Integrated circuit for wireless charging and operating method thereof

An integrated circuit for wireless charging and a wireless charging method in an integrated circuit are provided. The integrated circuit includes a first wireless communication unit configured to support a first wireless communication method; a second wireless communication unit configured to support a second wireless communication method; a first route selection unit configured to perform a selection from among a first power input according to wired charging and a second power input according to wireless charging to be allowed as input; a second route selection unit configured to perform a selection from among a power between a third power input from a battery and a fourth power input according to wireless charging to be allowed as input; a power block configured to receive the power from any the first and second route selection units; and a controller configured to control an operation of the first and second route selection units.

PRIORITY

This application claims priority under 35 U.S.C. §119(a) to Korean Application Serial Nos. 10-2012-0144794 & 10-2013-0140955, which were filed in the Korean Intellectual Property Office on Dec. 12, 2012 & Nov. 19, 2013, the entire content of each of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to wireless charging, and more specifically, to a Wi-Fi/Bluetooth combo Integrated Circuit that can be applied in a wireless charging field.

2. Description of the Related Art

Bluetooth Low Energy (BLE) standards have been recently determined to be employed for signaling in Alliance for Wireless Power (A4WP) in relation to the resonance type wireless charging technology. Accordingly, a BLE (e.g., Bluetooth (BT) 4.0 standards) single Integrated Circuit (IC) or a Wi-Fi/BT 4.0 combo IC may be used according to user's preference, as long as the signaling follows the BLE standards.

However, an interface (I/F) of existing Wi-Fi/BT combo ICs are too complex to be used in signaling for wireless charging. The Wi-Fi/BT combo IC is dominated by an Application Processor (AP). However, when performing wireless charging, control operations are performed and data is transmitted/received in an order of control operations performed by the AP, the Wi-Fi/BT combo IC, and a wireless charging power IC.

FIG. 1is a diagram illustrating a structure of a conventional terminal having a wireless charging device. Referring toFIG. 1, when the wireless charging device is installed within a terminal10such that a back cover15having a resonator14therein is mounted to the terminal10, a separate Integrated Circuit (IC) (i.e., a BLE unit IC16or a Wi-Fi/BT combo IC17) is used for BLE signaling.

FIG. 2is a diagram illustrating a structure of another conventional terminal having a wireless charging device. As illustrated inFIG. 2, an existing Wi-Fi/BT combo IC19employed for a terminal20may be embedded in the terminal20and used instead of a BLE unit IC18. When the Wi-Fi/BT combo IC19is used, wireless charging cannot be performed in a state in which the terminal20is turned off regardless of the presence of a back cover15having a resonator therein.

In general, in a case of a single combo chip in which Wi-Fi, BT, etc. are implemented, among a Bluetooth core and a Wi-Fi core, the Wi-Fi core operates as a master core. Thus, the Wi-Fi core consuming a large amount of power should be driven for BT and BLE communication. In addition, BT and BLE profiles required for the BT and BLE communication exist in a stack within an Application Processor (AP), and therefore wireless charging through the BT and BLE communication cannot be performed until the AP is driven. Namely, the wireless charging cannot be performed in the dead battery situation in which the AP cannot be driven.

SUMMARY OF THE INVENTION

Aspects of the present invention are provided to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below.

Accordingly, an aspect of the present invention is to provide an integrated circuit for wireless charging and a wireless charging method in an integrated circuit for wireless charging, in which a Wi-Fi/BT combo IC performs signaling during wireless charging, so that wireless charging can be performed even dead battery.

In accordance with an aspect of the present invention, an integrated circuit for wireless charging is provided. The integrated circuit includes a first wireless communication unit configured to support a first wireless communication method; a second wireless communication unit configured to support a second wireless communication method; a first route selection unit configured to perform a selection from among a first power input according to wired charging and a second power input according to wireless charging to be allowed as input; a second route selection unit configured to perform a selection from among a power between a third power input from a battery and a fourth power input according to wireless charging to be allowed as input; a power block configured to receive the power from any the first and second route selection units; and a controller configured to control an operation of the first and second route selection units.

In accordance with another aspect of the present invention, a wireless charging method in an integrated circuit for wireless charging is provided. The wireless charging method includes determining whether there is receipt of at least one of a first power input according to wired charging and a second power input according to wireless charging; performing a selection to allow supply of the first power input according to the wired charging in response to a determination that the first power is input according to the wired charging and the second power is input according to the wireless charging; and performing at least one of wireless network communication and contactless near field wireless communication by receiving the first power input according to the wired charging.

Embodiments of the present invention are described in detail as follows with reference to the accompanying drawings. Embodiments to the present invention are not limited to particular forms described herein, but include all modifications, equivalents, and alternatives falling within the scope of the invention.

