Charging circuit, charging method and electronic equipment

Abstract

The invention provides a charging circuit, a charging method and electronic equipment, and relates to the technical field of charging. The charging circuit comprises a controller and a power output circuit connected with the controller. Wherein the power supply output circuit has a constant voltage output state and a constant current output state, and comprises a charge pump and an adjusting circuit; the input end of the charge pump is connected with an external power supply; the output end of the charge pump is connected with the adjusting circuit; the adjusting circuit is used for adjusting the output of the charge pump to be constant-voltage output or constant-current output; the controller is used for controlling the power output circuit to be switched between a constant voltage output state and a constant current output state. According to the charging circuit provided by the embodiment of the invention, the power supply output circuit can perform constant voltage output or constant current output to the outside through the adjusting circuit connected in series with the charge pump, so that the requirements on the charging circuit in different charging processes are met, and the size and the manufacturing cost of the charging circuit are remarkably reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of charging technology, and in particular to a charging circuit, a charging method, and an electronic device. Background Art

[0002] Linear charging is a common charging method used in electronic devices. The linear charging process is typically divided into multiple stages, each with different power output requirements. To meet these requirements, related technologies typically connect a charge pump in parallel with a series-connected buck (Buck) voltage-step-down circuit and an LDO (Low-Drain Regulator) circuit. Depending on the actual charging needs, power is output through either the charge pump or the series-connected buck (Buck) voltage-step-down circuit and LDO voltage-regulator circuit.

[0003] However, the manufacturing cost of the charging circuit including the charge pump, the buck step-down circuit, and the LDO voltage regulator circuit is relatively high. In addition, since the charge pump and the series-connected buck step-down circuit and the LDO voltage regulator circuit are independent power circuits, the charging circuit including the charge pump, the buck step-down circuit, and the LDO voltage regulator circuit are usually large in size due to the heat dissipation of each circuit and the interference between the circuits. Summary of the Invention

[0004] To overcome the problems existing in the related art, the present disclosure provides a charging circuit, a charging method and an electronic device.

[0005] According to a first aspect of an embodiment of the present disclosure, there is provided a charging circuit, comprising: a controller and a power output circuit connected to the controller;

[0006] The power output circuit has a constant voltage output state and a constant current output state, and includes a charge pump and an adjustment circuit; the input end of the charge pump is connected to an external power supply, and the output end of the charge pump is connected to the adjustment circuit; the adjustment circuit is used to adjust the output of the charge pump to a constant voltage output or a constant current output;

[0007] The controller is used to control the power output circuit to switch between the constant voltage output state and the constant current output state.

[0008] In some embodiments, the adjustment circuit includes a first MOS transistor and an operational amplifier module;

[0009] The drain of the first MOS transistor is connected to the output end of the charge pump, the source of the first MOS transistor is connected to the inverting input end of the operational amplifier module, and the output end of the operational amplifier module is connected to the gate of the first MOS transistor.

[0010] In some embodiments, a first resistor is provided between the source of the first MOS tube and the inverting input terminal of the operational amplifier module, and a second resistor is provided between the inverting input terminal of the operational amplifier module and the ground line. The first resistor and the second resistor are used to adjust the input voltage of the operational amplifier module.

[0011] In some embodiments, the operational amplifier module includes a voltage operational amplifier and a current operational amplifier connected in parallel;

[0012] The controller is used to control the voltage operational amplifier and the current operational amplifier to switch between an on state and an off state.

[0013] In some embodiments, the charging circuit further includes a constant current control circuit;

[0014] The constant current control circuit is arranged between the controller and the adjustment circuit, and is used to control the current size of the constant current output of the charge pump.

[0015] In some embodiments, the constant current control circuit includes a second MOS transistor;

[0016] The drain and gate of the second MOS transistor are respectively connected to the controller, and the source of the second MOS transistor is connected to the gate of the first MOS transistor.

[0017] In some embodiments, the charging circuit further includes a protection circuit;

[0018] The protection circuit is provided between the input end of the charge pump and the external power supply, and is used to control the connection and disconnection between the charge pump and the external power supply.

