Fifty watt (50W) wireless power system with backward compatibility

Abstract

This disclosure provides systems, methods, and apparatuses for wireless power transfer according to a first mode or a second mode. Some techniques facilitate a Magnetic Power Profile (MPP) mode for 50W power transfer with backward compatibility by using a communication protocol that enables different nominal frequencies. A first mode can operate at a nominal frequency of 360 kHz, and a second mode operates at a lower frequency, such as 128 kHz. The disclosed techniques also enable a low frequency (e.g., 128 kHz) restricted mode. This restricted mode allows minimal communication and power transfer at a low power level—useful when a Power Receiver's battery is fully discharged—while supporting a transition to higher power levels when the receiver becomes capable. In some implementations, an MPP mode can be modified or adapted to support high power throughput using frequencies that are lower than a legacy MPP mode.

Description

Docket No. D25023W001FIFTY WATT (50W) WIRELESS POWER SYSTEM WITH BACKWARD COMPATIBILITY CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority benefit of India Provisional Patent Application No.202511074649, filed August 6, 2025, entitled “WIRELESS POWER PROTOCOL FOR LOW FREQUENCY RESTRICTED MODE,” India Provisional Patent Application No.202511049170, filed May 21, 2025, entitled “FIFTY WATT (50W) WIRELESS POWER AND FAST CHARGING,” and India Provisional Patent Application No. 202511017912, filed February 28, 2025, entitled “FIFTY WATT (50W) WIRELESS POWER SYSTEM WITH BACKWARD COMPATIBILITY,” the disclosure of which are incorporated herein.TECHNICAL FIELD

[0002] This disclosure relates generally to wireless power and some aspects relate to a fifty watt (50W) wireless power system with frequency selection and backward compatibility.BACKGROUND

[0003] A wireless power system includes a Power Transmitter (PTx, sometimes also referred to as a wireless power transmission apparatus) and a Power Receiver (PRx, sometimes also referred to as a wireless power reception apparatus). The Power Transmitter transmits power via an electromagnetic field or resonant frequency. The Power Receiver can receive the wireless power and provide it to a load (such as electronics or a power storage device, among other examples). An apparatus (sometimes also referred to as a device) might include a Power Transmitter, a Power Receiver, or both. For example, a first apparatus (such as a charging station) might include one or more Power Transmitters. A second apparatus (such as a computing device or user device) might include a Power Receiver as well as the load. A wireless power system can include apparatuses from different manufacturers. The manufacturers might implement a common standard wireless power transfer specification so that their respective Power Transmitter(s) or Power Receiver(s) are compatible with one another.

[0004] Wireless power technologies continue to evolve as developers envision techniques to increase the amount of power (such as 5 Watts (5W), 15W, 25W, etc.) that can be transferred from a Power Transmitter to a Power Receiver. There is a desire to enable wireless power transfer at higher power levels (including those above 25W). Meanwhile, traditional designs and protocols for 5W, 15W, and / or 25 W may be incompatible with higher power levels (suchDocket No. D25023W001as 50W). The field of wireless power transfer continues to evolve in order to meet growing consumer demands. Power delivery and communication between the Power Transmitter and the Power Receiver may be specified by a wireless power standard. One example wireless power standard is the Wireless Power Consortium (WPC) Qi standard.BRIEF SUMMARY

[0005] The systems, methods, and apparatuses of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0006] One aspect of the subject matter described in this disclosure can be implemented as a method of a Power Transmitter. The method includes the Power Transmitter detecting a Power Receiver, determining a nominal frequency for a wireless power signal, and transmitting the wireless power signal to the Power Receiver according to the nominal frequency.

[0007] Another aspect of the subject matter described in this disclosure can be implemented as a method of a Power Transmitter. The method includes communicating one or more messages during a negotiation phase between the Power Transmitter and a Power Receiver, determining, based on the one or more messages, whether the Power Transmitter and the Power Receiver both support wireless power transfer according to a first mode or a second mode, where the first mode is associated with a nominal power transfer of 25 watts (25W) and the second mode is associated with a nominal power transfer of greater than 25W, and transmitting wireless power to the Power Receiver according to a first frequency for the first mode or a second frequency for the second mode.

[0008] Another aspect of the subject matter described in this disclosure can be implemented as a method of a Power Receiver. The method includes communicating one or more messages during a negotiation phase between the Power Receiver and a Power Transmitter, determining, based on the one or more messages, whether the Power Transmitter and the Power Receiver both support wireless power transfer according to a first mode or a second mode, where the first mode is associated with a nominal power transfer of 25 W and the second mode is associated with a nominal power transfer of greater than 25 W, and receiving wireless power from the Power Transmitter according to a first frequency for the first mode or a second frequency for the second mode.

[0009] Another aspect of the subject matter described in this disclosure can be implemented as a Power Transmitter that includes an inverter to generate a wireless power signal for transmission from the Power Transmitter to a Power Receiver according to a first mode or aDocket No. D25023W001second mode, where the first mode is associated with a nominal power transfer of 25 watts (25W) and the second mode is associated with a nominal power transfer of greater than 25W, and a controller to perform one or more frequency control operations to change a frequency of the wireless power signal.

[0010] Another aspect of the subject matter described in this disclosure can be implemented as method of a Power Transmitter. The Power Transmitter transmits a 128 kilohertz (kHz) digital ping. The Power Transmitter receives a message from a Power Receiver in response to the 128 kHz digital ping, the message indicating that the Power Receiver is operating in a restricted mode. The Power Transmitter causes the Power Receiver to enter a low frequency restricted mode of a wireless power protocol, where the low frequency restricted mode is associated with a 128 kHz operating frequency. The Power Transmitter transmits a wireless power signal to the Power Receiver at the 128 kHz operating frequency while in the low frequency restricted mode.

[0011] Another aspect of the subject matter described in this disclosure can be implemented as a Power Transmitter that includes a plurality of capacitors to enable capacitance tuning at the Power Transmitter. The Power Transmitter also includes a controller to perform the capacitance tuning to set a capacitance of the Power Transmitter based on a first mode or a second mode, where the first mode is associated with a nominal power transfer of 25 watts (25W) and the second mode is associated with a nominal power transfer of greater than 25W, and where in the first mode, the capacitance tuning includes capacitance in a range from 68 nanofarads (nF) to 458 nF, and in the second mode, the capacitance tuning includes capacitance above 458 nF.

[0012] Another aspect of the subject matter described in this disclosure can be implemented as a Power Transmitter. The Power Transmitter includes a power transfer coil, a Power Transmitter (PTx) controller, and a communication unit to receive communications from a Power Receiver using an amplitude shift keying (ASK) modulation, where the ASK modulation includes either capacitive modulation or load modulation. The ASK modulation may be capacitive modulation in a default setting or when communication is reliable. The ASK modulation may be load modulation when the Power Transmitter sends a message to the Power Receiver indicating that the communication is unreliable, or the Power Transmitter sends a message to the Power Receiver requesting the Power Receiver to use the load modulation.

[0013] Another aspect of the subject matter described in this disclosure can be implemented as a Power Transmitter that includes a power transfer coil, an inverter, and an ActiveDocket No. D25023W001Harmonic Filter. A setting of the Active Harmonic Filter is based on an operating frequency of a first mode or a second mode, where the first mode is associated with a nominal power transfer of 25 watts (25W) and the second mode is associated with a nominal power transfer of greater than 25W.

[0014] Another aspect of the subject matter described in this disclosure can be implemented as a method of a Power Receiver that includes a power transfer coil to receive a wireless power signal from a Power Transmitter, a communication unit to communicate with the Power Transmitter using an ASK modulation of the wireless power signal, the communication unit including at least a first modulator for capacitive modulation and a second modulator for load modulation, and a controller to select the first modulator or the second modulator.

[0015] Another aspect of the subject matter described in this disclosure can be implemented as a Power Transmitter. The Power Transmitter includes a primary coil, and slew rate capacitors connected to the primary coil via switches. The Power Transmitter also includes a controller configured to selectively enable or disable the switches to adjust the capacitance added to the primary coil using the slew rate capacitors.

[0016] Another innovative aspect of the subject matter described in this disclosure can be implemented as an apparatus that includes a controller or processor configured to implement any one of the methods described herein.

[0017] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Like reference numbers and designations in the various drawings indicate like elements. Note that the relative dimensions of the figures may not be drawn to scale.

[0019] FIG. 1A illustrates an example wireless power system that includes a Power Transmitter and a Power Receiver.

[0020] FIG. IB illustrates an overview of changes to the wireless power system of FIG. 1 A to support a 50 Watt (50W) power transfer mode with backward compatibility.

[0021] FIG.2 illustrates example scenarios of Power Receivers and Power Transmitters that support different frequencies for various power levels / modes.

[0022] FIG. 3 is a message flow diagram in which the Power Receiver and the Power Transmitter use a first mode for a first power level.Docket No. D25023W001

[0023] FIG. 4 is a message flow diagram in which the Power Receiver supports a second mode (e.g., 50W) and the Power Transmitter does not support the second mode.

[0024] FIG. 5 is a message flow diagram in which the Power Receiver requests the Power Transmitter (PTx) to send a PTx Extended identifier (ID) packet, where the PTx Extended ID packet indicates whether the Power Transmitter supports the second mode.

[0025] FIG. 6 is a message flow diagram in which the Power Receiver does not support the second mode.

[0026] FIG. 7 is a message flow diagram in which the Power Receiver and the Power Transmitter both support a second mode (e.g., 50W).

[0027] FIG. 8A is a diagram of an example SRQ / freqsel packet.

[0028] FIG. 8B is a diagram of an example GET (PTx Extended ID) packet.

[0029] FIG. 9 illustrates example scenarios for capacitance tuning.

[0030] FIG. 10 illustrates an example diagram of the Power Transmitter and Power Receiver that can perform capacitance tuning.

[0031] FIG. 11A is a first chart showing example regulation limits for electromagnetic interference (EMI).

[0032] FIG. 11B is a second chart showing example regulation limits for EMI.

[0033] FIG. 12A illustrates various example frequencies and power levels.

[0034] FIG. 12B illustrates example techniques for variable frequency control.

[0035] FIG. 13 illustrates a wireless power system in which the Power Transmitter implements an active harmonic filter.

[0036] FIG. 14 illustrates an example of active harmonic filters.

[0037] FIG. 15 illustrates a wireless power system in which amplitude shift keying (ASK) modulation can depend on the power level / mode.

[0038] FIG. 16 illustrates example techniques for managing ASK modulation.

[0039] FIG. 17 shows an example Power Receiver capable of selecting between capacitive modulation and load modulation.

[0040] FIG. 18 shows example changes to a Power Transmitter and / or a Power Receiver to improve power transmission for a second mode (e.g., 50W).

[0041] FIG. 19 illustrates an example wireless power system that includes a Power Transmitter and a Power Receiver.Docket No. D25023W001

[0042] FIG.20A illustrates example scenarios of Power Receivers and a Power Transmitter that support different frequencies for various power levels / modes.

[0043] FIG.20B illustrates example scenarios of Power Receivers and a Power Transmitter that is limited to a particular nominal frequency for various power levels / modes.

[0044] FIG.21 illustrates example operations for selecting a nominal frequency for wireless power transmission based on a request from the Power Receiver.

[0045] FIG.22 illustrates example operations for selecting a nominal frequency for wireless power transmission based on a geographic location or region.

[0046] FIG.23 illustrates example operations for selecting a nominal frequency for wireless power transmission.

[0047] FIG. 24 illustrates example power profiles and nominal frequencies.

[0048] FIG. 25 illustrates a message flow diagram in which the Power Receiver and the Power Transmitter use a first mode for a first power level.

[0049] FIG. 26 illustrates example patterns to indicate nominal frequency.

[0050] FIG. 27 illustrates a message flow diagram in which the Power Receiver selects a nominal frequency based on operating region or location information of the Power Receiver.

[0051] FIG. 28 is a diagram of an example PTx Extended ID (XID) packet with an optional value for a Power Transmitter to indicate nominal frequency or region.

[0052] FIG. 29 is a diagram of an example MPP Extended ID (MPP-XID) packet with an optional value for a Power Receiver to indicate nominal frequency or region.

[0053] FIG. 30 illustrates a Power Receiver that can select a nominal frequency based on PRx location information.

[0054] FIG. 31 shows an example Power Transmitter with slew rate capacitors.

[0055] FIG. 32A is a diagram showing example scenarios of Power Receivers and a Power Transmitter that support different frequencies for a restricted mode.

[0056] FIG. 32B is a diagram showing example scenarios of Power Receivers and a Power Transmitter that is limited to a low frequency restricted mode.

[0057] FIG. 33A is a flowchart illustrating example operations for a Power Transmitter to enter a low frequency restricted mode.

[0058] FIG. 33B is another flowchart illustrating example operations for a Power Transmitter to enter a low frequency restricted mode.

[0059] FIG.34A is a sequence diagram illustrating a Power Transmitter and Power Receiver operating in a low frequency restricted mode.Docket No. D25023W001

[0060] FIG.34B is a sequence diagram illustrating a Power Transmitter and Power Receiver transitioning from a low frequency restricted mode to a full power mode based on a negotiation packet.

[0061] FIG.34C is a sequence diagram illustrating a Power Transmitter and Power Receiver exiting a low frequency restricted mode based on an End Power Transfer / Restart (EPT / rst) packet.

[0062] FIG. 34D is a sequence diagram illustrating a Power Transmitter selecting a low frequency restricted mode or baseline power profile (BPP) mode based on operating frequency information or protocol version information from the Power Receiver..

[0063] FIG. 35A is a flowchart illustrating example operations of a Power Transmitter in a 128 kHz configuration phase of a Magnetic Power Profile (MPP) protocol.

[0064] FIG. 35B is a flowchart illustrating example operations of a Power Transmitter in a 128 kHz configuration phase in which the Power Transmitter enables a low frequency restricted mode based on Power Transmitter settings.

[0065] FIG. 35C is a flowchart illustrating example operations of a Power Transmitter in a 128 kHz configuration phase in which the Power Transmitter enables a low frequency restricted mode based on Power Receiver information.

[0066] FIG. 35D is a flowchart illustrating example operations of a Power Transmitter in a 128 kHz configuration phase showing example alternatives for invoking a low frequency restricted mode.

[0067] FIG.36 is a flowchart illustrating example operations for managing a power transfer mode including a low frequency restricted mode.

[0068] FIG. 37 is a diagram showing different types of Power Transmitters and Power Receivers based on their supported operating modes, frequencies, and power levels.

[0069] FIG. 38 is a diagram of an example Extended Identification (XID) packet.

[0070] FIG. 39 is a diagram of an example XID packet with an optional value for a Power Transmitter to indicate frequency support.

[0071] FIG. 40 illustrates a block diagram of an example apparatus in a wireless power system.DETAILED DESCRIPTION

[0072] The following description is directed to certain implementations for the purpose of describing innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude ofDocket No. D25023W001different ways. The described implementations can be implemented in any means, apparatus, system, or method for transmitting or receiving wireless power.

[0073] A wireless power system includes a Power Transmitter (PTx, sometimes also referred to as a wireless power transmission apparatus) and a Power Receiver (PRx, sometimes also referred to as a wireless power reception apparatus). In some implementations, the Power Transmitter includes a primary coil that produces an electromagnetic field during a power state to induce a voltage in a secondary coil of the Power Receiver when the secondary coil is placed in an electromagnetic field of the primary coil. Alternatively, the Power Transmitter can transmit the power using a resonant frequency that induces a voltage in the resonant coil of the Power Receiver. The Power Receiver uses the induced voltage to generate power for a load. Some designs and communication protocols differ based on the amount of power (e.g., power level) being transferred from a Power Transmitter to a Power Receiver.

[0074] A wireless power standard can support different power levels (such as 5 Watts (5W), 15W, 25 W, 50W, etc.) using different operating parameters. For example, a baseline power profile (BPP) mode can support up to 5W wireless power transfer using an operating frequency in the range of 110 kilohertz (kHz) to 205 kHz (typically BPP mode has a nominal frequency of 128 kHz). An extended power profile (EPP) mode can support up to 15W of wireless power transfer. A magnetic power profile (MPP) mode can operate at higher frequencies (such as 360 kHz or 1.78MHz) and can support higher power levels (such as 15W, or higher). In some implementations, an MPP mode can be used when a Power Receiver and a Power Transmitter both have magnets that can improve the alignment and coupling of the two devices. MPP mode currently supports up to 25W and may continue to increase as the MPP mode is further developed. As technology progresses, there is a desire to support higher power systems (e.g., 50W power levels). The 50W mode can also be referred to by other names, such as “MPP with 50W,” MPP 50, 50W power profile (or 50PP), Fast Charging power profile, or other names which may be later conceived to refer to this technology improvement over existing wireless charging technology. The MPP mode and the 50W mode might have different protocols, frequencies, capacitance, modulation, or other aspects that differ based on the mode. Various aspects of this disclosure are related to a 50W mode. For clarity, this disclosure refers to a first mode for the MPP mode, and refers to the second mode for the 50W mode. However, it should be understood that power levels are examples, and any variety of power levels / modes can be used.

[0075] A wireless power standard may define different protocols (also referred to as profiles) to support different power levels and / or different operating frequencies of the wireless power signal. To facilitate operation with different frequencies, some Power Transmitters areDocket No. D25023W001capable of transmitting a wireless power signal at a variety of different frequencies. For example, some Power Transmitters are capable of supporting a 128 kHz nominal operating frequency, a 360 kHz (or 1.78 MHz) nominal operating frequency, or both. In some instances, a particular operating frequency may be restricted, such as due to government regulations in certain geographic regions or the wireless power standard. Additionally, a Power Receiver may have limitations that require a particular operating frequency.

[0076] This disclosure provides systems, methods and apparatuses for wireless power transfer according to a first mode (e.g., MPP mode) or a second mode (e.g., 50W mode). The first mode might operate using a wireless power signal in a first frequency range, such as a nominal frequency of 360 kHz (or 1.78 MHz). The second mode might operate in a second frequency range, such as a nominal frequency of 128 kHz (as an example). The second mode might be any variety of frequencies, including those described with reference to FIG. 12A. In some implementations, the frequency for the second mode may depend on a geographic region. Because the 50W mode might use the same frequency range (e.g., nominal frequency of 128 kHz) that was also previously associated with BPP / EPP modes for low power transfer (15W and lower), there is a potential for ambiguity. This disclosure includes several example techniques to facilitate coordination of the Power Transmitter and the Power Receiver to select the first mode, the second mode, or a third mode (e.g., BPP / EPP). Additionally, or alternatively, this disclosure provides several improvements to the design and operation of the Power Transmitter / Power Receiver to support a 50 Watt (50W) power transfer mode with backward compatibility.

[0077] In some aspects, a startup sequence or communication protocol during a negotiation phase can be modified to enable 50W mode while taking into consideration backward compatibility when either or both of the Power Transmitter or the Power Receiver do not support the 50W mode. For example, one or more messages can enable the Power Transmitter and the Power Receiver to start a negotiation according to an MPP mode for backward compatibility and then promote to the 50W mode when both devices support the 50W mode. The messages may include any combination of a GET (PTx Extended identification (ID)) packet, a specific request (SRQ) packet with a nominal power frequency selection (referred to as an SRQ / freqsel packet), or other message(s) that include a value to indicate the 50W mode or a frequency for the 50W mode. To ensure backward compatibility, the messaging in the negotiation phase can follow a protocol for the MPP mode, including changes to support a transition to the 50W mode.

[0078] In some aspects, the Power Transmitter (and / or the Power Receiver) can implement techniques of this disclosure for variable frequency control, capacitance tuning, or activeDocket No. D25023W001harmonic filtering. The variable frequency control can enable a variety of power levels and frequencies. Capacitance tuning may extend the capabilities of an MPP mode to include higher capacitance levels that would be useful for the 50W mode. Active harmonic filtering techniques can reduce electromagnetic interference, which may be a greater concern as power levels continue to increase above 25W.

