Wireless charging transmitter

• US 10,097,029 B2
• Filed: 07/26/2016
• Issued: 10/09/2018
• Est. Priority Date: 07/26/2016
• Status: Active Grant

• Current Assignee: NXP Semiconductors NV
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: van den Berg, Arjan
• Primary Examiner(s): DIAO, M BAYE
• Application Number:
  US15/219,901
• Publication Number:
  US 20180034302A1
• Time in Patent Office: 805 Days
• Field of Search: 320105, 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

A wireless charging transmitter has a rectifier circuit, a transmitter coil, a transmitter coil driving circuit, and a control circuit. The rectifier circuit receives an alternating current (AC) mains input voltage and provides a rectified mains voltage. The transmitter coil is provided for inductively coupling with a receiver coil on a device having a battery to be charged. The transmitter coil driving circuit directly receives the rectified mains voltage, and for providing a time-varying driving signal to the transmitter coil. The control circuit is coupled to the transmitter coil to receive charging information from a receiver battery inductively coupled to the transmitter coil through load modulation. In response, the control circuit controls a frequency and duty cycle of the time-varying driving signal based at least in part on the charging information.

Claims

1. A wireless charging transmitter comprising:

a rectifier circuit for receiving an alternating current (AC) mains input voltage, and for providing a rectified mains voltage;

a transmitter coil;

a transmitter coil driving circuit coupled to receive the rectified mains voltage, and for providing a time-varying driving signal to the transmitter coil, the time-varying driving signal having a frequency and a duty cycle;

a communication demodulation controller coupled to the transmitter coil to receive charging information from a receiver battery inductively coupled to the transmitter coil through load modulation, and coupled to the transmitter coil driving circuit for controlling the frequency and the duty cycle of the time-varying driving signal based at least in part on the charging information; and

a voltage converter coupled to receive the rectified mains voltage and for providing a power supply voltage at a lower voltage level than the rectified mains voltage to power the communication demodulation controller.

2. The wireless charging transmitter of claim 1, wherein the rectifier circuit is a full-wave rectifier.

3. The wireless charging transmitter of claim 1, wherein the transmitter coil driving circuit is a half-bridge converter.

4. The wireless charging transmitter of claim 1, wherein the AC mains input voltage is approximately equal to 110 volts, 60 Hertz.

5. The wireless charging transmitter of claim 1, wherein a frequency range of the time-varying driving signal is about 100 kHz to about 200 kHz.

6. The wireless charging transmitter of claim 1, wherein the communication demodulation controller further comprises a charging controller coupled to the transmitter coil for sensing a transmitter coil voltage and a transmitter coil current.

7. The wireless charging transmitter of claim 1, wherein the power supply voltage is in a range of about 3 to 7 volts.

8. The wireless charging transmitter of claim 1, wherein the voltage converter further comprises a low drop-out voltage regulator.

9. A wireless charging transmitter comprising:

a rectifier circuit for receiving an alternating current (AC) mains input voltage, and for providing a rectified mains voltage;

a transmitter coil;

a half-bridge converter circuit coupled to receive the rectified mains voltage, and for providing a time-varying driving signal to the transmitter coil, the time-varying driving signal having a frequency and a duty cycle;

a charging controller coupled to the transmitter coil for sensing a transmitter coil voltage and a transmitter coil current and for controlling the frequency and the duty cycle of the time-varying driving signal based at least in part on the sensed transmitter coil voltage and the transmitter coil current; and

a voltage converter coupled to receive the rectified mains voltage and for providing a power supply voltage at a lower voltage level than the rectified mains voltage to power the charging controller.

10. The wireless charging transmitter of claim 9, wherein the charging controller further comprises communication demodulation circuitry for receiving charging information from a battery being charged by the wireless charging transmitter.

11. The wireless charging transmitter of claim 9, wherein the rectifier circuit is a full-wave rectifier.

12. The wireless charging transmitter of claim 9, wherein the AC mains input voltage is approximately equal to 110 volts, 60 Hertz, and wherein a frequency range of the time-varying driving signal is about 100 kilo Hertz to about 200 kilo Hertz.

13. The wireless charging transmitter of claim 9, wherein the power supply voltage is in a range of about 3 to 7 volts.

14. A wireless charging transmitter comprising:

a full-wave rectifier circuit for receiving an alternating current (AC) mains input voltage, and for providing a rectified mains voltage;

a transmitter coil;

a half-bridge converter circuit coupled to receive the rectified mains voltage, and for providing a time-varying driving signal to the transmitter coil, the time-varying driving signal having a frequency and a duty cycle;

a charging controller and communication demodulator coupled to the transmitter coil for sensing a transmitter coil voltage and a transmitter coil current and for controlling the frequency and the duty cycle of the time-varying driving signal based at least in part on the sensed transmitter coil voltage and the transmitter coil current, and at least in part on charging information from a battery being charged to regulate a transmitted power to the battery; and

a voltage converter coupled to receive the rectified mains voltage and for providing a power supply voltage at a lower voltage level than the rectified mains voltage to power the charging controller.

15. The wireless charging transmitter of claim 14, wherein the AC mains input voltage is approximately equal to 110 volts, 60 Hertz, and wherein a frequency range of the time-varying driving signal is about 100 kilo Hertz to about 200 kilo Hertz.

16. The wireless charging transmitter of claim 14, wherein the charging controller and communication demodulator is implemented on a single integrated circuit.

17. The wireless charging transmitter of claim 14, wherein the voltage converter further comprises a low drop-out voltage regulator.

18. The wireless charging transmitter of claim 14, wherein the power supply voltage is in a range of about 3 to 7 volts.