While terms including ordinal numbers, such as “first” and “second,” etc., may be used to describe various components herein, such components are not limited by the above terms. The terms herein are used merely used for the purpose distinguishing elements from the other elements. For example, a first element could be termed a second element, and similarly, a second element could be also termed a first element without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

The terms used in this application are provided for the purpose of describing particular embodiments only and do not limit the invention. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms such as “include” and/or “have” may be construed to denote a certain characteristic, number, step, operation, constituent element, component or a combination thereof, but may not be construed to exclude the existence of or a possibility of addition of one or more other characteristics, numbers, steps, operations, constituent elements, components or combinations thereof.

According to an embodiment of the present invention, a wireless power receiver is a rechargeable battery powered device. Such a device may be, for example, a terminal, a portable terminal, a mobile terminal, a communication terminal, a portable communication terminal, a portable mobile terminal, or the like. When charging a battery of the wireless power receiver, electrical energy is supplied to the battery through a separate charging device. In general, the charging device and the battery have separate contact terminals, respectively, at respective exteriors thereof and are electrically connected to each other through mutual contact of the contact terminals. A power supplied through the electrical connection may be referred to as wired power. Meanwhile, power supplied through a method in which the battery is automatically charged only if the wireless power receiver is put on a charging pad while not being connected with the separate charging device may be referred to as wireless power.

A mobile phone is described herein as an example of representative configuration of the electronic device according to embodiments of the present invention. Some elements in the representative configuration of such an electronic device may be omitted or changed as needed in accordance with embodiments of the present invention.

FIG. 3is a block diagram illustrating a structure of a wireless power receiver having a Wi-Fi/Bluetooth (BT) combo Integrated Circuit (IC) therein according to an embodiment of the present invention. A portable terminal is described herein as representative configuration of the wireless power receiver inFIG. 3, and some elements in the representative configuration of the wireless power receiver may be omitted or changed as needed in accordance with embodiments of the present invention. Referring toFIG. 3, a terminal100includes an Application Processor (AP)110, a Power Management Integrated Circuit (PMIC)120, a Wireless Power Transfer (WPT) power IC130, and a Wi-Fi/BT combo IC150.

A back cover200including a resonator210is mounted to the terminal100, and the terminal100includes the Wi-Fi/BT combo IC150and is connected with a battery300. Further, the Wi-Fi/BT combo IC150is connected with a serial interface (I/F), an interrupt, and a power (e.g., battery300).

The resonator210receives a wireless resonance signal transmitted from a resonance signal generator of a wireless power transmitter (not shown).

The AP110may be configured with an integrated control chip (not shown) performing various functions of a Central Processing Unit (CPU), such as data conversion, a memory control, a bus control, etc. The AP110also includes (not shown) a non-volatile memory. Data required for low power wireless communication and data (a Wi-Fi profile, etc.) required for wireless network communication, such as Wi-Fi, are stored in the non-volatile memory.

A series of processes performed with respect to the AP110is described as follows. First, the AP110mounted to the terminal100is set to be woken up when a request for power-on is input. Accordingly, when a power-on request is input, the wireless power receiver checks a state of the battery300and wakes up the AP110when a level of the battery is at least equal to a threshold value.

The PMIC120performs both a function of receiving wired power supplied from the battery300mounted to the terminal100and a function of charging the battery300with wireless power received from the wireless power transmitter or a function of transferring the wireless power to a low power wireless communication unit (not shown) within the Wi-Fi/BT combo IC150.

The WPT power IC130includes an Electro-Magnetic Interference (EMI) filter131, an active synchronous rectifier132, a synchronous buck133, an output enabler134, an Over-Voltage Power (OVP) clamping circuit135, a Low Drop-Out (LDO) linear regulator136, an Analog-Digital Converter (ADC)137, and a serial Input/Output (I/O)138.

The EMI filter131removes noise from the signal received through the resonator210. The active synchronous rectifier132and the LDO136rectify Alternating Current (AC) power received through the resonator210to Direct Current (DC) power. The synchronous buck133supplies power of 5 V for other elements, such as the PMIC120, for example. As described above, the active synchronous rectifier132, the synchronous buck133, and the LDO136adjust the battery power and supply the power adjusted in advance as power for the respective elements of the wireless power receiver. Further, the OVP clamping circuit135prevents power loss due to power voltage overhead. The serial I/O138is connected to a serial I/O152of the Wi-Fi/BT combo IC150through an Inter-Integrated Circuit (I2C), and is connected to a Micro Controller Unit (MCU)153of the Wi-Fi/BT combo IC150through a start signal INT.

The Wi-Fi/BT combo IC150is a contactless near field wireless communication unit that supports a first wireless communication method and a second wireless communication method. A wireless network function and a low power wireless communication function are illustrated examples of the first and second wireless communication methods. The wireless network function is performed by a Wi-Fi communication unit (not shown), and the low power wireless communication function is performed by a BT communication unit (not shown) and a BLE communication unit (not shown). Here, the Wi-Fi communication unit is connected with a Radio Frequency (RF) switching151under the control of the BT communication unit operating as a master in order to connect with an external server or to execute an operation.

