Electronic device charging battery based on direct charging and operating method thereof

Abstract

To achieve the above objectives, an electronic device according to one aspect of the technical concept of the present disclosure may include a charging integrated circuit (IC) including a direct charging circuit and an application processor characterized by requesting an external power source to output a maximum voltage corresponding to a target current, performing a ramp-up of a charging current input to the charging IC according to the maximum voltage, compensating for the difference between the charging current and the target current in response to the charging current entering a constant current section, and entering a sleep mode during the constant current section in response to the charging current reaching the target current.

Description

Technology Field

[0001] The technical concept of the present disclosure relates to a charge management chip, and more specifically, to a charge management chip that charges a battery based on a direct charging method and a method of operation thereof. Background Technology

[0002] Electronic systems, such as mobile or portable devices, use batteries to supply power. Various methods can be used to charge batteries; for example, a battery can be charged directly using a charger that supports direct charging, or it can be charged via switching charging using a standard charger. Generally, direct charging can be more efficient than switching charging. The problem to be solved

[0003] The problem that the technical concept of the present disclosure aims to solve is to provide a charging management chip and a method of operation thereof that can improve charging efficiency by putting the processor into sleep mode while performing direct charging. means of solving the problem

[0004] To achieve the above objectives, an electronic device according to one aspect of the technical concept of the present disclosure may include a charging integrated circuit (IC) including a direct charging circuit and an application processor characterized by requesting an external power source to output a maximum voltage corresponding to a target current, ramping up a charging current input to the charging IC according to the maximum voltage, compensating for the difference between the charging current and the target current in response to the charging current entering a constant current section, and entering a sleep mode during the constant current section in response to the charging current reaching the target current.

[0005] To achieve the above objectives, a method of operation of an electronic device according to one aspect of the technical concept of the present disclosure may be characterized by comprising: a step of requesting an external power source to output a maximum voltage corresponding to a target current; a step of ramping up a charging current input to a charging integrated circuit (IC) according to the maximum voltage; a step of compensating for the difference between the charging current and the target current in response to the charging current entering a constant current section; and a step of entering a sleep mode during the constant current section in response to the charging current reaching the target current.

[0006] To achieve the above objectives, a charging integrated circuit (IC) according to one aspect of the technical concept of the present disclosure may include a direct charging circuit and a microcontroller that requests an external power source to output a maximum voltage corresponding to a target current, performs a ramp-up of a charging current input to the charging IC according to the maximum voltage, compensates for the difference between the charging current and the target current in response to the charging current entering a constant current section, and enters a sleep mode during the constant current section in response to the charging current reaching the target current. Effects of the invention

[0007] According to the charging management chip and the method of operation thereof according to the technical concept of the present disclosure, by omitting continuous monitoring and operating the processor in sleep mode while performing direct charging, the current consumption of the processor is reduced, thereby increasing charging efficiency and simultaneously suppressing heat generation.

[0008] According to the charging management chip and the method of operation thereof according to the technical concept of the present disclosure, since heat generation of the processor is suppressed, it is not necessary to lower the target value of the charging current while performing direct charging, so there is an effect of preventing a decrease in charging speed. Brief explanation of the drawing

[0009] FIG. 1 is a block diagram showing an electronic device and an external power source according to an exemplary embodiment of the present disclosure. FIG. 2 is a block diagram showing a charging IC according to an exemplary embodiment of the present disclosure. FIG. 3 illustrates an example of a switching charging circuit and a direct charging circuit according to an exemplary embodiment of the present disclosure. FIG. 4 is a flowchart illustrating the operation of an application processor according to an exemplary embodiment of the present disclosure. FIG. 5 is a flowchart for performing a charging current compensation algorithm according to an exemplary embodiment of the present disclosure. FIG. 6 is a flowchart illustrating an operation to change the output current field value of a PPS message according to an exemplary embodiment of the present disclosure. FIG. 7 is a flowchart illustrating an operation to change the output voltage field value of a PPS message according to an exemplary embodiment of the present disclosure. FIG. 8 is a graph showing the output voltage of TA, the charging current, and the battery voltage while direct charging is performed according to an exemplary embodiment of the present disclosure. Specific details for implementing the invention

[0010] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0011] FIG. 1 is a block diagram showing an electronic device and an external power source according to an exemplary embodiment of the present disclosure.

[0012] Referring to FIG. 1, an electronic device (10) and an external power source (20) are disclosed. In order to charge a battery (101) included in the electronic device (10), the electronic device (10) and the external power source (20) may be connected to each other via a wired or wireless connection.

[0013] The electronic device (10) according to various embodiments of the present invention may be implemented as various systems. For example, the electronic device (10) may be implemented as various types of devices such as a smartphone, a tablet PC, a mobile phone, a video phone, an e-book reader, a desktop PC, a laptop PC, a netbook computer, a workstation, a server, a PDA (personal digital assistant), a PMP (portable multimedia player), an MP3 player, a mobile medical device, a camera, or a wearable device.

[0014] According to various embodiments, the electronic device (10) may include a charging IC (Integrated Circuit) (100), a battery (101) charged by the charging IC (100), and an application processor (140).

