Radio frequency identification device

• US 7,786,847 B2
• Filed: 06/22/2007
• Issued: 08/31/2010
• Est. Priority Date: 07/18/2006
• Status: Expired due to Fees

• Current Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Inventors: Kang, Hee Bok
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): POINT, RUFUS C
• Application Number:
  US11/812,832
• Publication Number:
  US 20080018483A1
• Time in Patent Office: 1,166 Days
• Field of Search: 340/442, 340/443, 340/444, 340/445, 340/446, 340/447, 340/448, 340/449, 340/589, 340/10.1, 340/10.2, 340/10.3, 340/10.31, 340/10.4, 340/10.41, 340/10.5, 340/14.61
• US Class Current: 340/14.61
• CPC Class Codes: G01K 1/024 for remote indication

Abstract

An RFID device includes an analog block configured to receive a radio frequency signal so as to output an operation command signal, a digital block configured to output an address, a temperature address, an operation control signal, and a temperature sensor activation signal in response to the operation command signal received from the analog block and to provide a corresponding response signal into the analog block. The device further includes a memory block configured to receive the address, the temperature address, and the operation control signal so as to generate an internal control signal for controlling the internal operation, and to read/write data in a cell array including a non-volatile ferroelectric capacitor in response to the internal control signal, and a temperature sensor processing unit configured to detect a temperature change state of an RFID tag in response to the temperature sensor activation signal.

Claims

1. A radio frequency identification (RFID) device, comprising:

an analog block configured to receive a radio frequency signal so as to output an operation command signal;

a digital block configured to output an address, a temperature address, an operation control signal, and a temperature sensor activation signal in response to the operation command signal received from the analog block, and to supply a corresponding response signal to the analog block;

a memory block in the form of a ferroelectric random access memory configured to receive the address, the temperature address, and the operation control signal so as to generate an internal control signal for controlling an internal operation, and to read/write data in a cell array comprising a non-volatile ferroelectric capacitor in response to the internal control signal;

a temperature sensor processing unit configured to detect a temperature change of an RFID tag in response to the temperature sensor activation signal; and

a temperature memory included in the memory block and configured to store temperature data detected from the temperature sensor processing unit in a specific region of the cell array allotted by the temperature address,

wherein the temperature sensor processing unit is included in the memory block.

2. The RFID device according to claim 1, wherein the memory block further comprises:

a peripheral circuit unit configured to receive the address, the temperature address, and the operation control signal so as to generate the internal control signal;

the cell array configured to read/write the data in the non-volatile ferroelectric capacitor in response to the internal control signal; and

a sense amplifier unit configured to sense and amplify data stored in the cell array and an input/output unit configured to output input data received from a data bus into the cell array.

3. The RFID device according to claim 2, wherein the temperature sensor processing unit is controlled by the peripheral circuit unit.

4. The RFID device according to claim 1, wherein the temperature sensor processing unit comprises:

a sense unit configured to detect a temperature change in the RFID tag in response to the temperature sensor activation signal so as to output a reference voltage and a temperature detecting voltage; and

an analog-to-digital (A/D) converting unit configured to convert the reference voltage and the temperature detecting voltage in response to the temperature sensor activation signal.

5. The RFID device according to claim 4, wherein the temperature detecting voltage decreases when the temperature increases.

6. The RFID device according to claim 4, wherein the sense unit comprises:

a first temperature detecting unit configured to output a detected temperature change through a first MOS diode element as a first voltage value;

a first amplifying unit configured to compare a divided voltage value with an output signal of the first temperature detecting unit so as to output the temperature detecting voltage;

a second temperature detecting unit configured to output a temperature change detected through a second MOS diode element as a second voltage value;

a second amplifying unit configured to compare an output signal of the first temperature detecting unit with that of the second temperature detecting unit; and

a reference voltage generating unit configured to compare an output signal of the first amplifying unit with that of the second amplifying unit and to output a reference voltage.

7. The RFID device according to claim 6, wherein the first MOS diode element includes a NMOS transistor.

8. The RFID device according to claim 6, wherein the second MOS diode element includes a NMOS transistor.

9. The RFID device according to claim 6, wherein the first temperature detecting unit is connected in parallel to the first MOS diode element.

10. The RFID device according to claim 9, wherein a gate-drain voltage of the first MOS diode element has a fixed given value regardless of change of a power voltage.

11. The RF1D device according to claim 6, wherein the second temperature detecting unit is serially connected to the second MOS diode element.

12. The RFID device according to claim 6, wherein the sense unit further comprises a pull-up unit configured to activate the sense unit in response to the temperature sensor activation signal.

13. The RFID device according to claim 6, wherein a size of the first MOS diode is larger than a size of the second MOS diode.

14. The RFID device according to claim 6, wherein the reference voltage generating unit comprises:

first and second driving elements configured to receive output signals of the first amplifying unit and the second amplifying unit; and

a first resistor connected between the first and second driving elements and a ground voltage terminal.

15. The RFID device according to claim 6, wherein the first amplifying unit comprises:

an amplifier configured to compare the divided voltage value with the output signal of the first temperature detecting unit;

a third driving element configured to be driven selectively in response to an output signal of the amplifier; and

a second resistor and a third resistor connected between the third driving element and the ground voltage terminal and configured to output the divided voltage value.

16. The RFID device according to claim 4, wherein the A/D converting unit comprises:

a thermometer code generating unit configured to compare the temperature detecting voltage with the reference voltage so as to generate a plurality of thermometer code signals; and

a thermometer code processing unit configured to decode the plurality of thermometer code signals in response to the temperature sensor activation signal.

17. The RFID device according to claim 16, wherein the thermometer code generating unit comprises:

a plurality of resistors configured to divide the reference voltage so as to N-divide a plurality of temperature code sections and output a plurality of voltage values; and

a plurality of comparators configured to compare the temperature detecting voltage with the plurality of voltage values so as to generate the plurality of thermometer code signals.

18. The RFID device according to claim 16, wherein the thermometer code processing unit includes a decoding unit configured to decode the plurality of thermometer code signals so as to output the thermometer code signals into the data bus.