Foreign object detection based on transmitter input parameter

Patent metadata

Field	Value
Publication number	US-2023146600-A1
Application number	US-202217883948-A
Country	US
Kind code	A1
Filing date	Aug 9, 2022
Priority date	Nov 10, 2021
Publication date	May 11, 2023
Grant date	—

Abstract

Systems, apparatuses, and methods for detecting a foreign object on a wireless power charging region are described. A circuit can detect an object inductively coupled to a wireless power transmitter. The circuit can further measure an input parameter prior to a power transfer stage, the input parameter can be one of an input current and an input power. The circuit can further compare the measured input parameter with a predetermined value. The circuit can further determine whether the object is a foreign object or the wireless power receiver based on a result of the comparison between the measured input parameter with the predetermined value.

First claim

What is claimed is:

1 . A semiconductor device for wireless power transmitter comprising:
a driver circuit configured to drive a transmitter coil to provide wireless power to a wireless power receiver; a wireless power transmitter coupled to the driver circuit and configured to control the driver circuit, the wireless power transmitter configured to:
detect an object inductively coupled to a wireless power transmitter;
prior to a power transfer stage between the wireless power transmitter and the wireless power receiver, measure an input parameter, the input parameter being one of an input current and an input power,
compare the measured input parameter with a predetermined value; and
determine whether the object is a foreign object or the wireless power receiver based on a result of the comparison between the measured input parameter with the predetermined value.

2 . The semiconductor device of claim 1 , wherein the wireless power transmitter is further configured to:
control an input voltage, the input voltage being a voltage supplied to the driver circuit; measure a first input parameter and a second input parameter, the first input parameter being the input parameter when the input voltage is a first input voltage, and the second input parameter being the input parameter when the input voltage is a second input voltage which is different from the first input voltage; and determine whether the object is the foreign object or the wireless power receiver based on the first input parameter, second input parameter, the first input voltage, and the second input voltage.

3 . The semiconductor device of claim 2 , wherein the wireless power transmitter is further configured to:
determine whether the object is the foreign object or the wireless power receiver based on a value obtained by dividing a difference between the first input parameter and the second input parameter by a difference between the first input voltage to the second input voltage.

4 . The semiconductor device of claim 1 , wherein the wireless power transmitter is further configured to:
control an operation frequency for driving the driver circuit; measure a first input parameter and a second input parameter, the first input parameter being the input parameter when the operation frequency is a first operation frequency, and the second input parameter being the input parameter when the operation frequency is a second operation frequency which is different from the first operation frequency; and determine whether the object is the foreign object or the wireless power receiver based on the first input parameter, second input parameter, the first operation frequency, and the second operation frequency.

5 . The semiconductor device of claim 4 , wherein a wireless power transmitter is further configured to:
determine whether the object is the foreign object or the wireless power receiver based on a value obtained by dividing a difference between the first input parameter and the second input parameter by a difference between the first operating frequency and the second operating frequency.

6 . The semiconductor device of claim 1 , wherein the predetermined value is a fixed value of the measured input parameter, and the controller is configured to:
in response to the measured input parameter being different from the fixed value, determine that the object is the foreign object; and in response to the measured input parameter being same as from the fixed value, determine that the object is the wireless power receiver.

7 . The semiconductor device of claim 1 , wherein the predetermined value corresponds to a relationship between the input parameter and a distance between the foreign object and a reference location on a charging region of the wireless power transmitter.

8 . An apparatus comprising:
an integrated circuit configured to:
detect an object inductively coupled to a wireless power transmitter;
prior to a power transfer stage between the wireless power transmitter and a wireless power receiver, measure an input parameter, the input parameter being one of an input current and an input power,
compare the measured input parameter with a predetermined value; and
determine whether the object is a foreign object or the wireless power receiver based on a result of the comparison between the measured input parameter with the predetermined value.

9 . The apparatus of claim 8 , wherein the integrated circuit is further configured to:
measure a first input parameter and a second input parameter, the first input parameter being the input parameter when the input voltage is a first input voltage, and the second input parameter being the input parameter when the input voltage is a second input voltage which is different from the first input voltage; and determine whether the object is the foreign object or the wireless power receiver based on the first input parameter, second input parameter, the first input voltage, and the second input voltage.

10 . The apparatus of claim 9 , wherein the integrated circuit is further configured to:
determine whether the object is the foreign object or the wireless power receiver based on a value obtained by dividing a difference between the first input parameter and the second input parameter by a difference between the first input voltage to the second input voltage.

11 . The apparatus of claim 8 , wherein the integrated circuit is further configured to:
measure a first input parameter and a second input parameter, the first input parameter being the input parameter when the operation frequency is a first operation frequency, and the second input parameter being the input parameter when the operation frequency is a second operation frequency which is different from the first operation frequency; and determine whether the object is the foreign object or the wireless power receiver based on the first input parameter, second input parameter, the first operation frequency, and the second operation frequency.

12 . The apparatus of claim 11 , wherein the integrated circuit is further configured to:
determine whether the object is the foreign object or the wireless power receiver based on a value obtained by dividing a difference between the first input parameter and the second input parameter by a difference between the first operating frequency and the second operating frequency.

13 . The apparatus of claim 8 , wherein the predetermined value is a fixed value of the measured input parameter, and the integrated circuit is configured to:
in response to the measured input parameter being different from the fixed value, determine that the object is the foreign object; and in response to the measured input parameter being same as from the fixed value, determine that the object is the wireless power receiver.

14 . The apparatus of claim 8 , wherein the predetermined value corresponds to a relationship between the input parameter and a distance between the foreign object and a reference location on a charging region of the wireless power transmitter.

15 . A method for operating a wireless power transmitter, the method comprising:
detecting, by an integrated circuit, an object inductively coupled to a wireless power transmitter; prior to a power transfer stage between the wireless power transmitter and a wireless power receiver, measuring, by the integrated circuit, an input parameter, the input parameter being one of an input current and an input power; comparing, by the integrated circuit, the measured input parameter with a predetermined value; and determining, by the i

Assignees

• Renesas Electronics America Inc

Inventors

• Jeong Chan Young
• Qi Tao
• Ryu Young Chul
• Choi Kwangmuk
• Agrawal Pooja
• Solanki Krishal Jaswantsinh
• Dzebic Adnan

Classifications

• H02J50/10 Primary

  using inductive coupling · CPC title

• G01R19/165

  Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values · CPC title

• H02J50/60 Primary

  responsive to the presence of foreign objects, e.g. detection of living beings · CPC title

• G01R21/00

  Arrangements for measuring electric power or power factor (G01R7/12 takes precedence) · CPC title

• H02J50/80

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title