[0019] According to a second aspect of an embodiment of the present disclosure, there is provided a charging method, which is applied to the charging circuit of the first aspect, including:

[0020] When it is detected that an external power source is connected, the voltage of the battery to be charged is detected;

[0021] When it is detected that the voltage of the battery to be charged is less than or equal to the first voltage, requesting the external power supply to input a first power into the charge pump, controlling the charge pump to enter a first working state, and controlling the adjustment circuit to output a constant current with a first current magnitude;

[0022] When it is detected that the voltage of the battery to be charged is greater than the first voltage and less than or equal to the second voltage, requesting the external power supply to input a second power into the charge pump, controlling the charge pump to enter a second working state, and controlling the adjustment circuit to output a constant current with a second current magnitude;

[0023] When it is detected that the voltage of the battery to be charged is greater than the second voltage, requesting the external power supply to input a third power into the charge pump, controlling the charge pump to enter the first working state, and controlling the adjustment circuit to output a constant voltage;

[0024] Among them, the second power and the third power are both greater than the first power, the first current magnitude is smaller than the second current magnitude, the voltage adjustment ratio of the charge pump in the first working state is smaller than the voltage adjustment ratio in the second working state, and the voltage adjustment ratio is the ratio between the input voltage and the output voltage of the charge pump.

[0025] In some embodiments, the control adjustment circuit outputs a constant current with a first current magnitude, including:

[0026] The voltage input to the gate of the first MOS tube of the adjustment circuit is controlled to be in the constant current output region of the first MOS tube, so that the source of the first MOS tube outputs a constant current with a first current magnitude.

[0027] In some embodiments, the control adjustment circuit outputs a constant current with a first current magnitude, including:

[0028] Controlling the drain and source of the first MOS tube of the adjustment circuit to be fully turned on;

[0029] The current operational amplifier in the operational amplifier module of the adjustment circuit is turned on to enable the source of the first MOS tube to output a constant current with a first current magnitude.

[0030] In some embodiments, controlling the adjustment circuit to output a constant current at a second current magnitude includes:

[0031] The drain and source of the first MOS tube of the adjustment circuit are controlled to be fully turned on, so that the source of the first MOS tube outputs a constant current with a second current magnitude.

[0032] In some embodiments, controlling the regulating circuit to output a constant voltage includes:

[0033] Controlling the drain and source of the first MOS tube of the adjustment circuit to be fully turned on;

[0034] The voltage operational amplifier in the operational amplifier module of the adjustment circuit is turned on to enable the source of the first MOS tube to output a constant voltage.

[0035] According to a third aspect of an embodiment of the present disclosure, an electronic device is provided, comprising the charging circuit of the first aspect.

[0036] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0037] The charging circuit provided by the embodiment of the present disclosure includes a controller and a power output circuit connected to the controller. The power output circuit has a constant voltage output state and a constant current output state, and includes a charge pump and an adjustment circuit; the input end of the charge pump is connected to an external power supply, and the output end of the charge pump is connected to the adjustment circuit; the adjustment circuit is used to adjust the output of the charge pump to a constant voltage output or a constant current output; and the controller is used to control the power output circuit to switch between the constant voltage output state and the constant current output state. The charging circuit provided by the embodiment of the present disclosure can enable the power output circuit to output a constant voltage or a constant current to the outside through the adjustment circuit connected in series with the charge pump, thereby meeting the requirements for the charging circuit in different charging processes and significantly reducing the volume and manufacturing cost of the charging circuit.

[0038] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A schematic diagram of a linear charging state in an embodiment of the present disclosure is shown.

[0040] Figure 2 A circuit diagram of a charging circuit in an embodiment of the present disclosure is shown.

[0041] Figure 3 A circuit diagram of an operational amplifier module in an embodiment of the present disclosure is shown.

[0042] Figure 4 A schematic flow chart of a charging method in an embodiment of the present disclosure is shown.

