Transponder in power down mode during load modulation

• US 20030024985A1
• Filed: 07/24/2002
• Published: 02/06/2003
• Est. Priority Date: 08/03/2001
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Reis, Kuno
• Granted Patent: US 6,827,280 B2
• Time in Patent Office: Days
• US Class Current: 235/451
• CPC Class Codes: G06K 19/0707 the arrangement being capable of collecting energy from external energy sources, e.g. thermocouples, vibration, electromagnetic radiation G06K19/0702 takes precedence
• CPC Class Codes: G06K 19/0712 the arrangement being capable of triggering distinct operating modes or functions dependent on the strength of an energy or interrogation field in the proximity of the record carrier active means for hindering electromagnetic reading or writing G06K19/07336
• 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

Abstract

A data carrier (1) for the transmission of transmission data (UD) to a base station over a transmission time range (TT) containing load time ranges (TA) and load relief time ranges (TB0, TB1) comprises cut-off means (13) which, once activated, set principal power consumers (10, 12) of the data carrier (1) into an energy-saving operating condition for a cut-off time range containing the load time range (TA), so that the storage capacitor (9) for operation of the passive data carrier (1) over the load time ranges (TA) may advantageously have only a relatively low capacitance.

Claims

1. A data carrier (1) for the transmission of transmission data (UD) to a base station over a transmission time range (TT) containing load time ranges (TA) and load relief time ranges (TB0, TB1), having

receiving means (3) for the reception of a carrier signal (TS) from an electromagnetic carrier field (HF) and having

power generating means (7) for the generation and storage of a DC power (UB) from the received carrier signal (TS), the DC power (UB) being used for operation of the passive data carrier (1), and having

data processing means (12) for the processing and output of the transmission data (UD) to be transmitted and having

transmission means (3) for transmission of the transmission data (UD) to the base station over the transmission time range (TT), the electromagnetic carrier field (HF) being subjected to a load (6) by the transmission means (3) over the load time ranges (TA), so that over the load time ranges (TA) the amplitude of the received carrier signal (TS) is essentially less than over the load relief time ranges (TB0, TB1) and the data carrier (1) is operated over the load time ranges (TA) essentially with the stored DC power (UB), characterized in that

cut-off means (13) are provided which are designed to deactivate at least one power consumer (10, 12) of the data carrier (1) at a cut-off time (t_A1, t_A2) defined by the data processing means (12) or by the transmission means (3) immediately prior to or at the start of each load time range (TA) and which are designed to reactivate the deactivated power consumers (10, 12) once a cut-off time range (TA) following the cut-off time (t_A1, t_A2) has elapsed.

2. A data carrier (1) as claimed in claim 1, comprising

clock signal generating means (10) for the generation of a clock signal (CLK) for the data carrier (1) from the received carrier signal (TS), characterized in that the cut-off means (13) are designed to deactivate the clock signal generating means (10) at the cut-off time (t_A1, t_A2), and to reactivate the deactivated clock signal generating means (10) once the cut-off time range (TA) has elapsed.

3. A data carrier (1) as claimed in claim 2, characterized in that the cut-off means (13) are also designed to deactivate the data processing means (12) at the cut-off time (t_A1, t_A2), and to reactivate the deactivated data processing means (12) once the cut-off time range (t_A1, t_A2) has elapsed.

4. A data carrier (1) as claimed in claim 2, characterized in that the cut-off means (13) comprise a timer element with a capacitor (C) for determining the duration of the cut-off time range (TA), the capacitor (C) being charged and discharged, respectively, over the load relief time ranges (TB0, TB1) and discharged and charged, respectively, over the cut-off time ranges (TA).

5. A data carrier (1) as claimed in claim 2, characterized in that the transmission means (3) are designed for short-circuiting of the carrier signal (TS), received by the receiving means (3), over the load time ranges (TA).

6. A data carrier (1) as claimed in claim 1, characterized in that calibration means (12, 16) are provided for calibration of the cut-off time range (TA) generated by the cut-off means (13), the cut-off time range (TA) being compared with a predetermined number of N clock cycles generated by the clock signal generating means (10) in order to calibrate the cut-off means (13).

7. A circuit for a data carrier (1) for the transmission of transmission data (UD) to a base station, characterized in that the circuit is of integrated design and that the circuit connected to antenna means (3) forms the data carrier (1) as claimed in claim 1.

8. A circuit as claimed in claim 7, characterized in that clock signal generating means (10) are designed to generate a clock signal (CLK) for the circuit from the received carrier signal (TS), and that cut-off means (13) are designed to deactivate the clock signal generating means (10) at the cut-off time (t_A1, t_A2) and to reactivate the deactivated clock signal generating means (10) once a cut-off time range (TA) has elapsed.

9. A circuit as claimed in claim 7, characterized in that calibration means (12, 16) are provided for the calibration of the cut-off time range (TA) generated by the cut-off means (13), the cut-off time range (TA) being compared with a predetermined number of N clock cycles generated by the clock signal generating means (10) in order to calibrate the cut-off means (13).

10. A method of transmitting transmission data (UD) from a data carrier (1) to a base station over a transmission time range (TT) comprising load time ranges (TA) and load relief time ranges (TB0, TB1), the method comprising the following stages:

reception of a carrier signal (TS) from an electromagnetic carrier field (HF);

generation and storage of a DC power (UB) from the received carrier signal (TS), said DC power (UB) being used for operation of the passive data carrier (1);

processing and output of the transmission data (UD) to be transmitted;

transmission of the transmission data (UD) to the base station over the transmission time range (TT), the electromagnetic carrier field (HF) being subjected to a load (6) over the load time ranges (TA), so that over the load time ranges (TA) the amplitude of the received carrier signal (TS) is essentially less than over the load relief time ranges (TB0, TB1), and the data carrier (1) being operated over the load time ranges (TA) essentially by means of the stored DC power (UB), characterized in that

at least one power consumer (10, 12) of the data carrier (1) is deactivated at a cut-off time (t_A1, t_A2) fixed immediately prior to or at the start of each load time range (TA), and that the deactivated power consumer (10, 12) is reactivated once a cut-off time range (TA) following the cut-off time (t_A1, t_A2) has elapsed.

11. A method as claimed in claim 10, characterized in that the cut-off time range (TA) is calibrated, the cut-off time range (TA) being compared with a predetermined number of N clock cycles generated by the clock signal generating means (10).