[0079] In some aspects, communication between the Power Receiver and the Power Transmitter may depend on the power level, reliability of communication, or other factors. For example, the Power Receiver communicates with the Power Transmitter using amplitude shift keying (ASK) modulation. The ASK modulation scheme for the 50W mode might be either capacitive modulation or load modulation. While capacitive modulation might be preferred for better efficiency of the wireless power transfer, the reliability of communication may decrease if the ASK modulation depth is not sufficient for the Power Transmitter to demodulate the ASK modulations. Reliability of communication refers to the ability of the Power Transmitter to successfully demodulate and decode the communication. Load modulation tends to be more reliable but might reduce the efficiency of the wireless power transfer since the modulator would consume some of the received power. In some aspects, a Power Receiver may have a first modulator for capacitive modulation and a second modulator for load modulation. The Power Receiver and the Power Transmitter might change between capacitive modulation and load modulation based on the reliability of communication. For example, the ASK modulation might start with capacitive modulation and then switch to load modulation when there is a loss of packets, low ASK modulation depth, or other factors.

[0080] In some aspects, a coil design, magnetic ring, or other changes to the Power Receiver / Power Transmitter can improve the 50W power transfer capability. This disclosure includes some considerations and potential changes to legacy designs to enable 50W mode while maintaining backward compatibility.

[0081] In some aspects, a Power Transmitter has slew rate capacitors to adjust EMI, EMC, harmonics, power levels, ZVS operation, or the like. In this disclosure, the slew rate capacitors can be enabled or disabled to achieve a desired ZVS based on the active power level. Slew rate limiting capacitors can improve harmonic control in power systems. This involves implementing capacitors in strategic locations to manage electromagnetic interference (EMI) and enhance overall system performance. The proposal suggests that the Power Receiver (PRX) should be informed about the status and phase information of these capacitors to optimize their usage effectively. Potential technical advantages include improved EMI and EMC compliance, enhanced power level adjustments, or better overall system stability and efficiency.Docket No. D25023W001

[0082] The BPP mode is a basic power transfer protocol that uses one-way communication from the Power Receiver to the Power Transmitter. The MPP mode is an extension of the BPP that enables higher power transfer and improved efficiency. The MPP mode can operate in a full power mode with bi-directional communication or a restricted mode with one-way communication (similar to BPP). In some scenarios, the restricted mode might be used when the Power Receiver's battery is fully discharged (or low power available) and has limited power for communication. Presently, an MPP restricted mode operates at 360 kHz (or 1.78 MIIz) operating frequency, a frequency that may be restricted in some regions. In accordance with aspects of this disclosure, a wireless power system can use a low frequency (e.g., 128 kHz) restricted mode to limit power / communication during the restricted mode while maintaining the benefits of MPP (such as higher potential power levels and the ability to transition to full power mode without power interruption).

[0083] In some aspects, a wireless power transfer system can operate in a low frequency restricted mode. A PTx transmits a digital ping, such as at 128 kilohertz (kHz), according to a wireless power protocol (such as MPP, 50W, or a higher power profile). In response to the ping, the PTx can receive a message from a PRx indicating that the PRx is operating in a restricted mode. The PTx then causes the PRx to enter a low frequency restricted mode of the wireless power protocol, where the operating frequency of the low frequency restricted mode is 128 kHz. In some implementations, the low frequency restricted mode is used, for example, if the PTx is configured to only operate at 128 kHz, such as due to regional regulations that restrict 360 kHz operation, or if the PRx indicates it is only configured for the 128 kHz frequency. In some implementations, a PTx may be capable of selectively operating at either the 128 kHz frequency or the 360 kHz frequency, where the PTx might select the 128 kHz frequency based on a geographic region in which the PTx is currently operating.

[0084] Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. A wireless power system can deploy a 50W mode and associated protocol / design changes while maintaining compatibility with a legacy mode. The techniques of this disclosure enable a Power Transmitter and a Power Receiver to coordinate the protocols, frequencies, and communication schemes that enable 50W power transfer (or any power level greater than the existing MPP mode, e.g., 25W). In some aspects, the disclosed techniques enable a low frequency restricted mode, such as 128 kHz, which provides compatibility with regions that restrict higher frequencies like 360 kHz. Furthermore, this mode facilitates a seamless transition to full power mode without requiring a power interruption, enhancing user experience. The disclosed techniques provide an efficient way for devices with very lowDocket No. D25023W001power, such as a Power Receiver with a discharged battery, to initiate a low frequency restricted mode charging session.

[0085] FIG. 1A illustrates an example wireless power system 100 A that includes a Power Transmitter 110 and a Power Receiver 120. In FIG. 1A, dotted lines represent communications to distinguish from solid lines that represent electrical circuit lines. In some implementations, the Power Transmitter may include a countertop-mounted primary coil or a primary coil that is embedded or manufactured in a surface on which a Power Receiver can be placed. A Power Receiver can be configured to wirelessly receive power from the Power Transmitter. In some examples, the Power Receiver can be a device (such as a phone, computer, appliance, or machine) and the Power Transmitter can be any apparatus that provides wireless power to the Power Receiver according to a wireless power specification.

[0086] This disclosure includes a brief description of wireless power transfer for context. The Power Transmitter 110 and the Power Receiver 120 are two types of wireless power apparatuses that are used together. The Power Transmitter 110 includes a primary coil 112 and a Power Transmitter (PTx) controller 115. The primary coil 112 may be associated with a Power Transmitter circuit 114 (sometimes also referred to as a power signal generator or a driver circuit). The primary coil 112 may be any type of coil which transmits wireless power (which also may be referred to as wireless energy). The primary coil 112 may transmit wireless energy using an inductive or a resonant magnetic field. The Power Transmitter circuit 114 may include components (not shown) to prepare the wireless power. For example, the Power Transmitter circuit 114 may include one or more switches, drivers, series capacitors, rectifiers, inverters, or other components. In some implementations, the Power Transmitter circuit 114, PTx controller 115 and other components (not shown) may be collectively referred to as a Power Transmitter unit 111. Some or all of the Power Transmitter unit 111 may be embodied as an integrated circuit (IC) that implements features of this disclosure for controlling and transmitting wireless power to one or more wireless power reception apparatuses. The PTx controller 115 may be implemented as a microcontroller, dedicated processor, integrated circuit, application specific integrated circuit (ASIC) or any other suitable electronic device.

[0087] A power source 105 provides power to the Power Transmitter unit 111. In some implementations, the power source 105 may convert alternating current (AC) power to direct current (DC) power. For example, the power source 105 may include a converter that receives an AC power from an external power supply and converts the AC power to a DC power used by the Power Transmitter circuit 114. Alternatively, or additionally, a component (such as an inverter) of the Power Transmitter circuit 114 may convert the DC power to the AC power.Docket No. D25023W001The power source 105 may be integrated as part of the Power Transmitter 110 or may be external to the Power Transmitter 110.

[0088] In some implementations, the Power Transmitter 110 causes the power source 105 to regulate the DC output voltage of the power source 105. For example, the PTx controller 115 can set DC voltage of the power source 105 based on information (such as a value indicating a requested power) received from the Power Receiver 120. The Power Transmitter 110 can receive power configuration information from the Power Receiver 120 and use the information to set a parameter (such as the DC output voltage of the power source 105). The Power Transmitter 110 can receive the power configuration information during various operating states, such as the discovery state or power state. In some implementations, the Power Transmitter 110 includes a DC-DC converter (not shown) between the power source 105 and the Power Transmitter circuit 114 to control the variable DC output voltage.

[0089] The PTx controller 115 is connected to a first communication interface 116. In some implementations, the first communication interface 116 communicates using in-band signaling via the Power Transmitter circuit 114. Alternatively, the first communication interface 116 may be connected to a first communication coil 118. In some implementations, the first communication interface 116 and associated components (such as a modulator, a demodulator, the first communication coil 118, or other components) may be collectively referred to as the first communication unit 113. In some implementations, the first communication unit 113 may use frequency, amplitude, current, or voltage modulation of a wireless power signal to communicate via an in-band communication link that includes the primary coil 112.

[0090] The Power Receiver 120 may include a secondary coil 122, a rectifier 124, a Power Receiver (PRx) controller 125, a second communication interface 126, a load controller 127, a load 130, and a memory (not shown). In some implementations, the load 130 can include a battery charger to charge a power storage device (e.g., a battery, not shown). Alternatively, the load 130 can include electronics or other circuits that consume power from the rectifier 124. In some implementations, other components, such as a series switch (not shown) and / or capacitors (not shown), may be included in series with the secondary coil 122 or in series between the rectifier 124 and the load 130. Although shown as different components, some components may be packaged or implemented in the same hardware. For example, in some implementations, the PRx controller 125 and the load controller 127 may be implemented as a single controller. The PRx controller 125, the load controller 127, or any combination thereof, may be implemented as a microcontroller, dedicated processor, integrated circuit, application specific integrated circuit (ASIC) or any other suitable electronic device.Docket No. D25023W001

[0091] The PTx controller 115 may detect the presence or proximity of a Power Receiver 120. This detection may happen during a periodic pinging process of the first communication interface 116. During the pinging process, the first communication interface 116 also may supply power to the second communication interface 126 when the Power Receiver 120 is in proximity to the Power Transmitter 110. The second communication interface 126 may “wake up” and power-up the PRx controller 125 and may send a reply signal back to the first communication interface 116. Prior to power transfer, a handshaking process may take place during which the PTx controller 115 may receive identification and configuration data, among other information, from the Power Receiver 120. The PTx controller 115 may control characteristics of wireless power it provides to the Power Receiver 120 based on the configuration data.

[0092] A PRx controller 125 may be operationally coupled to the rectifier 124 and the second communication interface 126. The second communication interface 126 may contain modulation and demodulation circuits to communicate via the PRx tank circuit (e.g., the secondary coil 122, the rectifier 124, or any other components between the secondary coil 122 and the load 130). In some implementations, the PRx controller 125 may use load modulation to communicate via an in-band communication link that includes the secondary coil 122. Alternatively, the second communication interface 126 may communicate out-of-band using a second communication coil 128. In some implementations, the modulation / demodulation circuits are included in the PRx controller 125.

[0093] A load controller 127 may be operationally coupled to the load 130 and the second communication interface 126. The load controller 127 may detect changes to load states such as change in charging currents in a battery charging application. The load controller 127 also may determine a load voltage reference. The load controller 127 also may send load voltage references, load current, and any other suitable information to the PRx controller 125 or the second communication interface 126 for communication to the Power Transmitter 110. The PRx controller 125 may additionally determine and provide feedback information indicating a measured load voltage available to the load 130. In some feedback messages, the feedback information may include a reference value indicating a required voltage or power for the load 130. In some feedback messages, the feedback information may indicate an error in the output voltage of the load 130. In some feedback messages, the feedback information may include the required power for the load. Although the PRx controller 125 and load controller 127 are shown separately, they may be included in the same component of the Power Receiver 120.

[0094] Either the Power Transmitter 110 or the Power Receiver 120, or both, may have other components, the description of which is omitted for brevity. For example, the wireless powerDocket No. D25023W001apparatuses may have alignment aids. Either or both of the wireless power apparatus may have magnets to aid with alignment and / or wireless power transfer. Other circuit level details, such as capacitors, resisters, impedance matching circuits, and / or tuning circuits may be present.

[0095] At block 101, aspects of this disclosure facilitate 50W power mode, with some aspects enabling backward compatibility to MPP 25W mode. The 50W mode may use some protocol / messages (e.g., startup sequence) that begins the same as MPP mode (for 25W). The 50W mode might have different features (compared to the MPP 25W mode), such as changes related to frequency selection, voltage control, capacitance tuning, harmonic filtering, electromagnetic interference (EMI) considerations, material design, communication modulation, or power adapter control, among other examples.

[0096] FIG. IB illustrates an overview of changes 100B to the wireless power system of FIG. 1A to support a 50 Watt (50W) power transfer mode with backward compatibility. In FIG. IB, the capacitance Power Transmitter circuit 114 is further illustrated. The power source 105 (also referred to as a power adapter) provides an input voltage to the Power Transmitter circuit 114. The Power Transmitter circuit 114 can include one or more filters 146, a DC / DC converter 144, an inverter 142, and one or more capacitors 119 to provide capacitance to the PTx tank circuit. The PTx tank circuit refers to the capacitance 119, the primary coil 112, and any other components between the inverter 142 and the primary coil 112. The Power Receiver 120 is shown with the secondary coil 122, one or more capacitors 129 to provide capacitance, the rectifier 124, and the load 130.

[0097] This disclosure includes several aspects that may be relevant to a 50W mode. The aspects are conceptually organized and illustrated as blocks 150, 160, 170, 180, and 190. In some implementations, various concepts from blocks 150, 160, 170, 180, and 190 may be combined. Alternatively, concepts from the blocks might be implemented independently depending on design considerations and wireless power specifications.

[0098] One category of features is conceptually illustrated in block 150. In some implementations, the protocol and communication technique can be modified to support a 50W mode with backward compatibility to a legacy mode (e.g., an MPP mode). The protocol refers to message format and sequence of messaging. As further described with reference to FIG. 2 through FIG. 8B, the protocol can be adapted to enable both a first mode (e.g., MPP) and a second mode (e.g., 50W). In addition to protocol enhancements, this disclosure includes the ASK modulation aspects (block 151) that might be adapted for the second mode as further described with reference to FIG. 15 through FIG. 17.Docket No. D25023W001

[0099] Another category of features is conceptually illustrated in block 160, which describes frequency control aspects. The frequency control aspects are further described with reference to FIG. 11 A to FIG. 12B.

[0100] Another category of features is conceptually illustrated in block 170, which describes capacitance tuning aspects. The capacitance tuning aspects are further described with reference to FIG. 9 to FIG. 10.

[0101] Another category of features is conceptually illustrated in block 180, which describes active filter aspects. The active filter aspects are further described with reference to FIG. 13 to FIG. 14.

[0102] Another category of features is conceptually illustrated in block 190, which describes voltage control aspects. The voltage control aspects are further described with reference to FIG. 18 to FIG. 20.

[0103] In addition to the aspects shown in FIG. IB, this disclosure also describes potential changes related to hardware, such as coil design considerations, magnetic alignment aids, etc., as further described with reference to FIG. 18.

[0104] FIG.2 illustrates example scenarios 200 of Power Receivers and Power Transmitters that support different frequencies for various power levels / modes. As a design consideration, it may be desirable for 50W mode to use a common nominal operating frequency that is suitable for worldwide deployment. The MPP mode currently uses a 360 kHz nominal operating frequency. However, some authorities may limit the operating frequency options to below a threshold. For example, 360 kHz operating frequency may not be permitted for use in some parts of the world. In this disclosure, the 50W mode may use a lower frequency (than 360 kHz). In some implementations, the operating frequency for the 50W mode may be in a range from about 105 kHz to 150 kHz. For example, the 50W mode may use a nominal operating frequency around 128 kHz. The 128 kHz frequency is also used for lower power modes (e.g., BPP mode and EPP mode for power levels around 5W to 15W). Another design consideration is that the Power Transmitter, the Power Receiver, or both, might not support the 50W mode. It is desirable to have a communication protocol for 50W mode that is backward compatible for devices that support the MPP mode.

[0105] In FIG. 2, two example Power Transmitters are shown: a first Power Transmitter 210A supports the MPP mode (referred to as a 25 W PTx), and a second Power Transmitter 210B supports the 50W mode (referred to as a 50W PTx). Two example Power Receivers are shown: a first Power Receiver 220A supports the MPP mode (e.g., 25W PRx), and a second Power Receiver 220B supports the 50W mode (e.g., 50W PRx). FIG. 2 shows the PowerDocket No. D25023W001Transmitters and Power Receivers as a way to conceptually illustrate the various possible combinations of devices with different capabilities for the MPP mode and the 50W mode.

[0106] In a first scenario 251, the Power Transmitter 210A and the Power Receiver 220A both support the MPP mode (but not the 50W mode). In this first scenario 251, the devices may use a legacy communication protocol for the MPP mode, such as described in Qi wireless power specifications for the MPP mode. As an example, the legacy communication protocol may include a 360 kHz digital ping followed by power transfer phase for 25 W power.

[0107] In a second scenario 252, the Power Receiver 220B may support the 50W mode and the Power Transmitter 210A may not support the 50W mode. In this second scenario 252, the sequence of messaging in the negotiation phase (sometimes referred to as a startup sequence) will enable the Power Receiver 220B to discover that the Power Transmitter 210A supports the MPP / 25W mode but not the 50W mode. Because the Power Receiver 220B supports 50W mode, the 50W PRx might recognize two operating frequencies (e.g., 128 kHz and 360 kHz) but would request the 360 kHz operating frequency since the Power Transmitter 210A is a 25W PTx.

[0108] In a third scenario 253, the Power Transmitter 210B is a 50W PTx and the Power Receiver 220A is a 25W PRx. In some implementations, a 50W PTx may support two operating frequencies (e.g., 128 kHz and 360 kHz) for the 50W mode. In this third scenario 253, the startup sequence may begin with the MPP mode at 360 kHz so that the Power Receiver 220A can use the 25W mode.

[0109] In a fourth scenario 254, both the Power Transmitter 210B and the Power Receiver 220B support the 50W mode. For example, they may use a new protocol for 50W that makes use of a lower frequency (e.g., 128 kHz) with higher power transfer. In this fourth scenario 254, the new protocol may begin with the protocol for MPP mode (25W) and then change to the new protocol for the 50W mode once both devices have discovered that they both support the 50W mode. In some implementations, the 50W protocol may depend on region-specific, country-specific, or geographic regulation-specific parameters. For example, a Power Transmitter 210B manufactured for the 50W mode might use a 128 kHz nominal frequency in some geographic regions, while another Power Transmitter 210B for the 50W mode might use a 360 kHz nominal frequency in other geographic regions.

[0110] FIG. 3 is a message flow diagram 300 in which the Power Receiver and the Power Transmitter use a first mode (e.g., MPP mode with 25W) for a first power level. The diagram 300 shows a startup sequence that might be associated with the first scenario 251 of FIG. 2. The message flow begins with a 128 kHz digital ping 302. For example, the PowerDocket No. D25023W001Transmitter 110 transmits a 128 kHz digital ping signal. The Power Receiver 120 responds to the digital ping by sending a Signal Strength (SIG) packet 304, an Identification (ID) packet 306, an Extended Identification (XID) packet 308, and a Configuration packet (CFG) 310. In some implementations, the XID packet 308 indicates that the Power Receiver 120 is an MPP-compatible PRx. In some implementations, the Power Transmitter 110 transmits an MPP pattern 312 to confirm that the Power Transmitter 110 is also an MPP-compatible PTx. The MPP pattern invokes an MPP Negotiation phase 314.

[0111] In the negotiation phase 314, the Power Receiver 120 may transmit a General Request (GRQ) packet requesting an ID packet from the Power Transmitter 110. The nomenclature of GRQ [ID] refers to the General Request packet, where the ID packet is requested. In response to the GRQ [ID] packet 316, the Power Transmitter 110 sends the ID packet 318. In this example message flow (which is based on a legacy MPP protocol), the Power Receiver 120 optionally sends a Get Request packet (GET (PTx Extended ID) packet 320) to cause the Power Transmitter 110 to respond with the PTx Extended ID packet 322. In some implementations, a packet (e.g., similar to the GET (PTx Extended ID) packet) can be sent during a configuration phase. According to existing MPP protocols, the GET (PTx Extended ID) packet 320 and the PTx Extended ID packet 322 are optional.

[0112] During the negotiation phase 314, the Power Receiver 120 and the Power Transmitter 110 negotiate a power transfer contract. The Power Receiver 120 sends the Specific Request (SRQ) packet with a Frequency Selection element for the power transfer contract. The SRQ with Frequency Selection element is referred to as an SRQ / freqsel packet 324. In the example of FIG. 3, the SRQ / freqsel packet 324 might include a first value (e.g., “1”) that indicates a 360 kHz frequency for 25W or 50W MPP mode. The Power Transmitter 110 can support this frequency and responds with an acknowledgement 326.