[0043] Reference numerals:

[0044] 100-controller; 110-communication circuit; 120-control circuit; 130-detection circuit; 200-power output circuit; 210-charge pump; 220-adjustment circuit; 221-first MOS tube; 222-operational amplifier module; 2221-voltage operational amplifier; 2222-current operational amplifier; 223-first resistor; 224-second resistor; 300-constant current control circuit; 310-second MOS tube; 400-protection circuit. DETAILED DESCRIPTION

[0045] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0046] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0047] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0048] For ease of understanding, the following will be combined Figure 1 , the various stages of linear charging are introduced.

[0049] in, Figure 1 Vbat is the voltage of the battery to be charged, Vout is the output voltage of the charging circuit, and Iout is the output current of the charging circuit.

[0050] Exemplarily, linear charging includes at least three stages. When an external power source is connected to the input of the charging circuit and the battery to be charged is connected to the output of the charging circuit, if the voltage of the battery to be charged is too low and is in a dead state, the battery to be charged enters a low-current constant-current charging stage. In this stage, the charging circuit outputs a small constant current to avoid damage to the battery in the dead state caused by high current charging. The dead state can be understood as the state at the end of battery discharge, that is, the state when the battery is exhausted.

[0051] As the battery voltage rises, it exits the dead state and enters the high-current constant-current charging phase. During this phase, the charging circuit outputs a high current to quickly charge the battery. Simultaneously, as the battery charge increases, the battery voltage continues to rise, and so does the voltage output by the charging circuit.

[0052] When the voltage of the battery to be charged approaches the preset fully charged battery voltage, the battery to be charged enters the constant voltage charging stage. In this stage, the charging circuit will maintain a constant voltage output, while the output current will gradually decrease to ensure battery safety.

[0053] Next, exemplary embodiments of the present disclosure will be described in detail.

[0054] Figure 2 A circuit diagram of a charging circuit in the present disclosure is shown as follows: Figure 2As shown, the charging circuit provided by the embodiment of the present disclosure includes: a controller 100 and a power output circuit 200 connected to the controller 100, wherein the power output circuit 200 has a constant voltage output state and a constant current output state, and the controller 100 is used to control the power output circuit 200 to switch between the constant voltage output state and the constant current output state.

[0055] Specifically, the power output circuit 200 may include a charge pump 210 and an adjustment circuit 220. The input of the charge pump 210 is connected to an external power supply, and the output of the charge pump 210 is connected to the adjustment circuit 220. The adjustment circuit 220 is used to adjust the output of the charge pump 210 to a constant voltage output or a constant current output.

[0056] In some embodiments, the adjustment circuit 220 includes a first metal-oxide-semiconductor field-effect transistor (MOS transistor) 221 and an operational amplifier module 222 .

[0057] The output of the charge pump 210 is connected to the drain of the first MOS transistor 221. The source of the first MOS transistor 221 is connected to the inverting input of the operational amplifier module 222, and the output of the operational amplifier module 222 is connected to the gate of the first MOS transistor 221. The source of the first MOS transistor 221 is used to connect to an external battery to be charged, so as to charge the battery.

[0058] For example, the first MOS transistor 221 can be an N-channel MOS transistor. When the linear charging is in the low-current constant-current charging stage, the controller 100 controls the input voltage of the gate of the first MOS transistor 221, and according to the transfer characteristics of the MOS transistor, the first MOS transistor 221 can output a constant current at the source.

[0059] That is, when the drain voltage of the first MOS transistor 221 is constant, the source current of the first MOS transistor 221 can be adjusted by controlling the gate voltage of the first MOS transistor 221 , and the source of the first MOS transistor 221 can output a constant current.

[0060] In some embodiments, the charging circuit further includes a constant current control circuit 300. The constant current control circuit 300 is provided between the controller 100 and the adjustment circuit 220, and is used to control the current magnitude of the constant current output of the charge pump 210.

[0061] Exemplarily, the constant current control circuit 300 may include a second MOS transistor 310 . The drain and gate of the second MOS transistor 310 may be connected to the controller respectively, and the source of the second MOS transistor 310 is connected to the gate of the first MOS transistor 221 .

