NFC Device Combining Components of Antenna Driver and Shunt Regulator

• US 20130337744A1
• Filed: 06/14/2012
• Published: 12/19/2013
• Est. Priority Date: 06/14/2012
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: LEFLEY, Alastair
• Granted Patent: US 9,020,424 B2
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: G06K 19/0715 the arrangement including means to regulate power transfer to the integrated circuit
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/0037 for power transfer
• CPC Class Codes: H04B 5/0075 using inductive coupling transformers or inductances adapted for inductive coupling H01F38/14
• CPC Class Codes: H04B 5/02 using transceiver
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Embodiments of the present disclosure can be used to produce smaller, more compact antenna drivers at a reduced cost. Systems and methods for integrating components of an antenna driver with components of a shunt regulator and clamp are provided. By combining these components according to embodiments of the present disclosure, transistor count in an antenna driver can be reduced. This integrated device advantageously allows antenna driver functionality, regulator functionality, and clamp control functionality to be provided at a reduced manufacturing cost and with reduced real estate.

Claims

1. A circuit comprising:

an antenna port coupled to a first transistor, a second transistor, and a third transistor;

a predriver configured to be coupled to the first transistor, the second transistor, and the third transistor;

a voltage regulator configured to be coupled to the second transistor; and

a clamp control configured to be coupled to the third transistor.

2. The circuit of claim 1, wherein the first transistor is a P-type metal-oxide-semiconductor (PMOS) transistor, and wherein the second and third transistors are N-type metal-oxide-semiconductor (NMOS) transistors.

3. The circuit of claim 1, farther comprising:

a first switch configured to couple the predriver to the first transistor;

a second switch configured to couple the predriver to the second transistor; and

a third switch configured to couple the predriver to the third transistor.

4. The circuit of claim 3, farther comprising:

a fourth switch configured to couple the regulator to the second transistor;

a fifth switch configured to couple the clamp control to the third transistor.

5. The circuit of claim 4, wherein:

during a first mode, the first switch, the second switch, and the third switch are configured to close while the fourth switch and the fifth switch are open; and

during a second mode, the first switch, the second switch, and the third switch are configured to open while the fourth switch and the fifth switch are closed.

6. The circuit of claim 5, wherein the antenna port is an antenna port of an near field communications (NFC) device, wherein the antenna port is configured to support a reader mode of the NFC device during the first mode, and wherein the antenna port is configured to support a target mode of the NFC device during the second mode.

7. The circuit of claim 1, further comprising a diode coupled to the antenna port and the regulator, wherein the regulator is configured to:

receive a feedback signal from the diode;

compare the feedback signal to a reference signal; and

adjust a voltage supplied to the second transistor in response to the comparison between the feedback signal and the reference signal.

8. The circuit of claim 1, further comprising:

a second antenna port coupled to a fourth transistor, a fifth transistor, and a sixth transistor, wherein;

the predriver is further configured to be coupled to the fourth transistor, the fifth transistor, and the sixth transistor,

the voltage regulator is further configured to be coupled to the fifth transistor, and

the clamp control is further configured to be coupled to the sixth transistor.

9. The circuit of claim 8, wherein the clamp control is configured to:

determine whether a first voltage of the first antenna port or a second voltage of the second antenna port is lower;

create a short circuit at the first antenna port is the first voltage is lower; and

create a short circuit at the second antenna port is the second voltage is lower.

10. A near field communications (NFC) device comprising:

a first antenna port coupled to a first plurality of transistors;

a second antenna port coupled to a second plurality of transistors

a predriver configured to be coupled to the first plurality of transistors and the second plurality of transistors;

a voltage regulator configured to be coupled to the first antenna port and the second antenna port; and

a clamp control configured to be coupled to the first antenna port and the second antenna port.

11. The NFC device of claim 10, wherein the NFC device is configured to receive information instructing the NFC device to place the first antenna port in a reader mode or a target mode.

12. The NFC device of claim 11, wherein the NFC device is configured to couple the predriver to the first plurality of transistors and to decouple the voltage regulator and the clamp control from the first antenna port in response to receiving instructions to place the first antenna port in the reader mode.

13. The NFC device of claim 12, wherein the NFC device is configured to decouple the predriver from the second plurality of transistors and to couple the voltage regulator and the clamp control to the second antenna port in response to receiving instructions to place the first antenna port in the reader mode.

14. The NFC device of claim 11, wherein the NFC device is configured to decouple the predriver from the first plurality of transistors and to couple the voltage regulator and the clamp control to the first antenna port in response to receiving instructions to place the first antenna port in the target mode.

15. The NFC device of claim 12, wherein the NFC device is configured to couple the predriver to the second plurality of transistors and to decouple the voltage regulator and the clamp control from the second antenna port in response to receiving instructions to place the first antenna port in the target mode.

16. A method comprising:

determining whether an antenna port is used to receive a magnetic field or create the magnetic field; and

in response to determining that the antenna port is used to create the magnetic field;

coupling a predriver to a first transistor, a second transistor, and a third transistor,

decoupling a regulator from the second transistor, and

decoupling a clamp control from the third transistor.

17. The method of claim 16, further comprising:

in response to determining that the antenna port is used to create the magnetic field;

decoupling the predriver from a second antenna port,

coupling the regulator to the second antenna port, and

coupling a clamp control to the second antenna port.

18. The method of claim 16, further comprising:

in response to determining that the antenna port is not used to create the magnetic field;

decoupling the predriver from the first transistor, the second transistor, and the third transistor,

coupling the regulator to the second transistor, and

coupling the clamp control to the third transistor.

19. The method of claim 16, further comprising:

in response to determining that the antenna port is not used to create the magnetic field;

coupling the predriver to a second antenna port,

decoupling the regulator from the second antenna port, and

decoupling a clamp control from the second antenna port.

20. The method of claim 16, further comprising determining whether the antenna port is used to receive the magnetic field or create the magnetic field based on instructions received from a host near field communications (NFC) device.