Hereinafter, an embodiment of the present invention is described with reference toFIGS. 3 and 4.FIG. 4is a diagram illustrating a structure of a Wi-Fi/BT combo IC illustrated inFIG. 3. Referring toFIG. 4, due to the structure of Wi-Fi/BT combo IC150, the terminal100is able to wake up the Wi-Fi/BT combo IC150during wireless charging, even in a situation where a battery of a device that includes the Wi-Fi/BT combo IC150is dead. The dead battery situation indicates a state in which the battery300of the terminal100is completely discharged so that the terminal100is powered off. Therefore, the above-described embodiment of the present invention provides a Wi-Fi/BT combo IC150that can perform wireless charging even in the state in which the terminal100is powered off.

Referring toFIG. 4, a first route selection unit154and a second route selection unit155are connected to an internal power terminal156of the Wi-Fi/BT combo IC150. Here, a combination of the first and second route selection units154and155may form a switching circuit that is controlled by the MCU153within the Wi-Fi/BT combo IC150through a control line. A combination of the first and second route selection units154and155may also be referred to as a reverse blocking circuit. The internal power terminal156switches external input power on/off, and thereby is able to select at least one of an existing power of 1.8 V from the PMIC120, existing power received from a battery, power supplied through wireless charging, and power of 1.8 V supplied from the WPT power IC130through wireless charging, according to various situations. The internal power terminal156is a power block that receives power and supplies the power to the respective elements within the Wi-Fi/BT combo IC150, and receives the power provided via any one of the first and second route selection units154and155.

The first route selection unit154performs a selection such that any one of a first power input according to wired charging and a second power input according to wireless charging is input to the internal power terminal156under the control of the MCU153.

The second route selection unit155performs a selection such that any one of a third power input from the battery and a fourth power input according to wireless charging is input to the internal power terminal156under the control of the MCU153.

The power block (i.e., the internal power terminal156) receives power from any one of the first and second route selection units154and155, and supplies the power to the respective elements within the Wi-Fi/BT combo IC150. For example, when only the existing power (the existing power of 1.8 V or the existing power received from the battery) is supplied, the first route selection unit154may allow the existing power to be input to the internal power terminal156by control signaling from the Wi-Fi/BT combo IC150. When both the existing power and the wireless charging power (the power of 1.8 V supplied through the wireless charging or the power supplied through the wireless charging) are supplied, the internal power terminal156may preferentially receive an input of the existing power. Further, when only the wireless charging power but not the existing power is supplied, the internal power terminal156may receive the wireless charging power to use the same as an input.

As another example, when the existing power is supplied, the internal power terminal156may use the existing power as an input. When both the existing power and the wireless charging power are supplied, the second route selection unit155may allow the wireless charging power to be preferentially input to the internal power terminal156by control signaling from the Wi-Fi/BT combo IC150. Further, when only the wireless charging power but not the existing power is supplied, the internal power terminal156may receive the wireless charging power to use the same as an input. The power supplied through the internal power terminal156as described above is supplied to the respective elements within the Wi-Fi/BT combo IC150, and the Wi-Fi/BT combo IC150is supplied with the power to perform wireless network communication or contactless near field wireless communication.

FIG. 5is a diagram illustrating a configuration of an internal circuit of a power receiver according to an embodiment of the present invention.

FIG. 5illustrates a connection relation between respective elements and input signals. Although the internal circuit of the power receiver may be configured as illustrated inFIG. 5, the internal circuit may also be configured as illustrated inFIGS. 6 and 7.FIG. 6is a diagram illustrating a configuration of an internal circuit of a power receiver according to another embodiment of the present invention, andFIG. 7is a diagram illustrating a configuration of an internal circuit of a power receiver according to further another embodiment of the present invention. Elements inFIGS. 5 to 7that perform the same functions as corresponding elements inFIG. 3, are denoted by the same reference numerals.

Power input terminals of a Wi-Fi/BT combo IC150may be divided into two types, i.e., a power input terminal for wired charging and a power input terminal for wireless charging. Switching between the two power input terminals may exert a large influence on power efficiency of the wireless power receiver. Accordingly, the switching between the two power input terminals may be performed based on the following table. Table 1 corresponds to an example of a VIO 1.8 V power switching table.

TABLE 1From Power IC forInput power source of Power blockFrom PMICwireless chargingwithin ComboLLCOMBO IC OFFLHPOWER IC FOR WIRELESSCHARGINGHHFROM WIRELESS POWER ICHLVIO FROM PMIC

Referring to Table 1 above, when a low (‘L’) signal is input from a PMIC120and an ‘L’ signal is input from a power IC130for wireless charging, there is no input for wired charging and wireless charging. Thus, the combo IC, i.e., the Wi-Fi/BT combo IC150is maintained in an Off state. Meanwhile, when an ‘L’ signal is input from the PMIC120and a high (‘H’) signal is input from the power IC130for wireless charging, there is a power input for wireless charging. Thus, the Wi-Fi/BT combo IC150receives power from the power IC130for wireless charging.