[0062] That is, the controller 100 can control the source output voltage of the second MOS transistor 310 through the drain and gate of the second MOS transistor 310, so as to control the gate input voltage of the first MOS transistor 221, thereby realizing control over the state of the first MOS transistor 221. For example, the controller 100 can control the conduction and cutoff between the drain and source of the first MOS transistor 221, or, when the drain voltage of the first MOS transistor 221 is constant, control the source constant current of the first MOS transistor 221 to output a current of a specified magnitude based on the transfer characteristics of the MOS transistor.

[0063] It should be noted that the operational amplifier module 222 and the first MOS transistor 221 in the embodiment of the present disclosure can form a negative feedback circuit. Under the negative feedback of the operational amplifier module 222, the source of the first MOS transistor 221 can output a relatively stable constant current or constant voltage.

[0064] Specifically, in the embodiment of the present disclosure, the source of the first MOS transistor 221 can be connected to the inverting input terminal (-) of the operational amplifier module 222, and the non-inverting input terminal (+) of the operational amplifier module 222 can be connected to the reference voltage, so that the operational amplifier module 222 can play a negative feedback regulation role on the first MOS transistor 221.

[0065] For example, when the voltage at the non-inverting input of the operational amplifier module 222 is higher than the voltage at the inverting input, the output of the operational amplifier module 222 outputs a high level to the gate of the first MOS transistor 221, and conduction occurs between the drain and source of the first MOS transistor 221. At this point, the source voltage of the first MOS transistor 221 increases, and the voltage at the inverting input of the operational amplifier module 222 increases accordingly. When the voltage at the inverting input of the operational amplifier module 222 is higher than the voltage at the non-inverting input, the output of the operational amplifier module 222 outputs a low level to the gate of the first MOS transistor 221, and conduction occurs between the drain and source of the first MOS transistor 221. At this point, the source voltage of the first MOS transistor 221 decreases, and the voltage at the inverting input of the operational amplifier module 222 decreases accordingly. This reciprocating process enables the source of the first MOS transistor 221 to achieve a relatively stable constant current output or constant voltage output.

[0066] In some embodiments, a first resistor 223 is provided between the source of the first MOS transistor 221 and the inverting input terminal of the operational amplifier module 222, and a second resistor 224 is provided between the inverting input terminal of the operational amplifier module 222 and the ground line. The first resistor 223 and the second resistor 224 are used to adjust the input voltage of the inverting input terminal of the operational amplifier module 222, so that the source of the first MOS transistor 221 can output a constant current or a constant voltage according to a preset magnitude.

[0067] For example, Figure 3 FIG. 1 shows a circuit diagram of an operational amplifier module according to an embodiment of the present disclosure. Figure 3As shown, the operational amplifier module 222 may include a voltage operational amplifier 2221 and a current operational amplifier 2222 connected in parallel. Accordingly, the inverting input terminal of the operational amplifier module 222 includes the inverting input terminal of the voltage operational amplifier 2221 and the inverting input terminal of the current operational amplifier 2222, and the output terminal of the operational amplifier includes the output terminal of the voltage operational amplifier 2221 and the output terminal of the current operational amplifier 2222.

[0068] The voltage operational amplifier 2221 and the current operational amplifier 2222 can be configured to be in a normally closed state, and the controller can be used to control the voltage operational amplifier and the current operational amplifier to switch between an on state and an off state. During the linear charging process, according to the actual demand for power output, the voltage operational amplifier 2221 can be turned on alone to make the source of the first MOS tube 221 output a constant voltage according to a preset voltage, or the current operational amplifier 2222 can be turned on alone to make the source of the first MOS tube 221 output a constant current according to a preset current.

[0069] It is understandable that due to the transfer characteristics of the MOS transistor, the current output from the source of the first MOS transistor 221 can be controlled to a relatively low constant current, thereby meeting the requirement for relatively low constant current charging during the linear charging process. Therefore, the op amp module 222 can also be composed solely of a voltage operational amplifier 2221 to meet the requirement for constant voltage charging during the linear charging process. Such an arrangement can also enable the charging circuit to independently meet the power output requirements of each stage of the linear charging process, further reducing the size and manufacturing cost of the charging circuit, thereby reducing the space occupied by the electronic device.

[0070] In some embodiments, the controller 100 may include a control circuit 120 , a communication circuit 110 , and a detection circuit 130 .