[0015] According to one embodiment, the charging IC (100) may be implemented in various forms, and as an example, may be implemented as a single semiconductor device (or a semiconductor chip or a semiconductor package, etc.). According to exemplary embodiments, the charging IC (100) may further include a switching charging circuit (110) and a direct charging circuit (120). In this case, when the charging IC (100) is implemented as a single semiconductor chip, various circuits provided in the switching charging circuit (110) and the direct charging circuit (120) may be formed on a single (or identical) semiconductor substrate. Additionally, the circuits provided in the switching charging circuit (110) and the direct charging circuit may be formed on the same semiconductor substrate using the same semiconductor process.

[0016] An external power source (20) can supply power to an electronic device (10). Depending on various embodiments, the external power source (20) may include a travel adapter (TA) (21) and a wireless charger (22).

[0017] The wireless charger (22) can charge the electronic device (10) by wirelessly transmitting power through the air instead of supplying power through a wire. Depending on various embodiments, the wireless charger (22) can transmit power based on various wireless charging methods, such as magnetic induction, magnetic resonance, electromagnetic induction, and non-radiative wireless charging (WiTricity).

[0018] TA (21) can supply power through a wire connected to the charging IC (100) of the electronic device (10). TA (21) can convert power supplied from household AC 110V to 220V or other power supply means (e.g., a computer) into DC power required for charging the battery (101) and provide it to the electronic device (10). Depending on various embodiments, TA (21) may support direct charging. For example, an application processor (140) can identify whether TA (21) supports direct charging by using the resistance value of the CC (Configuration Channel) pin.

[0019] As an example of one implementation, an electronic system in which a charging IC (100) is embedded may include a wired interface (TAIN) and a wireless charging interface (WCIN), and power from TA (21) may be provided to the charging IC (100) through the wired interface (TAIN), and power from a wireless charger (22) may be provided to the charging IC (100) through the wireless interface (WCIN). At least some of the power from the wired charger and the wireless charger may be used as a charging power source to charge the battery (101).

[0020] The wired interface (TAIN) is equipped with various types of connectors, such as USB (universal serial bus), and can be connected to an external wired charger through the connector. Additionally, the wireless interface (WCIN) is equipped with a coil (e.g., a conductive pattern) and a wireless charging IC, and can wirelessly transmit and receive power to and from a wireless charger, such as a charging pad.

[0021] Meanwhile, the charging IC (100) can charge the battery (101) using various methods such as normal charging, fast charging, direct charging, and PPS (programmable power supply) methods. As an example, the switching charging circuit (110) can charge the battery (101) through the normal charging method and the fast charging method, and the direct charging circuit (120) can charge the battery (101) through the direct charging method. The direct charging method is a method of directly providing power from an external power source (20) to the battery (101), which improves power efficiency, thereby reducing heat generation and shortening the charging time of the battery (101). The above PPS may refer to a fast charging method that satisfies various standards such as QC (quick charge) and AFC (adaptive fast charge).

[0022] For example, the charger may support only a general charging function or a fast charging function, and the switching charging circuit (110) may perform general charging with a charging capacity of about 5 W to 15 W or fast charging with a charging capacity of about 15 W to 20 W depending on the type of charger, and in the case of the switching charging method, it may have a charging efficiency of approximately 90 to 93%. On the other hand, if the charger supports a direct charging function, the direct charging circuit (120) may perform direct charging with a charging efficiency of approximately 96% to about 98%, and since the charging efficiency of direct charging is high, the heat dissipation characteristics may also be improved.

[0023] Each of the switching charging circuit (110) and the direct charging circuit (120) may include a charging path that transmits charging power from a charger to the battery (101), and as an example, the switching charging circuit (110) or the direct charging circuit (120) may selectively charge the battery (101), or the switching charging circuit (110) and the direct charging circuit (120) may charge the battery (101) together.

[0024] According to an exemplary embodiment, the switching charging circuit (110) and the direct charging circuit (120) may include circuits for switching the charging power, and the application processor (140) may control the circuits to change the charging method of the battery (101). Additionally, as the charging IC (100) is implemented as a single semiconductor chip, it may include one or more terminals connected to external devices, and as an example, the charging management chip (100) may include terminals connected to a wired interface (TAIN) and a wireless interface (WCIN), and terminals connected to the battery (101).

[0025] According to various embodiments, the application processor (140) may control the overall operations of the electronic device (10). According to one embodiment, the application processor (140) may control the charging IC (100) to control the charging state of the battery (101). For example, the application processor (140) may receive information (Info_B) regarding the state of the battery (101) from the charging IC (100) and request the travel adapter to change the charging current and charging voltage based on the information regarding the state of the battery (101). According to one embodiment, the application processor (140) may further include a PPS management circuit (142). The PPS management circuit (142) may correspond to a circuit that controls the charging current to match the target current by changing the output voltage field value and / or output current field value included in the PPS message and transmitting it to the TA (21) when the charging current is different from the target current.

[0026] In various embodiments, a receptacle interface (150) may be included. The receptacle interface (150) may connect the electronic device (10) and an external power source (20) via a USB (universal serial bus) cable. In one embodiment, the receptacle interface (150) may correspond to a USB Type-C interface, and the USB cable may correspond to a USB Type-C cable. The USB Type-C interface may be implemented based on the definition of USB 2.0 or USB 3.1. The receptacle interface (150) may include a plurality of pins. The plurality of pins may include pins for power supply, pins for data transmission, and CC (configuration channel) pins.

