Patent Description:
The Wireless Power Consortium (WPC) standard (or Qi standard) supports various foreign object detection (FOD) techniques. For example, an electronic device that wirelessly transmits power may apply a ping signal to a coil and determine whether a wireless power receiver or a foreign object is placed in the charging area based on whether a change in characteristics (e.g., a frequency and/or quality factor (Q-factor)) occurs. For example, an electronic device that wirelessly transmits power may receive (or demodulate) information about the level of received power from the wireless power receiver during a power transfer. The electronic device may identify the level of a power loss Ploss based on information about the level of transmitted power PPT and the level of received power PPR and determine whether a foreign object is placed nearby during power transfer based on the level of power loss Ploss.

The power loss Ploss when a foreign object is placed nearby may indicate the level of power dissipated in the foreign object from the magnetic field of the electronic device. The electronic device may identify the level of transmitted power PPT by subtracting the internal power loss PPTloss dissipated in the electronic device from the level of power Pin provided to the input terminal. The internal power loss PPTloss in the electronic device may include at least one of the power loss in the inverter, the power loss in the primary coil, the power loss in the resonant capacitor, the power loss in the shielding of the primary coil assembly, or the power loss in any metal part of the electronic device. Further, the received power PPR may be identified by adding the level of power Pout at the output terminal and the internal power loss Pprloss dissipated in the wireless power receiver by the wireless power receiver. The internal power loss PPrloss of the wireless power receiver may include at least one of the power loss in the rectifier, the power loss in the secondary coil, the power loss in the resonant capacitor, the power loss in the shielding of the secondary coil assembly, or the power loss in any metal part of the wireless power receiver. Further, document (<CIT>) discloses conventional method for foreign object detection which uses Q-factors for determining a calibrated strength signal.

The electronic device and the wireless power receiver may calculate the above-described internal power losses PPTloss and PPrloss and, in this case, a systematic bias may occur. Such a bias may degrade the accuracy of foreign object detection. The electronic device and the wireless power receiver may perform calibration to remove an influence caused by the bias. During calibration, the electronic device and/or the wireless power receiver may identify parameters using the level (e.g., a magnitude) of the transmitted power PPT and the level of the received power PPR under a plurality of load conditions. The electronic device and the wireless power receiver may calibrate the transmitted power PPT and/or the received power PPR using the identified parameters and may thereby remove the influence caused by the bias, enhancing the accuracy of foreign object detection. However, if a foreign object is placed nearby during calibration, inaccurate parameters may be obtained. If an inaccurate parameter is used for foreign object detection, the accuracy of foreign object detection may be degraded.

In accordance with an aspect of the present disclosure, an electronic device for wirelessly transmitting power includes a power transmitting circuit and a control circuit configured to control the power transmitting circuit to apply a first power to a coil of the power transmitting circuit, control the power transmitting circuit to stop applying the first power and prevent power from being applied to the coil during a first period, identify a first Q-factor during the first period, control the power transmitting circuit to apply, to the coil, a second power during a calibration operation for identifying at least one parameter used for identifying a power loss during power transmission, control the power transmitting circuit to stop applying the second power and prevent power from being applied to the coil during a second period, identify a second Q-factor during the second period, and identify a validity of the at least one parameter based on at least one of the first Q-factor or the second Q-factor.

In accordance with another aspect of the present disclosure, a method for controlling an electronic device is provided as defined by the appended claims.

According to various embodiments, there may be provided an electronic device, a wireless power receiver, and a method for operating the same, which may verify parameters obtained as a result of calibration, based on the Q-factor identified based on the start and/or end of the calibration. Thus, it is possible to secure the validity of the parameter calculated as a result of calibration and thus to enhance the accuracy of foreign object detection.

Other various effects may be provided directly or indirectly in the disclosure.

Various embodiments of the present disclosure are described with reference to the accompanying drawings. However, various embodiments of the present disclosure are not limited to particular embodiments, and it should be understood that modifications, equivalents, and/or alternatives of the embodiments described herein can be variously made. With regard to description of drawings, similar components may be marked by similar reference numerals.

According to various embodiments of the disclosure, an electronic device, a wireless power receiver, and a method for operating the same may verify parameters obtained as a result of calibration, based on the Q-factor identified in accordance with the start and/or end of the calibration.

According to various embodiments of the disclosure, an electronic device, a wireless power receiver, and a method for operating the same may identify the validity of a parameter obtained as a result of calibration, based on the Q-factor identified at a designated time and enhance the accuracy of foreign object detection.

<FIG> is a block diagram illustrating a wireless power receiver and an electronic device, according to an embodiment.

Referring to <FIG>, an electronic device <NUM> may wirelessly transmit power <NUM> to a wireless power receiver <NUM> through, for example, an induction scheme. When the electronic device <NUM> adopts the induction scheme, the electronic device <NUM> may include a power source, a direct current (DC)-alternating current (AC) converting circuit, an amplifying circuit, an impedance matching circuit, at least one capacitor, at least one coil, and/or a communication modulation/demodulation circuit. The at least one capacitor together with the at least one coil may constitute a resonance circuit. The electronic device <NUM> may be implemented in a manner defined in the WPC standards (or Qi standards).

Alternatively, the electronic device <NUM> may transmit the power <NUM> through a resonance scheme. Adopting the resonance scheme, the electronic device <NUM> may include a power source, a DC-AC converting circuit, an amplifying circuit, an impedance matching circuit, at least one capacitor, at least one coil, and an out-band communication circuit (e.g., a Bluetooth™ low energy (BLE) communication circuit). The at least one capacitor and the at least one coil may constitute a resonance circuit. The electronic device <NUM> may be implemented in a manner defined in the Alliance for Wireless Power (A4WP) standards (or Air Fuel Alliance (AFA) standards). The electronic device <NUM> may include a coil that is capable of produce a magnetic field when letting an electric current flow thereacross by a resonance or induction scheme. The process of generating an induced magnetic field by the electronic device <NUM> may be referred to as the "electronic device <NUM> wirelessly transmits the power <NUM>. " Further, the wireless power receiver <NUM> may include a coil that produces an induced electromotive force by the magnetic field generated around and varying in magnitude over time. The process of producing an induced electromotive force through the coil may be referred to as the "wireless power receiver <NUM> wirelessly receives the power <NUM>. " For example, the electronic device <NUM> may be implemented in the manner defined in wireless power transmission-related standards, such as the airfuel inductive (e.g., Power Matters Alliance (PMA)) standard, the airfuel resonant (e.g., rezence) standard, or a Qi standard.

The electronic device <NUM> may communicate with the wireless power receiver <NUM> according to, for example, an in-band scheme. The electronic device <NUM> may modulate data to be transmitted according to a frequency shift keying (FSK) modulation scheme, and the wireless power receiver <NUM> may perform modulation according to an amplitude shift keying (ASK) modulation scheme. The electronic device <NUM> and/or the wireless power receiver <NUM> may determine the data transmitted from the counterpart device based on the frequency and/or amplitude of the current, voltage, or power of the coil. The operation of performing modulation based on the ASK modulation scheme and/or the FSK modulation scheme may be understood as an operation for transmitting data according to the in-band communication scheme. The operation of determining the data transmitted from the counterpart device by performing demodulation based on the frequency and/or amplitude of the current, voltage, or power of the coil may be understood as an operation for receiving data according to the in-band communication scheme.

Alternatively, the electronic device <NUM> may communicate with the wireless power receiver <NUM> according to an out-of-band scheme. The electronic device <NUM> or the wireless power receiver <NUM> may transmit and receive data using a communication circuit (e.g., a BLE communication module) provided separately from the coil or patch antenna.

As set forth herein, when the electronic device <NUM> or the wireless power receiver <NUM> performs a particular operation, this may mean that various hardware devices, e.g., a control circuit, such as a processor (e.g., a transmission integrated circuit (IC) or micro controlling unit (MCU)) or coil included in the electronic device <NUM> or the wireless power receiver <NUM>, performs the particular operation. When the electronic device <NUM> or the wireless power receiver <NUM> performs a particular operation, this may also mean that the processor controls another hardware device to perform the particular operation. When the electronic device <NUM> or the wireless power receiver <NUM> performs a particular operation, this may mean that the processor or another hardware device triggers the particular operation as an instruction for performing the particular operation, which is stored in a storage circuit (e.g., a memory) of the electronic device <NUM> or the wireless power receiver <NUM>, is executed.