[0071] Specifically, the communication circuit 110 and the detection circuit 130 can both be connected to the control circuit 120. The communication circuit 110 can communicate with the external power supply to adjust the output power of the external power supply. For example, the communication circuit 110 can request the external power supply to input a specified power into the charge pump 210 according to a preset charging protocol. The charging protocol can be a PD (Power Delivery) protocol, a QC (Quick Charge) protocol, etc., which is not limited in the embodiments of the present disclosure.

[0072] The first detection end of the detection circuit 130 can be connected to the access side of the external power supply to detect the access status of the external power supply. The second detection end of the detection circuit 130 can be connected to the source output side of the first MOS tube 221 to detect the voltage of the battery to be charged. For example, when the detection circuit 130 detects that the external power supply has been connected and the voltage of the battery to be charged is lower than the dead power voltage of the battery, the communication circuit 110 can request a smaller output power from the external power supply, so that the external power supply inputs the charge pump 210 with a smaller power, thereby avoiding high-power charging from causing damage to the battery to be charged in a dead power state. Among them, the dead power state can be understood as the state at the end of battery discharge, that is, the state after the battery is exhausted. Correspondingly, the dead power voltage can be understood as the voltage at the end of battery discharge, that is, the voltage after the battery is exhausted.

[0073] It should be noted that the first output terminal of the control circuit 120 is connected to the controlled terminal of the charge pump 210 .

[0074] In other words, the control circuit 120 can control the charge pump 210 to be turned on and off, or switch the operating mode of the charge pump 210, through the first output terminal, i.e., adjust the voltage adjustment ratio of the charge pump 210. The voltage adjustment ratio can be understood as the ratio between the input voltage and the output voltage of the charge pump 210.

[0075] It should be noted that the second output terminal of the control circuit 120 is connected to the controlled terminal of the operational amplifier module 222 .

[0076] That is, the control circuit 120 can control the turning on and off of each operational amplifier in the operational amplifier module 222 through the second output terminal. It will be understood that the number of second output terminals can be consistent with the number of operational amplifiers in the operational amplifier module 222. In the case where the operational amplifier module 222 includes a voltage operational amplifier 2221 and a current operational amplifier 2222, the number of second output terminals can be two. The two second output terminals are respectively connected to different operational amplifiers to independently control the voltage operational amplifier 2221 and the current operational amplifier 2222. In the case where the operational amplifier module 222 only includes a voltage operational amplifier 2221, the number of second output terminals can be one, thereby independently controlling the voltage operational amplifier 2221.

[0077] It should be noted that the third output terminal of the control circuit 120 is connected to the drain of the second MOS transistor 310, the fourth output terminal of the control circuit 120 is connected to the gate of the second MOS transistor 310, and the source of the second MOS transistor 310 is connected to the gate of the first MOS transistor 221, so that the control circuit 120 can control the source output voltage of the second MOS transistor 310, thereby realizing control of the state of the first MOS transistor 221.

[0078] In some embodiments, the charging circuit 400 further includes a protection circuit 400. The protection circuit 400 is disposed between the input of the charge pump 210 and the external power supply, and is used to control the connection between the charge pump 210 and the external power supply. For example, if the detection circuit 130 detects that the charging state of the battery to be charged is abnormal or charging is complete, the protection circuit 400 can be activated, thereby closing the path between the external power supply and the charge pump 210 to protect the battery to be charged. If it is detected that the battery to be charged requires charging, the protection circuit 400 can be disabled, thereby connecting the external power supply to the charge pump 210 to charge the battery to be charged.

[0079] For example, the fifth output terminal of the control circuit 120 may be connected to the controlled terminal of the protection circuit 400 so as to control the on and off of the protection circuit 400 .

[0080] Figure 4 A schematic diagram of a charging method according to an embodiment of the present disclosure is shown. Figure 2 The charging circuit shown in Figure 1 is as follows. Figure 4 As shown, the method includes the following steps.

[0081] S401 , when it is detected that an external power source is connected, the voltage of the battery to be charged is detected.