[0113] During the negotiation phase 314, the 120 may send other requests related to the power transfer contract, such as an SRQ packet with a re-ping delay (rep) parameter (shown as SRQ / rep packet 328). For each request that the Power Transmitter 110 can support, the Power Transmitter 110 can send a corresponding acknowledgement 330. At the conclusion of the negotiation phase 314, the Power Receiver 120 sends an SRQ packet to end the negotiation (shown as the SRQ / en packet 332), which may also be acknowledged 334 before proceeding to the power transfer phase 336.

[0114] After selecting the new frequency (e.g., 360 kHz for MPP mode) and terminating the negotiation using the SRQ / en packet 332, the Power Receiver 120 can request a re-ping using an end power transfer (EPT) with re-ping packet (shown as EPT / rep packet 338) to allow theDocket No. D25023W001Power Transmitter 110 to activate the new selected frequency. The Power Transmitter 110 may send an acknowledgement 340 and then proceed with a 360 kHz digital ping 342.

[0115] Having described the MPP protocol for 25W (360 kHz) mode, now the potential improvements / modifications are further described with reference to PIG. 4 through FIG. 7. For brevity, the descriptions of messages already described in FIG. 3 are not repeated in the descriptions of FIG. 4 to FIG. 7. Rather the descriptions of FIG. 4 through FIG. 7 will focus on the changes.

[0116] FIG. 4 is a message flow diagram 400 in which the Power Receiver 120 supports a second mode (e.g., 50W) and the Power Transmitter 110 does not support the second mode, such as the second scenario 252 of FIG. 2. Instead of the SRQ / freqsel packet 324 (FIG. 3) indicating the 25W (360 kHz) mode, in the example of FIG. 4, the Power Receiver 120 sends a first SRQ / freqsel packet 424a that indicates a frequency associated with the 50W mode. For example, the first SRQ / freqsel packet 424a may include a value (e.g., “2”) that is associated with 128 kHz 50W power transfer (see, for example, the SRQ / freqsel packet shown in FIG.8A). In the example of FIG. 4, the Power Transmitter 110 does not support or recognize the requested mode. Therefore, the Power Transmitter 110 may respond by sending a nonacknowledgement 426a. When the Power Receiver 120 receives the non-acknowledgement 426a in response to the first SRQ / freqsel packet 424a, the Power Receiver 120 can determine that the Power Transmitter 110 does not support the 50W 128 kHz mode. The Power Receiver 120 can then send a second SRQ / freqsel packet 424b that indicates the 25W (360 kHz) mode. The second SRQ / freqsel packet 424b may be similar to the SRQ / freqsel packet 324 described with reference to FIG. 3. The Power Transmitter can send an acknowledgement 426b, and the remaining MPP negotiation phase can continue as described with reference to FIG. 3.

[0117] A potential technical advantage of the startup sequence in FIG. 4 is that the Power Receiver 120 and the Power Transmitter 110 can use the MPP negotiation phase with the addition of a follow up SRQ / freqsel packet. Thus, the protocol is backward compatible and can result in a negotiation of the frequency for the MPP 25W mode or 50W mode.

[0118] FIG. 5 is a message flow diagram 500 in which the Power Receiver requests the Power Transmitter (PTx) to send a PTx Extended ID packet, where the PTx Extended ID packet indicates whether the Power Transmitter supports the second mode. FIG. 5 might be an example of the fourth scenario 254 or the second scenario 252 of FIG. 2. The sequence is similar to the sequence described with reference to FIG. 3, except that the Get (PTx Extended ID) packet 520 is always sent (rather than optional GET (PTx Extended ID) packet 320 in FIG. 3). For example, a wireless power specification for the MPP protocol can mandate thatDocket No. D25023W001the Power Receiver 120 sends the Get (PTx Extended ID) packet 520 and the Power Transmitter 110 responds with the PTx Extended ID packet 322. The PTx Extended ID packet 322 can include an indication to indicate whether the Power Transmitter 110 supports the 50W mode or not, such as the example PTx Extended ID packet described with reference to FIG. 8B.

[0119] FIG.6 is a message flow diagram 600 in which the Power Receiver does not support the 50W mode. FIG. 6 might be an example of the third scenario 253 of FIG. 2. The message sequence in FIG. 6 is identical to the message sequence in FIG. 3, with the only difference being that the Power Transmitter 110 in FIG. 6 is a 50W-compatible PTx. FIG. 6 illustrates an example of the backward compatible advantages of this design. The Power Receiver 120 transmits the SRQ / freqsel packet 324 indicating 360 kHz frequency for MPP 25W mode. Even though the Power Transmitter 110 may support the 128 kHz 50W mode, the Power Transmitter 110 can still operate using the requested frequency / mode. Thus, the Power Transmitter 110 responds with the acknowledgement 326, and the remaining MPP negotiation phase can continue as described with reference to FIG. 3.

[0120] FIG. 7 is a message flow diagram 700 in which the Power Receiver and the Power Transmitter both support a second mode (e.g., 50W). This shows an example of the proposed protocol when used in the fourth scenario 254 of FIG. 2. When the Power Receiver 120 sends the SRQ / freqsel packet 724 indicating a frequency (e.g., 128 kHz) for the 50W mode, and the Power Transmitter 110 supports the requested frequency / mode, the Power Transmitter 110 can respond with the acknowledgement 726. In this example, both devices can determine that they support the 128 kHz frequency for 50W mode. After the EPT / rep packet, the Power Transmitter 110 can transmit a 128 kHz digital ping 742 associated with the MPP mode (e.g., 50W or 25 W mode using 128 kHz or 360 kHz frequency).

[0121] As shown in FIG. 4 through FIG. 7, a similar startup sequence can be used during MPP negotiation phase (which supports backward compatibility) while still enabling either of the 360 kHz 25 W mode or the 50W mode (e.g., at 128 kHz) depending on which modes are supported by the Power Transmitter 110 and the Power Receiver 120.

[0122] Several figures of this disclosure include diagrams of example formats and data in various packets. The sizes and placement of the fields are shown for illustrative purposes and any of the described fields can be increased or decreased in size or placed in different byte / bit locations. A technical specification may specify the byte / bit locations and sizes of the fields. Furthermore, the values described for various message types or extension fields can refer to a value in a lookup table. For ease of reference, possible values are shown in the figures andDocket No. D25023W001described in the text. However, the example values may be replaced with any numerical value in the lookup table. Furthermore, this disclosure includes possible names for various packets / messages. The described names are intended to provide clarity and can be replaced with any other word or name.

[0123] FIG. 8A is a diagram 800a of an example SRQ / freqsel packet. The SRQ / freqsel packet includes a Message Type Selector field 802, a reserved field, and a Frequency Selector field 804 field. The Message Type Selector field 802 is populated with a value (e.g., OxFO) that indicates the packet is an SRQ / freqsel packet. The Frequency Selector field 804 is populated with a value to indicate the Frequency Selection parameter of the power transfer contract. Block 806 and Table 1 show example values for the Frequency Selector field 804.Table 1. Example Frequency Selector field values

[0124] It is noted that 128 kHz is a nominal operating frequency for some legacy wireless power modes (e.g., BPP, EPP) associated with lower power (e.g., 5W to 15W). As shown in FIG. 3 through FIG. 7, because the XID packet 308 (or any packet before MPP pattern 312) already invoked the MPP protocol, a Power Transmitter can determine that the Power Receiver supports the 50W mode (with 128 kHz) based on a combination of the XID packet 308 (or other packet) and the SRQ / freqsel packet with Frequency Selector field 804 being populated with the value for 128 kHz. Although described for the 50W mode (with 128 kHz), the SRQ / freqsel packet can also be used for 25W mode, 50W mode, either of which might operate in the a frequency range that includes 128 kHz nominal operating frequency or a frequency range that includes 360 kHz nominal operating frequency.

[0125] Although Table 1 shows example values, other values and meanings can be specified. For example, different values could be used for 128 kHz, 138 kHz, 140 kHz, and / or 148 kHz. Furthermore, while Frequency Selector field 804 is currently specified as 2 bits (limiting the number of potential values in Table 1 to four options, the wireless power specification can increase the size of the Message Type Selector field 802 to enable more potential value options for the Frequency Selector field 804.

[0126] FIG. 8B is a diagram 800b of an example PTx Extended ID packet. The PTx Extended ID packet includes a Selector header field, an active alignment power profile (APP) bit, a unique ID (UID) bit, a Device Identifier field, and a manufacturer (Mfg) reserved field.Docket No. D25023W001The APP bit is set to ONE in a PTX with a moving primary coil. The APP bit is set to ZERO in an MPP-compliant PTx. When the UID bit is set to ONE, the UID bit indicates that the Device Identifier was generated by the manufacturer to have a high probability of being unique to this unit.

[0127] In accordance with some aspects of this disclosure, the PTx Extended ID packet can include an indicator field 808 (which may be referred to as a 50W indicator bit or 50W protocol bit) to indicate whether the Power Transmitter supports the 128 kHz 50W mode.

[0128] FIG. 9 illustrates example scenarios 900 for capacitance tuning. Similar to FIG. 2, FIG. 9 shows various combinations of Power Transmitters 210A, 210B and Power Receivers 220A, 220B capable of operating in a 25W (360 kHz) mode or a 50 W (e.g., 128 kHz) mode.

[0129] In a first scenario 971, the Power Transmitter 210A is a 25W PTx and the Power Receiver 220A is a 25W PRx. The devices may follow a legacy capacitance tuning defined in a wireless power specification (e.g., Qi specification for 25W MPP).

[0130] In a second scenario 972, the Power Receiver 220B is a 50W-compatible PRx but the Power Transmitter 210A is a 25W PTx. In this second scenario 972, the Power Receiver 220B may determine the PRx capacitance based on the PTx capabilities.

[0131] In a third scenario 973, the Power Transmitter 210B is a 50W-compatible PTx and has supports two operating frequencies - 128Khz and 360Khz for higher power transfer. The Power Transmitter 210A determines the PTx capacitance based on the PRx capabilities. In this third scenario 973, the Power Receiver 220A is a 25W (360 kHz) PRx.

[0132] In a fourth scenario 974, both the Power Transmitter 210B and the Power Receiver 220B may support the 50W mode. In this fourth scenario 974, the capacitance tuning may further depend on the selected frequency (e.g., 128 kHz or 360 kHz). In some implementations, the Power Transmitter 210B (or the Power Receiver 220B) may have additional capacitance levels to enable more capacitance tuning than previously available for legacy 25W-compatible devices.

[0133] In some implementations, an existing capacitance switching algorithm can be used when shifting the frequencies and power levels, such as described in a wireless power specification. Ctx refers to the capacitance of the PTx, and Crx refers to the capacitance of the PRx. A system model for the wireless power specification may describe considerations and subroutines for managing the Ctx and the Crx. For example, the system model may perform Ctx capacitance tuning as a preferred option first and then perform Crx capacitance tuning when the Ctx reaches a capacitance level. In some implementations, the CtxDocket No. D25023W001capacitance tuning is based on an input voltage of the inverter, coupling of the primary / secondary coils, or other considerations.

[0134] In a high-power mode (e.g., 25 W or higher), the system model may use a 15V (or higher) adapter input voltage, which significantly shrinks the input voltage range, especially the lower bound (16V). The system model may use an equation, G(s) = Vrect I Vinv, to carefully constrain so that the inverter voltage (Vinv) needed to reach the desired rectifier voltage (Vrect) is within the narrow range of 16V-20V. Additionally, the system model may choose the capacitor that guarantees zero voltage switch (ZVS) operation and yields the best efficiency. A higher Ctx may lead to smaller G(s) amplitude (thus needing a higher Vinv to regulate power) and / or more inductive Zin(s) (thus less ZVS risk). A higher Crx may lead to smaller G(s) amplitude (thus needing a higher Vinv to regulate power), and / or more inductive Zin(s) (thus less ZVS risk). At the same time, a lower power level runs higher risks of exhausting the lower bound of Vinv and losing ZVS, thus a higher Ctx and Crx values are desirable. A strategy of capacitor tuning in MPP mode is summarized as: starting with the highest Ctx and Crx value, dynamically switch to the next smaller value whenever the current value cannot meet the power delivery goal. In some implementations, switching Ctx is prioritized over switching Crx, i.e., Crx is switched only if all Ctx values have been exhausted. In some implementations, an additional Ctx value (134 nF) is added to Ctx value choices. Otherwise, the gap between 458 nF and 101 nF is too big to guarantee operations across all power levels.

[0135] Crx switching algorithm: As discussed above, in nominal power mode and high power mode, the system model PRx switches Crx dynamically during power transfer. Specifically, there are two Crx values to select from: the “low” value (e.g., 174 nF) requires lower Vinv to deliver higher power but with more ZVS risk; the “high” value (e.g., 710 nF) has less ZVS risk but requires higher Vinv to deliver power. The Crx switching algorithm may include two subroutines: a “Checks witchToLow” subroutine, in a state where Crx holds the high value, the system model PRx constantly checks if it should switch to the low value. In a “CheckSwitchToHigh” subroutine the system model PRx checks if it should switch to the high value if it holds the low value.

[0136] PTx capacitor selection algorithm: in high-power mode, the system model PTx dynamically selects Ctx. There are four selectable Ctx values, and for the sake of simplicity, the system model uses an index ctx_ind to denote these four example values in increasing order:ctx_ind = 0: Ctx = 68 nFDocket No. D25023W001• ctx_ind = 1: Ctx = 101 nF• ctx_ind = 2: Ctx = 134 nF• ctx_ind = 3: Ctx = 458 nF

[0137] A smaller value of Ctx needs a smaller Vin to deliver the same level of power, but at the same time, increases the non-ZVS risk. Therefore, the system model’s strategy of Ctx switching is:• Start with the highest value (ctx_ind = 3, Ctx = 458 nF for k, > 0.8 * ak threshold, or ctx_ind = 2, Ctx = 134 nF for ki < 0.8 * ak_threshold). This capacitance is set in the beginning of 360 kHz Digital Ping phase and preserves its value throughout Gain Measurement.• When PTx reaches the upper limit of the inverter drive, Ctx will switch to the next lower value.• When PTx reaches the lower limit of the inverter drive, Ctx will switch to the next higher value.

[0138] Another consideration is that when Ctx switches, the power level should be restricted to reduce stress at the switched capacitor bank. In some implementations, the system model makes sure this is the case via a combination of two approaches: setting Vin to just above the lowest Vin value (or above the lowest Vin) to limit the inverter output during Ctx switch; and limiting XCEV_max to 0 to effectively prevent any increase on inverter drive The high-level flow of the Ctx switching algorithm has four subroutines:• Recover: Restore temporary settings while performing Ctx switch.• “Checks witchToHigh” subroutine: Routine to check if the system model Ctx needs to switch to a higher value; and if so, perform the switch.• “Checks witchToLow” subroutine: Routine to check if the system model Ctx needs to switch to a lower value; and if so, perform the switch.• Reset subroutine: Reset a counter that was used by the Checks witchToLow subroutine.

[0139] FIG. 10 illustrates an example diagram of the Power Transmitter and Power Receiver that can perform capacitance tuning. FIG. 10 omits (for brevity) some elements of the Power Transmitter and the Power Receiver shown in FIG. 1. The Power Transmitter and Power Receiver can include the elements described in FIG. 1. For brevity, the power source and inverter (Power Transmitter circuit 114) are collectively shown as an input voltage 1002 on the Power Transmitter side. On the Power Receiver side, the diagram 1000 focuses on the capacitance elements, while other elements (such as a rectifier, bridge circuit, converter, etc.) are collectively shown as a load 1004.Docket No. D25023W001

[0140] FIG. 10 shows that the Power Transmitter can have multiple capacitance levels (shown as CTxl through CTxn. The Power Receiver can have multiple capacitance levels (shown as CRxl through CRxn. Table 2 further lists these example capacitance levels for reference.Table 2. 25W capacitance levels

[0141] In a PTx for 25W MPP mode, the PTx can have 68nF, 33nF, 390nF, and 33nF capacitors to support Ctx capacitance in a range from 68nF to 458nF - using capacitance level steps at 68nF, lOlnF, 134nF, 458nF based on combination of various capacitors.

[0142] In some implementations, a 5()W-compatible PTx may need additional capacitance levels, e.g., greater than 458nF. Thus, in some implementations, a 50W-compatible PTx may include an additional capacitor 1006 (e.g., “CTx5”) of 174nF that gives a range of 68nF to 632nF. Having the ability to select a higher Ctx capacitance level may be useful when operating at high power, lower frequencies.

[0143] In some implementations, a 50W-compatiblc PRx might have different capacitance levels compared to the 25W capacitance levels. Alternatively, the 50W-compatible PRx might use the same capacitance levels as the 25W capacitance levels but use a different Crx algorithm that is tailored for 50W. For example, a 25W-compatible PRx might have two capacitors: 174nF and 536nF (capable of capacitance levels in a range from 174nF to 710nF). The Crx switching algorithm might define different operations of these capacitors when using 50W mode.

[0144] Some aspects of this disclosure are related to frequency control. Since the 50W mode might use lower frequencies (e.g., 128 kHz to 148 kHz) for high power, there may be a greater potential for EMI. With wireless power operating at a wide range of power levels (e.g., 5W to 50W), the concern about EMI may prompt changes to how frequencies are selected at a particular power level. Authorities or geographic areas may have regulations that limit EMI that can be generated by a particular class of devices.

[0145] FIG. 11A is a first chart 1100a showing example regulation limits for EMI. EN 55011 is a European standard that pertains to electromagnetic compatibility (EMC) requirements for industrial, scientific, and medical (ISM) equipment. EN 55011 specifies limits for radio disturbance characteristics to ensure that electrical equipment operatesDocket No. D25023W001without causing or suffering from harmful interference. This standard is part of the European EMC Directive, which mandates that electrical and electronic equipment must comply with EMC standards to ensure the protection of the electromagnetic environment in the European Economic Area. Compliance with the EN 55011 standard gives partial presumption of conformity with the European EMC Directive, 2004 / 108 / EC. CISPR stands for the International Special Committee on Radio Interference. CISPR is an organization that creates standards for EMC.

[0146] The chart 1100a shows the EN 55011 CISPR regulations limit. The lines in the chart 1100a show maximum allowed EMI (vertical axis) permitted by different classes of devices (Class A and Class B) based on the frequency (horizontal axis).

[0147] FIG. 11B is a second chart 1100b showing example regulation limits for EMI. The chart 1100b is based on United States Federal Communications Commission (FCC) Part 15 regulations, which limit the amount of electromagnetic interference from electronic devices in a Code of Federal Regulations. For reference the second chart 1100b shows the FCC Part 15 limit (dashed lines) in comparison to the EN 55011 CISPR limits.

[0148] FIG. 12A illustrates various example frequencies 1200a and power levels. To meet the limits for regulations (e.g., the charts 1100a, 1100b, or other regulations), the Power Transmitter may change the frequency of operation. For example, if the Power Transmitter cannot provide the required power with voltage and phase changes taking into account the ZVS or EMI issues, the Power Transmitter might change the frequency of operation.

[0149] Whenever the frequency of operation is changed, the Power Transmitter may perform gain measurements. In some implementations, the Power Transmitter pauses power transfer when making the gain measurements during a power transfer phase. To avoid this scenario, it may be desirable to perform gain measurements for different frequencies during the negotiation phase before the power transfer phase begins. During the negotiation phase, the Power Transmitter and the Power Receiver negotiate the nominal operating frequency. The Power Transmitter can perform gain measurements and use the gain measurements to adjust or select a frequency based on the nominal operating frequency.