[0027] In various embodiments, the power meter (130) can obtain information regarding input / output voltage and current. The power meter (130) can sense the magnitude of the charging voltage and charging current input to the charging IC (100).

[0028] In various embodiments, the fuel gauge (135) can sense the battery (101). For example, the fuel gauge (135) can sense the state of charge (SoC), charging voltage, charging current, and battery temperature of the battery (101). The state of charge is the ratio of the current capacity to the maximum capacity of the battery (101), and can be defined in percentage (%) units.

[0029] In various embodiments, the battery (101) may include at least one battery cell. For example, the battery (101) may correspond to a multi-cell battery comprising a plurality of battery cells connected in series. In another example, the battery (101) may correspond to a single-cell battery comprising one battery cell. The battery (101) may receive power through a charging IC (100) when the electronic device (10) is connected to an external power source (20). In various embodiments, the battery (101) may include a nickel-cadmium (Ni-Cd) battery, a nickel-hydrogen (Ni-MH) battery, a lithium-ion battery, etc., but the scope of the present invention is not limited thereto.

[0030] In the above-described embodiment, the charging IC (100) is shown to perform charging of the battery (101) under the control of the application processor (140), but is not limited thereto. In various embodiments, the charging IC (100) may further include a microcontroller (MCU) internally. The microcontroller may be a dedicated controller for controlling the charging of the battery (101).

[0031] FIG. 2 is a block diagram showing a charging IC according to an exemplary embodiment of the present disclosure.

[0032] Referring to FIG. 2, the switching charging circuit (110) may include an input switching circuit (111), a buck control circuit (112), and a power path control circuit (113). Additionally, the direct charging circuit (120) may include a switching circuit (121) connected between an input node (VIN) and an output node (VOUT). The switching circuit (121) may correspond to a capacitor divider. In addition, according to the above-described embodiment, the charging IC (100) may be connected to circuit elements related to charging the battery (101), and as an example, an inductor (L) and a capacitor (C) connected to one or more nodes of the switching charging circuit (110) are further illustrated.

[0033] Meanwhile, as illustrated in FIG. 2, an overcurrent protection circuit (OCP) IC (102) may be further provided in the electronic system, and charging power from a wired charger may be provided to the charging IC (100) through the OCP IC (102). In one embodiment, the OCP IC (102) may be implemented as a separate semiconductor chip, and accordingly, the OCP IC (102) may be placed outside the charging IC (100). The OCP IC (102) can prevent damage to the circuits inside the charging IC (100) by blocking the supply of power from the wired charger to the charging IC (100) when the current provided from the wired charger corresponds to an overcurrent.

[0034] The input switching circuit (111) may transfer charging power into the charging IC (100) by performing a switching operation for charging power from a wired charger and a wireless charger, by including one or more switches. As an example, the input switching circuit (111) may provide charging power to a BUCK control circuit (112) or provide charging power directly to the charging circuit (120) through a first node (VBYP).

[0035] The BUCK control circuit (112) can control the operation of converting the charging power received through the input switching circuit (111) into a voltage or current level suitable for charging the battery (101), and can also control the operation of converting the power from the battery (101) into a voltage or current level suitable for use within the electronic system. As an example, the BUCK control circuit (112) includes one or more switches and can control the charging operation or the system voltage (Vsys) generation operation by controlling the switches according to various modes. The system voltage (Vsys) may refer to the voltage provided to the remaining components, including the application processor (140). The BUCK control circuit (112) may be connected to one end of an external inductor (L) through a second node (LX) and can provide the charging power to the second node (LX) through the switching operation described above.

[0036] Meanwhile, the power path control circuit (113) can perform the operation of controlling the power path so that the charging power provided from the charger is supplied to the battery (101), or controlling the power path so that the power from the battery (101) is supplied as a system voltage (Vsys) used inside the electronic system. The power path control circuit (113) can be connected to the third node (VSYS) and the fourth node (VBAT) to perform the control operation of the power path described above.

[0037] As an example, the power path control circuit (113) includes one or more switches and can control the power path so that a portion of the power provided from the charger is provided to the battery (101) as a charging power, and another portion is provided as a system voltage (Vsys) used within the electronic system. As an example of operation, when the power of the electronic system is off, the power provided from the charger may be provided to the battery (101) as a charging power, and when the power of the electronic system is on, a portion of the power provided from the charger may be provided to the battery (101) as a charging power.

[0038] Meanwhile, the switching circuit (121) provided in the direct charging circuit (120) may include one or more switches, and the electrical connection between the input node (VIN) and the output node (VOUT) may be controlled according to the switching state of the switching circuit (121). As an example, the direct charging circuit (120) may perform the function of a voltage divider (or a capacitor divider) and distribute the charging power applied to the input node (VIN) to provide it to the output node (VOUT), and the charging power delivered to the output node (VOUT) may be provided to the battery (101). The switching circuit (121) may be implemented in various forms, and depending on the implementation form of the switching circuit (121), power of the same level as the charging power provided to the input node (VIN) may be provided to the output node (VOUT), or power of a different level from the charging power provided to the input node (VIN) may be provided to the output node (VOUT).

[0039] Meanwhile, as described above, the various components illustrated in FIG. 2 may include one or more switches, and the switches may be controlled by control signals (not shown) generated within the charging IC (100). As an example, the charging IC (100) may include circuits that generate a control signal based on a voltage / current detected from various nodes within it, or generate a control signal based on the result of detecting the voltage / current of the battery (101), and the various switches within the charging IC (100) may be controlled based on the result of detecting the voltage / current.