Further, when an ‘H’ signal is input from the PMIC120and an ‘H’ signal is input from the power IC130for wireless charging, there are both a power input for wired charging and a power input for wireless charging. In this case, the Wi-Fi/BT combo IC150receives power from the PMIC120since the wired charging is stable. Moreover, when an ‘H’ signal is input from the PMIC120and an ‘L’ signal is input from the power IC130for wireless charging, there is only a power input for wired charging. Thus, the Wi-Fi/BT combo IC150receives power from the PMIC120.

Meanwhile, Table 2 corresponds to an example of a VBATT power switching table.

TABLE 23.3 V From Power ICInput power source of Power blockFrom Batteryfor wireless chargingwithin ComboLLCOMBO IC OFFLHFROM WIRELESS POWER ICHHVBATT FROM BATTERYHLVBATT FROM BATTERY

Table 2 is different from Table 1 in that power (VBATT) is input from a battery300but not from the PMIC120in a case in which an ‘H’ signal is input from the battery300and an ‘H’ signal is input from the power IC130for wireless charging, and in a case in which an ‘H’ signal is input from the battery300and an ‘L’ signal is input from the power IC130for wireless charging.

As described above, if the power of 1.8 V is supplied from the power IC130for wireless charging to the Wi-Fi/BT combo IC150, a BLE function within the Wi-Fi/BT combo IC150automatically starts.

An operation of the internal circuit of the wireless power receiver ofFIGS. 5 to 7according to the wired and/or wireless charging is described as follows.

FIG. 8is a flowchart illustrating an operation in accordance with wired charging and a wireless charging input during the wired charging while a wireless power receiver is turned off, according to an embodiment of the present invention.

Referring toFIG. 8, when reception of wired power is detected in step1000in a state where the wireless power receiver is turned off, the power is supplied to all elements including an AP110in step1005. For example, the wireless power receiver may be connected with a wired charging terminal through an external device connection unit such as a charging connection jack of the wireless power receiver. When a wired charger is connected to the wireless power receiver as described above, an IF PMIC140ofFIG. 5detects a wired connection to transmit an On signal to a PMIC120, and supplies power of VBatteryand power of VPH_PWR to the battery300and the PMIC120, respectively, for power supply to the battery and the entire system. Then, the PMIC120supplies the power to a display (not shown) and a clock (not shown) as well as the AP110and a Wi-Fi/BT combo IC150, which require power for a minimum power mode. At this time, 1.8V clock power is used for the Wi-Fi/BT combo IC150.

Next, the PMIC120applies a PWR_RESET to the AP110. Then, the AP110resets peripheral devices while booting up, and initializes General Purpose Input/Output (GPIO). At this time, if a user pushes a hold key to identify a charging state, the AP110processes the key input. Accordingly, an icon that indicates the charging state may be displayed on a display unit. At this time, since the wired charging is being performed, the Wi-Fi/BT combo IC150for wireless charging is not required to operate. When reception of wireless power is not detected during the wired charging in step1010, the operation flow returns to step1000and a determination of whether the reception of the wired power is continued is performed. If the reception of the wired power is interrupted (e.g., when a user removes the wired charger from the wireless power receiver), power supply to the entire system of the wireless power receiver is interrupted and then the wireless power receiver is maintained in an Off state, in step1015.

However, when there is a determination that the wireless power is received in step1010(e.g., when a user puts the wireless power receiver on a wireless charging pad while the wired charging terminal is connected to the wireless power receiver), a power of 1.8 V is applied from a power IC130to the Wi-Fi/BT combo IC150. Accordingly, in step1020, elements related to low power near field wireless communication (i.e., the Wi-Fi/BT combo IC150) is enabled and boots up by using a BLE stack (not shown) within the Wi-Fi/BT combo IC150. At this time, the power IC130may identify that the wired charging is being performed, by receiving a wired charging detection signal by a TA-DET pin (not shown) from a TA-USB. Accordingly, the power IC130sets continuation of the wired charging in an internal register and sends a start signal INT to an MCU153.

The Wi-Fi/BT combo IC150may ascertain a situation of the power IC130through I2C communication, and before starting the wireless charging, a determination is performed as to whether the wired charging is being performed, in step1025.

If the wired charging is interrupted, charging is performed by using wireless power, in step1030. Specifically, if a connection for the wired charging is lost, a TA-DET pin of the power IC130becomes ‘L’ to thereby generate a start signal INT. Then, the Wi-Fi/BT combo IC150ascertains a situation within the power IC130and informs a wireless power transmitter of the situation. Accordingly, the wireless power transmitter increases the power transmitted to the wireless power receiver and then issues a charge command CHARGER ENable (EN). Then, the Wi-Fi/BT combo IC150of the wireless power receiver allows the power IC130to transmit the power to the IF PMIC140. More specifically, the power is transmitted to the IF PMIC140in order to charge the battery300.