<FIG> is a view schematically illustrating a wireless charging system, according to an embodiment.

Referring to <FIG>, a wireless charging system may include an electronic device <NUM> and a wireless power receiver <NUM>. The electronic device <NUM> may be a charging pad that transmits wireless power based on the power supplied from a charger (e.g., a travel adapter (TA)). The electronic device <NUM>, as a device including a wireless power transmission function, may be implemented as a smart phone, but is not limited thereto. The wireless power receiver <NUM> may be an electronic device, such as a smart phone or a wearable device, but is not limited thereto.

<FIG> is a block diagram illustrating a wireless charging system, according to an embodiment.

Referring to <FIG>, a wireless charging system may include an electronic device <NUM> or a wireless power receiver <NUM>. When the wireless power receiver <NUM> is mounted on the electronic device <NUM>, the electronic device <NUM> may wirelessly supply power to the wireless power receiver <NUM>.

The electronic device <NUM> may include a power transmitting circuit <NUM>, a control circuit <NUM>, a communication circuit <NUM>, and/or a sensing circuit <NUM>.

The power transmitting circuit <NUM> may include a power adapter 311a to receive power from the outside and to properly convert the received power, a power generating circuit 311b to generate power, and/or a matching circuit 311c to enhance the efficiency between a transmission coil <NUM> and a reception coil <NUM>.

The power transmitting circuit <NUM> may include at least one of a power adapter 311a, a power generating circuit 311b, a transmission coil <NUM>, or a matching circuit 311c to be able to transmit power to at least one wireless power receiver (e.g., a first wireless power receiver and a second wireless power receiver).

The control circuit <NUM> may control the electronic device <NUM>, generate various messages (e.g., instructions) required for wireless power transmission, and transmit the messages to the communication circuit <NUM>. The control circuit <NUM> may calculate power (e.g., an amount of power) to be transmitted to the wireless power receiver <NUM> based on information received from the communication circuit <NUM>. The control circuit <NUM> may control the power transmitting circuit <NUM> to transmit the power generated by the transmission coil <NUM> to the wireless power receiver <NUM>.

The communication circuit <NUM> may include at least one of a first communication circuit 313a or a second communication circuit 313b. The first communication circuit 313a may communicate with the first communication circuit 323a of the wireless power receiver <NUM> in an in-band (IB) communication scheme using a frequency equal to or adjacent to the frequency used for power transmission in the transmission coil <NUM>.

The first communication circuit 313a may communicate with the first communication circuit 323a of the wireless power receiver <NUM> using the transmission coil <NUM>. The data (or communication signals) generated by the first communication circuit 313a may be transmitted using the transmission coil <NUM>. The first communication circuit 313a may transfer data to the wireless power receiver <NUM> using an FSK modulation scheme. The first communication circuit 313a may communicate with the first communication circuit 323a of the wireless power receiver <NUM> by allowing the frequency of the power signal transmitted through the transmission coil <NUM> to be varied. Alternatively, the first communication circuit 313a may communicate with the first communication circuit 323a of the wireless power receiver <NUM> by permitting data to be included in or with the power signal generated by the power generating circuit 311b. For example, the first communication circuit 313a may perform modulation by raising or lowering the frequency of the power transmission signal. The wireless power receiver <NUM> may identify the data from the electronic device <NUM> by performing demodulation based on the frequency of the signal measured at the reception coil <NUM>.

The second communication circuit 313b may communicate with the second communication circuit 323b of the wireless power receiver <NUM> in an out-of-band (OOB) communication scheme using a frequency different from the frequency used for power transmission in the transmission coil <NUM>. For example, the second communication circuit 313b may obtain information (e.g., a voltage after the rectification, rectified voltage (Vrect) information, information about the current (lout) flowing through the rectifying circuit 321b, various packets, authentication information, and/or a message) related to the charging state from the second communication circuit 323b using any one of various short-range communication schemes, such as Bluetooth™, BLE, wireless-fidelity (Wi-Fi), or a near-field communication (NFC).

The sensing circuit <NUM> may include one or more sensors and may detect at least one state of the power transmitter <NUM> using the one or more sensors.

The sensing circuit <NUM> may include at least one of a temperature sensor, a motion sensor, a magnetic field sensor (e.g., a Hall sensor), or a current (or voltage) sensor. The sensing circuit <NUM> may detect the temperature state of the electronic device <NUM> using the temperature sensor, and the motion state of the electronic device <NUM> using the motion sensor. In addition, the sensing circuit <NUM> may detect whether the electronic device is coupled with the wireless power receiver <NUM> using the magnetic field sensor, and detect the state of the output signal (e.g., a current level, a voltage level, and/or a power level) of the electronic device <NUM> using the current (or voltage) sensor.

The current (or voltage) sensor may measure signals at the power transmitting circuit <NUM>. The current (or voltage) sensor may measure signals at, at least, part of the matching circuit 311c or the power generating circuit 311b. For example, the current (voltage) sensor may include a circuit for measuring signals at a front end of the transmission coil <NUM>.

The sensing circuit <NUM> may be a circuit for foreign object detection (FOD).

The wireless power receiver <NUM> may include a power receiving circuit <NUM>, a processor <NUM>, a communication circuit <NUM>, sensors <NUM>, a display <NUM>, or a sensing circuit <NUM>. The sensors <NUM> may include the sensing circuit <NUM>.

The power receiving circuit <NUM> may include a reception coil <NUM> for wirelessly receiving power from the electronic device <NUM>, an Rx integrated circuit (IC) <NUM>, a charging circuit 321d (e.g., a power management integrated circuit (PMIC), a direct current / direct current (DC/DC) converter, a switched capacitor, or a voltage divider), and/or a battery 321e (e.g., the battery <NUM>). The Rx IC <NUM> may include a matching circuit 321a connected to the reception coil <NUM>, a rectifying circuit 321b for rectifying the received AC power to DC power, or a power adjusting circuit (e.g., a low-dropout (LDO) circuit) 321c for adjusting the charging voltage.

The processor <NUM> may overall control the wireless power receiver <NUM>, generate various messages required for wireless power reception, and transmit the generated messages to the communication circuit <NUM>.

The communication circuit <NUM> may include at least one of a first communication circuit 323a or a second communication circuit 323b. The first communication circuit 323a may communicate with the electronic device <NUM> through the reception coil <NUM>.

The first communication circuit 323a may communicate with the first communication circuit 313a of the electronic device <NUM> using the reception coil <NUM>. The data (or communication signals) generated by the first communication circuit 323a may be transmitted using the reception coil <NUM>. The first communication circuit 323a may transmit data to the electronic device <NUM> using an ASK modulation scheme. For example, the first communication circuit 323a may cause a change in the load of the electronic device <NUM> according to the modulation scheme. Accordingly, at least one of the magnitudes of voltage, current, or power measured at the transmission coil <NUM> may be changed. The first communication circuit 313a of the electronic device <NUM> may identify data by the wireless power receiver <NUM> by demodulating the change in magnitude. The second communication circuit 323b may communicate with the electronic device <NUM> using any one of various short-range communication schemes, such as Bluetooth™, BLE, Wi-Fi, or NFC.

Packets, information, or data transmitted and received by the electronic device <NUM> and the wireless power receiver <NUM> may use at least one of the first communication circuit 323a or the second communication circuit 323b.

The sensors <NUM> may include one or more of a current/voltage sensor, a temperature sensor, an illuminance sensor, or an acceleration sensor. The sensors <NUM> may be the same as or separate components from the sensor module <NUM> of <FIG>.

The display <NUM> may display various types of display information required for wireless power transmission/reception.

The sensing circuit <NUM> may detect the electronic device <NUM> by sensing the detection signal or power received from the electronic device <NUM>. The sensing circuit <NUM> may detect a signal variation at the input/output terminals of the rectifying circuit 321b, matching circuit <NUM>, or coil <NUM>, based on the signal at the coil <NUM> generated by the signal output from the electronic device <NUM>. The sensing circuit <NUM> may be included in the receiving circuit <NUM>.

<FIG> illustrates a comparative example of a level of power input to a transmission coil of an electronic device, according to an embodiment. It will be appreciated by one of ordinary skill in the art that the operation of the electronic device <NUM> according to the comparative example of <FIG> may also be performed by the electronic device <NUM> according to an embodiment of the disclosure.

