Circuit and method for activating an NFC device
First Claim
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1. A near-field communication (NFC) router, comprising:
- a first terminal;
a second terminal;
a third terminal configured to be coupled to a voltage source through a first switch that is external to the NFC router;
a rectifier bridge having input terminals coupled to terminals of an antenna external to the NFC router, the rectifier bridge being configured to rectify a signal detected by the antenna external to the NFC router; and
a trigger circuit, comprising;
a second switch internal to the NFC router and coupled between the first terminal of the NFC router and the second terminal of the NFC router; and
a filter comprising a resistive element having a first terminal and a second terminal, the first terminal of the resistive element being coupled to form a node with an output terminal of the rectifier bridge, the second terminal of the resistive element being coupled to form a node with a control terminal of the second switch, wherein the first switch comprises a first transistor of a first conductivity type, and wherein the second switch comprises a second transistor of a second conductivity type different from the first conductivity type.
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Abstract
An embodiment near-field communication (NFC) router, includes a first switch coupled between a first terminal of the NFC router and a second terminal of the NFC router; and a rectifier bridge having an output terminal coupled to a control terminal of the first switch, the rectifier bridge being configured to rectify a signal detected by an antenna external to the NFC router.
19 Citations
19 Claims
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1. A near-field communication (NFC) router, comprising:
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a first terminal; a second terminal; a third terminal configured to be coupled to a voltage source through a first switch that is external to the NFC router; a rectifier bridge having input terminals coupled to terminals of an antenna external to the NFC router, the rectifier bridge being configured to rectify a signal detected by the antenna external to the NFC router; and a trigger circuit, comprising; a second switch internal to the NFC router and coupled between the first terminal of the NFC router and the second terminal of the NFC router; and a filter comprising a resistive element having a first terminal and a second terminal, the first terminal of the resistive element being coupled to form a node with an output terminal of the rectifier bridge, the second terminal of the resistive element being coupled to form a node with a control terminal of the second switch, wherein the first switch comprises a first transistor of a first conductivity type, and wherein the second switch comprises a second transistor of a second conductivity type different from the first conductivity type. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system, comprising:
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a near-field communication (NFC) router, comprising; a first terminal configured to be coupled to a battery by a first electrical path; a second terminal configured to be coupled to a reference potential; a third terminal configured to be coupled to the battery by a second electrical path different from the first electrical path; a rectifying circuit configured to rectify a signal detected by an antenna; and a trigger circuit, comprising; a first switch coupled between the first terminal and the second terminal; and a first resistive element having a first terminal and a second terminal, the first terminal of the first resistive element being coupled to form a node with an output terminal of the rectifying circuit, the second terminal of the first resistive element being coupled to form a node with a control terminal of the first switch; and a second switch external to the NFC router and coupled along the second electrical path between the battery and the third terminal of the NFC router, wherein a control terminal of the second switch is coupled to the first terminal of the NFC router. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method for activating a contactless communication router, the method comprising:
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decoupling a first terminal of the contactless communication router from a second terminal of the contactless communication router in response to no signal being detected by an antenna, the first terminal of the contactless communication router being controllably coupled to a reference potential via a first switch coupled between the first terminal and the second terminal of the contactless communication router, the second terminal of the contactless communication router being tied to the reference potential; decoupling a third terminal of the contactless communication router from a power supply voltage in response to no signal being detected by the antenna via a second switch coupled between the third terminal and the power supply voltage, the third terminal being configured to supply the power supply voltage to communication circuitry of the contactless communication router; coupling the first terminal of the contactless communication router to the reference potential in response to a signal being detected by the antenna; and coupling the third terminal of the contactless communication router to the power supply voltage in response to the coupling of the first terminal of the contactless communication router to the reference potential. - View Dependent Claims (17, 18, 19)
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Specification