[0150] In some implementations, gain measurements can be performed for at least 2 frequencies. When considering a potential frequency range for the 50W mode, it is possible to have multiple frequency modes within the 50W mode. For example, a two frequency mode scenario (shown on the left side of FIG. 12 A) may include 50W power at 128KHz and 35 W power at 140 KHz. A three frequency mode scenario (shown on the right side of FIG. 12A) may include 50W power at 128 KHz, 40W power at 138KHz, and 30W power at 148 KHz.Docket No. D25023W001Other frequency modes may be specified. The frequency mode may refer to the nominal operating frequency associated within a particular power level of a 50W power protocol. The actual operating frequency may still be adjusted up or down from the nominal operating frequency based on power requirements, transfer efficiency, EMI compliance, and / or other factors.

[0151] In some implementations, an engineer may test the system with different power and nominal frequencies to check for the EMI compliance within the limits (e.g., charts 1100a or chart 1100b).

[0152] FIG. 12B illustrates example techniques 1200b for variable frequency control. An example technique (shown in block 1262) is that gain measurements are performed during the negotiation phase. Based on the gain measurements, the Power Transmitter can determine whether changes to the frequency are needed to satisfy a power transmission efficiency threshold and / or EMI considerations.

[0153] In another technique (shown in block 1264), a communication protocol is defined to communicate regarding changes in frequency, such as shifting from one frequency mode to another frequency mode (referring to potential frequency modes as described with reference to FIG. 12A). For example, the Power Transmitter or the Power Receiver can initiate a change in frequency when needed to comply with EMI limits. In some implementations, a Power Receiver can send an SRQ / freqsel packet to select the new frequency. Then the Power Transmitter and the Power Receiver can initiate a new ping process for the new frequency. In some implementations, before performing the new ping process, the power transfer phase ends and wireless power is stopped.

[0154] In some implementations (shown in block 1266), the SRQ / freqsel packet can be used to adjust the operating frequency during the power transfer phase. In some implementations, the Power Transmitter and the Power Receiver can perform the change in operating frequency during a cloak phase. Cloaking lets a wireless charging system pause active power transfer while still maintaining a PTx-PRx link such that power transfer can be resumed any time without going through the entire start up sequence and power negotiation messaging. In some implementations, the Cloak phase is initiated by a cloak message specifying the reason of frequency change. During the frequency change cloak period, the required tuning capacitance may be changed to meet the new frequency requirements

[0155] FIG. 13 illustrates a wireless power system in which the Power Transmitter implements an active harmonic filter. The diagram 1300 includes similar blocks as described with reference to FIG. IB, and the descriptions of those blocks are omitted here for brevity.Docket No. D25023W001In addition to the DC / DC converter 144 and inverter 142, the Power Transmitter circuit 114 can include an Active Harmonic Filter 1382 (AHF). In some implementations (shown in block 1380), a harmonic sensor 1388 provides input to the AHF.

[0156] A 50 W wireless power system may operate to provide power for a wide range of load powers (e.g., potentially ranging from 5W to 50W), and with multiple operating frequencies 360Khz, 128Khz, or 148Khz, among other examples. As described earlier with reference to capacitance tuning, the system model might select various capacitors to be switched in a manner that provides a good system level efficiency. Depending on the frequencies and capacitance tuning, the wireless power system can induce various harmonics into the grid that might cause the Power Transmitter system to fail EMI limits.

[0157] In some implementations, the use of the passive filters can prevent the Power Transmitter from sending the harmonics into the power source 105. However, some passive harmonic filters can be bulky, and the inclusion of various passive harmonic filters to cover the wide range of the frequencies and power levels can result in a more expensive or larger Power Transmitter device. Some passive filters use inductance (L) or capacitance (C) to filter out harmonic signals. Examples of different passive filters include L, C, LC, LLC filters. The concern with harmonics might also be related to the EMI concerns, as described above -such as EMI limits based on Part 15 (for the United States) and / or EN 55011 (for Europe). Conducted EMI is measured from 150 kHz to 30 MHz. These limits aim to ensure that consumer electronics do not cause interference to other devices or systems through the power supply cord to the power source 105 or power grid. The use of an Active Harmonic Filter 1382 may address these concerns and reduce overall cost / complexity by providing a component that can reduce current harmonics introduced by the power converter (e.g., DC / DC converter 144 and / or inverter 142).

[0158] In some implementations, the sensor 1388 can perform current sensing at the input of the DC / DC converter 144. The sensor 1388 provides measurements (samples) of the potentially distorted current. The Active Harmonic Filter 1382, using power electronics switching devices, draws a current from the source of such magnitude, frequency composition, and phase shift to cancel the harmonic in the load.

[0159] In some implementations, a controller of the Active Harmonic Filter 1382 may be the PTx controller 115 or a different controller (not shown). Control of the Active Harmonic Filter 1382 may depend on the particular cases / limits, such as the 5W - 360KHz, 5W -128Khz, 25W- 360Khz, 50W - 128Khz / 148Khz scenarios. To ensure that the system meetsDocket No. D25023W001the EMI requirements, the filters of the Active Harmonic Filter 1382 can be turned on or off to improve the efficiency of the system.

[0160] In some implementations, the Active Harmonic Filter 1382 (e.g., its controller) can calculate the total harmonic distortion (THD) of a signal and use the magnitude of the calculation to create as a current input to the harmonic filter. In some implementations, the Active Harmonic Filter 1382 (e.g., its controller) predicts the harmonics based on the frequency of operation, PTx capacitor selection, PRx capacitor selection and power level. A potential technical advantage of this approach is that the Active Harmonic Filter 1382 can reach the required control point faster than would otherwise occur. In some implementations, the Active Harmonic Filter 1382 (e.g., its controller) can have a look up table control if the number of 50W frequency states are known or specified. In some implementations, the look up table or wireless power specification can indicate combinations of frequency states, power modes (e.g., low power mode, nominal power mode, high power mode). Based on the PRx power requirement, the PTx Active harmonic controller can act upon the harmonic levels more dynamically. In some implementations, the Active harmonic filter controller can provide an input to the PTx controller 115 to stop / change the power mode when needed to reduce power to limit the harmonics.

[0161] FIG. 14 illustrates an example of active harmonic filters. Active harmonic filters (AHFs) are power electronics-based devices that mitigate harmonics by injecting currents that cancel out the harmonic distortion in an electrical system, improving power quality and equipment lifespan. An active harmonic filter (AHF) to reduce the amount of power harmonics induced into the transmitter boost converter and DC / AC converter, ASK communication induced and any load converter induced will be sensed and filtered out actively to reduce the conducted EMI. AHF is a power conditioning system that monitors the current waveform and injects a current waveform of equal magnitude and opposite phase to cancel out the harmonic distortion.

[0162] FIG. 14 shows two example types of AHF: a shunt-type AHF 1400a and a series-type AHF 1400b. Shunt active harmonic filters address current harmonics by injecting compensating currents, while series active filters mitigate voltage harmonics by regulating and isolating the load from the supply. AHFs operate by acting as a controlled current source, providing any kind of current waveform in real time.

[0163] FIG. 15 illustrates a wireless power system in which amplitude shift keying (ASK) modulation can depend on the power level / mode. The diagram 1500 includes similar blocks as described with reference to FIG. IB, and the descriptions of those blocks are omitted hereDocket No. D25023W001for brevity. FIG. 15 illustrates further details regarding the first communication interface 116 and the second communication interface 126. In accordance with a wireless power specification, the Power Transmitter may use frequency shift keying (FSK) modulation when communication from the PTx to the PRx. The Power Receiver may use ASK modulation when communication from the PRx to the PTx. To enable both types of modulation (for PTx-to-PRx and PRx-to-PRx communication), the respective communication units have different modulators and demodulators. For example, the first communication interface 116 of the Power Transmitter may include an FSK modulator 1508 and an ASK demodulator 1504. The second communication interface 126 of the Power Receiver may have an FSK demodulator 1510 and an ASK modulator 1506.

[0164] Focusing on the ASK modulation there may be different types of ASK modulation techniques. A capacitive modulation refers to the use of capacitors in a PRx tank circuit to modulate the amplitude of the wireless power signal in an alternating current (AC) domain. A load modulation refers to the use of a modulation switch at the load, such as in the direct current (DC) domain. While capacitive modulation may provide better efficiency of the wireless power transfer, there is a possibility of communication errors (i.e., lower communication reliability), particularly when a modulation depth is not sufficient due to the higher power levels. Load modulation may provide lower efficiency of the wireless power transfer since it consumes some of the power, but may have a higher communication reliability. In the 25W MPP system, the Power Receiver uses ASK with load modulation (sometimes referred to as iLoad modulation, since current (I) is modulated at the load). However, load modulation may not be as efficient for a 50W system, particularly as the power levels increase above 25W. In accordance with aspects of this disclosure, the Power Receiver can shift (block 15020 between load modulation and capacitive modulation based on communication reliability.

[0165] FIG. 16 illustrates example techniques 1600 for managing ASK modulation. The techniques can be combined in a variety of ways. In some implementations, the Power Transmitter 110 monitors communication reliability (at block 1602). For example, the Power Transmitter 110 can track instances where an expected message was not received, the received message is deformed or invalid (such as due to a missed demodulation in the ASK demodulator), or other communication errors. In some implementations, the Power Transmitter 110 can monitor for loss of packets based on power ripple, modulation depth, or other reasons.

[0166] In some implementations (shown at block 1604), the Power Transmitter 110 can communicate a message indicating low communication reliability. For example, the PowerDocket No. D25023W001Transmitter 110 can indicate loss of packets. The low communication reliability may be determined based on the monitoring (at block 1602). The Power Transmitter 110 can send the message in a response to a data stream response (DSR) poll message. In some implementations, the Power Transmitter sends an attention (ATN) message to indicate it has a communication to send. The Power Receiver sends a DSR / poll to request the communication (i.e., the message regarding communication reliability) from the Power Transmitter. In some implementations, the message may be an error status message, a communication status message, or other type of message. In some implementations, the Power Transmitter 110 may send messages to indicate communication reliability according to a regular / periodic interval. In some implementations, the Power Receiver 120 may periodically or regularly send a request message (e.g., a DSR / poll) to the Power Transmitter 110 and the Power Transmitter 110 can respond with a communication reliability report in a response message for the DSR / poll. Another way for the Power Transmitter to inform the Power Receiver about the loss of packets is by the Power Transmitter sending the ATN command, receiving the DSR / poll message from the Power Receiver, and then sending a DSR message indicating the loss of packets.

[0167] In some implementations (shown at block 1606), the Power Receiver 120 can detect communication reliability. For example, the Power Receiver 120 may determine a low communication reliability based on a lack of responses from the PTx over a plurality of N communication cycles. For example, N may be 3, such that if the Power Transmitter 110 fails to respond to 3 communications (such as DSR / poll messages, control messages, or other messages) within a time period, the Power Receiver 120 may assume degradation of communication reliability. Alternatively, the Power Receiver 120 can detect the low communication reliability based on a communication reliability report / status from the Power Transmitter 110.

[0168] In some implementations (shown at block 1608), the Power Receiver 120 may ask the Power Transmitter 110 about the modulation depth or other communication quality metric. The Power Receiver 120 may send a first message to request the Power Transmitter 110 send the ASK modulation depth being measured at the Power Transmitter 110. The Power Transmitter 110 can respond with a value that indicates the ASK modulation depth sensed at the Power Transmitter 110.

[0169] In some implementations (shown at block 1610), the Power Receiver 120 may change between capacitive modulation and load modulation based on the communication reliability. For example, the system may begin with capacitive modulation and then switch to load modulation when the load modulation would improve the reliability in communication. TheDocket No. D25023W001technique of block 1610 may include one or more messages according to a protocol between the Power Transmitter 110 and the Power Receiver 120 so that the devices can coordinate the selected ASK modulation technique, timing, capacitive tuning, or other aspects that impact the ASK modulation.

[0170] In some implementations (shown at block 1612), changes to the ASK modulation technique may be performed during a cloak phase, in which power is temporarily paused without restarting power negotiation). For example, the cloak phase can be initiated with a reason code that is associated with changing the ASK modulation technique. The ASK modulation technique can be changed during the cloak time. In some implementations, the capacitance tuning can also be adjusted in association with the change of the modulation, such as when the change in ASK modulation technique will change the system parameters, gain, or other factors.

[0171] FIG. 17 shows a diagram 1700 of an example Power Receiver capable of selecting between capacitive modulation and load modulation. The Power Receiver includes a PRx tank circuit 1702 (such as the secondary coil 122, capacitors for Crx capacitance tuning, or other components between the secondary coil 122 and the rectifier 124). In some implementations, the Power Receiver includes a first modulator for capacitive modulation 1703 and a second modulator for load modulation 1704. The terms “modulator” and “modulation circuit” can be used interchangeable in this disclosure. The controller of the Power Receiver can select between the first modulator and the second modulator, such as by any of the techniques described with reference to FIG. 16.

[0172] In some implementations, the Power Receiver selects the first modulator as a default setting or when communication is reliable. The Power Receiver can select the second modulator based on a variety of conditions, such as when the Power Receiver determines that communication is unreliable based on lack of responses from the Power Transmitter, when the Power Receiver receives a message from the Power Transmitter indicating that the communication is unreliable, or when the Power Receiver receives a message from the Power Transmitter requesting the Power Receiver to use the load modulation.

[0173] In some implementations, the Power Receiver may select from among multiple modulators (e.g., the first modulator for capacitive modulation 1703 or the second modulator for load modulation 1704) based on ASK depth reported by the Power Transmitter.

[0174] In some implementations, once the Power Receiver changes to load modulation the wireless power system will continue to use the load modulation until there is a change in power mode / operating points. A potential technical advantage of this feature is that it canDocket No. D25023W001prevent multiple back and forth switching (between load modulation and capacitive modulation) while the wireless power system is in a present operating point / mode.

[0175] FIG.18 shows example changes to a Power Transmitter 110 and / or a Power Receiver 120 to improve power transmission for a second mode (e.g., 50W). The Power Receiver 120 may have a magnetic ring 1801 to enable magnetic alignment 1806 to the Power Transmitter 110. The magnetic ring 1801 may have an inner polarity 1802 and an outer polarity 1803 that corresponds to the outer polarity 1804 and the inner polarity 1805, respectively, of a magnetic ring in the Power Transmitter 110.

[0176] Some changes to the mechanical or material design of the Power Transmitter and Power Receiver may facilitate higher power (e.g., the 50W mode). In some implementations (shown at block 1812), the Power Transmitter 110 may have heat pipes around or near the primary coil 112 to redistribute the heat. In some implementations (shown at block 1810), the magnetic ring of the Power Receiver 120 and / or the Power Transmitter 110 may be modified to improve the magnetic field or to support tighter coupling / mounting between the devices. In some implementations (shown at block 1808), a ferrite component might be changed to reduce the equivalent series resistance (ESR) associated with the ferrite component. For example, the ferrite component might be constructed with magnetic materials that conduct electricity better so that the ferrite component does not overhead due to ESR.

[0177] In some implementations, coil inductance of the primary coil 112 in a PTx may decrease when designed for a 50W system. It is desirable to support the backward compatibility and minimize the deviation from inductance (L), quality factor (Q), and k-coupling (K) boundaries. In some implementations, a primary coil for 50W-compatible PTx may support higher voltage and current, compared to a legacy 25W MPP primary coil. For example, for 25W MPP, the Vin Max is 20V and the coil current is < 1.25 Amps. For 50W, the Vin Max might be 32 V and the coil current might be approximately 1.56 Amps. The primary coil 112, in a Power Transmitter that supports 50W power transmission, might have a higher thickness, diameter, or gauge of coil.

[0178] In some implementations, the insulation of the primary coil 112 (or the secondary coil 122) may be increased to sustain higher voltage between the coils.

[0179] FIG. 19 illustrates an example wireless power system 1900 that includes a Power Transmitter 110 and a Power Receiver 120. In FIG. 19, dotted lines represent communications to distinguish from solid lines that represent electrical circuit lines. In some implementations, the Power Transmitter may include a countertop-mounted primary coil or a primary coil that is embedded or manufactured in a surface on which a Power Receiver can be placed. A PowerDocket No. D25023W001Receiver can be configured to wirelessly receive power from the Power Transmitter. In some examples, the Power Receiver can be a device (such as a phone, smart watch, computer, appliance, wearables, or machine) and the Power Transmitter can be any apparatus that provides wireless power to the Power Receiver according to a wireless power specification.

[0180] This disclosure includes a brief description of wireless power transfer for context. The Power Transmitter 110 and the Power Receiver 120 are two types of wireless power apparatuses that are used together. The Power Transmitter 110 includes a primary coil 112 and a Power Transmitter (PT ) controller 115. The primary coil 112 may be associated with a PTx resonant circuit 1914 (sometimes also referred to as a power signal generator or a driver circuit). The primary coil 112 may be any type of coil which transmits wireless power (which also may be referred to as wireless energy). The primary coil 112 may transmit wireless energy using an inductive or a resonant magnetic field. The PTx resonant circuit 1914 may include components (not shown) to prepare the wireless power. For example, the PTx resonant circuit 1914 may include one or more switches, drivers, series capacitors, rectifiers, inverters, or other components. In some implementations, the PTx resonant circuit 1914, PTx controller 115 and other components (not shown) may be collectively referred to as a Power Transmitter unit. Some or all of the Power Transmitter unit may be embodied as an integrated circuit (IC) that implements features of this disclosure for controlling and transmitting wireless power to one or more wireless power reception apparatuses. The PTx controller 115 may be implemented as a microcontroller, dedicated processor, integrated circuit, application specific integrated circuit (ASIC) or any other suitable electronic device.

[0181] A power source 105 provides power to the DC / DC converter 1912 (if present) or the Inverter 1913 (if the DC / DC converter 1912 is not present). In some implementations, the power source 105 may convert alternating current (AC) power to direct current (DC) power. For example, the power source 105 may include a converter that receives an AC power from an external power supply and converts the AC power to a DC power used by the PTx resonant circuit 1914. Alternatively, or additionally, a component (such as an inverter) of the PTx resonant circuit 1914 may convert the DC power to the AC power. The power source 105 may be integrated as part of the Power Transmitter 110 or may be external to the Power Transmitter 110.

[0182] In some implementations, the Power Transmitter 110 causes the power source 105 to regulate the DC output voltage of the power source 105. For example, the PTx controller 115 can set DC voltage of the power source 105 based on information (such as a value indicating a requested power) received from the Power Receiver 120. The Power Transmitter 110 can receive power configuration information from the Power Receiver 120 and use theDocket No. D25023W001information to set a parameter (such as the DC output voltage of the power source 105). The Power Transmitter 110 can receive the power configuration information during various operating states, such as the discovery state or power state. In some implementations, the Power Transmitter 110 includes a DC-DC converter (not shown) between the power source 105 and the PTx resonant circuit 1914 to control the variable DC output voltage.

[0183] The PTx controller 115 is connected to a communication element(s) 1916. In some implementations, the communication element(s) 1916 communicates using in-band signaling via the PTx resonant circuit 1914. Alternatively, the communication element(s) 1916 may be connected to a communication coil. In some implementations, the communication element(s) 1916 and associated components (such as a modulator, a demodulator, or other components) may be collectively referred to as a first communication unit. In some implementations, the first communication unit may use frequency, amplitude, current, or voltage modulation of a wireless power signal to communicate via an in-band communication link that includes the primary coil 112.

[0184] The Power Receiver 120 may include a secondary coil 122, a rectifier 124, a Power Receiver (PRx) controller 125, communication element(s) 126, a load 130, and a memory (not shown). In some implementations, the load 130 can include a battery charger to charge a power storage device (e.g., a battery, not shown). Alternatively, the load 130 can include electronics or other circuits that consume power from the rectifier 124. In some implementations, other components, such as a series switch (not shown) and / or capacitors (not shown), may be included in series with the secondary coil 122 or in series between the rectifier 124 and the load 130. Although shown as different components, some components may be packaged or implemented in the same hardware. The PRx controller 125 may be implemented as a microcontroller, dedicated processor, integrated circuit, application specific integrated circuit (ASIC) or any other suitable electronic device.

