Wireless power receiving device, receiver circuit thereof, and control method of wireless power receiving device

• US 10,224,763 B2
• Filed: 07/14/2015
• Issued: 03/05/2019
• Est. Priority Date: 07/17/2014
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Abe, Shinichi, Iwasaki, Tatsuya
• Primary Examiner(s): Zhou, Zixuan
• Application Number:
  US14/799,064
• Publication Number:
  US 20160020643A1
• Time in Patent Office: 1,330 Days
• Field of Search: 320108, 307104
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

The wireless power receiving device includes a receiving antenna, a rectifier circuit connected to the receiving antenna, that generates a rectified voltage, a charging circuit to receive the rectified voltage and charge a power storage device, and a modulator that modulates a voltage or current of the receiving antenna by changing a charging current of the charging circuit based on data to be transmitted to a wireless power transmitting device.

Claims

1. A wireless power receiving device, comprising:

a receiving antenna;

a rectifier circuit connected to the receiving antenna, that generates a rectified voltage;

a charging circuit to receive the rectified voltage and charge a power storage device; and

a modulator that modulates a voltage or current of the receiving antenna by changing a charging current of the charging circuit based on data to be transmitted to a wireless power transmitting device,

wherein the charging circuit allows the charging current to be switched between a first current amount and a second current amount, and

wherein the charging circuit includes;

a first current source configured to continuously supply the first current amount to the power storage device during an operation time of the charging circuit; and

a second current source configured to supply an additive current amount, which is a differential current between the first current amount and the second current amount, to the power storage device in an on-off manner according to the data.

2. A wireless power receiving device comprising:

a receiving antenna;

a rectifier circuit connected to the receiving antenna, that generates a rectified voltage; and

a modulator that is provided on a path of a current flowing from the rectifier circuit into a load and modulates a voltage or current of the receiving antenna by changing the current flowing into the load based on data to be transmitted to a wireless power transmitting device,

wherein the modulator is configured to;

allow the current flowing into the load to be switched between a first current amount and a second current amount;

control a first current source that continuously supplies the first current amount to the load during an operation time of the modulator; and

control a second current source that supplies an additive current amount, which is a differential current between the first current amount and the second current amount, to the load according in an on-off manner to the data.

3. A receiver circuit for use in a wireless power receiving device together with a receiving antenna comprising:

a rectifier circuit connected to the receiving antenna, that generates a rectified voltage;

a charging circuit to receive the rectified voltage and charge a power storage device; and

a modulator that modulates a voltage or current of the receiving antenna by changing a charging current of the charging circuit based on data to be transmitted to a wireless power transmitting device,

wherein the charging circuit allows the charging current to be switched between a first current amount and a second current amount, and

wherein the charging circuit includes;

a first current source configured to continuously supply the first current amount to the power storage device during an operation time of the charging circuit; and

a second current source configured to supply an additive current amount, which is a differential current between the first current amount and the second current amount, to the power storage device in an on-off manner according to the data.

4. The receiver circuit of claim 3, wherein the receiver circuit is integrated on a single semiconductor substrate.

5. A receiver circuit for use in a wireless power receiving device together with a receiving antenna comprising:

a rectifier circuit connected to the receiving antenna, that generates a rectified voltage; and

a modulator that is provided on a path of a current flowing from the rectifier circuit into a load and modulates a voltage or current of the receiving antenna by changing the current flowing into the load based on data to be transmitted to a wireless power transmitting device,

wherein the modulator is configured to;

allow the current flowing into the load to be switched between a first current amount and a second current amount;

control a first current source that continuously supplies the first current amount to the load during an operation time of the modulator; and

control a second current source that supplies an additive current amount, which is a differential current between the first current amount and the second current amount, to the load in an on-off manner according to the data.

6. A control method of a wireless power receiving device comprising:

receiving a power signal at a receiving antenna,

rectifying a current induced in the receiving antenna and generating a rectified voltage,

charging a power storage device based on the rectified voltage,

modulating a voltage or current of the receiving antenna by changing a charging current for the power storage device based on data to be transmitted to a wireless power transmitting device, and transmitting the data to the wireless power transmitting device,

wherein changing the charging current includes switching the charging current between a first current amount and a second current amount by;

continuously supplying the first current amount to the power storage device during the act of charging the power storage device; and

supplying an additive current amount, which is a differential current between the first current amount and the second current amount, to the power storage device in an on-off manner according to the data.