CIRCUITS AND METHODS FOR FIELD-BASED COMMUNICATION

• US 20140070850A1
• Filed: 09/07/2012
• Published: 03/13/2014
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Darwhekar, Yogesh, Singh, Vikas, Issac, Ronen, Ben-Shachr, Matan
• Granted Patent: US 8,824,597 B2
• Time in Patent Office: Days
• US Class Current: 327/74
• 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: H04B 5/0025 Near field system adaptations
• CPC Class Codes: H04B 5/70 specially adapted for specific purposes

Abstract

Several circuits and methods for field-based communication are provided. In an embodiment, a field-based communication circuit includes a receiver circuit, a detection circuit and a control circuit. The receiver circuit is configured to receive a field input signal from a field source. The detection circuit includes a voltage detection circuit and a current detection circuit configured to detect a voltage signal and a current signal, respectively associated with the field input signal. The control circuit is configured to trigger a selection of one of the voltage detection circuit and the current detection circuit based on a detection of a signal magnitude of one of the voltage signal and the current signal relative to at least a first predetermined threshold level, wherein the selection of one of the voltage detection circuit and the current detection circuit facilitates a demodulation of one of the voltage signal and the current signal.

Claims

1. A field-based communication circuit comprising:

a receiver circuit configured to receive a field input signal from a field source;

a detection circuit communicatively associated with the receiver circuit, the detection circuit comprising;

a voltage detection circuit communicatively associated with the receiver circuit, the voltage detection circuit configured to detect a voltage signal associated with the field input signal;

a current detection circuit communicatively associated with the receiver circuit, the current detection circuit configured to detect a current signal associated with the field input signal; and

a control circuit communicatively associated with the voltage detection circuit and the current detection circuit, the control circuit configured to estimate a first signal magnitude and a second signal magnitude corresponding to the voltage signal and the current signal, respectively, compare the first signal magnitude and the second signal magnitude with at least a first predetermined threshold level to thereby conduct a signal comparison, and trigger a selection of one of the voltage detection circuit and the current detection circuit based on the signal comparison such that the selection facilitates a demodulation of one of the voltage signal and the current signal.

2. The circuit of claim 1, wherein the detection circuit further comprises:

a current control circuit communicatively associated with the current detection circuit for controlling the second signal magnitude corresponding to the current signal relative to at least a second predetermined threshold level by attenuating the current signal.

3. The circuit of claim 2, wherein on triggering the selection of the current detection circuit, the control circuit is further configured to:

vary the attenuation of the current signal based on a first reference database, the first reference database comprising a plurality of attenuation values corresponding to a plurality of values of the second signal magnitude of the current signal;

perform comparison of the second signal magnitude of the current signal subsequent to the attenuation, with a plurality of pre-determined reference values; and

determine a second signal magnitude of the current signal suitable for performing demodulation based on the comparison.

4. The circuit of claim 3 further comprising a demodulation circuit communicatively associated with the detection circuit and the control circuit, the demodulation circuit configured to:

amplify the second signal magnitude of the current signal based on a second reference database, the second reference database comprising a plurality of values for gain parameters corresponding to a plurality of values of the second signal magnitude of the current signal; and

demodulate the amplified second signal magnitude of the current signal.

5. The circuit of claim 4, wherein the control circuit is further configured to select a value of the gain parameter from among the plurality of values of the gain parameters in the second reference database, corresponding to the second signal magnitude of the current signal for amplification of the second signal magnitude of the current signal.

6. The circuit of claim 1, wherein on triggering the selection of the voltage detection circuit, the control circuit is further configured to:

perform comparison of the first signal magnitude of the voltage signal with a plurality of pre-determined reference values; and

determine a first signal magnitude of the voltage signal suitable for performing demodulation based on the comparison.

7. The circuit of claim 6, further comprising a demodulation circuit communicatively associated with the detection circuit and the control circuit, the demodulation circuit configured to:

amplify the first signal magnitude of the voltage signal based on a second reference database, the second reference database comprising a plurality of values for gain parameters corresponding to a plurality of first signal magnitudes of the voltage signal; and

demodulate the amplified first signal magnitude of the voltage signal.

8. The circuit of claim 7, wherein the control circuit is further configured to select a value of the gain parameter from among the plurality of values of the gain parameters in the second reference database, corresponding to the first signal magnitude of the voltage signal for amplification of the first signal magnitude of the voltage signal.

9. A method of field-based communication comprising:

accessing a receiver circuit, a voltage detection circuit, a current detection circuit, and a control circuit, each of the voltage detection circuit and the current detection circuit being communicatively associated with both of the receiver circuit and the control circuit;

receiving a field input signal from a field source at the receiver circuit;

performing, at the control circuit;

actuating one of the current and voltage detection circuits to thereby determine one of a current signal and a voltage signal, respectively, the determined signal being associated with the field input signal;

estimating a signal magnitude of the determined signal;

comparing the signal magnitude with a first predetermined threshold level; and

triggering a selection of one of;

the voltage detection circuit based on a determination that the signal magnitude is one of lesser than and equal to the first predetermined threshold level, and

the current detection circuit based on a determination that the signal magnitude is greater than the first predetermined threshold level.

