CIRCUIT AND METHOD FOR MEASURING AVAILABLE POWER IN A WIRELESS POWER SYSTEM

• US 20140036560A1
• Filed: 07/30/2013
• Published: 02/06/2014
• Est. Priority Date: 08/03/2012
• Status: Active Grant

• Current Assignee: MediaTek Singapore Pte. Ltd. (MediaTek, Inc.)
• Original Assignee: MediaTek Singapore Pte. Ltd. (MediaTek, Inc.)
• Inventors: Satyamoorthy, Anand, Riehl, Patrick Stanley
• Granted Patent: US 9,735,701 B2
• Time in Patent Office: Days
• US Class Current: 363/126
• CPC Class Codes: G01R 29/0871 Complete apparatus or systems; circuits, e.g. receivers or amplifiers G01R29/0878, G01R29/0892 take precedence; dosimeters, warning devices G01R29/0857
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02M 7/066 particular circuits having a special characteristic

Abstract

A resonant wireless power receiver that includes an electromagnetic resonator having one or more inductive elements that are arranged to form a receiver coil and a network of passive components arranged to form a matching network. A rectifier circuit converts ac power from the electromagnetic resonator to dc power. An available-power indicator measures the rectified power to assess the instantaneous power available to the receiver.

Claims

1. A resonant wireless power receiver comprising:

an electromagnetic resonator that includes one or more inductive elements that are arranged to form a receiver coil and a network of passive components arranged to form a matching network;

a rectifier circuit that converts ac power from the electromagnetic resonator to dc power; and

an available-power indicator that measures the rectified power to assess the instantaneous power available to the receiver.

2. The resonant wireless power receiver of claim 1, wherein the receiver comprises a regulator to convert rectified power to regulated output power.

3. The resonant wireless power receiver of claim 1, wherein the available-power indicator comprises an analog-to-digital converter (ADC) used to measure the rectified voltage.

4. The resonant wireless power receiver of claim 1, wherein the available-power indicator comprises a microcontroller unit (MCU) that is used to perform the available power calculation and control a plurality of power switches.

5. The resonant wireless power receiver circuit of claim 4, wherein one of the power switches is used to disconnect the wireless power receiver circuit from a load circuit until it is determined the available power is sufficient to drive the load circuit.

6. The resonant wireless power receiver circuit of claim 5, wherein the available power is measured using a resistive element coupled to another of the power switches.

7. The resonant wireless power receiver circuit of claim 1, wherein the available power is measured using a two-point measurement.

8. A method of measuring available power of a resonant wireless power receiver circuit comprising:

providing an electromagnetic resonator that includes one or more inductive elements that are arranged to form a receiver coil and a network of passive components arranged to form a matching network;

converting ac power using a rectifier circuit from the electromagnetic resonator to dc power; and

measuring the rectified power using an available-power indicator to assess the instantaneous power available to the receiver.

9. The method of claim 8, further comprising converting the rectified power to regulated output power.

10. The method of claim 8, wherein the step of measuring the rectified voltage is performed based on an analog-to-digital conversion.

11. The method of claim 8, wherein the available-power indicator performs the available power calculation and controls a plurality of power switches.

12. The method circuit of claim 11, wherein one of the power switches is used to disconnect the wireless power receiver circuit from a load circuit until it is determined the available power is sufficient to drive the load circuit.

13. The method circuit of claim 12, wherein the available power is measured using a resistive element coupled to another of the power switches.

14. The method circuit of claim 8, wherein the available power is measured using a two-point measurement.