Referring to <FIG>, the electronic device <NUM> may periodically apply the ping signal <NUM> to the transmission coil <NUM> for the duration Δt1. When the application of the ping signal <NUM> is terminated, the power <NUM> of the transmission coil <NUM> of the electronic device <NUM> may be attenuated. For example, the attenuation in the time domain of the envelope of the voltage V(t) for the power <NUM> may follow Math <FIG>), below.

V(<NUM>) may be the initial voltage value, w may be the angular frequency of the AC signal, and Q may be the Q-factor. Accordingly, the Q-factor may be calculated using Math <FIG>), based on the voltages V<NUM> and V<NUM> corresponding to two time points t<NUM> and t<NUM> constituting the envelope. In Math <FIG>), shown below, T may be the period which is the reciprocal of the frequency.

As described above, the electronic device <NUM> may perform Q-factor measurement based on the application of the ping signal <NUM>. The electronic device <NUM> may store the Q-factor when no foreign object is disposed as a reference. When a foreign object is placed on the electronic device <NUM>, the Q-factor may be changed (e.g., decreased). When the Q-factor measured later has a difference outside the tolerance range as a result of comparison with the reference, the electronic device <NUM> may identify that the wireless power receiver <NUM> or a foreign object is placed. Meanwhile, the electronic device <NUM> may detect the placement of the wireless power receiver <NUM> or a foreign object based on a change in the resonance frequency as well as the Q-factor.

The operations using the Q-factor may be replaced with operations using a change in resonant frequency, or may be replaced with operations using both of the Q-factor and the change in resonant frequency. The application of a ping signal <NUM> and the detection phase based on the Q factor and/or frequency may be referred to as a selection phase and a ping phase, and the ping signal <NUM> may be referred to as a Q-ping.

If a difference occurs based on the result of a comparison, the electronic device <NUM> may apply a digital ping signal <NUM>. While the digital ping signal <NUM> is applied, the electronic device <NUM> may perform at least one operation corresponding to the identification phase and configuration phase with the wireless power receiver <NUM>, and the corresponding operation may follow the Qi standard.

As described above, the electronic device <NUM> and the wireless power receiver <NUM> may perform in-band communication. When the electronic device <NUM> fails to obtain data from the wireless power receiver <NUM> while the digital ping signal <NUM> is applied (e.g., failure to verify valid data as a result of demodulation), the electronic device <NUM> may determine that a foreign object is positioned nearby. When the operations in the identification phase and configuration phase are successfully completed, the electronic device <NUM> may perform at least one operation corresponding to the negotiation phase while applying power <NUM>, and the corresponding operation may follow (e.g., operations employing the Qi standard).

The electronic device <NUM> may receive a first received power packet RP1 from the wireless power receiver <NUM>. Based on the reception of the first received power packet RP1, the electronic device <NUM> may enter a calibration phase. However, depending on the implementation, the electronic device <NUM> may receive the first received power packet after entering the calibration phase. Further, although the calibration phase is shown as differing from the power transfer phase in <FIG>, this is merely an example, and the calibration phase may be understood as part of the power transfer phase.

The wireless power receiver <NUM> may provide a report for information about the strength of received power in a plurality of load states (e.g., a light load state and a heavy load state) in the calibration phase. Here, the load states may be classified based on the level of the current input to the load of the wireless power receiver <NUM> (or the level of the current output from the rectifier and/or the converter). A state in which the level of the current input to the load is relatively small may be referred to as a light state, and a state in which the level of the current input to the load is relatively large may be referred to as a heavy state.

The wireless power receiver <NUM> may transmit the first received power packet PR1 including the received power level in a first load state. The wireless power receiver <NUM> may identify the received power level based on the level of the received power and transmit (e.g., modulate) a first received power packet PR1 including the power level. Here, the received power level may be a value that is defined by the Qi standard, and may be a received power value or an estimated received power value. The received power level may be obtained as a result of processing (e.g., processing as defined by the Qi standard) the power level (e.g., in watts) measured (or estimated) by the wireless power receiver <NUM> but, without limitations thereto, the measured (or estimated) power level itself may be implemented.

The first received power packet RP1 is for indicating a first calibration data point, and the received power level included in the first received power packet RP1 may not be more than <NUM>% of the reference power level included in the power transfer contract. The first received power packet may have a type value of "<NUM>" (e.g., <NUM>), and the electronic device <NUM> may identify that the first received power packet RP1 is received based on the type value of "<NUM>".

The electronic device <NUM> may receive a second received power packet RP2 from the wireless power receiver <NUM> while the power <NUM> is applied. The wireless power receiver <NUM> may transmit the second received power packet RP2 including the received power level in a second load state. The second received power packet RP2 may be for indicating a second calibration data point (or its subsequent data point), and may be a value close to the reference power level included in the power transmission contract. The second received power packet may have a type value of "<NUM>" and the electronic device <NUM> may identify that the second received power packet RP2 is received based on the type value of "<NUM>" (e.g., <NUM>).

The electronic device <NUM> may calculate a parameter based on the values of two (or more) calibration data points. For example, the electronic device <NUM> may identify the transmitted power level (P<NUM>transmitted) and received power level (P<NUM>received) in the first load state and the transmitted power level (P<NUM>transmitted) and received power level (P<NUM>received) in the second load state (e.g., a connected load state). The electronic device <NUM> may identify the slope (a) based on the interpolation defined by Math <FIG>), below, and may identify the intercept (b) defined by Math <FIG>), below. <MAT><MAT>.

After identifying the parameters, the electronic device <NUM> may enter a power transfer phase and apply power <NUM> for charging. The wireless power receiver <NUM> may identify the power Ptransmitted transmitted in the power transmission phase, and calibrate it into the power Pcalibrated, as defined by Math <FIG>), below.

Further, the electronic device <NUM> may identify the power loss Ploss according to Math <FIG>), below.

Preceived in Math <FIG>) may be the received power level in the wireless power receiver <NUM> identified based on in-band communication from the power receiver <NUM>. The electronic device <NUM> may determine whether a foreign object is placed while power transmission is underway based on whether the power loss Ploss is greater than or equal to a preset reference value. Alternatively, the electronic device <NUM> may calculate the power loss using the result of performing calibration on the strength of the received power. However, the validity of the parameters (e.g., a and b) may be required to be ensured for accurate detection of the placement of a foreign object. If a foreign object is placed before or while entering the calibration phase, the parameters (e.g., (a) and (b)) may be inaccurate values. Accordingly, verification of at least one parameter calculated according to calibration is required.

Meanwhile, the above-described method for obtaining parameters (e.g., (a) and (b)) for a linear model based on the two calibration data is merely an example. Alternatively, the electronic device <NUM> may identify the calibration curve by processing (e.g., interpolating) a plurality of calibration data. The electronic device <NUM> may identify an effective foreign object detection (FOD) threshold from the calibration curve. The electronic device <NUM> may detect a foreign object based on whether the result of subtracting the received power level from the level of the transmitted power is greater than the effective FOD threshold.

The electronic device <NUM> may determine whether a foreign object is positioned nearby (e.g., placed in the vicinity of the electronic device <NUM>) during the power transfer phase based on at least one parameter, the received power level included in the received power packet (e.g., RP0), and the power <NUM> for charging in the power transfer phase. However, when a foreign object is positioned nearby before or in the middle of the calibration phase, at least one parameter may be invalid, which may cause a decrease in the accuracy of detection of the placement of a foreign object.

<FIG> is a flowchart illustrating a method for operating an electronic device, according to an embodiment. The embodiment of <FIG> is described with reference to <FIG> is a graph illustrating a level of transmitted power of an electronic device, according to an embodiment.

In step <NUM>, the electronic device <NUM> (e.g., the control circuit <NUM>) may control to apply first power (e.g., the power <NUM> of <FIG>) to a coil (e.g., the transmission coil <NUM>). For example, the electronic device <NUM> may apply the first power <NUM> in the negotiation phase, but the time of application is not limited thereto. For example, the electronic device <NUM> may perform operations to be described below even in a re-calibration phase, and in this case, the electronic device <NUM> may apply the designated first power <NUM> before the re-calibration phase. For example, the first power <NUM> may be power based on the negotiation phase, but may also be power based on other various phases.