[0185] The PTx controller 115 may detect the presence or proximity of a Power Receiver 120. This detection may happen during a periodic pinging process of the communication element(s) 1916. During the pinging process, the communication element(s) 1916 also may supply power to the communication element(s) 1926 when the Power Receiver 120 is in proximity to the Power Transmitter 110. The communication element(s) 1926 may “wake up” and power-up the PRx controller 125 and may send a reply signal back to the communication element(s) 1916. Prior to power transfer, a handshaking process may take place during which the PTx controller 115 may receive identification and configuration data, among other information, from the Power Receiver 120. The PTx controller 115 may controlDocket No. D25023W001characteristics of wireless power it provides to the Power Receiver 120 based on the configuration data.

[0186] A PRx controller 125 may be operationally coupled to the rectifier 124 and the communication element(s) 1926. The communication element(s) 1926 may contain modulation and demodulation circuits to communicate via the PRx tank circuit (e.g., the secondary coil 122, the rectifier 124, or any other components between the secondary coil 122 and the load 130). In some implementations, the PRx controller 125 may use load modulation to communicate via an in-band communication link that includes the secondary coil 122. Alternatively, the communication element(s) 1926 may communicate out-of-band using a communication coil. In some implementations, the modulation / demodulation circuits are included in the PRx controller 125.

[0187] Either the Power Transmitter 110 or the Power Receiver 120, or both, may have other components, the description of which is omitted for brevity. For example, the wireless power apparatuses may have alignment aids. Either or both of the wireless power apparatus may have magnets to aid with alignment and / or wireless power transfer. Other circuit level details, such as capacitors, resisters, impedance matching circuits, and / or tuning circuits may be present.

[0188] FIG. 20A illustrates example scenarios of Power Receivers and a Power Transmitter that support different frequencies for various power levels / modes. FIG. 20A illustrates example scenarios 2000A of Power Receivers and Power Transmitters that support different frequencies for various power levels / modes. As a design consideration, it may be desirable for 50W mode to use a common nominal operating frequency that is suitable for worldwide deployment. The MPP mode currently uses a 360 kHz (or 1.78 MHz) nominal operating frequency. However, some authorities may limit the operating frequency options to below a threshold. For example, 360 kHz (or 1.78 MHz) operating frequency may not be permitted for use in some parts of the world. In this disclosure, the 50W mode may use a lower frequency (than 360 kHz (or 1.78 MHz)). In some implementations, the operating frequency for the 50W mode may have a nominal frequency of 360 kHz (or 1.78 MHz) or in a range from about 105 kHz to 128 kHz using the MPP protocol. For example, the 50W mode may use a nominal operating frequency around 128 kHz. The 128 kHz frequency is also used for lower power modes (e.g., BPP mode and EPP mode for power levels around 5W to 15W). Another design consideration is that the Power Transmitter, the Power Receiver, or both, might not support the 50W mode. It is desirable to have a communication protocol for 50W mode that is backward compatible for devices that support the MPP mode or 50W modeDocket No. D25023W001(which also may be referred to as fast charging, ultra high power mode, or extended high power mode).

[0189] FIG. 20A and FIG. 20B show example Power Transmitters. In FIG. 20A, a Power Transmitter 2010A supports the 128 kHz and / or the 360 kHz (or 1.78 MHz) nominal first frequencies.

[0190] In a first scenario 2051, the Power Transmitter 2010A and the first Power Receiver 2020A both support the MPP mode using 360 kHz (or 1.78 MHz). In this first scenario 2051, the devices may use a legacy communication protocol for the MPP mode, such as described in Qi wireless power specifications for the MPP mode. As an example, the legacy communication protocol may include a 360 kHz (or 1.78 MHz) digital ping followed by power transfer phase for 25W power.

[0191] In a second scenario 2052, the Power Transmitter 2010A is a 50W PTx and the second Power Receiver 2020B only supports EPP (without MPP) using 128KHz. By relaxing the LQK boundaries for EPP, the second Power Receiver 2020B may be capable of receiving 15W power (if not magnetic) or up to 25W power if the second Power Receiver 2020B also has a magnetic ring for coupling.

[0192] In a third scenario 2053, the third Power Receiver 2020C and the Power Transmitter 2010A may both support the 50W mode using 360 kHz (or 1.78 MHz). In a fourth scenario 2054, the fourth Power Receiver 2020D and the Power Transmitter 2010A may both support the 50W mode using 128 kHz.

[0193] In FIG. 20B, a Power Transmitter 2010B is limited to the 128 kHz nominal frequency. Continuing with the various scenarios described above, in FIG. 20B, a fifth scenario 2055 shows the Power Transmitter 2010B and the fifth Power Receiver 2020E might use MPP at 128 kHz, assuming that the fifth Power Receiver 2020E can be field upgraded to enable MPP protocol using 128 kHz. In a sixth scenario 2056, the Power Transmitter 2010B and the sixth Power Receiver 2020F both support the 50W mode natively using the 128 kHz nominal frequency. In the seventh scenario 2057, the Power Transmitter 2010A is paired with a seventh Power Receiver 2020G. The seventh Power Receiver 2020G implements an EPP mode but also has coils that are compatible (e.g., “compatible coils”) where the Power Transmitter 2010B magnet does not saturate the seventh Power Receiver 2020G coils / ferrite enabling the seventh Power Receiver 2020G to receive higher power.

[0194] FIG.21 illustrates a diagram 2100 of example operations of a Power Transmitter for selecting a nominal frequency for wireless power transmission based on a request from the Power Receiver. At block 2102, the Power Transmitter receives a communication from theDocket No. D25023W001Power Receiver. At block 2104, the Power Transmitter determines if the communication indicates a requested frequency (e.g., based on the Power Receiver location). If the communication indicates a first frequency, the flow proceeds to block 2106; otherwise, if the communication indicates a second frequency, the flow proceeds to block 2108. At block 2106, the Power Transmitter enables 128 kHz for the selected power profile (e.g., MPP or EPP). At block 2108, the Power Transmitter enables 360 kHz (or 1.78 MHz) for the selected power profile (e.g., MPP or EPP).

[0195] FIG. 22 illustrates a diagram 2200 of example operations for selecting a nominal frequency for wireless power transmission based on a geographic location or region. At block 2202, the Power Transmitter detects the Power Receiver. At block 2204, the Power Transmitter obtains its location information. At block 406, the Power Transmitter checks if it is operating in a first or second geographic region. If the Power Transmitter is operating in the first region, the flow proceeds to block 2208; .otherwise, if the Power Transmitter is operating in the second region, the flow proceeds to block 2210. At block 408, the Power Transmitter enables 128 kHz for the selected power profile (e.g., MPP or EPP). At block 410, the Power Transmitter enables 360 kHz (or 1.78 MHz) for the selected power profile (e.g., MPP or EPP).

[0196] FIG. 23 illustrates a diagram 2300 of example operations for selecting a nominal frequency for wireless power transmission. At block 502, the Power Transmitter detects the Power Receiver. At block 2304, the Power Transmitter provides PTx frequency information in a packet to the Power Receiver. At block 506, the Power Transmitter selects a frequency based on at least one of the following: PTx frequency information, Power Receiver capabilities, or the operating region.

[0197] In some implementations, frequency selection can be performed based on the information from a global navigation satellite system (GNSS). Examples of a GNSS include a Global Positioning System (GPS), GLONASS, BeiDou Navigation Satellite System, India regional navigation satellite system (NAVIC), and Galileo, among other examples. Alternatively, or additionally, the Power Transmitter (or the Power Receiver) can obtain location information from a cellular communication system of the region, Wi-Fi positioning system, or other sources.

[0198] FIG. 24 illustrates 2400 example power profiles and nominal frequencies for fast charging. An Extended Power Profile (EPP) 2402 can support fast charging at 128 kHz and >15W if EPP PRx has coil compatible with MPP / 50W PTx 2408. A Magnetic Power Profile (MPP) 2404 can support fast charging using an MPP enabled for 128 kHz 610 or an MPP forDocket No. D25023W001Fast Charging at 360 kHz (or 1.78 MHz) if permitted in geo region 612. Alternatively, a New 50W Power Profile (50PP) 2406 may be defined for fast charging, and might use either or both of the 128 kHz or 360 kHz (or 1.78 MHz) nominal frequency options.

[0199] FIG.25 is a message flow diagram 2500 in which the Power Receiver and the Power Transmitter use a first mode (e.g., MPP mode with 50W) for a first power level. The diagram 2500 shows a startup sequence that might be associated with the first scenario 2051 of FIG.20A. The message flow begins with a 128 kHz digital ping 2502. For example, the Power Transmitter 110 transmits a 128 kHz digital ping signal. The Power Receiver 120 responds to the digital ping by sending a Signal Strength (SIG) packet 2504, an Identification (ID) packet 2506, an Extended Identification (XID) packet 2508, and a Configuration packet (CFG) 2510. In some implementations, the XID packet 2508 indicates that the Power Receiver 120 is an MPP-compatible PRx. In some implementations, the Power Transmitter 110 transmits an MPP pattern 2512 to confirm that the Power Transmitter 110 is also an MPP-compatible PTx. The MPP pattern invokes an MPP Negotiation phase 2514.

[0200] In the negotiation phase 2514, the Power Receiver 120 may transmit a General Request (GRQ) packet requesting an ID packet from the Power Transmitter 110. The nomenclature of GRQ [ID] refers to the General Request packet, where the ID packet is requested. In response to the GRQ [ID] packet 316, the Power Transmitter 110 sends the ID packet 2518. In this example message flow (which is based on a legacy MPP protocol), the Power Receiver 120 optionally sends a Get Request packet (GET (PTx Extended ID) packet 2520) to cause the Power Transmitter 110 to respond with the PTx Extended ID packet 2522. In some implementations, a packet (e.g., similar to the GET (PTx Extended ID) packet) can be sent during a configuration phase. According to existing MPP protocols, the GET (PTx Extended ID) packet 2520 and the PTx Extended ID packet 2522 are optional.

[0201] During the negotiation phase 2514, the Power Receiver 120 and the Power Transmitter 110 negotiate a power transfer contract. The Power Receiver 120 sends the Specific Request (SRQ) packet with a Frequency Selection element for the power transfer contract. The SRQ with Frequency Selection element is referred to as an SRQ / freqsel packet 2524. In the example of FIG. 25, the SRQ / freqsel packet 2524 might include a first value (e.g., “1”) that indicates a 360 kHz (or 1.78 MHz) frequency for power transfer (e.g., using a 25W mode, 50W mode, or for power delivery ranging from 1 to 50W). The Power Transmitter 110 can support this frequency and responds with an acknowledgement 2526.

[0202] During the negotiation phase 2514, the 120 may send other requests related to the power transfer contract, such as an SRQ packet with a re-ping delay (rep) parameter (shownDocket No. D25023W001as SRQ / rep packet 2528). For each request that the Power Transmitter 110 can support, the Power Transmitter 110 can send a corresponding acknowledgement 2530. At the conclusion of the negotiation phase 2514, the Power Receiver 120 sends an SRQ packet to end the negotiation (shown as the SRQ / en packet 2532), which may also be acknowledged 2534 before proceeding to the power transfer phase 2536.

[0203] After selecting the new frequency (e.g., 360 kHz (or 1.78 MHz)) and terminating the negotiation using the SRQ / en packet 2532, the Power Receiver 120 can request a re-ping using an end power transfer (EPT) with re-ping packet (shown as EPT / rep packet 2538) to allow the Power Transmitter 110 to activate the new selected frequency. The Power Transmitter 110 may send an acknowledgement 2540 and then proceed with a 360 kHz (or 1.78 MHz) digital ping.

[0204] In some implementations, after selecting a new frequency (e.g., 128kHz) and terminating the negotiation using the SRQ / en packet 2532, the Power Receiver 120 can request a transition to power transfer phase without stopping the power by EPT / rep. The reason for this is current frequency (e.g., 128kHz) and new frequency (e.g., 128kHz) might be the same.

[0205] Having described the MPP protocol for 25 W (360 kHz (or 1.78 MHz)) mode, now the potential improvements / modifications are further described below.

[0206] Shown at block 2542, a new MPP pattern can be used to distinguish between the legacy 360 kHz (or 1.78 MHz) MPP mode and a new 128 kHz MPP mode.

[0207] FIG. 26 illustrates example patterns to indicate nominal frequency. For example a first pattern 2602 can be an example of a legacy MPP pattern where MPP supports 360 kHz (or 1.78 MHz) nominal frequency. A second pattern 2604 can be an example of a new MPP pattern to indicate MPP using 128 kHz nominal frequency. Alternatively, or additionally, a new pattern 2606 can be used for new power profiles or nominal frequencies.

[0208] FIG. 27 illustrates a message flow diagram in which the Power Receiver selects a nominal frequency based on operating region or location information of the Power Receiver. The message sequence in FIG. 27 is identical to the message sequence in FIG. 25, with the difference being that the Power Receiver 120 might perform a region check 2702 before transmitting the SRQ / freqsel packet 2524. The region check 2702 is so that the Power Receiver 120 can determine if it is located in a region that allows for 360 kHz (or 1.78 MHz) wireless power transfer or limited to 128 kHz wireless power transfer. The value of the requested frequency in the SRQ / freqsel packet 2524 may depend on the results of the region check 2702.Docket No. D25023W001

[0209] FIG. 28 is a diagram 2800 of an example PTx Extended ID packet. The PTx Extended ID packet includes a Selector header field, an active alignment power profile (APP) bit, a unique ID (UID) bit, a Device Identifier field, and a manufacturer (Mfg) reserved field. The APP bit is set to ONE in a PTX with a moving primary coil. The APP bit is set to ZERO in an MPP-compliant PTx. When the UID bit is set to ONE, the UID bit indicates that the Device Identifier was generated by the manufacturer to have a high probability of being unique to this unit.

[0210] In accordance with some aspects of this disclosure, the PTx Extended ID packet can include an indicator field 2802 (which may be referred to as a frequency / region indicator) to indicate whether the Power Transmitter supports the 128 kHz MPP or 50W mode using 128 kHz. The value of the indicator field 2802 can indicate frequency supported, region restriction(s), or fast charging capability information, among other examples.

[0211] FIG. 29 is a diagram 2900 of an example MPP Extended ID (MPP-XID) packet with an optional value for a Power Receiver to indicate nominal frequency or region. FIG. 29 shows that the MPP-XID might be populated with an indicator field 2802 (as described with reference to FIG. 28) instead of the PTx Extended ID packet (FIG. 28).. There could be any other packet coming from Transmitter to Receiver to show its identity (e.g., an XID packet or ECAP pacekt) and that can be sent during ping, configuration or negotiation phase. One of that packet could be MPP-XID packet where 2 bits or more in B7 can be used by PTx to communicate that the PTx is in a 128 kHz or 360 kHz (or 1.78 MHz) region, as shown in FIG.29.

[0212] In some aspects, a Power Transmitter can indicate its frequency capabilities to a Power Receiver to facilitate dynamic frequency selection. For example, a "smart transmitter" can dynamically change its operating frequency between different nominal frequencies, such as 128 kHz and 360 kHz (or 1.78 MHz). To enable this functionality, the Power Transmitter can use the XID packet to indicate the transmitter's frequency capabilities. In one implementation, specific values within the XID packet can represent different transmitter configurations. For instance, a value of "01" can indicate a normal transmitter fixed at 360 kHz (or 1.78 MHz), while a value of "10" can indicate a normal transmitter fixed at 128 kHz. To support dynamic frequency changes, a value of "11" can be used in the XID packet to identify the PTx as a smart transmitter. When a PRx receives an XID packet with the "11" value, the PRx can then expect that the PTx will further specify the operating frequency (e.g., 128 kHz or 360 kHz (or 1.78 MHz)) in a subsequent ECAP packet.Docket No. D25023W001

[0213] FIG. 30 illustrates a Power Receiver that can select a nominal frequency based on PRx location information 3004. FIG. 30 shows another variation in which the Power Receiver PRx controller 125 determines its location and selects the 128 kHz or the 360 kHz (or 1.78 MHz) nominal frequency based on PRx location information 3004. Furthermore, shown at block 3006, the capacitance tuning may change depending on whether the Power Receiver is in a 128 kHz region or a 360 kHz (or 1.78 MHz) region.

[0214] CAP tuning, Vrect target will be changed between the 128 Khz and 360Khz full power operation. In a first consideration, for the PTx 360Khz - e.g., 3 CTx (56n, 56, 300f) will be used; and for the PTx 128Khz - e.g., 4 CTx (e.g., 56nF, 56nF, 170nF, 130nF) are used. In a second consideration, nominal VRect might be set such as 28V for 360Khz 50W or 25V for 128Khz.

[0215] FIG. 31 shows a diagram 3100 of an example Power Transmitter with slew rate capacitors 3130 (such as C4, C5, C6, C7). Slew rate capacitors are the capacitors that are connected to the primary coil 3124 with / without switches (e.g., such as switch 3126 and switch 3128). The Power Transmitter can also include switches 3120 and 3122 to selectively enable or disable resonant tuning capacitors. Switches for connecting the slew rate capacitors 3130 can be engaged or disengaged based on any combination of considerations, such as EMI / EMC / Harmonics, Power level / modes, ZVS operation, etc.

[0216] Note that the slew rate capacitors 3130 are different from tuning capacitors Ctxl 3110, Ctx23112, Ctx3 3114 for resonant tuning. Rather the slew rate capacitors 3130 enable harmonic filtering or other control.

[0217] Here are some example control inputs to slew rate capacitors:• A new packet informs the number of slow rate caps and current engagement / connect to primary coil, PTX informs PRX• PRx requests for the phase information using a new packet from PTx and PRx decides to switch the power modes / slew capacitors.• ZVS switching. It recommended to have at least 20 degrees of phase lag between the voltage and current for the good ZVS control on the Power Transmitter. One of the control to change the phase angle / lag is by controlling the slew rate caps. In some implementations, a Power Transmitter has a sensor to monitor the ZVS. Based on the ZVS risk, the Power Transmitter may choose to turn on or off various ones of the slew rate capacitors 3130.

[0218] In some implementations, at the design stage based on the circuit configurations, in scenarios where the EMC fails, switch the capacitors on and off. A manufacturer or designerDocket No. D25023W001can load this information in the controller based on the exiting power level and configuration transmitter would switch the capacitors (i.e., based on number of harmonics present).

[0219] FIG. 32A is a diagram showing example scenarios 3300A of Power Receivers and a Power Transmitter that support different frequencies for a restricted mode. In some implementations, a restricted mode is used when an MPP-capable Power Receiver has a low or dead battery condition. The Power Transmitter 3310A can support multiple operating frequencies, such as a 128 kHz operating frequency and a 360 kHz (or 1.78 MHz) operating frequency. The Power Transmitter 3310A might also support multiple power transfer protocols. In this example, the Power Transmitter 3310A supports an MPP mode with 50W (or 50W mode), and can operate the 50W mode using either 128 kHz frequency or 360 kHz (or 1.78 MHz) frequency.

[0220] In a first scenario 3351, a first Power Receiver 3320A is placed on the Power Transmitter 3310A. The first Power Receiver 3320A supports an MPP mode at 360 kHz (or 1.78 MHz). In this scenario, the Power Transmitter 3310A and the first Power Receiver 3320A can operate in a 360 kHz (or 1.78 MHz) restricted mode of the MPP protocol.

[0221] In a second scenario 3352, a second Power Receiver 3320B is placed on the Power Transmitter 3310A. The second Power Receiver 3320B supports an MPP mode at 128 kHz. In this scenario, the Power Transmitter 3310A and the second Power Receiver 3320B can operate in the low frequency restricted mode of the MPP protocol at the 128 kHz operating frequency in accordance with aspects of this disclosure.

[0222] In a third scenario 3353, a third Power Receiver 220C is placed on the Power Transmitter 3310A. The third Power Receiver 220C may not support the MPP mode, such as a legacy Power Receiver. In this example, the third Power Receiver 220C and the Power Transmitter 3310A may revert to a legacy mode (c.g., the BPP mode) at the 128 kHz operating frequency.