[0041] FIG. 3 illustrates an example of a switching charging circuit and a direct charging circuit according to an exemplary embodiment of the present disclosure.

[0042] Referring to FIG. 3, a switching charging circuit (110), a direct charging circuit (120), and a battery (101) are disclosed.

[0043] According to various embodiments, the switching charging circuit (110) and the direct charging circuit (120) may share an input power supply. Referring to FIG. 3, the first transistor (TR1) may be connected between a wired input power supply (TAIN) and a first node (ND1), and the wired input power supply may correspond, for example, to TA (210) of FIG. 1. The second transistor (TR2) may be connected between a wireless input power supply (WCIN) and a first node (ND1), and the wireless input power supply may correspond to a wireless charger (220) of FIG. 1. The first node (ND1) may be connected to a cap divider (310) through a sixth transistor (TR6) and a tenth transistor (TR10), and may be connected to a buck converter (320) through a third transistor (TR3).

[0044] According to one embodiment, when the third transistor (TR3) is turned off, the input power is transferred to the capacitor divider (310) through the input power supply and can be transferred to the battery (101). That is, when the connection with the buck converter (320) is disconnected, the charging IC (100) can operate as a direct charging circuit (120).

[0045] According to another embodiment, when the sixth transistor (TR6) and the tenth transistor (TR10) are each turned off, the input power is transferred to the buck converter (320) through the input power supply, and can be transferred to the battery (101) by the third transistor (TR3) and the fourth transistor (TR4) alternately turning on and off according to a constant period. That is, when the connection with the cap divider (310) is disconnected, the charging IC (100) can operate as a switching charging circuit (110).

[0046] The switching charging circuit (110) may include a third transistor (TR3) through a fifth transistor (TR5) and an inductor (L). For example, the third transistor through the fifth transistor (TR5) may be implemented as power switches. However, the structure of the switching charging circuit (110) is not limited thereto, and depending on the embodiments, the number of transistors and the number of inductors included in the switching charging circuit (110) may vary. The third transistor (TR3) may be connected between a first node (ND1) and a switching node (LX) and may receive an input current through the first node (ND1). The fourth transistor (TR4) may be connected between a switching node (LX) and a ground node (GND) and may provide a ground voltage to the switching node (LX). The inductor (L) may be connected between a switching node (LX) and a first output node (ND2). The fifth transistor (TR5) can be connected between the first output node (ND2) and the second output node (ND3). The fifth transistor (TR5) receives voltage from the inductor (L) through the first output node (ND2) and can provide the received voltage to the battery (101) through the second output node (ND3). When the fifth transistor (TR5) is turned on, the charging current (ICHG) can be provided to the battery (101) through the second output node (ND3). Additionally, in one embodiment, when the fifth transistor (TR5) is turned on, the battery current from the battery (101) can be provided to the system load. The battery current can flow in the opposite direction to the charging current.

[0047] The direct charging circuit (120) may include a first capacitor (C1), a second capacitor (C2), and a sixth transistor (TR6) to a thirteenth transistor (TR13). The capacitor divider (310) may be referred to as a current doubler or an inverting charge pump. Referring to FIG. 3, the switching operation of the sixth to thirteenth transistors (TR6 to TR13) within the first capacitor (C1) and the second capacitor (C2) may be controlled during the charging operation according to the direct charging method. For example, the second capacitor (C2) may be discharged while the first capacitor (C1) is being charged, and the second capacitor (C2) may be charged while the first capacitor (C1) is being discharged. Thus, the voltage of the output node (VOUT) provided to the battery (101) may be maintained at a constant level. The voltage value of the output node may be half the voltage level of the first node (ND1).

[0048] FIG. 4 is a flowchart illustrating the operation of an application processor according to an exemplary embodiment of the present disclosure.

[0049] Referring to FIG. 4, in operation S110, the application processor (140) can determine whether direct charging is possible. In operation S110, the TA (21) can be connected to the electronic device (10) via a wired cable. The application processor (140) can identify that the TA (21) for charging the battery (101) is connected via the CC pin of the receptacle interface (150). The application processor (140) can determine whether the TA (21) supports direct charging by using the resistance value of the CC (Configuration Channel) pin. Additionally, the application processor (140) can receive information (Info_B) regarding the current state of the battery (101) from the fuel gauge (135) and determine whether direct charging can be performed based thereon. The information regarding the current state of the battery (101) may include information such as the state of charge (SoC) of the battery (101), charging voltage, charging current, and battery temperature. The above charge state is the ratio of the current capacity to the maximum capacity of the battery (101), and can be defined in percent (%) units.

[0050] For example, if the voltage value of the battery (101) does not exceed 3.5V, the application processor (140) can control the charging IC (100) to perform charging using the switching charging circuit (110) until the voltage value of the battery (101) reaches 3.5V. As another example, even if the voltage value of the battery (101) exceeds 3.5V but the charge state of the battery (101) already exceeds 95%, the application processor (140) can fully charge the battery (101) using the switching charging circuit (110) without using the direct charging circuit (120) in order to prevent overcharging of the battery (101). That is, the application processor (140) can determine that charging can be performed through the direct charging circuit (120) when the current voltage value of the battery (101) exceeds 3.5V and the charge state is less than 95%.

