COMMUNICATION APPARATUS AND OPERATION METHOD THEREOF

• US 20140035521A1
• Filed: 07/27/2013
• Published: 02/06/2014
• Est. Priority Date: 08/01/2012
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Endo, Takefumi
• Granted Patent: US 9,160,196 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H04B 1/3883 Arrangements for mounting batteries or battery chargers

Abstract

A communication apparatus includes a communication coil, a power receiving portion, a charge control portion, a first switch portion, a second switch portion, a communication circuit, and a processor. A voltage detection circuit of the power receiving portion generates first control signal of first state when a terminal voltage of the communication coil exceeds power supply threshold voltage. The first switch portion is controlled to turn on between first terminal and third terminal in response to first control signal. The voltage detection circuit generates second control signal of third state when a terminal voltage of the communication coil exceeds first and second charge threshold voltages during a period to charge the secondary cell. The second switch portion is controlled to turn off in response to second control signal.

Claims

1. A communication apparatus comprising:

a communication coil;

a power receiving portion;

a charge control portion;

a first switch portion;

a second switch portion;

a communication circuit; and

a processor,

wherein the communication coil receives a transmission signal transmitted from another communication apparatus;

wherein the power receiving portion generates a power-supply voltage from the transmission signal received by the communication coil;

wherein the charge control portion is connectable to a secondary cell;

wherein the charge control portion is capable of charging the secondary cell using the power-supply voltage;

wherein the communication coil is coupled to a transmission/reception terminal of the communication circuit via the second switch portion;

wherein the processor is coupled to the communication circuit;

wherein a first terminal of the first switch portion is supplied with the power-supply voltage;

wherein a second terminal of the first switch portion is capable of being supplied with battery voltage;

wherein a third terminal of the first switch portion couples with the communication circuit;

wherein the power receiving portion includes a voltage detection circuit responding to terminal voltage of the communication coil;

wherein the voltage detection circuit generates a first control signal of a first state when the terminal voltage of the communication coil exceeds a specified power supply threshold voltage;

wherein the first switch portion is controlled to turn on between the first terminal and the third terminal in response to the first control signal of the first state;

wherein the voltage detection circuit generates the first control signal of a second state different from the first state when the terminal voltage of the communication coil does not exceed the specified power supply threshold voltage;

wherein the first switch portion is controlled to turn on between the second terminal and the third terminal in response to the first control signal of the second state;

wherein the voltage detection circuit generates the second control signal of a third state during a period to charge the secondary cell when the terminal voltage of the communication coil exceeds a charge threshold voltage higher than the specified power supply threshold voltage;

wherein the second switch portion is controlled to turn off in response to the second control signal of the third state;

wherein the voltage detection circuit generates the second control signal of a fourth state different from the third state when the terminal voltage of the communication coil does not exceed the charge threshold voltage higher than the specified power supply threshold voltage;

wherein the second switch portion is controlled to turn on in response to the second control signal of the fourth state; and

wherein the communication circuit is capable of communicating with the other communication apparatus during a period in which the second switch portion is controlled to turn on.

2. The communication apparatus according to claim 1,

wherein the charge threshold voltage includes a first charge threshold voltage higher than the specified power supply threshold voltage and a charge threshold voltage higher than the first charge threshold voltage;

wherein the voltage detection circuit generates the second control signal of the third state during the period to charge the secondary cell when the terminal voltage of the communication coil exceeds the second charge threshold voltage; and

wherein the voltage detection circuit generates the second control signal of the fourth state different from the third state when the terminal voltage of the communication coil becomes lower than the first charge threshold voltage.

3. The communication apparatus according to claim 2,

wherein the communication circuit is capable of communicating with the other communication apparatus using the communication coil during a communication period in which the second switch portion is controlled to turn on in response to the second control signal of the fourth state.

4. The communication apparatus according to claim 3,

wherein the power receiving portion, the charge control portion, and the communication circuit are coupled through wiring that transfers information about charging of the secondary cell;

and

wherein the communication circuit is capable of communicating the information about charging of the secondary cell with the other communication apparatus during the communication period.

5. The communication apparatus according to claim 4,

wherein the charge control portion is capable of charging the secondary cell using the power-supply voltage and the second switch portion is controlled to turn off in response to the second control signal of the third state during the period to charge the secondary cell.

6. The communication apparatus according to claim 5,

wherein the communication circuit is operable during the charging period using the power-supply voltage supplied to a third terminal of the first switch portion.

7. The communication apparatus according to claim 6,

wherein the processor is coupled to a third terminal of the first switch portion;

and

wherein the processor is operable during the charging period using the power-supply voltage supplied to a third terminal of the first switch portion.

8. The communication apparatus according to claim 7,

wherein the communication circuit is capable of NFC with the other communication apparatus during the communication period.