[0223] FIG. 32B is a diagram showing example scenarios 3300B of Power Receivers and a Power Transmitter that is limited to a low frequency restricted mode. One difference between FIG. 32B and FIG. 32A is that the Power Transmitter 3310B of FIG. 32B only supports 128 kHz frequency. This limitation may be due to the Power Transmitter's design or regional regulations that restrict other frequencies. According to aspects of this disclosure, even though the Power Transmitter 3310B may be limited to 128 kHz frequency, the Power Transmitter 3310B does support the MPP mode using the 128 kHz frequency.

[0224] In a fourth scenario 3356, a fourth Power Receiver 3320D, which supports an MPP mode at 128 kHz, is placed on the Power Transmitter 3310B. The Power Transmitter 3310BDocket No. D25023W001and the fourth Power Receiver 3320D can operate in the low frequency restricted mode (or the full power mode) of the MPP protocol at the 128 kHz operating frequency.

[0225] In a fifth scenario 3357, a fifth Power Receiver 3320E is placed on the Power Transmitter 3310B. The fifth Power Receiver 3320E may not support the MPP mode at the 128 kHz frequency. Instead, in this example, the fifth Power Receiver 3320E and the Power Transmitter 3310B may revert to a legacy mode (e.g., the BPP mode) at the 128 kHz operating frequency.

[0226] FIG. 33A is a flowchart 3300a illustrating example operations for a Power Transmitter to enter a low frequency restricted mode. The example operations may be performed by a Power Transmitter capable of different operating frequencies, such as the Power Transmitter 3310A of FIG. 32A. At block 3302, the Power Transmitter transmits a 128 kHz digital ping for a wireless power protocol (such as MPP or a higher power profile). At block 3304, the Power Transmitter receives a message, from a Power Receiver, which indicates a restricted mode. For example, the message may be an Identification (ID) or Extended Identification (XID) packet that includes a value to indicate the restricted mode.

[0227] At block 3310, the Power Transmitter determines whether to select a low frequency (e.g., 128 kHz) restricted mode. In some implementations, the decision is based on the Power Transmitter having the 128 kHz restricted mode capability and the Power Receiver indicating a protocol version (e.g., in an earlier ID packet) that supports the 128 kHz restricted mode. In some implementations, the decision is based on the Power Transmitter receiving any data packet that indicates the Power Receiver being configured for 128 kHz operating frequency. In some implementations, the Power Transmitter selects the low frequency restricted mode based on one or more criterion: geographic location information of the Power Transmitter, a software setting of the Power Transmitter that configures an operational parameter (e.g., a software parameter configuring 128 kHz or 360 kHz (or 1.78 MHz) operating frequency), or a hardware based toggle to select 128 kHz or 360 kHz (or 1.78 MHz).

[0228] In some implementations, at block 3312, the Power Transmitter refrains from responding to the message and waits for a timeout. The timeout intentionally causes the Power Receiver to enter the low frequency restricted mode. At block 3314, the Power Transmitter proceeds to operate in the low frequency restricted mode. In some alternative scenarios, the Power Transmitter may decide at block 3 10 to not select the low frequency restricted mode. For example, the Power Receiver may only support a legacy MPP protocol that is limited to 360 kHz (or 1.78 MHz) restricted mode. In such cases, Power TransmitterDocket No. D25023W001may attempt, at block 3316, a 360 kHz (or 1.78 MHz) restricted mode or a 128 kHz BPP mode.

[0229] FIG. 33B is another flowchart 3300b illustrating example operations for a Power Transmitter to enter a low frequency restricted mode. The example operations may be performed by a Power Transmitter that is limited to only 128 kHz frequency, such as the Power Transmitter 3310B of FIG. 32B. Blocks having the same number as those in FIG. 33A are the same as described above and not duplicated here. FIG. 33B differs from FIG. 33A in that the flowchart 3300b does not include a block 3310 for selecting the low frequency restricted mode. Instead, the flowchart 3300b may proceed directly to block 3312.

[0230] In some implementations, the Power Transmitter may make a decision at block 3306 regarding whether the Power Receiver can support the low frequency restricted mode. If so, the Power Transmitter performs the operations of blocks 3312 and 3314 as described above. If the Power Receiver does not support the low frequency restricted mode (i.e., the “No” branch of block 3306), then the Power Transmitter reverts to 128 kHz frequency BPP mode at block 3308. While FIG. 33A and FIG. 33B are illustrated separately, it should be understood that the features of the flowcharts 3300a and 3300b can be combined in some implementations.

[0231] FIG. 34A is a sequence diagram 3400a illustrating an example interaction between a Power Transmitter 110 and a Power Receiver 120 to enter a low frequency restricted mode. The sequence begins with a ping and selection phase 3402, where the Power Transmitter 110 sends a 128 kHz digital ping. The Power Receiver 120 responds to the digital ping by sending a Signal Strength (SIG) packet 3404, an ID packet 3406, an XID packet 3408. These packets may also be considered part of the configuration phase for the wireless power protocol.

[0232] In this example, the XID packet 3408 indicates that the Power Receiver 120 is operating in a restricted mode. For example, the XID packet 3408 can include an indication of flag that is set to a value associated with the restricted mode. To cause the Power Receiver 120 to enter the low frequency (LF) restricted mode, the Power Transmitter 110 refrains 3416 from sending a response to the XID packet 3408. This lack of a response within a specified time window can also be referred to as a timeout 3412. The timeout 3412 causes the Power Receiver 120 to enter the LF restricted mode of the wireless power protocol. According to the wireless power protocol (similar to BPP), the Power Receiver 120 transmits a configuration (CFG) packet 3414 to configure settings for the LF restricted mode. At block 3418, the Power Transmitter 110 proceeds to transfer wireless power according to the LF restricted mode.Docket No. D25023W001

[0233] FIG. 34B is a sequence diagram 3400b illustrating a Power Transmitter and Power Receiver transitioning from a low frequency restricted mode to a full power mode based on a data packet, such as negotiation (NEGO) packet. The sequence begins the same as described with reference to FIG. 34A. For brevity, the descriptions of elements from FIG. 34A are not repeated in the description of FIG. 34B.

[0234] During the LF Restricted Mode power transfer phase, the Power Receiver 120 may periodically send a control error (CE) packet 3420. Following each CE packet 3420, the wireless power protocol specifies as Power Control Hold-off (PCH) time interval. During the PCH time interval, the Power Transmitter 110 may transmit an MPP response pattern 3424 (also referred to as a pattern message). In the LF restricted mode, the Power Receiver 120 may not respond to the MPP response pattern and the devices will remain in the LF restricted mode. In accordance with aspects of this disclosure, the Power Receiver 120 may request an exit of the LF restricted mode and transition to the full power mode by responding to the MPP response pattern 3424. For example, the Power Receiver 120 may send a data packet (such as a NEGO packet 3426) in response to the MPP response pattern (or any type of pattern message). The data packet can represent a request for a transition to a negotiation phase associated with the full power mode 3455. Advantageously, in some implementations, the transition from the LF restricted mode 414 to the full power mode 3455 can occur without interrupting the power transfer.

[0235] In the negotiation phase 3428, the Power Receiver 120 may transmit a General Request (GRQ) packet 3430 requesting an ID packet from the Power Transmitter 110. The nomenclature of GRQ [ID] refers to the General Request packet, where the ID packet is requested. In response to the GRQ [ID] packet 3430, the Power Transmitter 110 sends the ID packet 3422. In this example message flow (which is based on a legacy MPP protocol), the Power Receiver 120 optionally sends a Get Request packet (GET (PTx Extended ID) packet 3432) to cause the Power Transmitter 110 to respond with the PTx Extended ID packet 3434. The nomenclature of GET [x] refers to a request from the Power Receiver 120 to receive an x packet from the Power Transmitter 110, where the Power Transmitter 110 would respond by sending the x packet as requested.

[0236] During the negotiation phase, the Power Receiver 120 and the Power Transmitter 110 negotiate a power transfer contract. The Power Receiver 120 sends the Specific Request (SRQ) packet with a Frequency Selection element for the power transfer contract. The SRQ with Frequency Selection element is referred to as an SRQ / freqsel packet 3436. In the example of FIG. 34A, the SRQ / frcqscl packet 3436 might include a predefined value (c.g., “1” or “2”) that indicates a 128 kHz operating frequency for full power mode. The PowerDocket No. D25023W001Transmitter 110 can support this frequency and responds with an acknowledgement (ACK) 3438.

[0237] During the negotiation phase 3428, the Power Receiver 120 may send other negotiation messages related to the power transfer contract. For each negotiation message that the Power Transmitter 110 can support, the Power Transmitter 110 can send a corresponding acknowledgement. The FIG. 34B shows other negotiation and acknowledgement messages 3440 to represent any such messaging. Examples of the other negotiation and acknowledgement messages 3440 include a GETfECAP] message, the ECAP message response, a GETfPLAP] message, and a PLAP response, and so on. A response to the GET[ECAP] is ECAP, response to ECAP is ACK, response to GETfPLAP] is PLAP, and response to PLAP is ACK.

[0238] In some implementations, the Power Receiver 120 may send an SRQ packet with a re-ping delay (rep) parameter (shown as SRQ / rep packet 3442). For each request that the Power Transmitter 110 can support, the Power Transmitter 110 can send a corresponding acknowledgement (such as ACK 3444). At the conclusion of the negotiation phase 3428, the Power Receiver 120 sends an SRQ packet to end the negotiation (shown as the SRQ / en packet 3446), which may also be acknowledged 3448 before proceeding to the power transfer phase 3450 using the full power mode.

[0239] FIG. 34C is a sequence diagram 3400c illustrating a Power Transmitter and Power Receiver exiting a low frequency restricted mode based on an End Power Transfer / Restart (EPT / rst) packet 3456. The sequence diagram 3400c illustrates an alternative way for a Power Transmitter 110 and a Power Receiver 120 to exit the low frequency restricted mode. For brevity, the descriptions of elements from FIG. 34A are not repeated in the description of FIG. 34C.

[0240] While operating in the LF restricted mode power transfer phase 3418, the Power Receiver 120 send an EPT / rst packet 3456 to exit the LF Restricted Mode power transfer phase 3418. For example, this could be due to a change in the Power Receiver's charging status or another condition. Upon receiving the EPT / rst packet 3456, the Power Transmitter 110 stops the wireless power transmission 3452 and can initiate a new power transfer session by, for example, transmitting a new MPP digital ping in a new MPP ping phase 3458. After completing the MPP ping phase, the Power Receiver 120 and the Power Transmitter 110 can configure and negotiate a full power mode of the MPP protocol.

[0241] FIG. 34D is a sequence diagram illustrating a Power Transmitter selecting a low frequency restricted mode or baseline power profile (BPP) mode based on operatingDocket No. D25023W001frequency information or protocol version information from the Power Receiver. For brevity, the descriptions of elements from FIG. 34A are not repeated in the description of FIG. 4D.

[0242] In some implementations, the ID packet 3406 (or the XID packet 3410) may include protocol version information or an indication whether the Power Receiver 120 supports a protocol version of the wireless power protocol that defines the LF restricted mode. In some implementations, the XID packet 3410 (or another packet, not shown) may indicate operating frequency information of the Power Receiver 120, where the operating frequency information informs the Power Transmitter 110 whether the Power Receiver 120 can support the 128 kHz frequency of the MPP protocol.

[0243] At block 3460, the Power Transmitter 110 may determine whether the Power Receiver 120 supports the LF restricted mode based on the protocol version information, the operating frequency information, or both. For example, the Power Transmitter 110 may consider protocol version information in the ID packet 3406 and / or operating frequency information in the ID packet 3406 or the XID packet 3410. An older protocol version of the MPP protocol might not support the LF restricted mode, so when the ID packet 3406 indicates the older protocol version, the Power Transmitter 110 may revert to a BPP Mode 3464.

[0244] In this example, the ID packet 3406 may indicate a newer protocol version of the MPP protocol that does support the LF restricted mode 3462 at 128 kHz. To cause the Power Receiver 120 to enter the LF restricted mode, the Power Transmitter 110 refrains 3416 from sending a response to the XID packet 3408. This lack of a response within a specified time window causes the Power Receiver 120 to enter the LF restricted mode at block 3462.

[0245] FIG. 35A is a flowchart 3500a illustrating example operations of a Power Transmitter in a 128 kHz configuration phase of an MPP protocol. At block 3502, the Power Transmitter detects a PRx device. At block 3504, the Power Transmitter sends a 128 kHz digital ping to initiate communication. At block 3506, the Power Transmitter receives a SIG packet from the PRx. At block 3508, the Power Transmitter receives an ID packet and, if available, an XID packet, from the PRx.

[0246] At block 3510, the Power Transmitter determines if the PRx indicates support for the MPP protocol. If the PRx does not support MPP, the process moves to block 3512, where the Power Transmitter proceeds with a legacy non-MPP wireless power profile (such as BPP or EPP).

[0247] If the PRx does support MPP, at block 3510, the flowchart 3500a continues to block 3514, where the Power Transmitter determines if the received XID packet indicates a restricted mode. If the XID does not indicate restricted mode, the process moves to blockDocket No. D25023W0013524, where the Power Transmitter continues with a configuration phase for the MPP protocol. For example, the Power Transmitter receives a CFG packet from the PRx. Following the receipt of the CFG packet at block 3524, the process moves to block 3526. At block 3526, the Power Transmitter determines whether communication has been established using a low (e.g., Qi_HB_Low) digital ping level. If communication has not been established ("No" branch from block 3526), the Power Transmitter sets an error condition at block 3530 and sends a negative-acknowledge (NAK) Frequency-Shift Keying (FSK) pattern. If the communication has been established ("Yes" branch from block 3526), the process moves to block 3528, where the Power Transmitter sends an MPP FSK pattern to confirm the configuration. Following either block 3528 or block 3530, the process moves to block 3532, where the Power Transmitter proceeds to the MPP negotiation phase.

[0248] Returning to block 3514, if the XID does indicate restricted mode ("Yes" branch from block 3514), the process proceeds to block 3516. At block 3516, the Power Transmitter determines whether communication has been established using the low digital ping level. If yes, the Power Transmitter removes the power signal (at block 3518), sets its operating frequency to 360 kHz (or 1.78 MHz) (at block 3520), and proceeds to a 360 kHz (or 1.78 MHz) digital ping (at block 3522) to enter the high-frequency (360 kHz (or 1.78 MHz)) restricted mode. If the determination at block 3516 is no (i.e., communication has not been established using the low digital ping level), the flowchart returns to block 3504.

[0249] While FIG. 35A shows how the MPP protocol configuration phase can support the 360 kHz (or 1.78 MHz) restricted mode, the current protocol for MPP configuration phase does not provide a mechanism to enter a low frequency (e.g., 128 kHz frequency) restricted mode. FIG. 35B through FIG. 35D provide some example modifications to the MPP protocol configuration phase to support low frequency restricted mode. For brevity, the descriptions of each of the Figures will omit descriptions of blocks already described for a previous figure, and instead focus on the differences from the preceding figures.

[0250] FIG. 35B is a flowchart 3500b illustrating example operations of a Power Transmitter in a 128 kHz configuration phase in which the Power Transmitter enables a low frequency restricted mode based on Power Transmitter settings. FIG. 35B differs from FIG.35A in that FIG. 35B adds a pathway for a Power Transmitter to enter a low frequency (e.g., 128 kHz) restricted mode. The process follows the flow of FIG. 35 A until block 3514. The differences are highlighted by bolded boxes.

[0251] At block 3514, if the XID packet from the PRx indicates a restricted mode, the process continues to a new block 3534. At block 3534, the Power Transmitter determines ifDocket No. D25023W001it is configured to operate in the low frequency restricted mode. This determination can be based on various factors. For example, the Power Transmitter may be designed to operate only at the 128 kHz operating frequency and may not support 360 kHz (or 1.78 MHz) wireless power transmission. In another example, the Power Transmitter may be operating in a geographic region where regulations restrict the use of the 360 kHz (or 1.78 MHz) frequency band.

[0252] If the Power Transmitter is not configured for the low frequency restricted mode ("No" branch from block 3534), the process proceeds to block 3516, which is consistent with the flow described in FIG. 35 A for entering a 360 kHz (or 1.78 MHz) restricted mode. Alternatively, if the Power Transmitter is incapable or, or regulated from, using the 360 kHz (or 1.78 MHz) restricted mode, the flowchart may end the MPP protocol and revert to a BPP mode.

[0253] However, if the Power Transmitter determines that it is configured for the low frequency restricted mode ("Yes" branch from block 3534), the process moves to block 3536. At block 3536, the Power Transmitter waits for a timeout without responding to the PRx, and thus causes the PRx to enter the low frequency restricted mode. At block 3538, the Power Transmitter enters the 128 kHz restricted mode of the MPP protocol. In this mode, the Power Transmitter begins to supply power to the PRx at the 128 kHz operating frequency. This allows the PTx to initiate charging a PRx that is in a restricted state (e.g., due to a depleted battery) while using the 128 kHz frequency, which can be useful when the 360 kHz (or 1.78 MHz) frequency is unavailable or unsupported. This also enables a subsequent seamless transition to a full power mode at 128 kHz without interrupting the power transfer.

[0254] FIG. 35C is a flowchart 3500c illustrating example operations of a Power Transmitter in a 128 kHz configuration phase in which the Power Transmitter enables a low frequency restricted mode based on Power Receiver information. The flowchart 3500c in FIG. 35C illustrates another example of operations for a Power Transmitter to enter a low frequency restricted mode, differing from FIG. 35B in how the decision is made. The process is similar to that described in FIG. 35 A and FIG. 35B up to block 3514.

[0255] At block 3514, if the XID packet from the Power Receiver indicates a restricted mode, the process continues to block 3540. At block 3540, the Power Transmitter determines whether to enable the low frequency restricted mode based on information received from the Power Receiver. For example, the Power Transmitter may have received an ID packet or an XID packet from the Power Receiver that contains specific information. This information can include protocol version information indicating that the Power Receiver is compatible withDocket No. D25023W001the 128 kHz restricted mode. In another example, the packet may contain operating frequency information indicating that the Power Receiver is configured to operate with the 128 kHz operating frequency and may not support the 360 kHz (or 1.78 MHz) frequency.

[0256] If the information from the Power Receiver does not support using the low frequency restricted mode ("No" branch from block 3540), the process proceeds to block 3516, consistent with the flow for entering the 360 kHz (or 1.78 MHz) restricted mode as described in FIG. 35A or alternatively reverting to a BPP mode (not shown). If the information from the Power Receiver indicates that the low frequency restricted mode should be used ("Yes" branch from block 3540), the process moves to block 3536. At block 3536, the Power Transmitter can cause the Power Receiver to enter the low frequency restricted mode, for instance, by refraining from sending a response, which leads to a timeout. Following this, at block 3538, the Power Transmitter proceeds with power transfer in the 128 kHz restricted mode. This approach allows the Power Transmitter to dynamically select the appropriate restricted mode based on the capabilities of the specific Power Receiver it is interacting with.

[0257] FIG. 35D is a flowchart 3500d illustrating example operations of a Power Transmitter in a 128 kHz configuration phase showing example alternatives for invoking a low frequency restricted mode. This flowchart introduces alternative actions the Power Transmitter can take after determining that the low frequency restricted mode should be used. The process is similar to that described in FIG. 35A up to the "Yes" branch from block 3516. Although FIG. 35B and FIG. 35C used a lack of PTx response to cause the PRx to enter the LF restricted mode, FIG. 35D shows some examples in which a signal (or combination of signals) from the Power Transmitter can prompt the Power Receiver to enter the LF restricted mode.

[0258] In one example, shown at block 3542, the Power Transmitter can actively inform the Power Receiver that it is configured to operate in the low frequency restricted mode. There are several ways the Power Transmitter can accomplish this. For example, the Power Transmitter can transmit a specific (i.e., predefined) MPP pattern associated with the low frequency restricted mode. A response from the Power Receiver (not shown) can confirm the MPP pattern and move both devices to the low frequency restricted mode (block 3538).