[0051] In operation S120, the application processor (140) can set direct charging parameters. The direct charging parameters may include an initial target TA voltage, an initial PPS message, a debouncing time, the magnitude of the top-off current, a floating battery voltage value, etc.

[0052] In operation S130, the application processor (140) can ramp up to a maximum voltage value for the target current. The application processor (140) can request the TA (21) to output the maximum voltage value through the receptacle interface (150). A ramp up for the charging current can be performed based on the maximum voltage value output from the TA (21). At this time, the charging current value input to the battery (101) may differ from the value of the target current. This is because if the TA (21) is requested to output a maximum voltage value greater than the initial requested voltage, it should output the maximum allowable current, but due to the unstable operation of the TA (21), it outputs a charging current value different from the maximum allowable current.

[0053] In operation S140, the application processor (140) may perform a charging current compensation algorithm in response to entry into a constant current (CC) period. The compensation algorithm may refer to an algorithm that controls the value of current and / or voltage requested by the TA (21) so that the charging current tracks the target current, since the charging current output from the TA (21) is different from the target current. When the compensation algorithm is performed, the TA (21) can stably output the target current.

[0054] In operation S150, the application processor (140) may enter sleep mode. The sleep mode may refer to entering an inactive state by reducing the resources and power used by the application processor (140). The sleep mode may be referred to by various terms including low-power mode, sleep mode, inactive mode, inactive state, deactivation state, etc. When the application processor (140) enters sleep mode, it may bypass monitoring of the charging current and charging voltage input from the TA (21). Due to the entry into the sleep mode, the power consumption of the application processor (140) is significantly reduced, so charging efficiency can be further improved and heat generation can also be reduced.

[0055] In operation S160, the application processor (140) may periodically release sleep mode and send a PPS message in response to entry into a constant voltage (CV) period. The application processor (140) may disable auto PPS when the voltage value of the battery (101) reaches a preset value. When auto PPS is disabled, the application processor (140) may not maintain sleep mode throughout the constant voltage period, but may wake up at regular intervals and send a PPS message to TA (21). The regular interval may be 10 seconds. The application processor (140) may repeat releasing sleep mode at regular intervals, monitoring the charging current value input from TA (21) for 100ms to 150ms, sending a PPS message, and re-entering sleep mode.

[0056] In operation S170, the application processor (140) can determine whether the magnitude of the charging current input from TA (21) has reached an off-current value. The application processor (140) can unlock the sleep mode and receive information (Info_B) about the state of the battery (101) from the fuel gauge (135) to sense the magnitude of the charging current. The off-current value may refer to a specific current value to prevent overcharging by performing charging using the switching charging circuit (110) when the charge state of the battery (101) approaches 100%. For example, the value of the off-current may be 1A.

[0057] In one embodiment, the application processor (140) can activate the switching charging circuit (110) and deactivate the direct charging circuit (120) when the magnitude of the charging current reaches the off-current value. Additionally, the application processor (140) can repeat operation S140 again when the magnitude of the charging current has not reached the off-current value, as direct charging of the battery (101) is still required. At this time, the application processor (140) can change parameters for determining entry into the CC section and entry into the CV section.

[0058] FIG. 5 is a flowchart for performing a charging current compensation algorithm according to an exemplary embodiment of the present disclosure.

[0059] Referring to FIG. 5, in operation S210, the application processor (140) can control the output current requested from TA (21) by comparing the charging current and the target current.

[0060] In operation S220, the application processor (140) can determine whether the magnitude of the charging current deviates from a predefined range from the magnitude of the target current. The predefined range is,

[0061] In operation S230, the application processor (140) can control the output voltage of the TA (21). The application processor (140) can compare the values ​​of the charging current and the target current and request the TA (21) to change the output current. For example, if the value of the charging current is greater than the target current, the application processor (140) can decrease the value of the output current field included in the PPS message and transmit the PPS message to the TA (21). Here, the value of the output current field can be increased or decreased in increments of 50mA. As another example, if the value of the charging current is less than the value of the target current, the application processor (140) can increase the value of the output current field included in the PPS message.

[0062] According to various embodiments, the application processor (140) may request the TA (21) to change the output current a first number of times that is predetermined. For example, the first number of times that is predetermined may correspond to 20 times. That is, the application processor (140) may repeat the change and transmission of the value of the output current field included in the PPS message to the TA (21) 20 times, and if it exceeds 20 times, it may no longer change the value of the output current field to track the target current. For example, if there is no repetition limit for the first number of times that is predetermined, the transmission of the PPS message may be repeated until the charging current reaches the target current during the CC interval.

[0063] In operation S220, the application processor (140) can determine whether the magnitude of the charging current deviates from a predefined range from the magnitude of the target current. That is, the application processor (140) can determine whether the output current value of TA (21) is within a range that can be tracked by changing the output current field value of TA (21) in operation S210, by repeatedly changing and requesting the output current field value of TA (21). The predefined range may correspond to an upper bound value of 150mA from the target current and a lower bound value of 50mA from the target current. If the magnitude of the charging current is greater than 150mA or less than the target current, or is less than 50mA or less than the target current, the application processor (140) can perform operation S230 to control the output voltage of TA (21). As another example, the application processor (140) may terminate the charging current compensation algorithm when the value of the charging current falls within the aforementioned predefined range. That is, when the value of the charging current is within the aforementioned predefined range from the target current, the charging current successfully follows the target current, so the application processor (140) may enter a sleep mode during the constant current interval.