9. The communication apparatus according to claim 8,

wherein the second switch portion includes a plurality of enhancement type field-effect transistors having current pathways coupled in series between a first port coupled to the communication coil and a second port coupled to the communication circuit;

and

wherein the second control signal generated from the voltage detection circuit is supplied to a plurality of gates of the plurality of enhancement type field-effect transistors.

10. The communication apparatus according to claim 8,

wherein the second switch portion includes a plurality of PIN diodes coupled in series between a first port coupled to the communication coil and a second port coupled to the communication circuit.

11. The communication apparatus according to claim 8,

wherein the second switch portion includes a plurality of MEMS switches coupled in series between a first port coupled to the communication coil and a second port coupled to the communication circuit.

12. A method of operating a communication apparatus including a communication coil, a power receiving portion, a charge control portion, a first switch portion, a second switch portion, a communication circuit, and a processor, the method comprising:

wherein the communication coil receives a transmission signal transmitted from another communication apparatus;

wherein the power receiving portion generates a power-supply voltage from the transmission signal received by the communication coil;

wherein the charge control portion is connectable to a secondary cell;

wherein the charge control portion is capable of charging the secondary cell using the power-supply voltage;

wherein the communication coil is coupled to a transmission/reception terminal of the communication circuit via the second switch portion;

wherein the processor is coupled to the communication circuit;

wherein a first terminal of the first switch portion is supplied with the power-supply voltage;

wherein a second terminal of the first switch portion is capable of being supplied with battery voltage;

wherein a third terminal of the first switch portion couples with the communication circuit;

wherein the power receiving portion includes a voltage detection circuit responding to terminal voltage of the communication coil;

wherein the voltage detection circuit generates a first control signal of a first state when the terminal voltage of the communication coil exceeds a specified power supply threshold voltage;

wherein the first switch portion is controlled to turn on between the first terminal and the third terminal in response to the first control signal of the first state;

wherein the voltage detection circuit generates the first control signal of a second state different from the first state when the terminal voltage of the communication coil does not exceed the specified power supply threshold voltage;

wherein the first switch portion is controlled to turn on between the second terminal and the third terminal in response to the first control signal of the second state;

wherein the voltage detection circuit generates the second control signal of a third state during a period to charge the secondary cell when the terminal voltage of the communication coil exceeds a charge threshold voltage higher than the specified power supply threshold voltage;

wherein the second switch portion is controlled to turn off in response to the second control signal of the third state;

wherein the voltage detection circuit generates the second control signal of a fourth state different from the third state when the terminal voltage of the communication coil does not exceed the charge threshold voltage higher than the specified power supply threshold voltage;

wherein the second switch portion is controlled to turn on in response to the second control signal of the fourth state; and

wherein the communication circuit is capable of communicating with the other communication apparatus during a period in which the second switch portion is controlled to turn on.

13. The method of operating the communication apparatus according to claim 12,

wherein the charge threshold voltage includes a first charge threshold voltage higher than the specified power supply threshold voltage and a charge threshold voltage higher than the first charge threshold voltage;

wherein the voltage detection circuit generates the second control signal of the third state during the period to charge the secondary cell when the terminal voltage of the communication coil exceeds the second charge threshold voltage; and

wherein the voltage detection circuit generates the second control signal of the fourth state different from the third state when the terminal voltage of the communication coil becomes lower than the first charge threshold voltage.

14. The method of operating the communication apparatus according to claim 13,

wherein the communication circuit is capable of communicating with the other communication apparatus using the communication coil during a communication period in which the second switch portion is controlled to turn on in response to the second control signal of the fourth state.

15. The method of operating the communication apparatus according to claim 14,

wherein the power receiving portion, the charge control portion, and the communication circuit are coupled through wiring that transfers information about charging of the secondary cell;

and

wherein the communication circuit is capable of communicating the information about charging of the secondary cell with the other communication apparatus during the communication period.

16. The method of operating the communication apparatus according to claim 15,

wherein the charge control portion is capable of charging the secondary cell using the power-supply voltage and the second switch portion is controlled to turn off in response to the second control signal of the third state during the period to charge the secondary cell.

17. The method of operating the communication apparatus according to claim 16,

wherein the communication circuit is operable during the charging period using the power-supply voltage supplied to a third terminal of the first switch portion.

18. The method of operating the communication apparatus according to claim 17,

wherein the processor is coupled to a third terminal of the first switch portion;

and

wherein the processor is operable during the charging period using the power-supply voltage supplied to a third terminal of the first switch portion.

19. The method of operating the communication apparatus according to claim 18,

wherein the communication circuit is capable of NFC with the other communication apparatus during the communication period.

20. The method of operating the communication apparatus according to claim 19,

wherein the second switch portion includes a plurality of enhancement type field-effect transistors having current pathways coupled in series between a first port coupled to the communication coil and a second port coupled to the communication circuit;

and

wherein the second control signal generated from the voltage detection circuit is supplied to a plurality of gates of the plurality of enhancement type field-effect transistors.