation of charges in the capacitors is controlled by the transistor, and

wherein discharge of charges from the capacitors is controlled by the diode.

2. The semiconductor device according to claim 1, further comprising:

a logic circuit electrically connected to the voltage circuit;

a demodulation circuit electrically connected between the logic circuit and the rectifier circuit; and

a modulation circuit electrically connected between the logic circuit and the antenna.

3. The semiconductor device according to claim 2, 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.

4. the semiconductor device according to claim 1, wherein the transistor included in the semiconductor device is a thin film transistor.

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

6. a semiconductor device comprising:

an antenna;

a rectifier circuit electrically connected to the antenna;

a charge accumulation circuit electrically connected to the rectifier circuit; and

a voltage circuit electrically connected to the charge accumulation circuit, wherein the charge accumulation circuit includes switches and capacitors, wherein each of the capacitors in the charge accumulation circuit has a first electrode and a second electrode, wherein each of the first electrode of the capacitors in the charge accumulation circuit is connectable to each other via one of the switches, wherein all of the capacitors in the charge accumulation circuit are directly connected to ground lines via the second electrodes,

wherein each of the switches comprises a transistor and a diode,

wherein one of source and drain of the transistor is electrically connected to one terminal of the diode, and the other one of source and drain of the transistor is electrically connected to the other terminal of the diode such that when a charge accumulated in a capacitor is determined to reach a predetermined threshold level, the transistor is switched on to allow charge accumulation of the next capacitor,

wherein accumulation of charges in the capacitors is controlled by the transistor, and

wherein discharge of charges from the capacitors is controlled by the diode.

7. The semiconductor device according to claim 6, further comprising:

a logic circuit electrically connected to the voltage circuit;

a demodulation circuit electrically connected between the logic circuit and the rectifier circuit; and

a modulation circuit electrically connected between the logic circuit and the antenna.

8. The semiconductor device according to claim 7, 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.

9. the semiconductor device according to claim 6, wherein the transistor included in the semiconductor device is a thin film transistor.

10. An IC label, an IC tag, or an IC card comprising the semiconductor device described in claim 6.

11. a semiconductor device comprising:

an antenna;

a rectifier circuit electrically connected to the antenna;

a charge accumulation circuit electrically connected to the rectifier circuit; and

a voltage circuit electrically connected to the charge accumulation circuit, wherein the charge accumulation circuit includes switches, capacitors, and a charge accumulation control circuit, wherein all of the capacitors in the charge accumulation circuit are configured to be connected in parallel to one another through the switches,

wherein the charge accumulation control circuit controls on or off of the switches in accordance with a voltage to be applied to the voltage circuit,

wherein all of the capacitors in the charge accumulation circuit are directly connected to ground lines,

wherein each of the switches comprises a transistor and a diode,

wherein one of source and drain of the transistor is electrically connected to one terminal of the diode, and the other one of source and drain of the transistor is electrically connected to the other terminal of the diode such that when a charge accumulated in a capacitor is determined to reach a predetermined threshold level, the transistor is switched on to allow charge accumulation of the next capacitor;

wherein accumulation of charges in the capacitors is controlled by the transistor, and

wherein discharge of charges from the capacitors is controlled by the diode.

12. The semiconductor device according to claim 11, further comprising:

a logic circuit electrically connected to the voltage circuit;

a demodulation circuit electrically connected between the logic circuit and the rectifier circuit; and

a modulation circuit electrically connected between the logic circuit and the antenna.

13. The semiconductor device according to claim 12, 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.

14. the semiconductor device according to claim 11, wherein the transistor included in the semiconductor device is a thin film transistor.

15. An IC label, an IC tag, or an IC card comprising the semiconductor device described in claim 11.

16. a semiconductor device comprising:

an antenna;

a rectifier circuit electrically connected to the antenna;

a charge accumulation circuit electrically connected to the rectifier circuit; and

a voltage circuit electrically connected to the charge accumulation circuit, wherein the charge accumulation circuit includes switches and capacitors, and a charge accumulation control circuit, wherein each of the capacitors in the charge accumulation circuit has a first electrode and a second electrode, wherein each of the first electrode of the capacitors in the charge accumulation circuit is connectable to each other via one of the switches,

wherein the charge accumulation control circuit controls on or off of the switches in accordance with a voltage to be applied to the voltage circuit,

wherein all of the capacitors in the charge accumulation circuit are directly connected to ground lines via the second electrodes,

wherein each of the switches comprises a transistor and a diode, and wherein one of source and drain of the transistor is electrically connected to one terminal of the diode, and the other one of source and drain of the transistor is electrically connected to the other terminal of the diode such that when a charge accumulated in a capacitor is determined to reach a predetermined threshold level, the transistor is switched on to allow charge accumulation of the next capacitor;

wherein accumulation of charges in the capacitors is controlled by the transistor, and

wherein discharge of charges from the capacitors is controlled by the diode.

17. The semiconductor device according to claim 16, further comprising:

a logic circuit electrically connected to the voltage circuit;

a demodulation circuit electrically connected between the logic circuit and the rectifier circuit; and

a modulation circuit electrically connected between the logic circuit and the antenna.

18. The semiconductor device according to claim 17, 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.

19. the semiconductor device according to claim 16, wherein the transistor included in the semiconductor device is a thin film transistor.

20. An IC label, an IC tag, or an IC card comprising the semiconductor device described in claim 16.