[0064] FIG. 6 is a flowchart illustrating an operation to change the output current field value of a PPS message according to an exemplary embodiment of the present disclosure.

[0065] Referring to FIG. 6, in operation S310, the application processor (140) can identify the magnitude of the charging current and set the count value to "0". The application processor (140) can receive information about the magnitude of the charging current from the power meter (130). The count value may correspond to a value for tracking the number of times the application processor (140) changes the value of the output current field and transmits a PPS message to the TA (21). That is, the time at which operation S310 is performed may correspond to the time when the CC interval is entered after the output of the maximum voltage value for the target current has been requested.

[0066] In operation S320, the application processor (140) can determine whether the value of the charging current exceeds the value of the target current. Since a request was made to output the maximum voltage for the target current, the current value output by TA (21) may differ from the target current. For example, if the magnitude of the charging current is greater than the magnitude of the target current, the application processor (140) can perform operation S330, and if the magnitude of the charging current is smaller than the magnitude of the target current, the application processor (140) can perform operation S360.

[0067] In operation S330, the application processor (140) may request the TA (21) to step down the output current field value by 1 step and increase the count value by 1. The step is the minimum unit by which the output current field value can be adjusted, and in the case of direct charging supporting PPS, the minimum unit may correspond to 50mA.

[0068] In operation S340, the application processor (140) may determine again whether the magnitude of the charging current is smaller than the magnitude of the target current. That is, this is to determine whether the magnitude of the charging current has become smaller than the magnitude of the target current by simply decreasing the output current field of the PPS message by one step and requesting it from TA (21). If, in operation S340, it is determined that the magnitude of the charging current is smaller than the magnitude of the target current, the magnitude of the charging current identified in operation S310 may be determined to be larger than the magnitude of the target current but nearly similar. That is, if, in operation S340, it is determined that the magnitude of the charging current is smaller than the magnitude of the target current, it may be understood as being included within the predefined range of operation S220. That is, the application processor (140) may return to operation S220 to terminate the charging current compensation algorithm. As another example, if, in operation S340, it is determined that the magnitude of the charging current is still larger than the magnitude of the target current, the application processor (140) may perform operation S350.

[0069] In operation S350, the application processor (140) can determine whether the count value exceeds a first number of times. The first number of times is a predefined value and may correspond, for example, to 20 times. However, the above-described embodiment is not limited thereto, and the value of the first number of times may be varied by the manufacturer or user. For example, if the count value does not exceed 20, it may mean that the number of times the value of the output current field is requested to the TA (21) by stepping down does not exceed 20 times. The application processor (140) may repeat operation S330 again. On the other hand, if the count value exceeds the first number of times, the application processor (140) will return to operation S220 of FIG. 5 to determine whether the magnitude of the charging current is included within a predefined range from the target current.

[0070] In operation S360, the application processor (140) may request the TA (21) to step up the output current field value by 1 and increase the count value by 1. That is, since the magnitude of the charging current is smaller than the magnitude of the target current, the application processor (140) may request the TA (21) to output an additional charging current of 50mA in order to bring the magnitude of the charging current closer to the magnitude of the target current.

[0071] In operation S370, the application processor (140) can determine whether the magnitude of the charging current exceeds the magnitude of the target current. That is, it is to determine whether the magnitude of the charging current exceeds the magnitude of the target current simply by increasing the output current field of the PPS message by one step and requesting TA (21). If, in operation S370, it is determined that the magnitude of the charging current is greater than the magnitude of the target current, the magnitude of the charging current identified in operation S310 may be determined to be a current value that is smaller than the magnitude of the target current but close to the magnitude of the target current. That is, if, in operation S370, it is determined that the magnitude of the charging current is smaller than the magnitude of the target current, it may be understood as being included within the predefined range of operation S220. That is, the application processor (140) may return to operation S220 to terminate the charging current compensation algorithm. As another example, if, in operation S370, it is determined that the magnitude of the charging current is still smaller than the magnitude of the target current, the application processor (140) may perform operation S380. In operation S380, the application processor (140) can determine whether the count value exceeds a first number of times. A specific description of operation S380 may be provided with reference to operation S350.

[0072] FIG. 7 is a flowchart illustrating an operation to change the output voltage field value of a PPS message according to an exemplary embodiment of the present disclosure. FIG. 7 may correspond to a specific flowchart of operations S220 and S230 illustrated in FIG. 5.

[0073] Referring to FIG. 7, in operation S410, the application processor (140) can initialize the count value. The application processor (140) performing operation S410 may mean that the operation requesting step-down or step-up of the output current field value of the PPS message in operation S330 or operation S360 of FIG. 6, respectively, has been repeated the first number of times, but the magnitude of the charging current and the magnitude of the target current have never crossed each other. That is, the application processor (140) determines that the magnitude of the charging current cannot follow the magnitude of the target current by only changing the output current field of the PPS message, and can perform FIG. 7 to change the output voltage field of the PPS message. Accordingly, in operation S410, the application processor (140) can initialize the count value that has already been increased while performing FIG. 6.

