Method for performing wireless charging control of an electronic device with aid of predetermined data in non-volatile memory, and associated apparatus

A method for performing wireless charging control of an electronic device and an associated apparatus are provided, where the method includes: performing at least one detection operation at a direct current (DC) output terminal of a rectifier of the electronic device to generate at least one detection result, wherein two alternating current (AC) input terminals of the rectifier are coupled to two terminals of a power input coil of the electronic device, and the at least one detection operation is not performed at the power input coil; and estimating input power of the power input coil according to the at least one detection result with aid of a set of predetermined data, and sending a packet carrying information corresponding to the estimated input power, for performing wireless charging foreign object detection (FOD), wherein the set of predetermined data is stored in a non-volatile (NV) memory of the electronic device.

BACKGROUND

The present invention relates to foreign object detection (FOD) of a wireless power transfer system, and more particularly, to a method for performing wireless charging control of an electronic device, and an associated apparatus.

According to the related art, a conventional wireless power transfer system may comprise a conventional transmitter pad that is arranged to charge a conventional electronic device wirelessly. As a foreign object nearby, such as a metallic objects or magnetic object, may absorb energy from the conventional transmitter pad, the foreign object may be heated. In a situation where the temperature of the foreign object increases rapidly, it may be harmful and dangerous. In order to solve this problem, some conventional FOD methods are proposed. However, further problems such as some side effects may occur. For example, inaccuracy of the input power estimation of the conventional electronic device may cause a false alarm or detection failure. In another example, the input power estimation of the conventional electronic device typically relies on a hardware component that may need to be carefully tuned in a design phase or a mass production phase of the conventional electronic device, causing related costs to be increased. Thus, a novel method is required to enhance the accuracy of the input power estimation for electronic devices that are wirelessly charged.

SUMMARY

It is an objective of the claimed invention to provide a method for performing wireless charging control of an electronic device, and an associated apparatus, in order to solve the above-mentioned problems.

According to at least one preferred embodiment, a method for performing wireless charging control of an electronic device is provided, where the method comprises the steps of: performing at least one detection operation at a direct current (DC) output terminal of a rectifier of the electronic device to generate at least one detection result, wherein two alternating current (AC) input terminals of the rectifier are coupled to two terminals of a power input coil of the electronic device; and estimating input power of the power input coil according to the at least one detection result with aid of a set of predetermined data, and sending a packet carrying information corresponding to the estimated input power, for performing wireless charging foreign object detection (FOD), wherein the set of predetermined data is stored in a non-volatile (NV) memory of the electronic device.

According to at least one preferred embodiment, an apparatus for performing wireless charging control of an electronic device is provided, where the apparatus comprises at least one portion of the electronic device. The apparatus comprises a NV memory, a detection module, and a controller, where the detection module is coupled to a DC output terminal of a rectifier of the electronic device, and the controller is coupled to the NV memory and the detection module. More particularly, two AC input terminals of the rectifier are coupled to two terminals of a power input coil of the electronic device. In addition, the NV memory is arranged to store information for the electronic device, and the detection module is arranged to perform at least one detection operation at the DC output terminal of the rectifier to generate at least one detection result. Additionally, the controller is arranged to estimate input power of the power input coil according to the at least one detection result with aid of a set of predetermined data, and send a packet carrying information corresponding to the estimated input power, for performing wireless charging FOD, wherein the set of predetermined data is stored in the NV memory.

It is an advantage of the present invention that the present invention method and the associated apparatus can accurately estimate the input power of the power input coil, and therefore the related art problems such as the aforementioned false alarm or detection failure can be prevented. In addition, as the set of predetermined data can be prepared in advance for products implemented according to the present invention method and the associated apparatus, it is unnecessary to use the aforementioned hardware component that needs to be carefully tuned.