[0259] In another example, shown at block 3544, the Power Transmitter might transmit a new digital ping at a predetermined frequency that is specifically defined to invoke the low frequency restricted mode. In another alternative, the PTx might send a different frequency other than 128 kHz during a re-ping (e.g., a 135 kHz digital ping) and await a response fromDocket No. D25023W001the PRx, where the response might be a CFG packet for a BPP mode (not shown) at 128 kHz frequency.

[0260] As another example, shown at block 3546, the Power Transmitter could transmit a second 128 kHz digital ping. If the PRx receives two 128 kHz digital pings, then the PRx should send the CFG packet to move to the BPP mode or the LF restricted mode.

[0261] FIG. 36 is a flowchart 3600 illustrating example operations for managing a power transfer mode including a low frequency restricted mode. At block 3602, the Power Transmitter transmits a 128 kHz analog ping and digital ping to detect a Power Receiver. For example, the Power Transmitter may repeatedly send out a digital ping to determine if a Power Receiver has been placed on its charging surface.

[0262] At block 3604, the Power Transmitter receives a message from the Power Receiver during a configuration phase. In some implementations, the Power Transmitter may receive an XID packet, which may include a bit or field indicating that the Power Receiver is to operate in a restricted mode, for example, due to a low battery state of the Power Receiver.

[0263] At block 3606, the Power Transmitter refrains from responding to the message received at block 3604 to cause the Power Receiver to enter a LF restricted mode. For instance, this lack of a response within a predetermined time window signals the Power Receiver to enter the LF restricted mode.

[0264] At block 3608, the Power Transmitter provides power at a 128 kHz operating frequency while operating in the LF restricted mode. During this mode, the Power Transmitter may transmit an MPP pattern, for example, during a PCH interval, to check if the Power Receiver is ready to transition to a full power mode.

[0265] At block 3610, the Power Transmitter receives a NEGO packet from the Power Receiver. The NEGO packet may serve as a request to end the LF restricted mode and transition to a full power mode without interrupting power transfer, allowing the system to seamlessly move from a low-power state to a higher-power, fully communicative state.

[0266] At block 3612, the Power Transmitter engages in the negotiation phase following the receipt of the NEGO packet. This may include the Power Transmitter sending its ID and XID packets to the Power Receiver to exchange further capability information.

[0267] At block 3614, the Power Transmitter receives a frequency selection (FREQSEL) packet from the Power Receiver, which confirms or selects the operating frequency for the full power mode. For example, the Power Receiver may select a frequency of 128 kHz if both devices support it. At block 3616, the Power Transmitter receives a Specific Request / End Negotiation (SRQ / en) packet from the Power Receiver, which concludes the negotiationDocket No. D25023W001phase. At block 3618, the Power Transmitter enters the full power transfer phase, operating according to the negotiated parameters, such as the agreed-upon frequency and power level.

[0268] In some implementations, the Power Transmitter only supports 128 kHz operating frequency (sometimes referred to as a 128 kHz-only transmitter). In this case, some of the frequency checking options described with reference to FIG. 35B to FIG. 35D might be omitted. For example, a Power Transmitter that exclusively supports the 128 kHz frequency can determine the operating mode of the PRx by reading the PRX's XID packet. If the PRx indicates a restricted mode, the Power Transmitter can remain in the configuration state, refraining from communication or power removal. This inaction signals the PRx to send Configuration (CFG) packets and enter an MPP low frequency restricted mode. This mode operates at 128 kHz, similar to the BPP mode with two distinctions. To facilitate a transition to full MPP mode without a power cycle, the PTx periodically transmits an MPP response pattern during the PCH time after each CE packet. The PRx can then respond with a NEGO data packet to initiate the transition. Following the NEGO packet, the PTx and PRx enter a negotiation phase where they exchange identifiers (PTx ID and XID), agree on a frequency selection, and finalize the negotiation before commencing the power transfer phase with an Extended Control Error (XCE) packet. Alternatively, the PRx may choose to exit the LF restricted mode by sending an End Power Transfer / Restart (EPT / rst) packet, which prompts the PTx to cease power transmission and initiate a new 128 kHz digital ping.

[0269] FIG. 37 is a chart 3700 showing different types of Power Transmitters and Power Receivers based on their supported operating modes, frequencies, and power levels. The chart shows which mode might be selected based on Power Transmitter and Power Receiver capability.

[0270] Some Power Transmitters (such as a 360 kHz (or 1.78 MHz) 50W PTx 3702 or a 360 kHz (or 1.78 MHz) 25 W PTx 3704) may not support the 128 kHz operating frequency for MPP. If either of the 360 kHz (or 1.78 MHz) 50W PTx 3702 or the 360 kHz (or 1.78 MHz) 25W PTx 3704 encounter a 50W MPP PRx 3706 or a 25W MPP PRx 3708, they may only enable the 360 kHz (or 1.78 MHz) restricted mode of the MPP protocol, regardless of whether the Power Receivers 3706 and 3708 support 128 kHz restricted mode. This is because the Power Transmitters 3702 and 3704 do not implement the 128 kHz restricted mode.

[0271] In an example where the 128 kHz 50W PTx 3710 supports the 128 kHz restricted mode and encounters a 50W MPP PRx 3714 that also supports the 128 kHz restricted mode, they can proceed with the 128 kHz restricted mode.Docket No. D25023W001

[0272] In an example where the 128 kHz 50W PTx 3712 might support the 128 kHz restricted mode but encounters a legacy 25 W MPP PRx 3716 (which may not support 128 kHz restricted mode), the system would revert to BPP mode. Similarly, a legacy EPP / BPP PTx 3718 (which does not support MPP at all) that encounters a 25W MPP PRx 3716 or a 50W MPP PRx 3720 would revert to the BPP mode because the EPP / BPP PTx 3718 does not recognize MPP at all. Table 3 shows a summary of some possible interactions between PRx and PTx of various types.Table 3. Matrix of Restricted Mode options

[0273] Table 4 shows a full compatibility matrix of legacy / new types of PRx and PTx and the expected behaviors.Docket No. D25023W001Table 4. Matrix of Compatibility options

[0274] Below arc some example scenarios showing interactions from the Table 4.

[0275] A first example scenario might be a 50W 128 kHz PTx with a 25 W 360 kHz PRx. In this scenario, the PRx communicates its restricted mode information. Upon receiving the PRx's protocol version information and restricted mode status, the PTx, instead attempting to enter a 360 kHz restricted mode, times out after receiving the CFG packet from the PRx. As a result of the timeout, the PRx enters the Baseline Power Profile (BPP) mode.

[0276] A second example scenario might be a 50W 128 kHz PTx with a 50W 360 kHz PRx. The PRx includes its protocol version and operating frequency information within its ID and X1D packets. The PTx uses this information to determine that it should not proceed to a 360 kHz (or 1.78 MHz) restricted mode. Consequently, the PTx times out after receiving the CFG packet from the PRx, causing the PRx to enter BPP mode. It might be specified that the PRx should include its operating frequency information in a packet, such as the XID packet, to facilitate this process.

[0277] A third example scenario might be a 50W 360 kHz (or 1.78 MHz) PTx with a 50W 128 kHz PRx. There might be two potential outcomes described for this scenario. In the first option (Option 1), the devices might use MPP High-Frequency (HF) restricted mode. The PRx sends its restricted mode information. The PTx receives this information and proceeds to enter the 360 kHz (or 1.78 MHz) restricted mode, which is designated as MPP HF restricted mode. In the second option (Option 2), the devices might use BPP Mode. The PRx sends its restricted mode information, including its protocol version and frequency capabilities. The PTx receives this information and, instead of entering a high-frequency mode, proceeds to establish a connection in BPP mode.

[0278] To address potential interoperability issues between devices with different capabilities, the wireless power protocol can define specific behaviors. For example, when a PRx that supports a newer protocol version (e.g., a “New” 50W-capable PRx) is aware that it is communicating with a legacy PTx (e.g., the PTx does not support the 50W protocol), the PRx may ignore the XID reserved bit fields in a PTx XID packet from the legacy PTx.

[0279] FIG. 38 is a diagram of an example ID packet 3800. In some implementations, the ID packet 3800 is transmitted from a Power Receiver to a Power Transmitter to convey, among other information, the protocol version information of the Power Receiver. The packet 3800 may include several fields, including protocol version information fields (shown as “major version” and “minor version”). The Power Receiver can use this protocol version information to indicate which protocol version of a wireless power protocol it supports. ForDocket No. D25023W001instance, a specific value in this field can signal that the Power Receiver is compatible with a low frequency restricted mode, such as a 128 kHz restricted mode. Based on this information, the Power Transmitter can determine whether to engage in the low frequency restricted mode or to use a different mode, such as a legacy BPP mode, ensuring interoperability between devices with different protocol capabilities.

[0280] In some implementations, the communication protocol between a Power Transmitter and a Power Receiver can account for different device protocol versions and capabilities to ensure proper operation. For example, consider a scenario where a new PRx (supporting MPP with 50W) is placed on an older PTx that supports an older MPP (25W) power profile. The PRx may communicate a GRQ[ID] request to the PTx to discover the protocol version of MPP supported by the PTx. In response, the PTx provides an ID packet, which contains PTx protocol version information. Upon receiving the PTx protocol version information, the PRx can determine that the PTx is an older protocol version. Based on this determination, the PRx can adjust its communication protocol. For instance, the PRx may disregard frequency selection bits that might be present in the PTx ID packet because the older PTx protocol version may not properly signal those bits. Based on the PTx being an older MPP (25W) power profile, the PRx may exit the negotiation phase for 128 kHz MPP50. For example, the PRx can send an SRQ / Freqsel packet that requests, for example, 360 kHz (or 1.78 MHz). In some implementations, the PTx can indicate supported frequencies via a PTx XID packet or an ECAP packet, which the PRx then uses to inform its frequency selection via the SRQ / Freqsel packet. The PRx can send an EPT / rep packet to proceed with a re-ping and restart the digital ping phase. In some implementations, the PRx can revert to BPP if the PRx and the PTx are located in a geographic region that does not permit 360 kHz (or 1.78 MHz) wireless power transfer.

[0281] FIG. 39 is a diagram of an example XID packet with an optional value for a Power Receiver to indicate frequency support. In some implementations, the PRx XID packet can include an indicator field 3902 to indicate whether the Power Receiver supports the 128 kHz MPP LF restricted mode or 50W mode using 128 kHz. The value of the indicator field 3902 can indicate the frequency supported by the PRx. For example, the value of the indicator field 3902 can be set to indicate support for a 128 kHz frequency. Another value can indicate support for a 360 kHz (or 1.78 MHz) frequency. In some implementations, the indicator field 3902 can be used to convey other information, such as region restrictions or fast charging capabilities.

[0282] FIG. 40 illustrates a block diagram of an example apparatus for use in a wireless power system. In some implementations, the apparatus 4000 may be a wireless powerDocket No. D25023W001apparatus (such as the Power Transmitter 110 or the Power Receiver 120) described herein. The apparatus 4000 can include a processor 4002 (possibly including multiple processors, multiple cores, multiple nodes, or implementing multi-threading, etc.). The apparatus 1200 also can include a memory 4004. The memory 4004 may be system memory or any one or more of the possible realizations of computer-readable media described herein. The apparatus 4000 also can include a bus 4006 (such as PCI, ISA, PCI-Express, HyperTransport®, InfiniBand®, NuBus,® AHB, AXI, etc.).

[0283] The apparatus 4000 may include one or more controllers 4008. In some implementations, the controller 4008 can be distributed within the processor 4002, the memory 4004, and the bus 4006. The controller 4008 may perform some or all of the operations described herein. For example, the controller 4008 may implement the processes described with reference to any one of FIG. 1 A through FIG. 39, or any combination thereof.

[0284] The memory 4004 can include computer instructions executable by the processor 4002 to implement the functionality of the implementations described herein. Any one of these functionalities may be partially (or entirely) implemented in hardware or on the processor 4002. For example, the functionality may be implemented with an application specific integrated circuit, in logic implemented in the processor 4002, in a co-processor on a peripheral device or card, etc. Further, realizations may include fewer or additional components not illustrated in FIG. 40. The processor 4002, the memory 4004, and the controller 4008 may be coupled to the bus 4006. Although illustrated as being coupled to the controller 4008, the memory 4004 may be coupled to the processor 4002.

[0285] The apparatus 4000 also includes a 50W module 4010. The 50W module 4010 might implement messages and protocols associated with the 50W mode. In accordance with aspects of this disclosure, the 50W module 4010 may be backward compatible to a legacy mode, such as MPP mode for 25 W. Furthermore, the 50W module 4010 may support a variety of frequencies (e.g., 128 kHz, 360 kHz (or 1.78 MHz)) for the MPP mode depending on the power level, geographic region, or manufacturer preferences.

[0286] Although some examples of this disclosure describe a 50W mode using 128 kHz, it should be understood that 128 kHz is only one possible frequency for a 50W system. Other frequencies or ranges (including or excluding 360 kHz (or 1.78 MHz)) may be used for 50W power transfer. A range that includes 128 kHz might include a variety of frequencies / power levels, such as between 128 kHz to 150 kHz for power transfer between 25 W and 50W. In some implementations, the frequencies and power levels are specified by a wireless power specification (sometimes also referred to as a wireless power standard).Docket No. D25023W001

[0287] FIG. 1 through FIG. 40 and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some operations differently.

[0288] This description includes several optional modifications to the revocation list update process and the associated messages. Other modifications are possible. For example, while a revocation list update process is described as potentially occurring after or with an authentication, it may be possible to implement all or part of a revocation list update process before the authentication. Further, in some implementations, the authentication may be omitted based on completion of the revocation list transfer. For explanation purposes, various communication messages are illustrated as individual packet transmission between devices to describe functions and operations; however, one skilled in the art will appreciate that transmission of these individual message packets can be optimized by combining one or more message packets into a single communication packet using various fields indicating corresponding operation and / or functionality. For example, as described above, the revocation list version or date information can be communicated between devices as part of authentication key exchange during the authentication phase, which can immediately lead to revocation list update prior to the beginning of power negotiation / transfer phases.

[0289] The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects. While the aspects of the disclosure have been described in terms of various examples, any combination of aspects from any of the examples is also within the scope of the disclosure. The examples in this disclosure are provided for pedagogical purposes. Alternatively, or in addition to the other examples described herein, examples include any combination of the following enumerated example implementation options (referred to as clauses for clarity).

[0290] Clause 1 : A method of a Power Transmitter, comprising: communicating one or more messages during a negotiation phase between the Power Transmitter and a Power Receiver; determining, based on the one or more messages, whether the Power Transmitter and the Power Receiver both support wireless power transfer according to a first mode or a second mode, where the first mode is associated with a nominal power transfer of 25 watts (25W) and the second mode is associated with a nominal power transfer of greater than 25W; andDocket No. D25023W001transmitting wireless power to the Power Receiver according to a first frequency for the first mode or a second frequency for the second mode.

[0291] Clause 2: The method of clause 1, wherein the first frequency is within a first range that includes 360 kHz (or 1.78 MHz) for the first mode; and wherein the second frequency is within a second range that includes 128 kHz, the second range being associated with the second mode and also associated with a third mode associated with a nominal power transfer of 15W or lower.

[0292] Clause 3: The method of clause 2, further comprising: determining whether to use the second mode or the third mode based, at least in part, on the one or more messages.

[0293] Clause 4: The method of any one of clauses 1 to 3, wherein the communicating the one or more messages includes: receiving a GET (Power Transmitter (PTx) Extended Identification (ID)) packet from the Power Receiver, where the GET (PTx Extended ID) packet is a mandatory message in the negotiation phase; and communicating a PTx Extended ID packet to the Power Receiver, the PTx Extended ID packet indicating whether the Power Transmitter supports the first mode or the second mode.

[0294] Clause 5: The method of any one of clauses 1 to 4, wherein the communicating the one or more messages includes: receiving, from the Power Receiver, a specific request (SRQ) with a frequency selection (SRQ / freqsel) packet indicating that the Power Receiver supports the first frequency associated with the first mode; and proceeding with the negotiation phase and a power transfer phase for the first mode based on the SRQ / freqsel packet.

[0295] Clause 6: The method of any one of clauses 1 to 4, wherein the communicating the one or more messages includes: receiving, from the Power Receiver, a specific request (SRQ) with a frequency selection (SRQ / freqsel) packet indicating that the Power Receiver supports the second frequency associated with the second mode; and communicating an acknowledgement to the Power Receiver in response to the SRQ / freqsel packet; and proceeding with the negotiation phase and a power transfer phase for the second mode based on the acknowledgement.

[0296] Clause 7: The method of any one of clauses 1 to 4, wherein the communicating the one or more messages includes: receiving, from the Power Receiver, a first specific request (SRQ) with a frequency selection (SRQ / freqsel) packet indicating that the Power Receiver supports the second frequency associated with the second mode; communicating a nonacknowledgement to the Power Receiver in response to the first SRQ / freqsel packet when the Power Transmitter does not support the second mode; receiving, from the Power Receiver, a second SRQ / freqsel packet that indicates the first frequency associated with the first mode;Docket No. D25023W001communicating an acknowledgement to the Power Receiver in response to the second SRQ / freqsel packet; and proceeding with the negotiation phase and power transfer phase for the first mode.

[0297] Clause 8: The method of any one of clauses 1 to 7, wherein the one or more messages includes at least one of: a PTx Extended ID packet having an indicator field populated with a value indicating that the Power Transmitter supports the second frequency and the second mode; or an SRQ / freqsel packet having a Frequency Selector field populated with a value indicating that the Power Receiver supports the second frequency and the second mode.

[0298] Clause 9: The method of any one of clauses 1 to 8, further comprising: performing capacitance tuning at the Power Transmitter, wherein: in the first mode, the capacitance tuning includes capacitance in a range from 68 nanofarads (nf) to 458 nf, and in the second mode, the capacitance tuning includes capacitance above 458 nf.

[0299] Clause 10: The method of any one of clauses 1 to 9, further comprising: performing one or more frequency control operations to change a frequency of a wireless power signal in the second mode, wherein the one or more frequency control operations include at least one of: communicating a message to change the frequency to a new frequency in a range associated with the second mode; participating in a ping process to change the frequency; or receiving an SRQ / freqsel packet to modify the frequency.

[0300] Clause 11: The method of any one of clauses 1 to 10, further comprising: receiving communications from the Power Receiver using an amplitude shift keying (ASK) modulation, wherein the ASK modulation includes either capacitive modulation or load modulation.

[0301] Clause 12: The method of clause 11, wherein the ASK modulation is the capacitive modulation in a default setting or when communication is reliable; and wherein the ASK modulation is the load modulation when: the Power Transmitter sends a message to the Power Receiver indicating that the communication is unreliable, or the Power Transmitter sends a message to the Power Receiver requesting the Power Receiver to use the load modulation.

[0302] Clause 13: The method of any one of clauses 1 to 12, further comprising: implementing an Active Harmonic Filter at the Power Transmitter, where a setting of the Active Harmonic Filter is based on an operating frequency of the first mode or the second mode.

[0303] Clause 14: The method of clause 13, further comprising: determining the setting based on at least one of: a lookup table, an algorithm that dynamically estimates harmonic levels, or an input from a harmonic sensor in the Power Transmitter.Docket No. D25023W001

[0304] Clause 15: A Power Receiver, comprising: a power transfer coil to receive a wireless power signal from a Power Transmitter; a communication unit to communicate with the Power Transmitter using an amplitude shift keying (ASK) modulation of the wireless power signal, the communication unit including at least a first modulator for capacitive modulation and a second modulator for load modulation; and a controller to select the first modulator or the second modulator.