In step <NUM>, the electronic device <NUM> may stop the application of the first power <NUM> and control to apply no power to the coil (e.g., restricts power from being applied to the coil) during a first period (e.g., Δt1 of <FIG>). The electronic device <NUM> may control to apply no power to the coil during the first period Δt1 based on a request from the wireless power receiver <NUM>. The wireless power receiver <NUM> may determine the period Δt1 based on the state of the wireless power receiver <NUM> (e.g., the voltage and/or load current at the output terminal of the rectifier of the wireless power receiver <NUM>), which is described below in greater detail. The wireless power receiver <NUM> may transmit a data packet including the determined first period Δt1. The electronic device <NUM> may stop application of power during the first period Δt1 requested from the wireless power receiver <NUM>. Stopping the application of power may be performed based on control of the power adapter 311a and/or the power generating circuit 311b.

Additionally or alternatively, the electronic device <NUM> may determine the first period Δt1. The electronic device <NUM> may stop applying power for a predetermined first period Δt1. The electronic device <NUM> may determine the first period Δt1 based on the level of power received from the wireless power receiver <NUM> and/or the level of the load current, but determining the first period is not limited thereto or thereby.

In step <NUM>, the electronic device <NUM> may identify a first Q-factor during the first period Δt1. As illustrated in <FIG>, as the application of the first power <NUM> is stopped, the power <NUM> may have a waveform that is attenuated and may correspond to an envelope. The electronic device <NUM> may identify the first Q-factor during the first period Δt1 based on the attenuation of the envelope of the power <NUM>. The electronic device <NUM> may identify the first Q-factor based on a plurality of data (e.g., a plurality of voltages) during the first period Δt1 based on Math <FIG>), but identifying the first Q-factor is not limited thereto. The electronic device <NUM> may be configured to identify the first Q-factor based on the remaining lobes except for a designated number of first lobes among a plurality of lobes during the first period Δt1. In addition, other types of data for identifying the first Q-factor may be used.

After the first period Δt1, the electronic device <NUM> may apply at least one power (e.g., <NUM> in <FIG>) for a calibration operation in step <NUM>. Although <FIG> illustrates that at least one power <NUM> has a constant level, this is merely an example, and the level of the power <NUM> may be changed during calibration. In step <NUM>, the electronic device <NUM> may stop the application of the power (e.g., stops the application of the last power of the at least one power) according to the calibration operation and prevents power from being applied to the coil during a second period (e.g., Δt2 in <FIG>). Although <FIG> illustrates that at least one power <NUM> for the calibration operation has a constant level, if the level of the power <NUM> is changed, the electronic device <NUM> may stop the application of power during the second period Δt2 after the last power in order of time is applied. Similar to stopping the application of power in the first period Δt1, the electronic device <NUM> may stop the application of power during the second period Δt2 based on the reception of a data packet including the second period Δt2. Alternatively, the electronic device <NUM> itself may identify the second period Δt2. The second period Δt2 may be different from the first period Δt1, but may be set to be identical thereto.

The electronic device <NUM> may identify a second Q-factor during the second period Δt2 in step <NUM>. Identifying the second Q-factor may be performed in the same manner as identifying the first Q-factor. In step <NUM>, the electronic device <NUM> may identify the validity of the parameter identified based on the calibration operation, based on the first Q-factor and the second Q-factor. For example, the electronic device <NUM> may identify at least one parameter, such as parameters (e.g., (a) and (b)) for calibration, and/or an effective FOD threshold, based on the calibration operation.

The electronic device <NUM> may determine the validity of the parameter based on a result of the comparison between the first Q-factor and the second Q-factor. If a foreign object is placed on the electronic device <NUM> while calibration is performed, the difference between the first Q-factor and the second Q-factor may be identified as greater than or equal to a threshold difference. As described above, the placement of a foreign object may affect a Q-factor, and accordingly, the second Q-factor may be changed compared to the first Q-factor. The electronic device <NUM> may determine that the parameter is invalid based on the difference being greater than or equal to the threshold difference. The electronic device <NUM> may determine that a foreign object is additionally placed. When the difference is less than the threshold difference, the electronic device <NUM> may determine that the parameter is valid.

When the wireless power receiver <NUM> is first placed (e.g., positioned near the electronic device <NUM>), the electronic device <NUM> may store the Q-factor measured based on a Q-ping signal (e.g., the ping signal <NUM>) as a reference. The electronic device <NUM> may identify the validity of the parameter based on a result of comparison between the reference and the first Q-factor and/or a result of comparison between the reference and the second Q-factor. If a foreign object is placed during a time period after the electronic device <NUM> detects the placement of the wireless power receiver <NUM> and before the application of the first power <NUM> is stopped, the difference between the reference and the first Q-factor may be greater than or equal to the threshold difference. If a foreign object is placed while calibration is performed, the difference between the reference and the second Q-factor may be greater than or equal to the threshold difference. The electronic device <NUM> may determine that the parameter is invalid if it is determined that a foreign object is placed based on at least one comparison result.

Parameters for which the validity is not guaranteed may be discarded, and degradation of the accuracy of foreign object detection in the power transfer phase may be prevented.

<FIG> is a flowchart illustrating a method for operating an electronic device, according to an embodiment. For convenience of description, the operations previously described in detail will be briefly described below.

The electronic device <NUM> (e.g., the control circuit <NUM>) may identify a first Q-factor in step <NUM>. For example, the electronic device <NUM> may stop applying the power which is being applied and identify the first Q-factor. In step <NUM>, the electronic device <NUM> may perform a calibration operation. In step <NUM>, the electronic device <NUM> may identify the second Q-factor. For example, the electronic device <NUM> may stop applying power (e.g., the last power of the at least one power) associated with the calibration operation and identify the second Q-factor. In step <NUM>, the electronic device <NUM> may determine whether the parameter identified based on the calibration operation is valid based on the first Q-factor and the second Q-factor. For example, the electronic device <NUM> may determine whether the identified parameter is valid based on a result of a comparison between the first Q-factor and the second Q-factor. When the difference between the first Q-factor and the second Q-factor is greater than or equal to the threshold difference, the electronic device <NUM> may determine that the identified parameter is invalid. When the difference between the first Q-factor and the second Q-factor is less than the threshold difference, the electronic device <NUM> may determine that the identified parameter is valid. The electronic device <NUM> may determine whether the parameter is valid based on a result of comparing the first Q-factor and the second Q-factor with a reference.

When it is determined that the parameter identified based on the calibration operation is valid (YES in step <NUM>), the electronic device <NUM> may detect the foreign object during the power transmission operation based on the identified parameter in step <NUM>. For example, when the electronic device <NUM> identifies a parameter (e.g., (a) or (b)) for calibrating the level of the transmitted power or the level of the received power, the electronic device <NUM> may calibrate either the level of the transmitted power or the level of the received power based on the parameter. The electronic device <NUM> may determine whether a foreign object is placed (e.g., positioned nearby) based on a difference between the calibrated level and the remaining level. For example, when the electronic device <NUM> identifies an effective FOD threshold as a result of the calibration, the electronic device <NUM> may determine whether a foreign object is positioned nearby based on whether the difference between the level of the transmitted power and the level of the received power is greater than or equal to the effective FOD detection threshold.

When it is determined that the parameter identified based on the calibration operation is invalid (NO in step <NUM>), the electronic device <NUM> determines that a foreign object is detected in step <NUM>. The electronic device <NUM> may perform an operation corresponding to detection of the foreign object. Further, the electronic device <NUM> may discard the parameter identified based on the calibration operation and perform a calibration operation again later. For example, after it is determined that the foreign object has been taken away, the electronic device <NUM> may perform a calibration operation again.

<FIG> is a graph illustrating a level of transmitted power of an electronic device, according to an embodiment.

The electronic device <NUM> (e.g., the control circuit <NUM>) may periodically apply a ping signal <NUM> to the transmission coil <NUM> for duration Δt1. The application of the ping signal <NUM> and other powers may be performed based on the control of the power adapter 311a and/or the power generating circuit 311b. When the application of the ping signal <NUM> is terminated, the power <NUM> of the transmission coil <NUM> of the electronic device <NUM> may be attenuated. Based on the attenuation of the power <NUM>, the electronic device <NUM> may identify the Q-factor. The electronic device <NUM> may determine the placement of the wireless power receiver <NUM> or a foreign object based on comparison between a reference, which is the Q-factor when no foreign object is placed, and the identified Q-factor.