[0082] For example, the detection module in the charging circuit can detect the connection status of the external power supply. When the connection of the external power supply is detected, the detection module in the charging circuit can also detect the voltage of the battery to be charged in real time.

[0083] S402, when it is detected that the voltage of the battery to be charged is less than or equal to the first voltage, requesting an external power supply to input a first power into the charge pump, controlling the charge pump to enter a first working state, and controlling the adjustment circuit to output a first constant current.

[0084] It should be noted that the first voltage can be understood as the dead battery voltage of the battery to be charged. When it is detected that the voltage of the battery to be charged is less than or equal to the first voltage, it is determined that the battery to be charged is in a dead battery state, and the battery to be charged can enter a low-current constant-current charging stage.

[0085] In this phase, the communication module in the charging circuit can request the external power supply to input a lower power (first power) into the charge pump. The voltage adjustment ratio of the charge pump in the first working state can be 1:1. In other words, the charge pump does not step down the voltage input from the external power supply, thereby enabling the charging circuit to output a lower charging current (first current magnitude), thus preventing high current charging from damaging the dead battery.

[0086] In some embodiments, the voltage input to the gate of the first MOS transistor of the adjustment circuit can be controlled in the constant current output region of the first MOS transistor, so that based on the transfer characteristics of the MOS transistor, the source of the first MOS transistor can output a stable constant current with a first current magnitude.

[0087] In other embodiments, when the operational amplifier module includes a current operational amplifier, the drain and source of the first MOS transistor of the adjustment circuit can be controlled to be fully conductive. Subsequently, the current operational amplifier in the operational amplifier module of the adjustment circuit is separately turned on (keeping the voltage operational amplifier turned off) so that the source of the first MOS transistor outputs a stable constant current at the first current magnitude.

[0088] S403, when it is detected that the voltage of the battery to be charged is greater than the first voltage and less than or equal to the second voltage, request the external power supply to input the charge pump with the second power, control the charge pump to enter the second working state, and control the adjustment circuit to output a constant current with a second current size.

[0089] It should be noted that the second voltage can be a pre-set voltage value. The second voltage can be understood as the voltage of the battery to be charged when it switches from the high-current constant-current charging stage to the constant-voltage charging stage. Therefore, the second voltage can be set to a value close to the battery voltage when it is fully charged.

[0090] When it is detected that the voltage of the battery to be charged is greater than the first voltage and less than or equal to the second voltage, it is determined that the battery to be charged has the conditions for high-current fast charging, and the battery to be charged can enter the high-current constant-current charging stage.

[0091] In this phase, the communication module in the charging circuit can request the external power supply to input a higher power (the second power) into the charge pump. The voltage adjustment ratio of the charge pump in the second operating state can be 2:1, 4:1, or other voltage adjustment ratios for stepping down the voltage. In other words, the charge pump will step down the voltage input from the external power supply, so that the charging circuit can output a higher charging current (the second current magnitude) at the same power, thereby improving the charging speed of the battery to be charged.

[0092] In some embodiments, because the stability requirements for the constant current output of the charging circuit are generally lower during high current charging, the drain and source of the first MOS transistor of the adjustment circuit can be controlled to be fully conductive, so that the charge pump directly outputs a constant current at the second current magnitude through the source of the first MOS transistor.

[0093] In other embodiments, for scenarios with higher requirements for constant current output stability, the method of the previous stage can be referred to. After the drain and source of the first MOS tube of the control adjustment circuit are fully turned on, the current operational amplifier in the operational amplifier module is turned on separately (keeping the voltage operational amplifier turned off) to enable the source of the first MOS tube to output a stable constant current with a second current magnitude.

[0094] It can be understood that the magnitude of the second current is greater than the magnitude of the first current, and the voltage adjustment ratio of the charge pump in the second working state is greater than the voltage adjustment ratio in the first working state.

[0095] S404 , when it is detected that the voltage of the battery to be charged is greater than the second voltage, requesting an external power source to input a third power into the charge pump, controlling the charge pump to enter the first working state, and controlling the regulating circuit to output a constant voltage.