[0305] Clause 16: The Power Receiver of clause 15, wherein the controller is configured to: select the first modulator as a default setting or when communication is reliable; and select the second modulator when the Power Receiver: determines that communication is unreliable based on lack of responses from the Power Transmitter, receives a message from the Power Transmitter indicating that the communication is unreliable, or receives a message from the Power Transmitter requesting the Power Receiver to use the load modulation.

[0306] Clause 17: A method of a Power Transmitter, comprising: detecting a Power Receiver; determining a nominal frequency for a wireless power signal; and transmitting the wireless power signal to the Power Receiver according to the nominal frequency.

[0307] Clause 18: The method of clause 17, wherein the nominal frequency is one of a 128 kilohertz (kHz) frequency or a 360 kHz (or 1.78 MHz) frequency, and wherein determining the nominal frequency is based on an operating region of the Power Transmitter, the Power Receiver, or both.

[0308] Clause 19: The method of clause 17 or 18, wherein determining the nominal frequency includes determining the nominal frequency based on at least one of: a non-volatile memory of the Power Transmitter that stores the nominal frequency; a frequency selection communication, received from the Power Receiver, that indicates the nominal frequency; a pattern of a signal from the Power Transmitter to the Power Receiver; geographic or regional location information of the Power Transmitter; or geographic or regional location information of the Power Receiver.

[0309] Clause 20: The method of any one of clauses 17 to 19, wherein transmitting the wireless power signal includes: transmitting the wireless power signal according to a Magnetic Power Profile (MPP) adapted to use the nominal frequency of a 128 kHz.

[0310] Clause 21: The method of any one of clauses 17 to 19, wherein transmitting the wireless power signal includes: transmitting the wireless power signal according to an Extended Power Profile (EPP) adapted to use the nominal frequency of a 128 kHz with a power level above 15 watts (15W).Docket No. D25023W001

[0311] Clause 22: The method of any one of clauses 17 to 21, further comprising: determining that the Power Transmitter is operating in a geographic region that does not permit 360 kHz (or 1.78 MHz) fast charging using a Magnetic Power Profile (MPP) protocol; and wherein transmitting the wireless power signal enabling 128 kHz fast charging using the MPP protocol.

[0312] Clause 23: The method of any one of clauses 17 to 22, further comprising: communicating a packet that indicates the Power Transmitter supports wireless power transmission for a Magnetic Power Profile (MPP) protocol or 50 Watt (50W) power profile (50PP) protocol, the packet indicating whether the MPP or 50PP is enabled for a 128 kHz nominal frequency or 360 kHz (or 1.78 MHz) nominal frequency.

[0313] Clause 24: The method of any one of clauses 17 to 23, further comprising: performing capacitance tuning based on the nominal frequency and a rectified voltage (Vrect) of the Power Receiver, wherein: when the nominal frequency is 360 kHz (or 1.78 MHz), the capacitance tuning uses 56n, 56, 300f; and when the nominal frequency is 128 kHz, the capacitance tuning uses 56nF, 56nF, 170nF, 130nF.

[0314] Clause 25: The method of any one of clauses 17 to 24, wherein determining the nominal frequency includes: transmitting a Magnetic Power Profile (MPP) pattern to the Power Receiver, wherein the MPP pattern is one of a first pattern for a first nominal frequency or a second pattern for a second nominal frequency; and receiving communication from the Power Receiver; and determining that the Power Receiver supports the first nominal frequency or the second nominal frequency based on the communication from the Power Receiver being in response to the first pattern or the second pattern.

[0315] Clause 26: A Power Transmitter, comprising: a primary coil; and slew rate capacitors connected to the primary coil via switches; and a controller configured to selectively enable or disable the switches to adjust the capacitance added to the primary coil using the slew rate capacitors.

[0316] Clause 27: The Power Transmitter of clause 26, further comprising: a communication unit to communicate a packet to a Power Receiver indicating a quantity of slew rate capacitors enabled or the capacitance of the slew rate capacitors.

[0317] Clause 28: The Power Transmitter of clause 26 or 27, further comprising: a sensor to monitor zero voltage switching (ZVS) risk; and the controller configured to adjust the capacitance of the primary coil using the slew rate capacitors based on the ZVS risk.

[0318] Clause 29: The Power Transmitter of clause 26, wherein the controller is further configured to: determine which slew rate capacitors to enable based on a configuration settingDocket No. D25023W001in a memory of the Power Transmitter, the memory including a plurality of configuration settings, each associated with at least one of a power level, frequency information, harmonic information, electromagnetic interference, electromagnetic compatibility, or any combination thereof.

[0319] Clause 30: A method of a Power Transmitter, comprising: transmitting a 128 kilohertz (kHz) digital ping; receiving at least a first message from a Power Receiver in response to the 128 kHz digital ping, the first message indicating that the Power Receiver is operating in a restricted mode; causing the Power Receiver to enter a low frequency restricted mode of a first wireless power protocol, wherein the low frequency restricted mode is associated with a 128 kHz operating frequency; and transmitting a wireless power signal to the Power Receiver at the 128 kHz operating frequency while in the low frequency restricted mode.

[0320] Clause 31: The method of clause 30, wherein the 128 kHz digital ping conforms to a wireless power protocol based on a Magnetic Power Profile (MPP) or higher power profile.

[0321] Clause 32: The method of clause 30 or 31, wherein the causing the Power Receiver to enter the low frequency restricted mode includes: refraining from sending a response to the first message or other configuration message during a configuration phase.

[0322] Clause 33: The method of any one of clauses 30 to 32, wherein the causing the Power Receiver to enter the low frequency restricted mode includes: after receiving the first message, informing the Power Receiver that the Power Transmitter is configured to operate in the low frequency restricted mode by performing at least one of: transmitting an MPP pattern associated with the low frequency restricted mode; transmitting a second 128 kHz digital ping; or transmitting a new digital ping to invoke the low frequency restricted mode.

[0323] Clause 34: The method of any one of clauses 30 to 33, wherein the causing the Power Receiver to enter the low frequency restricted mode is based on a determination that the Power Transmitter is configured to operate in the low frequency restricted mode due to at least one of: the Power Transmitter being configured to operate at only the 128 kHz operating frequency; the Power Transmitter selecting the 128 kHz operating frequency based on a predetermined condition; the Power Transmitter operating in a geographic region that restricts the 360 kHz (or 1.78 MHz) operating frequency; or the Power Receiver supporting the 128 kHz operating frequency.

[0324] Clause 35: The method of any one of clauses 30 to 34, further comprising: receiving operating frequency information from the Power Receiver during the configuration phase, wherein the causing the Power Receiver to enter the low frequency restricted mode is basedDocket No. D25023W001on the operating frequency information indicating that the Power Receiver is configured to operate with the 128 kHz operating frequency.

[0325] Clause 36: The method of any one of clauses 30 to 35, further comprising: receiving protocol version information from the Power Receiver, the protocol version information indicating whether the Power Receiver is compatible with the low frequency restricted mode.

[0326] Clause 37: The method of clause 36, further comprising: causing the Power Receiver to enter the low frequency restricted mode when the protocol version information indicates that the Power Receiver is compatible with the low frequency restricted mode of the first wireless power protocol; or operating in a second wireless power protocol with the Power Receiver when the protocol version information indicates that the Power Receiver is not compatible with the low frequency restricted mode.

[0327] Clause 38: The method of any one of clauses 30 to 37, further comprising: receiving a request from the Power Receiver indicating to exit the low frequency restricted mode: and stopping wireless power transmission and initiating a digital ping for a new power transfer session.

[0328] Clause 39: The method of any one of clauses 30 to 38, further comprising: transmitting a pattern message during a predetermined time; remaining in the low frequency restricted mode if the Power Transmitter does not receive a response to the pattern message; and transitioning to a full power mode of the first wireless power protocol with a 128 kHz operating frequency without interrupting power transfer if the Power Transmitter receives a data packet from the Power Receiver in response to the pattern message.

[0329] Clause 40: A wireless power apparatus, comprising: a communication unit; and a controller or processor configured to perform a method according to any one of clauses 1 to 14.

[0330] Clause 41: A method of a Power Transmitter, comprising: communicating one or more messages to a Power Receiver during a negotiation phase between the Power Transmitter and the Power Receiver, the one or more messages indicating frequency capabilities of the Power Transmitter, the frequency capabilities including support for at least one of a first frequency range or a second frequency range; receiving, from the Power Receiver, a frequency selection indicating a nominal operating frequency in a selected one of the first frequency range or the second frequency range; transmitting an acknowledgement in response to the frequency selection; and transmitting wireless power to the Power Receiver using an operating frequency in the selected one of the first frequency range or the second frequency range.Docket No. D25023W001

[0331] Clause 42: The method of clause 41, wherein the first frequency range includes a 128 kilohertz (kHz) nominal operating frequency and the second frequency range includes a 360 kHz (or 1.78 MHz) nominal operating frequency.

[0332] Clause 43: The method of clause 41 or 42, wherein the Power Transmitter supports a single frequency range based on at least one of a country, a region, or a protocol version associated with the Power Transmitter.

[0333] Clause 44: The method of any one of clauses 41 to 43, further comprising: transmitting the wireless power using a baseline power profile (BPP) mode or a lower power mode when the Power Transmitter does not support the selected one of the first frequency range or the second frequency range.

[0334] Clause 45: The method of any one of clauses 41 to 44, wherein the communicating the one or more messages includes: receiving, from the Power Receiver, a request for at least one of an Identification (ID) packet, an Extended Identification (XID) packet, or an extended capabilities (ECAP) packet during the negotiation phase; and communicating the frequency capabilities in the ID packet, the XID packet, or the ECAP packet.

[0335] Clause 46: The method of any one of clauses 41 to 45, wherein the receiving the frequency selection includes: receiving the frequency selection via a specific request frequency selection (SRQ / freqsel) packet.

[0336] Clause 47: The method of any one of clauses 41 to 46, further comprising: receiving, from the Power Receiver, a request for a low frequency restricted mode based on a low battery state or dead battery state of the Power Receiver; and operating in the low frequency restricted mode based on the request and a determination that the Power Transmitter supports the low frequency restricted mode.

[0337] C lause 48: The method of clause 47, further comprising: determining the Power Transmitter supports the low frequency restricted mode based on at least one of a country, a region, or a protocol version, or the frequency capabilities of the Power Transmitter.

[0338] Clause 49: The method of clause 47 or 48, further comprising, after operating in the low frequency restricted mode: receiving, from the Power Receiver, a negotiation (NEGO) packet that initiates a transition from the low frequency restricted mode to a full power mode.

[0339] Clause 50: The method of any one of clauses 41 to 49, wherein the selected one of the first frequency range or the second frequency range includes a 128 kHz nominal operating frequency, and wherein transmitting the wireless power includes transmitting the wireless power according to a Magnetic Power Profile (MPP) mode using the 128 kHz nominalDocket No. D25023W001operating frequency based on a determination that the Power Transmitter and the Power Receiver both support the MPP mode using the 128 kHz nominal operating frequency.

[0340] Clause 51: A method of a Power Receiver, comprising: receiving one or more messages from a Power Transmitter during a negotiation phase between the Power Transmitter and the Power Receiver, the one or more messages indicating frequency capabilities of the Power Transmitter, the frequency capabilities including support for at least one of a first frequency range or a second frequency range; transmitting, to the Power Transmitter, a frequency selection indicating a nominal operating frequency in a selected one of the first frequency range or the second frequency range; receiving an acknowledgement from the Power Transmitter in response to the the frequency selection; and receiving wireless power from the Power Transmitter using an operating frequency in the selected one of the first frequency range or the second frequency range.

[0341] Clause 52: The method of clause 51, wherein the first frequency range includes a 128 kilohertz (kllz) nominal operating frequency and the second frequency range includes a 360 kHz (or 1.78 MHz) nominal operating frequency.

[0342] Clause 53: The method of clause 51 or 52, wherein the Power Receiver supports a single frequency range based on at least one of a country, a region, or a protocol version associated with the Power Receiver.

[0343] Clause 54: The method of any one of clauses 51 to 53, further comprising: receiving the wireless power using a baseline power profile (BPP) mode or a lower power mode when the Power Transmitter does not support the selected one of the first frequency range or the second frequency range.

[0344] Clause 55: The method of any one of clauses 51 to 54, further comprising: transmitting, to the Power Transmitter, a request for at least one of an Identification (ID) packet, an Extended Identification (XID) packet, or an extended capabilities (ECAP) packet during the negotiation phase; and receiving the frequency capabilities in the ID packet, the XID packet, or the ECAP packet.

[0345] Clause 56: The method of any one of clauses 51 to 55, wherein the transmitting the frequency selection includes: transmitting the frequency selection via a specific request frequency selection (SRQ / freqsel) packet.

[0346] Clause 57: The method of any one of clauses 51 to 55, further comprising: transmitting, to the Power Transmitter, a request for a low frequency restricted mode based on a low battery state or dead battery state of the Power Receiver; and operating in the lowDocket No. D25023W001frequency restricted mode based on the request and a determination that the Power Transmitter supports the low frequency restricted mode.

[0347] Clause 58: The method of clause 57, further comprising: determining the Power Transmitter supports the low frequency restricted mode based on at least one of a country, a region, or a protocol version, or the frequency capabilities of the Power Transmitter.

[0348] Clause 59: The method of clause 57 or 58, further comprising, after operating in the low frequency restricted mode: transmitting a negotiation (NEGO) packet to initiate a transition from the low frequency restricted mode to a full power mode.

[0349] Clause 60: A wireless power apparatus, comprising: a communication unit; and a controller or processor configured to perform a method according to any one of clauses 41 to 59.

[0350] Another innovative aspect of the subject matter described in this disclosure can be implemented as a computer-readable medium having stored therein instructions which, when executed by a processor, causes the processor to perform any one of the above-mentioned functionalities.

[0351] Another innovative aspect of the subject matter described in this disclosure can be implemented as a system having means for implementing any one of the above-mentioned functionalities.

[0352] Another innovative aspect of the subject matter described in this disclosure can be implemented as an apparatus having one or more processors configured to perform one or more operations from any one of the above-mentioned functionalities.

[0353] As used herein, a phrase referring to “at least one of’ or “one or more of’ a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover the possibilities of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.

[0354] The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes describedDocket No. D25023W001above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.

[0355] The hardware and data processing apparatus used to implement the various illustrative components, logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes, operations and methods may be performed by circuitry that is specific to a given function.

[0356] As described above, some aspects of the subject matter described in this specification can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor-executable or computer-executable instructions encoded on one or more tangible processor-readable or computer-readable storage media for execution by, or to control the operation of, a data processing apparatus including the components of the devices described herein. By way of example, and not limitation, such storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

[0357] Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded with the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.Docket No. D25023W001

[0358] Additionally, various features that are described in this specification in the context of separate implementations can be implemented in combination to form a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0359] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together into a single software product or packaged into multiple software products.

Claims

Docket No. D25023W001CLAIMSWhat is claimed is:

1. A method of a Power Transmitter, comprising:communicating one or more messages to a Power Receiver during a negotiation phase between the Power Transmitter and the Power Receiver, the one or more messages indicating frequency capabilities of the Power Transmitter, the frequency capabilities including support for at least one of a first frequency range or a second frequency range;receiving, from the Power Receiver, a frequency selection indicating a nominal operating frequency in a selected one of the first frequency range or the second frequency range;transmitting an acknowledgement in response to the frequency selection; and transmitting wireless power to the Power Receiver using an operating frequency in the selected one of the first frequency range or the second frequency range.

2. The method of claim 1, wherein the first frequency range includes a 128 kilohertz (kHz) nominal operating frequency and the second frequency range includes a 360 kHz nominal operating frequency.

3. The method of claim 1 or 2, wherein the Power Transmitter supports a single frequency range based on at least one of a country, a region, or a protocol version associated with the Power Transmitter.

4. The method of any one of claims 1 to 3, further comprising:transmitting the wireless power using a baseline power profile (BPP) mode or a lower power mode when the Power Transmitter does not support the selected one of the first frequency range or the second frequency range.

5. The method of any one of claims 1 to 4, wherein the communicating the one or more messages includes:receiving, from the Power Receiver, a request for at least one of an Identification (ID) packet, an Extended Identification (XID) packet, or an extended capabilities (ECAP) packet during the negotiation phase; andcommunicating the frequency capabilities in the ID packet, the XID packet, or the ECAP packet.Docket No. D25023W0016. The method of any one of claims 1 to 5, wherein the receiving the frequency selection includes:receiving the frequency selection via a specific request frequency selection (SRQ / freqsel) packet.

7. The method of any one of claims 1 to 6, further comprising:receiving, from the Power Receiver, a request for a low frequency restricted mode based on a low battery state or dead battery state of the Power Receiver; andoperating in the low frequency restricted mode based on the request and a determination that the Power Transmitter supports the low frequency restricted mode.

8. The method of claim 7, further comprising:determining the Power Transmitter supports the low frequency restricted mode based on at least one of a country, a region, or a protocol version, or the frequency capabilities of the Power Transmitter.

9. The method of claim 7 or 8, further comprising, after operating in the low frequency restricted mode:receiving, from the Power Receiver, a negotiation (NEGO) packet that initiates a transition from the low frequency restricted mode to a full power mode.

10. The method of any one of claims 1 to 9,wherein the selected one of the first frequency range or the second frequency range includes a 128 kHz nominal operating frequency, andwherein transmitting the wireless power includes transmitting the wireless power according to a Magnetic Power Profile (MPP) mode using the 128 kHz nominal operating frequency based on a determination that the Power Transmitter and the Power Receiver both support the MPP mode using the 128 kHz nominal operating frequency.

11. A method of a Power Receiver, comprising:receiving one or more messages from a Power Transmitter during a negotiation phase between the Power Transmitter and the Power Receiver, the one or more messages indicating frequency capabilities of the Power Transmitter, the frequency capabilities including support for at least one of a first frequency range or a second frequency range;transmitting, to the Power Transmitter, a frequency selection indicating a nominal operating frequency in a selected one of the first frequency range or the second frequency range;Docket No. D25023W001receiving an acknowledgement from the Power Transmitter in response to the the frequency selection; andreceiving wireless power from the Power Transmitter using an operating frequency in the selected one of the first frequency range or the second frequency range.

12. The method of claim 11 , wherein the first frequency range includes a 128 kilohertz (kHz) nominal operating frequency and the second frequency range includes a 360 kHz nominal operating frequency.1 . The method of claim 11 or 12, wherein the Power Receiver supports a single frequency range based on at least one of a country, a region, or a protocol version associated with the Power Receiver.

14. The method of any one of claims 11 to 13, further comprising:receiving the wireless power using a baseline power profile (BPP) mode or a lower power mode when the Power Transmitter does not support the selected one of the first frequency range or the second frequency range.

15. The method of any one of claims 11 to 14, further comprising:transmitting, to the Power Transmitter, a request for at least one of an Identification (ID) packet, an Extended Identification (XID) packet, or an extended capabilities (ECAP) packet during the negotiation phase; andreceiving the frequency capabilities in the ID packet, the XID packet, or the ECAP packet.

16. The method of any one of claims 11 to 15, wherein the transmitting the frequency selection includes:transmitting the frequency selection via a specific request frequency selection (SRQ / freqsel) packet.

17. The method of any one of claims 11 to 15, further comprising:transmitting, to the Power Transmitter, a request for a low frequency restricted mode based on a low battery state or dead battery state of the Power Receiver; andoperating in the low frequency restricted mode based on the request and a determination that the Power Transmitter supports the low frequency restricted mode.

18. The method of claim 17, further comprising:Docket No. D25023W001determining the Power Transmitter supports the low frequency restricted mode based on at least one of a country, a region, or a protocol version, or the frequency capabilities of the Power Transmitter.

19. The method of claim 17 or 18, further comprising, after operating in the low frequency restricted mode:transmitting a negotiation (NEGO) packet to initiate a transition from the low frequency restricted mode to a full power mode.

20. A wireless power apparatus, comprising:a communication unit; anda controller or processor configured to perform a method according to any one of claims 1 to 19.

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