10. The method of claim 9, further comprising, on triggering the selection of the current detection circuit:

performing controlling of the signal magnitude of the current signal relative to at least a second predetermined threshold level by attenuating the current signal at a current control circuit communicatively associated with the current detection circuit.

11. The method of claim 10, further comprising:

varying, at the control circuit, the attenuation of the current signal based on a first reference database, the first reference database comprising a plurality of attenuation values corresponding to a plurality of values of the signal magnitude of the current signal;

comparing at the control circuit, the attenuated current signal with a plurality of predetermined reference values; and

determining at the control circuit, a signal magnitude of the attenuated current signal suitable for performing demodulation based on the comparison.

12. The method of claim 11, further comprising:

selecting, at the control circuit, a value of a gain parameter from among a plurality of values of gain parameters in a second reference database, for the determined signal magnitude of the current signal, the second reference database comprising the plurality of values for gain parameters corresponding to a plurality of signal magnitudes of the current signal;

amplifying, at a demodulation circuit communicatively associated with the detection circuit and the control circuit, the signal magnitude of the attenuated current signal based on the selected value of the gain parameter, and

demodulating, at the demodulation circuit, the amplified signal magnitude of the attenuated current signal.

13. The method of claim 9, further comprising, on triggering the selection of the voltage detection circuit:

performing, at the control circuit, a comparison of the voltage signal with the plurality of pre-determined reference values; and

determining, at the control circuit, a signal magnitude of the detected voltage signal suitable for performing demodulation based on the comparison.

14. The method of claim 13, further comprising:

selecting, at the control circuit, a value of a gain parameter from among a plurality of values of gain parameters in a second reference database, for the determined signal magnitude of the voltage signal, the second reference database comprising the plurality of values for gain parameters corresponding to a plurality of signal magnitudes of the current signal;

amplifying, at a demodulation circuit communicatively associated with the detection circuit and the control circuit, the signal magnitude of the detected voltage signal based on the selected value of the gain parameter; and

demodulating the amplified signal magnitude of the detected voltage signal.

15. A field-based communication circuit comprising:

a receiver circuit configured to receive a field input signal from a field source;

a detection circuit communicatively associated with the receiver circuit, the detection circuit comprising;

a voltage detection circuit communicatively associated with the receiver circuit, the voltage detection circuit configured to detect a voltage signal associated with the field input signal; and

a current detection circuit communicatively associated with the receiver circuit, the current detection circuit configured to detect a current signal associated with the field input signal, the current detection circuit comprising a current control circuit configured to implement an attenuation of the detected current signal; and

a control circuit communicatively associated with the voltage detection circuit and the current detection circuit, the control circuit configured to;

estimate a first signal magnitude and a second signal magnitude corresponding to the voltage signal and the current signal, respectively,

compare the first signal magnitude and the second signal magnitude with at least a first predetermined threshold level to thereby conduct a signal comparison,

trigger a selection of one of the voltage detection circuit and the current detection circuit based on the signal comparison such that the selection facilitates a demodulation of one of the voltage signal and the current signal, and

vary the attenuation of the detected current signal at the current control circuit communicatively associated with the detection circuit and the control circuit, based on a first reference database, and based on a triggering selection of the current detection circuit, the first reference database comprising a plurality of attenuation values corresponding to a plurality of signal magnitude values, respectively, of the current signal.

16. The circuit of claim 15, wherein the current control circuit is configured to control a signal magnitude of the current signal relative to at least a second predetermined threshold level through the attenuation.

17. The circuit of claim 15, wherein the control circuit is further configured to:

perform comparison of the current signal subsequent to the attenuation, with a plurality of pre-determined reference values; and

determine a signal magnitude of the current signal suitable for performing demodulation based on the comparison.

18. The circuit of claim 15, further comprising a demodulation circuit communicatively associated with the detection circuit and the control circuit, the demodulation circuit configured to:

amplify the signal magnitude of the current signal based on a second reference database, the second reference database comprising a plurality of values for gain parameters corresponding to a plurality of values of the signal magnitude of the current signal; and

demodulate the amplified signal magnitude of the current signal.

19. The circuit of claim 15, wherein on triggering the selection of the voltage detection circuit, the control circuit is further configured to:

perform comparison of the voltage signal with the plurality of pre-determined reference values; and

determine a signal magnitude of the voltage signal suitable for performing demodulation based on the comparison.

20. The circuit of claim 19, further comprising a demodulation circuit communicatively associated with the detection circuit and the control circuit, the demodulation circuit configured to:

amplify the signal magnitude of the voltage signal based on a second reference database, the second reference database comprising a plurality of values for gain parameters corresponding to a plurality of signal magnitudes of the voltage signal; and

demodulate the amplified signal magnitude of the voltage signal.