DETAILED DESCRIPTION

Please refer toFIG. 1, which illustrates a diagram of an apparatus100for performing wireless charging control of an electronic device according to a first embodiment of the present invention, where the apparatus100may comprise at least one portion (e.g. a portion or all) of the electronic device. For example, the apparatus100may comprise a portion of the electronic device mentioned above, and more particularly, can be at least one hardware circuit such as at least one integrated circuit (IC) within the electronic device and associated circuits thereof. In another example, the apparatus100can be the whole of the electronic device mentioned above. In another example, the apparatus100may comprise a system comprising the electronic device mentioned above (e.g. a wireless power transfer system comprising the electronic device). Examples of the electronic device may include, but not limited to, a mobile phone (e.g. a multifunctional mobile phone), a personal digital assistant (PDA), and a personal computer such as a laptop computer.

As shown inFIG. 1, the apparatus100may comprise a non-volatile (NV) memory105(e.g. an electrically erasable programmable read only memory (EEPROM), or a Flash memory), a controller110(e.g. a microprocessor), a detection module120, an analog-to-digital converter (ADC)122, and a communications module130(labeled “Comm. module” inFIG. 1, for brevity), where the controller110is coupled to the NV memory105, and is coupled to the detection module120through the ADC122, and is further coupled to the communications module130, and the communications module130can be coupled to a coil such as a power input coil (not shown inFIG. 1) of the electronic device. According to this embodiment, the NV memory105is arranged to store information for the electronic device, such as predetermined information regarding wireless charging, and the controller110is arranged to perform wireless charging control. In addition, the detection module120is arranged to perform some detection operations (e.g. current detection operations and/or voltage detection operations) for the controller110, and the ADC122is arranged to perform analog-to-digital conversion on the detection signal Isense of the detection module120, in order to generate a digital signal, which may carry at least one digital value (e.g. one or more digital values). Additionally, the communications module130is arranged to wirelessly communicate with an external device (which is positioned outside the electronic device) for the controller110by utilizing the coil mentioned above, such as the aforementioned power input coil of the electronic device.

More particularly, the controller110may perform input power estimation in a situation where the electronic device is charged wirelessly, to generate accurate information regarding the power that is received through wireless charging, for performing wireless charging foreign object detection (FOD). As the apparatus100can accurately estimate the power that is received through wireless charging, the related art problems such as aforementioned false alarm or detection failure can be prevented. Regarding implementation details of the wireless charging FOD mentioned above, please refer to the Wireless Power Consortium (WPC) Qi V1.1 standard for more information.

Please note that, for better comprehension, the ADC122of this embodiment can be illustrated to be positioned outside the detection module120. This is for illustrative purposes only, and is not meant to be a limitation of the present invention. According to some variations of this embodiment, the ADC122can be integrated into the detection module120, while the associated operations of the detection module120and the ADC122mentioned in the embodiment shown inFIG. 1will not be hindered.

FIG. 2is a diagram of a wireless power transfer system200according to an embodiment of the present invention, where the apparatus100may comprise at least one portion (e.g. a portion or all) of the wireless power transfer system200. For example, the apparatus100may comprise a portion of the wireless power transfer system200, and more particularly, can be a wireless charging receiver100R (which can also be referred to as the receiver, for brevity) within the electronic device mentioned above, which means the apparatus100may comprise all components within the wireless charging receiver100R shown inFIG. 2. In another example, the apparatus100may comprise a portion of the wireless power transfer system200, and more particularly, can be the whole of the electronic device mentioned above, which means the apparatus100may comprise all components within the electronic device. In another example, the apparatus100can be the whole of the wireless power transfer system200.