If a difference occurs based on the result of comparison, the electronic device <NUM> may apply a digital ping signal <NUM>. While the digital ping signal <NUM> is applied, the electronic device <NUM> may perform at least one operation corresponding to the identification phase and configuration phase with the wireless power receiver <NUM>. When the operations in the identification phase and configuration phase are successfully completed, the electronic device <NUM> may perform at least one operation corresponding to the negotiation phase while applying power <NUM>.

The wireless power receiver <NUM> may enter (or maintain) a first load state (e.g., minimum load power). The wireless power receiver <NUM> may identify the received power level in the first load state. The wireless power receiver <NUM> may identify a power application interruption period (e.g., Δt2). The identification of the power application interruption period (e.g., Δt2) by the wireless power receiver <NUM> is described below. The wireless power receiver <NUM> may transmit a first received power packet PR1 including the received power level and the power application interruption period (e.g., Δt2) to the electronic device <NUM>.

The electronic device <NUM> may receive the first received power packet PR1. The electronic device <NUM> may identify and store the level of the power <NUM> and the data included in the first received power packet PR1 as a first calibration data point. If the first calibration data point is accepted, the electronic device <NUM> may transmit an acknowledgment (ACK) packet to the electronic device <NUM>.

The electronic device <NUM> may stop applying power during the power application interruption period (e.g., Δt2) included in the first received power packet PR1. When the application of the power <NUM> is terminated, the power <NUM> of the transmission coil <NUM> of the electronic device <NUM> may be attenuated. Based on the attenuation of the power <NUM>, the electronic device <NUM> may identify the first Q-factor.

The wireless power receiver <NUM> may enter a second load state (e.g., medium load power). While the wireless power receiver <NUM> enters the second load state, power <NUM> may be applied to the transmission coil <NUM> of the electronic device <NUM>. For example, as the load state of the wireless power receiver <NUM> changes, the level of the power <NUM> applied to the transmission coil <NUM> of the electronic device <NUM> may be changed, and/or the electronic device <NUM> may compare the level of the power <NUM> with the existing power <NUM> and change the same. The wireless power receiver <NUM> may identify the received power level in the second load state. The wireless power receiver <NUM> may identify a power application interruption period (e.g., Δt3). The wireless power receiver <NUM> may transmit a first received power packet PR1 including the received power level and the power application interruption period (e.g., Δt3) to the electronic device <NUM>. Meanwhile, the type of the data packet is not limited and may be replaced by the second received power packet PR2.

The electronic device <NUM> may receive the first received power packet PR1. The electronic device <NUM> may identify and store the level of the power <NUM> and the data included in the first received power packet PR1 as a second calibration data point.

The electronic device <NUM> may stop applying power <NUM> during the power application interruption period (e.g., Δt3) included in the first received power packet PR1. When the application of the power <NUM> is terminated, the power <NUM> of the transmission coil <NUM> of the electronic device <NUM> may be attenuated. Based on the attenuation of the power <NUM>, the electronic device <NUM> may identify the second Q-factor.

Additionally or alternatively, identification of the Q-factor may be optional at the other points than the start point and the end point of the calibration. The wireless power receiver <NUM> may refrain from requesting the electronic device <NUM> to stop applying power. In this case, the data packet transmitted by the wireless power receiver <NUM> may include only the received power level, or the power application interruption period may be set to zero.

The wireless power receiver <NUM> may enter a third load state (e.g., maximum load power). While the wireless power receiver <NUM> enters the third load state, power <NUM> may be applied to the transmission coil <NUM> of the electronic device <NUM>. As the load state of the wireless power receiver <NUM> changes, the level of the power <NUM> applied to the transmission coil <NUM> of the electronic device <NUM> may be changed, and/or the electronic device <NUM> may compare the level of the power <NUM> with the existing power <NUM> and change the same. The wireless power receiver <NUM> may identify the received power level in the third load state. The wireless power receiver <NUM> may identify a power application interruption period (e.g., Δt4). The wireless power receiver <NUM> may transmit a second received power packet PR2 including the received power level and the power application interruption period (e.g., Δt4) to the electronic device <NUM>. Meanwhile, the type of the data packet is not limited and may be replaced by the first received power packet PR1.

The electronic device <NUM> may receive the second received power packet PR2. The electronic device <NUM> may identify and store the level of the power <NUM> and the data included in the second received power packet PR2 as a third calibration data point.

The electronic device <NUM> may stop applying power <NUM> during the power application interruption period (e.g., Δt4) included in the second received power packet PR2. When the application of the power <NUM> is terminated, the power <NUM> of the transmission coil <NUM> of the electronic device <NUM> may be attenuated. Based on the attenuation of the power <NUM>, the electronic device <NUM> may identify the third Q-factor.

The electronic device <NUM> may identify at least one parameter based on the first calibration data point, the second calibration data point, and the third calibration data point. The electronic device <NUM> may determine whether at least one parameter is valid based on the first Q-factor, the second Q-factor, and the third Q-factor. When it is determined that at least one parameter is valid, the electronic device <NUM> may perform a foreign object detection operation using at least one parameter while transmitting the power <NUM> for charging. The electronic device <NUM> may determine whether a foreign object is placed based on the at least one parameter and the level of the received power included in the identified data packet (e.g., RP0) via communication.

When it is determined that no foreign object is placed, the electronic device <NUM> may transmit an ACK packet in the RP1 packet or the RP2 packet. When it is determined that a foreign object is placed, the electronic device <NUM> may transmit a negative acknowledgment (NAK) packet. When it is determined that no foreign object is placed, the electronic device <NUM> may transmit an not defined (ND) response.

<FIG> is a view illustrating operations of an electronic device and a wireless power receiver, according to an embodiment.

The electronic device <NUM> (e.g., the control circuit <NUM>) may apply a first power to the transmission coil <NUM> in step <NUM>. In step <NUM>, the wireless power receiver <NUM> (e.g., the processor <NUM>) may identify a first received power level in a first load state. In step <NUM>, the wireless power receiver <NUM> may transmit a first packet including the first received power level and a first period. It is merely an example that the received power level and the period for requesting power interruption are included in one data packet, and in another embodiment, the wireless power receiver <NUM> may individually include the pieces of information in two different packets and transmit them. The transmission operation in <FIG> may be to perform modulation corresponding to the first packet of the wireless power receiver <NUM>. In step <NUM>, the electronic device <NUM> may stop transmitting power during the first period and analyze the attenuation at the transmission coil <NUM> during the first period, thereby identifying the first Q-factor.

The electronic device <NUM> (e.g., the control circuit <NUM>) may apply Nth power to the transmission coil <NUM> in step <NUM>. The Nth power may be different from or equal to the first power. In step <NUM>, the wireless power receiver <NUM> (e.g., the processor <NUM>) may identify an Nth received power level in an Nth load state. In step <NUM>, the wireless power receiver <NUM> may transmit an Nth packet including the Nth received power level and an Nth period. In step <NUM>, the electronic device <NUM> may stop transmitting power during the Nth period and analyze the attenuation at the transmission coil <NUM> during the Nth period, thereby identifying the Nth Q-factor. Here, N may be a natural number of <NUM> or more. When N is <NUM> or more, the electronic device <NUM> and the wireless power receiver <NUM> may further perform identification of the received power level, transmission of a packet, interruption of power transmission, and identification of a Q-factor N-<NUM> times. Meanwhile, in the intermediate operations except for the first operation and the last operation, interruption of power transmission and identification of the Q-factor may be omitted.

In step <NUM>, the electronic device <NUM> may identify at least one parameter based on the first to Nth power and the first to Nth received power levels. In step <NUM>, the electronic device <NUM> may verify the validity of at least one parameter based on the first to Nth Q-factors.

<FIG> is a view illustrating a comparative example of a structure of a data packet, according to an embodiment.

According to the comparative example, the wireless power receiver <NUM> may transmit an RP1 packet having the structure of <FIG> to the electronic device <NUM>. The RP1 packet may be based on a <NUM>-bit received power packet defined in the Qi standard. The RP1 packet may include a reserved field <NUM>, a mode field <NUM>, and an estimated received power value field <NUM>. The estimated received power value field <NUM> or <NUM> may be referred to as a received power value according to the version of the standard. The bit string expressed in the mode field <NUM> or <NUM> may provide additional information about the received power value. For example, "<NUM>" (<NUM>) in the mode field <NUM> may indicate the first load state, and "<NUM>" (<NUM>) may indicate the second load state. The estimated received power value is a value obtained by processing the level of the received power measured by the wireless power receiver <NUM>, and may be one of the above-described received power levels, and used as a calibration data point.