However, after a determination in step1025that the wired power is being received (i.e., the Wi-Fi/BT combo IC150is simultaneously performing the wired and wireless charging), in step1035, a power switch that allows the power to be supplied through the wired charging is selected and used, and the wireless power receiver may communicate with the wireless power transmitter to inform the wireless power transmitter that the wired charging is being performed. Namely, a first interrupter151may be switched on/off such that the power supplied through the wired charging is selected. Accordingly, the IF PMIC140supplies the power to all the elements within the wireless power receiver so that the wired charging may be performed.

The wireless power transmitter may output an indication that the wired charging is being performed on the wireless charging pad. The wireless power transmitter may reduce the power transmitted to the wireless power receiver. The wireless power transmitter may also operate in a standby state without transmitting the power for a predetermined period of time until wireless charging with the wireless power receiver is restarted.

FIG. 9is a flowchart illustrating an operation in accordance with wireless charging and a wired charging input during the wireless charging in a state where a wireless power receiver is turned off, according to an embodiment of the present invention.

Referring toFIG. 9, when reception of wireless power is detected in a state where the wireless power receiver is turned off in step1100, an element related to low power near field wireless communication (i.e., a Wi-Fi/BT combo IC150) is enabled and then boots up by using a BLE stack, in step1105. Specifically, when the power reception for wireless charging is detected, a power IC130supplies power of 1.8 V to the Wi-Fi/BT combo IC150and the Wi-Fi/BT combo IC150is then enabled by itself, so as to operate a crystal of 37.4 MHz, and boots up by using the BLE stack. Since the power of 1.8 V is not applied from a PMIC120to a VIO of the Wi-Fi/BT combo IC150, the Wi-Fi/BT combo IC150ascertains that the wireless charging is being performed in the Off state, and in step1110, notifies a wireless power transmitter that the wireless charging is being performed in the Off state.

When a charge command is received from the wireless power transmitter in response to the notification, the Wi-Fi/BT combo IC150performs charging by using the wireless power in step1115. Specifically, the Wi-Fi/BT combo IC150activates a CHARGER_EN pin (not shown) and allows the wireless charging power IC130to transmit the power to an IF PMIC140. More specifically, the power is transmitted to the IF PMIC140for charging of a battery300. The IF PMIC140supplied with the power transfers an On signal to the PMIC120, and supplies power of VBattery and power of VPH_PWR for power supply to the battery and the entire system. Then, the PMIC120starts to operate as the On signal is transferred, and supplies the power to a display and a clock as well as an AP110and the Wi-Fi/BT combo IC150.

The AP110preferentially resets peripheral ICs and then initializes GPIO in a boot-up step. The Wi-Fi/BT combo IC150may be reset by a signal such as BT_REG_ON, WL_REG_ON, etc., which are transferred from the AP110. When the VIO of the Wi-Fi/BT combo IC150receives power of 1.8 V from the PMIC120, an internal SWitch (SW) MUltipleXer (MUX) circuit uses the power of the PMIC120. Here, although the signal BT_REG_ON from the AP110represents an ‘L’ state, the Wi-Fi/BT combo IC150operates by using the power of 1.8 V transferred from the power IC130.

Next, in step1120, the Wi-Fi/BT combo IC150determines whether the wireless charging is completed. If the wireless charging is completed, the Wi-Fi/BT combo IC150informs the wireless power transmitter of the completion of charging, in step1125. Specifically, if the Wi-Fi/BT combo IC150monitors a small amount of current exiting from the power IC130at the time of buffering, the Wi-Fi/BT combo IC150informs the wireless power transmitter of the completion of charging. Accordingly, the wireless power transmitter may display the completion of charging on a wireless charging pad.

Meanwhile, an input for wired charging may be entered during the wireless charging. For example, a user may connect a wired charging terminal to the wireless power receiver that has already been placed on the wireless charging pad.

Accordingly, before the wireless charging is completed in step1120, a determination is made in step1130as to whether reception of wired power is detected during the wireless charging. If the reception of the wired power is not detected, operation flow returns to step1115and the wireless charging is performed. However, if the reception of the wired power is detected, the power is supplied to all elements including the AP1110in step1135. More specifically, when an input for the wired charging is entered during the wireless charging, the wired charging is selected and the IF PMIC140charges the wireless power receiver by using the wired charging power.

Further, an ‘H’ signal is detected in TA-DET of the power IC130so that a start signal INT is generated, and the Wi-Fi/BT combo IC150may ascertain an event situation of the power IC130by using the I2C. More specifically, referring to Table 1 above, since an ‘H’ signal is detected from the power IC130and an ‘H’ signal according to a wired charging connection is detected from the PMIC130, an input power source within the Wi-Fi/BT combo IC150may be determined as wired charging. Accordingly, in step1140, the Wi-Fi/BT combo IC150performs charging by using the wired power and informs the wireless power transmitter that the wired charging is being performed. Next, the Wi-Fi/BT combo IC150deactivates the CHARGER_EN pin of the power IC130.

