Semiconductor Device

• US 20100079921A1
• Filed: 09/29/2009
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Fujita, Masashi
• Granted Patent: US 8,345,401 B2
• Time in Patent Office: Days
• US Class Current: 361/56
• 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: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors

Abstract

To provide a highly reliable semiconductor device (an RF tag) which operates normally even when a communication distance is extremely short, a protection circuit (a limiter circuit) for protecting an element which forms a semiconductor device (an RF tag) capable of wirelessly communicating data is provided. When the DC power supply potential which is generated in a rectifier circuit is equal to or greater than a predetermined value (a reference value), the protection circuit is made to operate, and the value of the generated DC power supply potential is reduced. On the other hand, when the DC power supply potential which is generated in the rectifier circuit is equal to or less than the predetermined value (reference value), the protection circuit is made not to operate, and the value of the generated DC power supply potential is used without change.

Claims

1. A semiconductor device comprising:

a rectifier circuit configured to rectify a carrier wave or an amplitude modulation wave received through an antenna, the rectifier circuit including;

a first diode, wherein an anode of the first diode is electrically connected to one terminal of the antenna; and

a capacitor, wherein one electrode of the capacitor is electrically connected to a cathode of the first diode and the other electrode of the capacitor is electrically connected to the other terminal of the antenna,

a protection circuit electrically connected to the rectifier circuit, the protection circuit including;

a first resistor, wherein one terminal of the first resistor is electrically connected to the cathode of the first diode and one electrode of the capacitor;

a second diode, wherein an anode of the second diode is electrically connected to the other terminal of the first resistor;

a second resistor, wherein one terminal of the second resistor is electrically connected to a cathode of the second diode and the other terminal of the antenna;

a transistor, wherein one of a source and a drain of the transistor is electrically connected to the other terminal of the second resistor, the other of a source and a drain of the transistor is electrically connected to one terminal of the first resistor and the cathode of the first diode, and a gate of the transistor is electrically connected to the other terminal of the first resistor and the anode of the second diode; and

a switch, wherein first terminal of the switch is electrically connected to the anode of the first diode and one terminal of the antenna, second terminal of the switch is electrically connected to the other terminal of the antenna, the other electrode of the capacitor, the cathode of the second diode and one terminal of the second resistor, and third terminal of the switch is electrically connected to one of a source and a drain of the transistor and the other terminal of the second resistor.

2. The semiconductor device according to claim 1, wherein the switch is turned on when a potential of the third terminal of the switch is higher than a predetermined potential, and the switch is turned off when the potential of the third terminal of the switch is lower than the predetermined potential.

3. The semiconductor device according to claim 1, wherein the first diode includes a diode-connected transistor, a lateral PN junction diode, or a lateral PIN junction diode.

4. The semiconductor device according to claim 1, wherein the second diode includes a plurality of diode-connected transistors which are connected in series, a lateral PN junction diode, or a lateral PIN junction diode.

5. The semiconductor device according to claim 1, further comprising the antenna electrically connected to the rectifier circuit.

6. The semiconductor device according to claim 1, further comprising a demodulation circuit, a constant voltage circuit, a logic circuit, and a modulation circuit.

7. The semiconductor device according to claim 1, further comprising a demodulation circuit, a constant voltage circuit, a logic circuit, a modulation circuit, and a clock generation circuit.

8. The semiconductor device according to claim 1, wherein the second resistor is a two-terminal device.

9. A semiconductor device comprising:

a rectifier circuit configured to rectify a carrier wave or an amplitude modulation wave received through an antenna, the rectifier circuit including;

a first diode, wherein an anode of the first diode is electrically connected to one terminal of the antenna; and

a capacitor, wherein one electrode of the capacitor is electrically connected to a cathode of the first diode and the other electrode of the capacitor is electrically connected to the other terminal of the antenna,

a protection circuit electrically connected to the rectifier circuit, the protection circuit including;

a first resistor, wherein one terminal of the first resistor is electrically connected to the cathode of the first diode and one electrode of the capacitor;

a second diode, wherein an anode of the second diode is electrically connected to the other terminal of the first resistor;

a second resistor, wherein one terminal of the second resistor is electrically connected to a cathode of the second diode and the other terminal of the antenna;

a first transistor, wherein one of a source and a drain of the first transistor is electrically connected to the other terminal of the second resistor, the other of a source and a drain of the first transistor is electrically connected to one terminal of the first resistor and the cathode of the first diode, and a gate of the first transistor is electrically connected to the other terminal of the first resistor and the anode of the second diode; and

a second transistor, wherein one of a source and a drain of the second transistor is electrically connected to the anode of the first diode and one terminal of the antenna, the other of a source and a drain of the second transistor is electrically connected to the other terminal of the antenna, the other electrode of the capacitor, the cathode of the second diode and one terminal of the second resistor, and a gate of the second transistor is electrically connected to one of a source and a drain of the first transistor and the other terminal of the second resistor.

10. The semiconductor device according to claim 9, wherein the second transistor is turned on when a potential of the gate of the second transistor is higher than a predetermined potential, and the second transistor is turned off when the potential of the gate of the second transistor is lower than the predetermined potential.

11. The semiconductor device according to claim 9, wherein the first diode includes a diode-connected transistor, a lateral PN junction diode, or a lateral PIN junction diode.

12. The semiconductor device according to claim 9, wherein the second diode includes a plurality of diode-connected transistors which are connected in series, a lateral PN junction diode, or a lateral PIN junction diode.

13. The semiconductor device according to claim 9, further comprising the antenna electrically connected to the rectifier circuit.

14. The semiconductor device according to claim 9, further comprising a demodulation circuit, a constant voltage circuit, a logic circuit, and a modulation circuit.

15. The semiconductor device according to claim 9, further comprising a demodulation circuit, a constant voltage circuit, a logic circuit, a modulation circuit, and a clock generation circuit.

16. The semiconductor device according to claim 9, wherein the second resistor is a two-terminal device.