<FIG> is a view illustrating a structure of a packet RP1 of received power transmitted from a wireless power receiver <NUM>, according to an embodiment. The wireless power receiver <NUM> may include a slot time <NUM> in a data packet using part of the existing reserved field <NUM>. The slot time <NUM> may have a value of <NUM> to <NUM>, of which <NUM> may indicate that the power application interruption period is <NUM>. When the slot time <NUM> is <NUM>, the electronic device <NUM> may skip power interruption and Q-factor measurement. The values may be individually matched to power application interruption periods. For example, <NUM> may represent <NUM> microseconds (µs), <NUM> may represent <NUM>, and <NUM> may represent <NUM>. When the slot time <NUM> is a non-zero value, the electronic device <NUM> may skip power application interruption and Q-factor measurement during the corresponding period.

The wireless power receiver <NUM> may include a settling time <NUM> in the data packet using part of the existing reserved field <NUM>. The settling time <NUM> may mean an interval between power slots when a plurality of power slots (i.e., interruption of power application and Q-factor measurement) are consecutively used. After the voltage Vrect at the output terminal of the rectifier of the wireless power receiver <NUM> is dropped by the power slot, its recovery may take time. If the settling time <NUM> is not sufficient, the voltage Vrect at the output terminal of the rectifier may not recover and drop, and in-band communication may be cut off. For example, the settling time <NUM> may have a value of <NUM> to <NUM>, of which <NUM> may indicate that the settling time is <NUM>. The values may be individually matched to settling times. For example, <NUM> may represent <NUM>, <NUM> may represent <NUM>, and <NUM> may represent <NUM>, but embodiments of the disclosure are not limited thereto. When the settling time <NUM> is a non-zero value, the electronic device <NUM> may wait for power application interruption for the corresponding period. In addition, after receiving an arbitrary PR/x packet (e.g., RP <NUM> or RP <NUM>), the electronic device <NUM> may transmit a response (e.g., an ACK packet) after the included settling time <NUM>.

The wireless power receiver <NUM> may identify version information (e.g., ID packet version) for the electronic device <NUM>. If the power slot function is not supported based on the version information for the electronic device <NUM>, the electronic device <NUM> may set the settling time <NUM> and the slot time <NUM> to <NUM> and transmit a data packet.

<FIG> is a flowchart illustrating a method for operating a wireless power receiver, according to an embodiment. <FIG> is described with reference to <FIG>. <FIG>, <FIG>, <FIG>, and <FIG> are views illustrating a peak reception voltage and an output voltage of a rectifier, according to various embodiments.

The wireless power receiver <NUM> (e.g., the processor <NUM>) may identify the level of the received power and/or the level of the load current in step <NUM>. The wireless power receiver <NUM> may identify the voltage Vrect at the output terminal of the rectifier as the level of the received power but the position where the level of the received power is defined may vary. The wireless power receiver <NUM> may identify the current input to a load (e.g., a charger or PMIC) as the load current, but the position where the load current is defined may vary.

In step <NUM>, the wireless power receiver <NUM> may identify a power transmission interruption period based on the level of the received power and/or load current.

Referring to <FIG>, in the first load state, the load current of the wireless power receiver <NUM> may be <NUM> milliamps (mA), and the initial value of the output voltage of the rectifier may be <NUM> volts (V). When the supply of power is stopped in the electronic device <NUM>, it may be identified that the reception peak voltage <NUM> falls so that the output voltage <NUM> of the rectifier drops as well. However, the output voltage <NUM> of the rectifier may be greater than or equal to a threshold voltage (under voltage lock out (UVLO)) <NUM> (e.g., <NUM> V) even after <NUM>. The threshold voltage <NUM> may be a value set to prevent in-band communication from being disconnected.

However, referring to <FIG>, in the second load state, the load current of the wireless power receiver <NUM> may be, e.g., <NUM> mA, and the initial value of the output voltage of the rectifier may be <NUM>. When the supply of power is stopped in the electronic device <NUM>, it may be identified that the reception peak voltage <NUM> falls so that the output voltage <NUM> of the rectifier drops as well. In this case, it may be identified that the output voltage <NUM> of the rectifier drops below the threshold voltage <NUM> (e.g., <NUM> V) at <NUM>.

Referring to <FIG> and <FIG>, in a load state in which the load current is large, the dropping speed of the output voltage of the rectifier may be relatively fast. Further, as the initial output voltage of the rectifier increases, the time to drop below the threshold voltage <NUM> may increase. Accordingly, the wireless power receiver <NUM> may determine a power application interruption period based on the output voltage and/or the load current of the rectifier. The power application interruption period needs to be set so that the output voltage of the rectifier does not drop below the threshold voltage <NUM>. For example, the wireless power receiver <NUM> may calculate the power application interruption period using the output voltage and/or the load current of the rectifier. Alternatively, the wireless power receiver <NUM> may identify the power application interruption period by referring to a pre-stored lookup table. In the case shown in <FIG>, the wireless power receiver <NUM> may determine that a period shorter than <NUM> is the power application interruption period.

Referring to <FIG>, in the first load state, the load current of the wireless power receiver <NUM> may be <NUM> mA, and the initial value of the output voltage of the rectifier may be <NUM> V. When the supply of power is stopped in the electronic device <NUM>, the reception peak voltage <NUM> may fall so that the output voltage <NUM> of the rectifier drops as well. However, the output voltage <NUM> of the rectifier may be greater than or equal to the threshold voltage <NUM> (e.g., <NUM> V) even after <NUM>. Referring to <FIG>, in the second load state, the load current of the wireless power receiver <NUM> may be <NUM> mA, and the initial value of the output voltage of the rectifier may be <NUM> V. When the supply of power is stopped in the electronic device <NUM>, the reception peak voltage <NUM> may fall so that the output voltage <NUM> of the rectifier drops as well. In this case, the output voltage <NUM> of the rectifier may drop below the threshold voltage <NUM> (e.g., <NUM> V) at <NUM>.

Referring to <FIG>, the wireless power receiver <NUM> may determine that a period shorter than <NUM> is the power application interruption period.

Referring to <FIG>, in the first load state, the load current of the wireless power receiver <NUM> may be <NUM> mA, and the initial value of the output voltage of the rectifier may be <NUM> V. When the supply of power is stopped in the electronic device <NUM>, the reception peak voltage <NUM> may fall so that the output voltage <NUM> of the rectifier drops as well. However, the output voltage <NUM> of the rectifier may be greater than or equal to the threshold voltage (e.g., <NUM> V) <NUM> even after <NUM>.

Referring to <FIG>, in the second load state, the load current of the wireless power receiver <NUM> may be <NUM> mA, and the initial value of the output voltage of the rectifier may be <NUM> V. When the supply of power is stopped in the electronic device <NUM>, the reception peak voltage <NUM> may fall so that the output voltage <NUM> of the rectifier drops as well. In this case, the output voltage <NUM> of the rectifier may drop below the threshold voltage <NUM> (e.g., <NUM> V) at <NUM>. In the embodiment shown in <FIG>, the wireless power receiver <NUM> may determine that a period shorter than <NUM> is the power application interruption period.

Referring again to <FIG>, the wireless power receiver <NUM> may transmit a data packet including the identified power transmission interruption period in step <NUM>. As described above, the slot time included in the data packet may be set to differ for each load state. Accordingly, disconnection of the in-band communication due to Q-factor measurement based on interruption of power application may be prevented.

The wireless power receiver <NUM> may determine the settling time based on the level of the received power and/or the level of the load current. As described above, the wireless power receiver <NUM> may estimate the output voltage of the rectifier after the power supply is stopped, based on the initial output voltage and load current of the rectifier. The increasing rate of the output voltage of the rectifier after power supply is resumed may also be estimated. The wireless power receiver <NUM> may determine the settling time by estimating (or referring to) a time required for the output voltage of the rectifier to recover to a certain level. The wireless power receiver <NUM> may include the identified settling time in the received power packet and transmit the same to the electronic device <NUM>. The electronic device <NUM> may identify the settling time included in the received power packet and transmit a response (e.g., an ACK packet) after the settling time passes from the time of reception of the received power packet (or the time of interruption of power application or the time of resuming application of power).

<FIG> is a flowchart illustrating a method for operating a wireless power receiver, according to an embodiment.