As shown inFIG. 2, in addition to the wireless charging receiver100R, the wireless power transfer system200may further comprise a transmitter pad20equipped with a power output coil28. For better comprehension, the power output coil28can be illustrated outside the transmitter pad20. This is for illustrative purposes only, and is not meant to be a limitation of the present invention. According to some variations of this embodiment, the power output coil28can be integrated into the transmitter pad20. According to this embodiment, in addition to the NV memory105, the controller110, the detection module120, the ADC122, and the communications module130mentioned above, the wireless charging receiver100R may further comprise a power input coil38, a matching circuit40, a rectifier50, and a low dropout (LDO) regulator60(labeled “LDO” inFIG. 2, for brevity), where the detection module120is coupled to the direct current (DC) output terminal T21of the rectifier50of the electronic device through the ADC122, and the two alternating current (AC) input terminals T11and T12of the rectifier50are coupled to the two terminals of the power input coil38of the electronic device. In this embodiment, the terminal T22of the rectifier50can be regarded as a ground terminal, and the two terminals T21and T22can be utilized for coupling the next stage such as the LDO regulator60. More particularly, the rectifier50may obtain an AC input from the power input coil38through the two AC input terminals T11and T12of the rectifier50, and rectifies the AC input to provide a DC output at the DC output terminal T21, such as a DC voltage level Vrect with respect to a ground voltage level at the terminal T22(i.e. the ground terminal), where the ADC122may utilize the DC voltage level Vrect mentioned above (i.e. the DC voltage level Vrect shown inFIG. 1). For example, the AC input can be obtained from the power input coil38when the electronic device is wirelessly charged through the power input coil38by the transmitter pad20.

In practice, the matching circuit40may comprise some impedance components such as some capacitors. In addition, the detection module120may comprise a current sensing resistor R, where one of the two terminals of the current sensing resistor R (e.g. the left terminal thereof in this embodiment) is coupled to the DC output terminal T21of the rectifier50, and another of the two terminals of the current sensing resistor R (e.g. the right terminal thereof in this embodiment) is coupled to a DC input terminal of the next stage of the rectifier50, such as the upper left terminal of the LDO regulator60in this embodiment. Additionally, the ADC122mentioned above is coupled to the detection module120, and more particularly, is coupled to the current sensing resistor R of the detection module120in this embodiment, for performing analog-to-digital conversion on the detection signal Isense of the detection module120, in order to generate the digital signal mentioned in the embodiment shown inFIG. 1.

Based on the architecture shown inFIG. 2, electric power may be transferred from the left side (e.g. the input labeled “DC Power In” in the leftmost ofFIG. 2) to the right side (e.g. the input labeled “DC Power Out” in the rightmost ofFIG. 2) stage by stage, where power loss may occur in some of the stages in this architecture. In a situation where a foreign object, such as a metallic objects or magnetic object, occasionally drops nearby and starts absorbing energy from the transmitter pad20of this embodiment, the controller110can accurately estimate the received power of the power input coil38and send a received power report corresponding to the received power (e.g. a received power packet corresponding to the estimated value of the received power) to the transmitter pad20through related components (e.g. the communications module130, the matching circuit40, the power input coil38, and the power output coil28) for performing wireless charging FOD. As a result, the transmitter pad20may stop outputting power toward the electronic device right away, where the related art problems such as the aforementioned false alarm or detection failure can be prevented.

According to this embodiment, the LDO regulator60can be utilized as the next stage of the rectifier50. This is for illustrative purposes only, and is not meant to be a limitation of the present invention. According to some variations of this embodiment, the LDO regulator60can be omitted, and some circuits of the electronic device mentioned above may directly utilize the aforementioned DC output such as the DC voltage level Vrect mentioned above.

FIG. 3illustrates a flowchart of a method300for performing wireless charging control of an electronic device according to an embodiment of the present invention. The method300shown inFIG. 3can be applied to the apparatus100shown inFIG. 1(more particularly, the wireless power transfer system200of the embodiment shown inFIG. 2), and can be applied to the controller110thereof. The method can be described as follows.