[0074] In operation S420, the application processor (140) can determine whether the magnitude of the charging current is smaller than the lower limit magnitude of the target current. The magnitude of the lower limit may correspond, for example, to 50 mA. If the magnitude of the charging current is smaller than 50 mA than the magnitude of the target current, the application processor (140) may define TA (21) as a type of TA in which the error of the output current increases as the value of the output voltage field increases. That is, TA (21) may be one of several types of TAs, and the first type of TA may correspond to a TA that outputs a current lower than the target current when an output voltage exceeding the target voltage mapped to the target current is requested. The second type of TA may correspond to a TA that outputs a current higher than the target current when an output voltage exceeding the target voltage value mapped to the target current is requested. In operation S420, if the application processor (140) determines that the magnitude of the charging current is smaller than the lower limit of the target current, the currently connected TA (21) may be defined as the TA of the above type. Accordingly, if the magnitude of the charging current is determined to be smaller than the lower limit of the target current, the application processor (140) may perform operation S440. As another example, if the magnitude of the charging current is determined to be larger than the lower limit of the target current, the application processor (140) may perform operation S430.

[0075] In operation S430, the application processor (140) can determine whether the magnitude of the charging current exceeds the upper limit of the target current. That is, in operation S420, even if the magnitude of the charging current is greater than the lower limit of the target current, if it exceeds the upper limit of the target current, it is not included in the predefined range of the target current. If the application processor (140) determines that the magnitude of the charging current is smaller than the upper limit of the target current, it can terminate the charging current compensation algorithm. This is because the magnitude of the charging current is smaller than the upper limit of the target current but larger than the lower limit, so it is included within the predefined range.

[0076] In operation S440, the application processor (140) can send a PPS message to the TA (21) by stepping down the value of the charging voltage field by one step. Since the application processor (140) has determined that the TA (21) currently connected to the electronic device (10) is the TA of the first type, it can send a PPS message to the TA (21) by stepping down the output voltage field by one step. The step is the minimum unit by which the output voltage field value can be adjusted, and in the case of direct charging that supports PPS, the minimum unit may correspond to 20mV. Although not shown in FIG. 7, the application processor (140) can increase the count value by one each time the value of the output voltage field is stepped down and determine whether the count value exceeds a predefined second number of times before returning to operation S420.

[0077] In operation S450, the application processor (140) can determine whether the count value is 0. That is, if the magnitude of the charging current exceeds the upper limit of the target current, the application processor (140) can additionally determine whether the count value is 0. If the count value is not 0, it is because the output voltage field of the PPS message was stepped down at least once in operation S440. If the count value is 0, the application processor (140) can proceed to operation S460. If the count value is not 0, the application processor (140) can perform operation S470 to determine whether the magnitude of the output current follows the magnitude of the target current by changing and monitoring the output voltage field again, since the TA (21) had a change in the output voltage field at a previous time.

[0078] In operation S460, the application processor (140) can reset the target current to the initially set target current and the maximum voltage value mapped thereto when the magnitude of the charging current exceeds the magnitude of the target current even though the count value is 0, i.e., the output voltage field value has never been changed, and continuously step down the output voltage field value.

[0079] In operation S470, the application processor (140) may request the TA (21) to step down the value of the output voltage field by one step. Operation S470 may refer to the description illustrated in operation S440.

[0080] FIG. 8 is a graph showing the output voltage of TA, the charging current, and the battery voltage while direct charging is performed according to an exemplary embodiment of the present disclosure.

[0081] Referring to FIG. 8, the charging current, battery voltage, and output voltage of TA (21) corresponding to FIG. 4 are disclosed.

[0082] In the interval T0 to T1, the application processor (140) can determine whether direct charging can be performed. That is, the application processor (140) receives information regarding the voltage and charging status of the battery (101) at time T0 from the fuel gauge (135) and determines whether direct charging is possible. Referring to FIG. 8, it can be seen that the initial voltage of the battery (101) is less than 3.5V. Therefore, in the interval T0 to T1, the application processor (140) cannot perform direct charging, and can charge the battery (101) according to the switching charging method using the switching charging circuit (110) until the voltage of the battery (101) reaches 3.5V.

[0083] In the T1 to T2 interval, the application processor (140) can set parameters for performing direct charging. For example, the application processor (140) can request an initial voltage from the TA (21).

[0084] In the T2 to T3 interval, the application processor (140) can perform a current ramp-up. The T2 to T3 interval is referred to as the ramp-up interval. The application processor (140) can request a maximum voltage value mapped to a target current value from the TA (21). Referring to FIG. 8, the maximum voltage value may correspond to 9V. Since the TA (21) is requested to provide a maximum voltage value rather than a target voltage value mapped to a target current value, and outputs the maximum voltage value, the charging current flowing into the battery (101) can be rapidly increased during the ramp-up interval.

[0085] In the interval T3 to T4, the application processor (140) may enter a sleep mode. The interval T3 to T4 may correspond to a first CC interval in which the battery (101) is rapidly charged by maintaining the charging current at a constant value. According to various embodiments, in response to entering the first CC interval at T3, the application processor (140) may perform a charging current compensation algorithm. Although not shown in FIG. 8, at the time of entering T3, the magnitude of the charging current may differ from the magnitude of the target current. Since TA (21) has been requested to have a maximum voltage exceeding the target voltage, TA (21) may output a charging current that has an error with respect to the magnitude of the target current. As described above in FIG. 5, the application processor (140) may control the PPS message value to TA (21) by stepping up or step down the output current field value so that the magnitude of the charging current follows the magnitude of the target current. Alternatively, if the magnitude of the charging current cannot approach the magnitude of the target current by only changing the output current field value, the application processor (140) can perform a charging current compensation algorithm by changing the value of the output voltage field. Once the magnitude of the charging current is compensated to approach the magnitude of the target current, the application processor (140) can enter sleep mode. Since the output voltage has already been requested to the TA (21) as the maximum voltage value during the ramp-up period, continuous monitoring is omitted, and by entering sleep mode, the effects of minimizing resource usage, improving power consumption, and reducing heat generation can be achieved.