The wireless power receiver <NUM> (e.g., the processor <NUM>) may identify the level of the received power and/or the level of the load current in step <NUM>. In step <NUM>, the wireless power receiver <NUM> may identify a power transmission interruption period based on the level of the received power level and/or the level of the load current. In step <NUM>, the wireless power receiver <NUM> may determine whether the level of the received power is in a stable state. When the level of the received power is not in the stable state (NO in step <NUM>), the electronic device <NUM> may identify the level of the received power and/or the load current and identify the corresponding power transmission interruption period again. Alternatively, the electronic device <NUM> may store the identified power transmission interruption period without further identifying the power transmission interruption period. The wireless power receiver <NUM> may determine whether the level of the received power is in the stable state based on whether the level of the received power (e.g., the level of the output voltage of the rectifier) is greater than or equal to the threshold voltage.

As described above, when the electronic device <NUM> stops applying power during the slot time, the output voltage of the rectifier in the wireless power receiver <NUM> may drop. Thereafter, when the electronic device <NUM> resumes application of power, the output voltage of the rectifier in the wireless power receiver <NUM> may rise again. The electronic device <NUM> may wait until the output voltage of the rectifier rises above the threshold voltage. If the electronic device <NUM> additionally stops applying power when the output voltage of the rectifier does not rise above the threshold voltage, and in-band communication may be cut off due to a drop in the output voltage of the rectifier. Accordingly, the electronic device <NUM> may refrain from transmitting a data packet until the output voltage of the rectifier recovers above the threshold voltage. When the level of the received power is in the stable state (YES in step <NUM>), the wireless power receiver <NUM> may transmit a data packet including the identified power transmission interruption period to the electronic device <NUM> in step <NUM>. The electronic device <NUM> may identify the power transmission interruption period from the received data packet, stop application of power during the identified power transmission interruption period, and identify the Q-factor.

When the electronic device <NUM>, which is the counterpart device, supports the functions of power application interruption and Q-factor measurement, the wireless power receiver <NUM> may transmit a data packet requesting the power application interruption. When the electronic device <NUM> complies with at least one first version of the Qi standard (e.g., version <NUM>. <NUM> or lower versions), the electronic device <NUM> may not support power application interruption and Q-factor measurement and, when the electronic device <NUM> complies with at least one second version of the Qi standard (e.g., version <NUM> or higher versions), the electronic device <NUM> may support interruption of power application and Q-factor measurement. The wireless power receiver <NUM> may determine whether the electronic device <NUM> supports the functions of power application interruption and Q-factor measurement based on the ID packet version.

The wireless power receiver <NUM> may determine whether the electronic device <NUM> supports the functions of power application interruption and Q-factor measurement based on the negotiation (NEG) field of the configuration packet (CFG packet). For example, when the value of the NEG field is <NUM>, the electronic device <NUM> may support the functions of power application interruption and Q-factor measurement. The wireless power receiver <NUM> may determine whether the electronic device <NUM> supports the functions of power application interruption and Q-factor measurement based on an ND response from the electronic device <NUM>. When an ND response is identified according to the general request(GRQ)/x packet, the electronic device <NUM> may support the functions of power application interruption and Q-factor measurement. The electronic device <NUM>, complying with Qi standard version <NUM> or higher and supporting the extended power profile (EPP) mode, may support the functions of power application interruption and Q-factor measurement, and identifying the corresponding information is not limited to a specific type of information. When it is determined that the electronic device <NUM> does not support the functions of power application interruption and Q-factor measurement, the electronic device <NUM> and the wireless power receiver <NUM> may be configured to enter a baseline power profile (BPP) mode, rather than the EPP mode.

The wireless power receiver <NUM> complying with Qi standard version <NUM> and supporting the EPP mode may be configured to start the operation in the BPP mode at the start time by transmitting a CFG/baseline profile (bp) packet (e.g., the NEG bit is null, and the other fields are set by the value of the CFG/extended profile (ep)). For example, when receiving a precedent ID packet having a version field of Qi standard version <NUM> or higher and the CFG/bp packet from the wireless power receiver <NUM>, the electronic device <NUM> complying with Qi standard version <NUM> and supporting the EPP mode may transmit an ND response in response to the CFG/bp packet. The wireless power receiver <NUM> complying with Qi standard version <NUM> and supporting the EPP mode may enter the EPP mode and transmit a GRQ/id packet based on reception of the ND response corresponding to the CFG/bp.

The electronic device <NUM> complying with version <NUM> and supporting the EPP mode may enter the EPP mode based on reception of the GRQ/id and the precedent ID packet of the field of Qi standard version <NUM> or higher. Thereafter, the electronic device <NUM> complying with Qi standard version <NUM> and supporting the EPP mode may transmit a TX ID data packet, power transmitter capabilities ('CAP') data packet, and an XCAP data packet of the slot length field for the power receiver (PRx) GRQ/id, /cap, and /xcap data packet. When the wireless power receiver <NUM> identifies that the value of the slot length field is <NUM>, the wireless power receiver <NUM> may not transmit the RP1 packet and the RP2 packet while operating at <NUM> watts (W) or less. When the wireless power receiver <NUM> identifies a non-zero slot length field value, the wireless power receiver <NUM> may skip initial calibration and authenticate the electronic device <NUM>. The wireless power receiver <NUM> may authenticate the electronic device <NUM> and, if necessary, select a new operating voltage. Thereafter, the wireless power receiver <NUM> and the electronic device <NUM> may perform calibration accompanied by Q-factor measurement.

An electronic device <NUM> that may be implemented as the electronic device <NUM> and/or the wireless power receiver <NUM> is described below, according to an embodiment.

<FIG> is a block diagram illustrating an electronic device <NUM> in a network environment <NUM> according to an embodiment. According to an embodiment, the electronic device <NUM> may include a processor <NUM>, memory <NUM>, an input module <NUM>, a sound output module <NUM>, a display module <NUM>, an audio module <NUM>, a sensor module <NUM>, an interface <NUM>, a connecting terminal <NUM>, a haptic module <NUM>, a camera module <NUM>, a power management module <NUM>, a battery <NUM>, a communication module <NUM>, a subscriber identification module (SIM) <NUM>, or an antenna module <NUM>. In some embodiments, at least one (e.g., the connecting terminal <NUM>) of the components may be omitted from the electronic device <NUM>, or one or more other components may be added in the electronic device <NUM>. According to an embodiment, some (e.g., the sensor module <NUM>, the camera module <NUM>, or the antenna module <NUM>) of the components may be integrated into a single component (e.g., the display module <NUM>).

The processor <NUM> may execute, e.g., software (e.g., a program <NUM>) to control at least one other component (e.g., a hardware or software component) of the electronic device <NUM> connected with the processor <NUM> and may process or compute various data. For example, when the electronic device <NUM> includes the main processor <NUM> and the auxiliary processor <NUM>, the auxiliary processor <NUM> may be configured to use lower power than the main processor <NUM> or to be specified for a designated function.

The auxiliary processor <NUM> may control at least some of functions or states related to at least one (e.g., the display module <NUM>, the sensor module <NUM>, or the communication module <NUM>) of the components of the electronic device <NUM>, instead of the main processor <NUM> while the main processor <NUM> is in an inactive (e.g., sleep) state or along with the main processor <NUM> while the main processor <NUM> is an active state (e.g., executing an application).

The display <NUM> may include, for example, a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, hologram device, and projector. According to an embodiment, the display <NUM> may include a touch sensor configured to detect a touch, or a pressure sensor configured to measure the intensity of a force generated by the touch.

According to an embodiment, the audio module <NUM> may obtain a sound through the input module <NUM> or output a sound through the sound output module <NUM> or an external electronic device (e.g., an electronic device <NUM> (e.g., a speaker or a headphone) directly or wirelessly connected with the electronic device <NUM>.

The communication module <NUM> may support establishing a direct (e.g., wired) communication channel or wireless communication channel between the electronic device <NUM> and an external electronic device (e.g., the electronic device <NUM>, the electronic device <NUM>, or the server <NUM>) and performing communication through the established communication channel. The communication module <NUM> may include one or more communication processors that are operable independently from the processor <NUM> (e.g., the AP) and supports a direct (e.g., wired) communication or a wireless communication. A corresponding one of these communication modules may communicate with the external electronic device <NUM> via a first network <NUM> (e.g., a short-range communication network, such as Bluetooth™, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or a second network <NUM> (e.g., a long-range communication network, such as a legacy cellular network, a <NUM> network, a next-generation communication network, the Internet, or a computer network (e.g., local area network (LAN) or wide area network (WAN)). The wireless communication module <NUM> may identify or authenticate the electronic device <NUM> in a communication network, such as the first network <NUM> or the second network <NUM>, using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module <NUM>.