The wireless power transmitter outputs an indication that the wired charging is being performed on the wireless charging pad. Then, the wireless power transmitter reduces the power transmitted to the wireless power receiver. At this time, if a user stops the wired charging, an ‘L’ signal is detected in the TA-DET of the power IC130so that a start signal INT is generated, and the Wi-Fi/BT combo IC150may grasp, by using the I2C, that the event situation of the power IC130indicates the interruption of the wired charging. Accordingly, the Wi-Fi/BT combo IC150requests the wireless power transmitter to increase the transmitting power again. More specifically, when the wired charging is interrupted, the Wi-Fi/BT combo IC150makes the request to the wireless power transmitter, in order for charging to continue via wireless charging.

As described above, when the wireless charging, the wired charging, the wired charging during the wireless charging, or the wireless charging during the wired charging is performed while the wireless power receiver is turned off, the Wi-Fi/BT combo IC150does not operate, or operates based on the BLE stack of the internal memory thereof to thereby operate in a Stand Alone (SA) mode. More specifically, when there is not enough power to wake up the application processor or an input through a power button is not entered, so that the wireless power receiver is maintained in the Off state, the Wi-Fi/BT combo IC150may not be supplied with a full stack from the AP110and therefore may not operate in a Non-Stand Alone (NSA) mode. The NSA mode is an operation mode based on the loaded stack by loading to the memory within Wi-Fi/BT combo IC150by inputting the stack, which is the communication method for the wireless charging from AP110.

However, when the wireless charging, the wired charging, the wired charging during the wireless charging, or the wireless charging during the wired charging is performed while the wireless power receiver is turned on, a mode change between the SA mode and the NSA mode is made. Accordingly, the Wi-Fi/BT combo IC150may operate based on the BLE stack of the internal memory thereof, or may also receive an input of the full stack from the AP110to operate based on the full stack from the AP110.

An operation of internal circuit elements of a wireless power receiver when the wireless power receiver is turned on is described as follows with reference toFIG. 10.

FIG. 10is a flowchart illustrating an operation in accordance with wired charging and a wireless charging input during the wired charging in a state where a wireless power receiver is turned on, according to an embodiment of the present invention.

Referring toFIG. 10, in step1200, reception of wired power is monitored while the wireless power receiver is turned on. For example, when a user inserts a wired charging terminal into a charging terminal of the wireless power receiver for wired charging, the wired power is received. Specifically, an IF PMIC140transmits an On signal to a PMIC120, and supplies power of VBattery and power of VPH_PWR for power supply to a battery and the entire system. Accordingly, an AP110ascertains that the wired charging is being performed, and controls display of a charging icon. At this time, the AP110transfers an ‘L’ signal to a Wi-Fi/BT combo IC150by BT_REG_ON. Then, as illustrated in Table 2, the Wi-Fi/BT combo IC150does not operate based on the ‘L’ signal output from a battery300through the AP110and an ‘L’ signal from a power IC130, which indicates that there is no connection for wireless charging.

Thereafter, when communicating with the Wi-Fi/BT combo IC150, the AP110outputs an ‘H’ signal by BT_WAKE and transfers the ‘H’ signal to the Wi-Fi/BT combo IC150by the BT_REG_ON, in order to wake up the circuit unit performing contactless near field wireless communication. Then, the Wi-Fi/BT combo IC150starts to operate, and transfers an ‘H’ signal to the AP110by BT_HOST_WAKE to communicate with the AP110through UART. When the Wi-Fi/BT combo IC150wakes up in the manner described above, the Wi-Fi/BT combo IC150is used through communication with a BT ear set and a BT product. Otherwise, when communication is not performed for a long period of time, the AP110outputs an ‘L’ signal by the BT_WAKE, and the Wi-Fi/BT combo IC150then shifts to a sleep state. At this time, the Wi-Fi/BT combo IC150receives, for example, a BT 4.0 full stack from the AP110to load the same into a RAM, and communicates with the wireless power transmitter based on the full stack.

Meanwhile, an input for wireless charging may be entered during the wired charging. For example, a user may put the wireless power receiver on a wireless charging pad, while a wired charging terminal is connected to the wireless power receiver.

Accordingly, before the wired charging is completed, a determination is made in step1210as to whether reception of wireless power is detected during the wired charging. If the reception of the wireless power is detected, the IF PMIC140charges the wireless power receiver by using the wired charging power.

At this time, a determination is made in step1215as to whether the element related to low power near field wireless communication, i.e., the Wi-Fi/BT combo IC150is in an active state. Namely, it is determined whether the AP110has transferred an ‘H’ signal to the Wi-Fi/BT combo IC150by BT_REG_ON.