[0086] In the T4 to T5 interval, the application processor (140) can periodically exit sleep mode and send a PPS message to TA (21). The T4 to T5 interval may correspond to a first CV interval in which the voltage of the battery (101) is maintained constant by reducing the charging current at a constant rate. During the first CV interval, the application processor (140) cannot maintain sleep mode because it must monitor the charging current and reduce the magnitude of the charging current. However, the application processor (140) can wake up at regular intervals to monitor the magnitude of the charging current, step down the magnitude of the charging current to send a PPS message to TA (21), and repeat the process of re-entering sleep mode. Since the time required for monitoring the charging current and sending the PPS message is only 100ms to 150ms, the operating time of the application processor (140) in the first CV interval may be shorter than in the past. The application processor (140) can reset the voltage value and target current value of the battery (101) to determine whether to enter the next sequence of CC and CV sections when the first CV section ends.

[0087] In the interval T5 to T6, the application processor (140) may enter a sleep mode. The interval T5 to T6 may correspond to a second CC interval in which the voltage of the battery (101) is charged while maintaining a second charging current value. According to various embodiments, if the magnitude of the charging current at time T5 differs from the magnitude of the changed target current, the charging current compensation algorithm may be performed again. The intervals T5 to T6 and T7 to T8 may refer to the description of the first CC interval, and the intervals T6 to T7 and T8 to T9 may refer to the description of the first CV interval.

[0088] At T9, the application processor (140) can terminate direct charging and activate the switching charging circuit (110). That is, at T9, the magnitude of the charging current can reach the top-off current value. When the top-off current value is reached, the application processor (140) can disable the direct charging circuit (120) to prevent overcharging of the battery (101).

[0089] As described above, exemplary embodiments have been disclosed in the drawings and specification. Although specific terms have been used to describe the embodiments in this specification, they are used only for the purpose of explaining the technical concept of this disclosure and are not intended to limit the meaning or the scope of this disclosure as defined in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of this disclosure should be determined by the technical concept of the appended claims.

Claims

Claim 1 An electronic device comprising: a charging integrated circuit (IC) including a direct charging circuit for charging a battery; and an application processor characterized by requesting an external power source to output a maximum voltage corresponding to a target current, performing a ramp-up of the charging current input to the charging IC according to the maximum voltage, compensating for the difference between the charging current and the target current in response to the charging current entering a constant current section, and entering a sleep mode during the constant current section in response to the charging current reaching the target current. Claim 2 An electronic device according to claim 1, wherein the application processor transmits information instructing the external power source to reduce the output current when the magnitude of the charging current exceeds the magnitude of the target current, and further transmits information instructing the external power source to increase the output current when the magnitude of the charging current is smaller than the magnitude of the target current. Claim 3 An electronic device according to claim 2, wherein the application processor increases a count value by 1 whenever it transmits information instructing to decrease the output current or information instructing to increase the output current, and bypasses the transmission when the count value exceeds a predefined first number of times. Claim 4 An electronic device according to claim 3, wherein the application processor compares the magnitude of the changed charging current with the magnitude of the target current in response to transmitting information instructing the external power source to reduce the output current, and enters the sleep mode if the magnitude of the charging current is smaller than the magnitude of the target current, or compares the magnitude of the changed charging current with the magnitude of the target current in response to transmitting information instructing the external power source to increase the output current, and enters the sleep mode if the magnitude of the charging current exceeds the magnitude of the target current. Claim 5 An electronic device according to paragraph 3, wherein the application processor enters the sleep mode when the magnitude of the charging current is smaller than the upper bound of the target current and larger than the lower bound. Claim 6 An electronic device according to claim 5, wherein the application processor transmits information instructing the external power source to reduce the output voltage when the magnitude of the charging current is smaller than the lower limit of the target current. Claim 7 An electronic device according to claim 4, wherein the application processor determines whether the count value is 0 when the magnitude of the charging current exceeds the upper limit of the target current, and when the count value is 0, requests the target current and maximum voltage that were initially requested from the external power source again. Claim 8 An electronic device according to claim 7, wherein the application processor transmits information instructing the external power source to reduce the output voltage when the count value is not zero. Claim 9 An electronic device according to claim 1, wherein the application processor releases the sleep mode at predetermined intervals in response to the battery voltage entering a constant voltage range in which the voltage is maintained constant, and monitors the decrease in the magnitude of the charging current. Claim 10 A method of operation of an electronic device comprising a charging integrated circuit (IC) and an application processor, comprising: requesting an external power source to output a maximum voltage corresponding to a target current; performing a ramp-up of a charging current input to the charging IC according to the maximum voltage; compensating for the difference between the charging current and the target current in response to the charging current entering a constant current section; and entering a sleep mode during the constant current section in response to the charging current reaching the target current.

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