The antenna module <NUM> may transmit or receive a signal or power to or from the outside (e.g., the external electronic device). According to an embodiment, the antenna module <NUM> may include one antenna including a radiator formed of a conductor or conductive pattern formed on a substrate (e.g., a printed circuit board (PCB)). According to an embodiment, the antenna module <NUM> may include a plurality of antennas (e.g., an antenna array). In this case, at least one antenna appropriate for a communication scheme used in a communication network, such as the first network <NUM> or the second network <NUM>, may be selected from the plurality of antennas by, e.g., the communication module <NUM>. According to an embodiment, other parts (e.g., radio frequency integrated circuit (RFIC)) than the radiator may be further formed as part of the antenna module <NUM>.

The external electronic devices <NUM> or <NUM> each may be a device of the same or a different type from the electronic device <NUM>. The electronic device <NUM> may provide ultra-low-latency services using, e.g., distributed computing or mobile edge computing. The electronic device <NUM> may be applied to intelligent services (e.g., smart home, smart city, smart car, or healthcare) based on <NUM> communication technology or loT-related technology.

According to an embodiment, an electronic device includes a power transmitting circuit configured to transmit power to a wireless power receiver, a communication circuit configured to perform communication with the wireless power receiver, and a control circuit configured to control the power transmitting circuit to apply first power to a coil of the power transmitting circuit, control the power transmitting circuit to stop applying the first power and prevent power from being applied (e.g., restrict power from being applied or allow no power to be applied) to the coil during a first period, identify a first Q-factor during the first period, control the power transmitting circuit to apply, to the coil, a second power based on a calibration operation for identifying at least one parameter used for identifying a power loss during power transmission, control the power transmitting circuit to stop applying the second power (e.g., a last power among at least one power based on the calibration operation) and prevent power from being applied to the coilduring a second period, identify a second Q-factor during the second period, and identify a validity of the at least one parameter based on at least one of the first Q-factor or the second Q-factor.

The control circuit may further be configured to, when the at least one parameter is determined to be valid, control the power transmitting circuit to apply power for charging the wireless power receiver to the coil, receive a data packet including a received power level from the wireless power receiver, using the communication circuit, while applying the power for charging, identify whether the power loss meets a predetermined condition based on the at least one parameter, the received power level, and a magnitude of the power for charging, and based on the power loss meeting the predetermined condition, determine that a foreign object is placed on the electronic device.

The control circuit may be configured to, as part of controlling the power transmitting circuit to stop applying the first power and prevent power from being applied to the coil 311Lduring the first period, identify a first received power packet from the wireless power receiver195, using the communication circuit, and control the power transmitting circuit to allow no power to be applied to the coil during the first period included in the first received power packet.

The first received power packet may be an RP1 packet of a Qi standard. The first period may be identified based on a bit in a slot time field.

The control circuit may further be configured to identify a first settling time included in the first received power packet, and control the communication circuit to transmit a response to the first received power packet based on the first settling time after receiving the first received power packet.

The control circuit may be further configured to identify the at least one parameter using a level of first received power included in the first received power packet. The wireless power receiver may be configured to transmit the first received power packet including the level of the first received power to the electronic device in a first load state.

The control circuit may further be configured to, as part of controlling the power transmitting circuit to stop applying the second power and prevent power from being applied to the coil during the second period, identify a second received power packet from the wireless power receiver, using the communication circuit, and control the power transmitting circuit to prevent power from being applied to the coil during the second period included in the second received power packet.

The second received power packet may be an RP2 packet of a Qi standard. The second period may be identified based on a bit in a slot time field.

The control circuit may further be configured to identify the at least one parameter using a magnitude of a second received power included in the second received power packet. The wireless power receiver may be configured to transmit the second received power packet including information indicating the magnitude of the second received power state to the electronic device in a second load.

The control circuit may further be configured to, as part of identifying the validity of the at least one parameter based on at least one of the first Q-factor or the second Q-factor, determine that the at least one parameter is invalid when a difference between the first Q-factor and the second Q-factor is greater than or equal to a threshold difference, and determine that the at least one parameter is valid when the difference between the first Q-factor and the second Q-factor is less than the threshold difference.

The control circuit may further be configured to, as part of identifying the validity of the at least one parameter based on at least one of the first Q-factor or the second Q-factor, determine that the at least one parameter is invalid when at least one of a first difference between the first Q-factor and a reference Q-factoror a second difference between the second Q-factor and the reference Q-factor is greater than or equal to a threshold difference, and determine that the at least one parameter is valid when at least one of the first difference or the second difference is less than the threshold difference.

The control circuit may further be configured to perform a predetermined operation in a negotiation phase with the wireless power receiver while the first power is applied to the coil.

The control circuit may further be configured to identify the at least one parameter based on a plurality of calibration data points obtained after the predetermined operation is performed in the negotiation phase. The plurality of calibration data points may include a plurality of received power levels corresponding to a plurality of load states of the wireless power receiver respectively and a plurality of transmitted power levels corresponding to the plurality of received power levels respectively.

The control circuit may further be configured to control the power transmitting circuit to apply power for charging the wireless power receiver to the coil, based on the at least one parameter being valid.

According to an embodiment, a wireless power receiver includes a coil configured to receive power from an electronic device, a rectifier configured to rectify AC power output from the coil into direct current DC power, a processor, and a communication circuit. The processor may be configured to control the communication circuit to transmit a first data packet for requesting that a first power is not applied during a first period, while the first power is received, and control the communication circuit to transmit a second data packet for requesting that a second power is not applied during a second period, while the second power is received, based on a calibration operation for identifying at least one parameter used for identifying power loss while transmitted power is received through the coil.

The first received power packet may be an RP1 packet of a Qi standard. The first period may be set based on a bit in a slot time field. The second data packet may be an RP2 packet of the Qi standard. The second period may be set based on a bit in a slot time field.

The first data packet may further include a first settling time, and the second data packet may further include a second settling time.

The processor may further be configured to include a magnitude of a first received power measured in a first load state of the wireless power receiver in the first data packet, and include a magnitude of a second received power measured in a second load state of the wireless power receiver in the second data packet.

The processor may further be configured to identify an output voltage of the rectifier, and identify at least one of the first period or the second period based on the output voltage of the rectifier.

The processor may further be configured to identify a magnitude of current input to a load of the wireless power receiver, and identify at least one of the first period or the second period based on the magnitude of the current input to the load.

According to an embodiment of the disclosure, the electronic device is not limited to the above-listed embodiments.

Various embodiments as set forth herein may be implemented as software (e.g., the program) including one or more instructions that are stored in a storage medium (e.g., internal memory or external memory) that is readable by a machine (e.g., the electronic device <NUM> and/or the wireless power receiver <NUM>). For example, a processor of the machine (e.g., the electronic device <NUM> and/or the wireless power receiver <NUM>) may invoke at least one of the one or more instructions stored in the storage medium, and execute it, with or without using one or more other components under the control of the processor.

According to an embodiment, a method may be included and provided in a computer program product.

Some of the plurality of entities may be separately disposed in different components.

Claim 1:
An electronic device, comprising:
a power transmitting circuit (<NUM>) configured to transmit power to a wireless power receiver (<NUM>);
a communication circuit (<NUM>) configured to perform communication with the wireless power receiver (<NUM>); and
a control circuit (<NUM>) configured to:
control the power transmitting circuit (<NUM>) to apply a first power (<NUM>) to a coil (<NUM>) of the power transmitting circuit (<NUM>),
control the power transmitting circuit (<NUM>) to stop applying the first power (<NUM>) and prevent power from being applied to the coil (<NUM>) during a first period (Δt1),
identify a first Q-factor during the first period,
control the power transmitting circuit (<NUM>) to apply, to the coil (<NUM>), a second power (<NUM>) during a calibration operation for identifying at least one parameter used for identifying a power loss during power transmission,
control the power transmitting circuit (<NUM>) to stop applying the second power (<NUM>) and prevent power from being applied to the coil (<NUM>) during a second period (Δt2),
identify a second Q-factor during the second period, and
identify a validity of the at least one parameter based on the first Q-factor or the second Q-factor.