In Step310, the detection module120performs at least one detection operation (e.g. one or more detection operations) at the DC output terminal T21of the rectifier50to generate at least one detection result (e.g. one or more detection results). More particularly, the detection module120detects at least one voltage difference (e.g. one or more voltage differences) between the two terminals of the current sensing resistor R, and utilizes the ADC122to convert the aforementioned at least one voltage difference into the aforementioned at least one detection result. For example, the aforementioned at least one detection result may represent at least one digital value (e.g. one or more digital values) carried by the digital signal mentioned in the embodiment shown inFIG. 1, and in this situation, the digital signal mentioned above may carry the aforementioned at least one detection result. In addition, the detection signal Isense of the detection module120may carry the aforementioned at least one voltage difference (e.g. the aforementioned one or more voltage differences).

In Step320, the controller110estimates input power of the power input coil38(e.g. the received power mentioned above) according to the aforementioned at least one detection result (more particularly, the detection result that is just obtained in Step310) with aid of a set of predetermined data, and sends a packet carrying information corresponding to the estimated input power, for performing wireless charging FOD, where the set of predetermined data is stored in the NV memory105. For example, the controller110sends the packet carrying the information corresponding to the estimated input power to the transmitter pad20through the related components mentioned above (e.g. the communications module130, the matching circuit40, the power input coil38, and the power output coil28).

In practice, the aforementioned at least one detection result may indicate a current that is output through the DC output terminal T21of the rectifier50, since the magnitude of the current passing through the current sensing resistor R can be derived from dividing the aforementioned at least one detection result such as the aforementioned at least one digital value (which can be regarded as the digital form of the aforementioned at least one voltage difference) by the resistance value of the current sensing resistor R.

According to this embodiment, the set of predetermined data mentioned in Step320can be prepared in advance, and can be stored in the NV memory105in a specific procedure (e.g. a calibration procedure) during the mass production phase of the electronic device mentioned above. As a result, the related art problem of relying on the aforementioned hardware component that needs to be carefully tuned can be prevented.

In addition, in this embodiment, the controller110may estimate the input power of the power input coil38according to the aforementioned at least one detection result by selectively utilizing at least one portion of the set of predetermined data as a look up table and by selectively utilizing a function obtained from curve fitting of at least one portion of the set of predetermined data (e.g. by selectively utilizing at least one portion of the set of predetermined data as a look up table and/or by utilizing a function obtained from curve fitting of at least one portion of the set of predetermined data), based on different conditions or needs. For example, the controller110may estimate the input power of the power input coil38according to the aforementioned at least one detection result by utilizing at least one portion of the set of predetermined data as a look up table. In another example, the controller110may estimate the input power of the power input coil38according to the aforementioned at least one detection result by utilizing a function obtained from curve fitting of at least one portion of the set of predetermined data. In another example, the controller110may estimate the input power of the power input coil38according to the aforementioned at least one detection result by utilizing at least one portion of the set of predetermined data as a look up table and by utilizing a function obtained from curve fitting of at least one portion of the set of predetermined data. As a result of selectively utilizing at least one portion of the set of predetermined data as a look up table and selectively utilizing a function obtained from curve fitting of at least one portion of the set of predetermined data, the input power of the power input coil38can be accurately estimated.

Additionally, the aforementioned at least one detection operation is typically performed in a DC power region of the electronic device, and the input power of the power input coil38belongs to an AC power region of the electronic device. Please note that the aforementioned at least one detection operation is not performed at the power input coil38, where the power input characteristics of the power input coil38will not be influenced by the detection module120and the aforementioned at least one detection operation since the power input coil38and the detection module120are positioned at different sides of the rectifier50in the architecture shown inFIG. 2, respectively, and are in different types of power regions (e.g. the AC power region and the DC power region mentioned above), respectively.

FIG. 4illustrates a control scheme involved with the method300shown inFIG. 3according to an embodiment of the present invention, where the controller110may estimate the input power of the power input coil38according to the aforementioned at least one detection result by selectively utilizing at least one portion of the set of predetermined data as a look up table and by selectively utilizing a function obtained from curve fitting of at least one portion of the set of predetermined data.