If the Wi-Fi/BT combo IC150is in the active state, the Wi-Fi/BT combo IC150has already been booted up based on the a full stack, and the AP110controls the Wi-Fi/BT combo IC150for communication with an external device (e.g., a BT ear set, a wireless charging pad, etc.) and communicates with the external device. Accordingly, when charging through the wired power, the Wi-Fi/BT combo IC150requests reduction of output power from the wireless power transmitter by using the full stack, in step1220.

Specifically, when the wireless power is received, the power IC130transmits power of 1.8 V/3.7 V to the Wi-Fi/BT combo IC150and an ‘H’ signal is output by TA_DET, so that a start signal INT is transferred to the Wi-Fi/BT combo IC150. When the power of 1.8 V or the start signal INT is input, the Wi-Fi/BT combo IC150ascertains the situation of the power IC130through the I2C, and thus ascertains that the wired and wireless chargings are being simultaneously performed. Accordingly, since the wired and wireless chargings are being simultaneously performed, the Wi-Fi/BT combo IC150requests an adjustment of the power during communication with the wireless power transmitter. Here, the Wi-Fi/BT combo IC150can communicate with the wireless power transmitter as well as a BT ear set, by using a single antenna through time division.

However, when the reception of the wired power is interrupted in step1230, the Wi-Fi/BT combo IC150requests an increase in the output power from the wireless power transmitter, by using the full stack in step1235. Specifically, when the wired charging terminal is removed from the wireless power receiver, the power IC130detects an ‘L’ signal by a TA_DET pin and transmits a start signal INT to the Wi-Fi/BT combo IC150. Then, the Wi-Fi/BT combo IC150recognizes an event situation of the power IC130in a state where 1.8 V according to the wireless charging is input, and may request the wireless power transmitter to increase the transmitting power. When the wireless power transmitter increases the transmitting power in response to the request, the Wi-Fi/BT combo IC150enables a buck output of the power IC130to transmit the power to the IF PMIC140, and the IF PMIC140charges the battery.

However, after a determination in step1215that the element related to the low power near field wireless communication (i.e., the Wi-Fi/BT combo IC150) is not in the active state (more specifically, if the AP110does not transfer an ‘H’ signal to the Wi-Fi/BT combo IC150by BT_REG_ON), a signal by BT_REG_ON is always an ‘L’ signal.

Accordingly, the Wi-Fi/BT combo IC150is enabled by itself, by detecting power of 1.8 V corresponding to the wireless charging in an initial stage of receiving the power from the power IC130, and boots up by using the BLE stack. Specifically, when the wireless power is received, the power IC130starts to operate. The power IC130transmits power of 1.8 V/3.7 V and at the same time, ascertains that the signal by the TA_DET pin is an ‘H’ signal, to transmit a start signal INT to the Wi-Fi/BT combo IC150. Then, the Wi-Fi/BT combo IC150boots up by detecting the 1.8 V output of the power IC130and operating a crystal of 37.4 MHz, and accesses the power IC130by using the I2C to ascertain the situation.

Next, the Wi-Fi/BT combo IC150informs the AP110that the wireless charging is being performed, and the AP110activates a BT function. Meanwhile, when the wireless charging is completed (more specifically, when a user removes the wireless power receiver from the wireless charging pad), the Wi-Fi/BT combo IC150is disabled. However, when the Wi-Fi/BT combo IC150informs the AP110that the wireless charging is being performed, the AP110recognizes that the wired and wireless chargings are simultaneously applied, informs the wireless power transmitter that the wired and wireless chargings are simultaneously applied, and activates the BT function to request an adjustment of the power. To this end, the AP110transmits an ‘H’ signal to the Wi-Fi/BT combo IC150by BT_REG_ON.

Then, in step1225, the Wi-Fi/BT combo IC150informs the wireless power transmitter that the Wi-Fi/BT combo IC150is to be reset, and thereafter restarts communication by using the full stack. Specifically, since the Wi-Fi/BT combo IC150will be reset, the wireless power transmitter is requested to maintain the power transmission, even if communication is lost for a predetermined period of time (e.g., 2 seconds). A response to maintain the power transmission may be received from the wireless power transmitter in response to the request, and the Wi-Fi/BT combo IC150receives the full stack from the AP110after being reset and restarts communication with the wireless power transmitter based on the full stack, thereby maintaining the wireless charging. When the wireless charging is input during the wired charging, the AP110selects the wired charging, but may maintain the wireless charging, uninterrupted. However, after a determination that the reception of the wired power is interrupted in step1230after the wireless charging is input, the AP110requests an increase in the output power by using the full stack, in step1235.

FIG. 11is a flowchart illustrating an operation in accordance with wireless charging in a state where a wireless power receiver is turned on, according to an embodiment of the present invention.