According to this embodiment, the set of predetermined data may comprise a plurality of data points of (Isense, PE), where the notation “PE” may stand for the estimated power. In addition, the power value of each data point within the plurality of data points of (Isense, PE), such as the estimated power PE, can be prepared in advance, and more particularly, can be an actual measurement value of (or associated with) the input power. As the plurality of data points of (Isense, PE) can be prepared in advance and can be stored in the NV memory105in advance, the plurality of data points of (Isense, PE) can be utilized as a function f1(Isense) for converting the aforementioned at least one detection result (more particularly, the detection result that is obtained in Step310) into the estimated input power mentioned in Step320. For example, the power value of each data point within the plurality of data points of (Isense, PE), such as the estimated power PE, can be an actual measurement value that is measured (and provided) by specific equipment such as CATS™ Q100 Qi MDT (Mobile Device Tester) known in the related art. For brevity, similar descriptions for this embodiment are not repeated in detail here.

For better comprehension, the horizontal axis in the embodiment shown inFIG. 4can be illustrated with the unit of milliampere (mA). This is for illustrative purposes only, and is not meant to be a limitation of the present invention. Please note that the aforementioned at least one detection result may indicate the current that is output through the DC output terminal T21of the rectifier50, since the magnitude of the current passing through the current sensing resistor R can be derived from dividing the aforementioned at least one detection result such as the aforementioned at least one digital value (which can be regarded as the digital form of the aforementioned at least one voltage difference) by the resistance value of the current sensing resistor R. Thus, according to some variations of the embodiment shown inFIG. 4, the horizontal axis can be illustrated with the actual unit of the aforementioned at least one detection result such as the aforementioned at least one digital value (which can be regarded as the digital form of the aforementioned at least one voltage difference), and more particularly, can be illustrated with any unit regarding voltage, such as millivolt (mV). For brevity, similar descriptions for these variations are not repeated in detail here.

In some embodiments of the present invention, such as some variations of the embodiment shown inFIG. 4, in order to send the aforementioned received power report corresponding to the received power (e.g. the aforementioned received power packet corresponding to the estimated value of the received power) to the transmitter pad20, the received power Preceived should be determined first. For example, in a variation of the embodiment shown inFIG. 4, given that the notation “PM” is used for representing the measured power, the apparatus100(more particularly, the controller110thereof) of this variation may determine the received power Preceived according to the following equations:
Preceived=PE+PM, withPM=Vrect*Isense; andPE=f1(Isense);
where the estimated power PE of this variation may represent the estimated power of the power input coil38, the matching circuit40, and the rectifier50, and the measured power PM of this variation may represent the measured power of the detection module120, the LDO regulator60, and the loading of the wireless charging receiver100R (i.e. the loading coupled to the LDO regulator60). This is for illustrative purposes only, and is not meant to be a limitation of the present invention. For brevity, similar descriptions for this variation are not repeated in detail here.

According to another variation of the embodiment shown inFIG. 4, the notation “f2” can be used for representing another function, and more particularly, a function for converting the aforementioned at least one detection result (more particularly, the detection result that is obtained in Step310) into the estimated input power mentioned in Step320. The apparatus100(more particularly, the controller110thereof) of this variation may determine the received power Preceived according to the following equation:
Preceived=f2(Isense);
where all of the power values that are needed for preparing the function f2 (Isense), such as those of the power input coil38, the matching circuit40, the rectifier50, the detection module120, the LDO regulator60, and the loading of the wireless charging receiver100R (i.e. the loading coupled to the LDO regulator60) can be measured (and provided) by the aforementioned specific equipment such as CATS™ Q100 Qi MDT (Mobile Device Tester) mentioned above in advance, and the function f2 (Isense) (or the data points thereof) can be stored in the NV memory105in advance. For brevity, similar descriptions for this variation are not repeated in detail here.