Referring toFIG. 11, reception of wireless power is monitored in step1300while the wireless power receiver is turned on. For example, when a user puts the wireless power receiver on a wireless charging pad for wireless charging, wireless power may be received. At this time, since the wireless power receiver is in an On state, a Wi-Fi/BT combo IC150is supplied with power of 1.8 V from a battery300through a PMIC120.

If the reception of the wireless power is detected, a determination is made in step1305as to whether an element related to low power near field wireless communication (i.e., the Wi-Fi/BT combo IC150) is in an active state. If the Wi-Fi/BT combo IC150is not in an active state, namely, a signal from an AP110by BT_REG_ON is an ‘L’ signal and power of 1.8 V is detected from a power IC130, the Wi-Fi/BT combo IC150is enabled by itself and boots up by using a BLE stack in step1310. Then, the Wi-Fi/BT combo IC150activates CHARGER_EN of the power IC130, after communicating with a wireless power transmitter, thereby controlling transmission of power to an IF PMIC140. The IF PMIC140accordingly supplied with the power transfers an On signal to the PMIC120, and supplies power of VBattery and power of VPH_PWR for power supply to a battery and the entire system, thereby performing the wireless charging.

Further, as the On signal is transferred, the PMIC120informs the AP110that the wireless charging is being performed, in step1315. Then, the AP110may ascertain that the wireless charging is being performed, and transmits an ‘H’ signal by BT_REG_ON to activate BT. In response to transmission of the ‘H’ signal, in step1320, the Wi-Fi/BT combo IC150reports to the wireless power transmitter that the Wi-Fi/BT combo IC150is to be reset. This report serves to request the wireless power transmitter to maintain the power for a predetermined period of time (e.g., 2 seconds), even if communication are lost, since the Wi-Fi/BT combo IC150itself will be reset. The Wi-Fi/BT combo IC150restarts communication with the wireless power transmitter by using the full stack in step1325after being reset, and continuously performs the wireless charging in step1330. Next, in step1335, a determination of whether the wireless charging is completed is performed. To this end, the Wi-Fi/BT combo IC150determine whether the wireless charging is completed by monitoring whether a current exiting from the power IC130is reduced. After a determination that the wireless charging has been completed, the Wi-Fi/BT combo IC150informs the wireless power transmitter of the completion of the charging in step1340.

However, if the Wi-Fi/BT combo IC150is in the active state in step1305(i.e., a signal from the AP110by BT_REG_ON is an ‘H’ signal), the Wi-Fi/BT combo IC150may have been booted up through the full stack. Since the wireless power has been received in this state, power of 1.8 V/3.7 V is transferred from the power IC130to the Wi-Fi/BT combo IC150. Accordingly, as power of 1.8 V or a start signal INT is input from the power IC130, the Wi-Fi/BT combo IC150may ascertain the situation of the power IC130and thus may identify that the wireless charging is being performed.

The Wi-Fi/BT combo IC150performs communication with the wireless power transmitter by using the full stack, in step1325. Next, the Wi-Fi/BT combo IC150allows the power IC130to transmit the power to the IF PMIC140, and performs charging by using the wireless power as in step1330.

Meanwhile, after the Wi-Fi/BT combo IC150informs the wireless power transmitter of the completion of the wireless charging, the wireless power transmitter may reduce the power transmitted to the wireless power receiver, or may inform that the wireless charging will be completed. In this case, the Wi-Fi/BT combo IC150may inform the AP110that the power supply by the wireless power transmitter will be interrupted together with the completion of the charging.

FIG. 12is a flowchart illustrating an operation in accordance with a wired charging input in a state where a wireless power receiver is turned on, according to an embodiment of the present invention.

Referring toFIG. 12, operations in steps1400to1430are the same as those in steps1300to1330ofFIG. 11, and therefore a further description of these steps is omitted. Meanwhile, in the process of performing charging by using wireless power, in step1435, a determination is performed as to whether reception of wired power is detected. If the reception of the wired power is detected, a Wi-Fi/BT combo IC150performs the charging by using the wired power and informs a wireless power transmitter that the wired charging is being performed, in step1440. In this way, the Wi-Fi combo IC150may request the wireless power transmitter to adjust transmitting power.

The Wi-Fi combo IC150operates through a BLE stack in a BT inactive state, namely, while an ‘L’ signal by BT_REG_ON is transferred. Then, the Wi-Fi combo IC150is reset after an ‘H’ signal by BT_REG_ON is transferred from an AP110, and may operate by using a full stack. However, since a signal from the AP110by BT_REG_ON is an ‘H’ signal in a BT active state, the Wi-Fi/BT combo IC150may have been booted up through the full stack, and thus may operate by using the full stack.

According to the embodiments of the present invention, the existing Wi-Fi/BT combo IC employed for the wireless power receiver performs signaling during wireless charging, so that a space within the wireless power receiver can be saved, manufacturing costs of the wireless power receiver can be reduced, and the wireless power receiver can be wirelessly charged even in the dead battery situation in which the battery of the wireless power receiver is dead so that the wireless power receiver is turned off.