[0096] It should be noted that when it is detected that the voltage of the battery to be charged is greater than the first voltage and less than or equal to the second voltage, it is determined that the battery to be charged is about to enter a fully charged state. At this time, in order to protect the battery, the battery to be charged can enter a constant voltage charging stage.

[0097] At this stage, the communication module in the charging circuit can request the external power supply to input a higher power (the third power) into the charge pump. The charge pump will then return to the first operating state, setting the charge pump voltage adjustment ratio to 1:1. In other words, the charge pump will not step down the voltage input from the external power supply. As a result, the charging circuit can output a higher charging voltage at the same power, gradually reducing the charging current and slowly charging the battery, thereby protecting the battery.

[0098] It is understood that both the second power and the third power are greater than the first power. Depending on actual needs, the third power may be equal to or different from the second power. When the third power is equal to the second power, the battery to be charged does not need to repeatedly request the same output power from the external power supply when it enters the constant voltage charging stage from the high-current constant current charging stage.

[0099] In some embodiments, because the constant voltage during the constant-voltage charging phase may affect battery safety, the constant-voltage output stability requirements are high during the constant-voltage charging phase. Therefore, after the drain and source of the first MOS transistor in the control adjustment circuit are fully conductive, the voltage operational amplifier in the operational amplifier module of the adjustment circuit can be turned on (keeping the current operational amplifier off) to ensure that the source of the first MOS transistor produces a stable constant voltage output.

[0100] In other embodiments, in scenarios where the stability requirements for the constant voltage output of the charging circuit are low, the drain and source of the first MOS tube can be directly controlled to be fully turned on, so that the charge pump can directly output a constant voltage through the source of the first MOS tube.

[0101] Therefore, the charging method provided by the embodiment of the present disclosure can meet the power output requirements of the battery to be charged at each stage by controlling the above-mentioned charging circuit, thereby achieving the purpose of realizing full-process charging using the charging circuit provided by the embodiment of the present disclosure.

[0102] Combination of the above Figure 2 and Figure 3 The charging circuit provided in the embodiment of the present disclosure is described in detail. Based on the same inventive concept, the present disclosure also provides an electronic device, which includes the above-mentioned Figure 2 The charging circuit is shown.

[0103] For example, the electronic device may be any device with a built-in battery, such as a mobile phone, a Bluetooth headset, or a smart bracelet. When an external power source is connected to a charging circuit in such an electronic device, the charging circuit can linearly charge the battery built into the electronic device.

[0104] For example, the electronic device can also be an external charging device for charging a battery. For example, it can be a charging head for charging a mobile phone, a charging box for charging Bluetooth headsets, or a charging clip for charging a smart bracelet. When an external power source is connected to the charging circuit in such an electronic device, the output end of the charging circuit can be connected to the charging port of the external battery to charge it.

[0105] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0106] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0107] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A charging circuit, characterized in that: include: A controller and a power output circuit connected to the controller; The power output circuit has a constant voltage output state and a constant current output state, and includes a charge pump and an adjustment circuit; the input end of the charge pump is connected to an external power supply, and the output end of the charge pump is connected to the adjustment circuit; the adjustment circuit is used to adjust the output of the charge pump to a constant voltage output or a constant current output; The controller is used to control the power output circuit to switch between the constant voltage output state and the constant current output state.

2. The charging circuit according to claim 1, wherein: The adjustment circuit includes a first MOS tube and an operational amplifier module; The drain of the first MOS transistor is connected to the output end of the charge pump, the source of the first MOS transistor is connected to the inverting input end of the operational amplifier module, and the output end of the operational amplifier module is connected to the gate of the first MOS transistor.

3. The charging circuit according to claim 2, wherein: A first resistor is provided between the source of the first MOS tube and the inverting input terminal of the operational amplifier module, and a second resistor is provided between the inverting input terminal of the operational amplifier module and the ground line. The first resistor and the second resistor are used to adjust the input voltage of the operational amplifier module.

4. The charging circuit according to claim 2, wherein: The operational amplifier module includes a voltage operational amplifier and a current operational amplifier connected in parallel with each other; The controller is used to control the voltage operational amplifier and the current operational amplifier to switch between an on state and an off state.

5. The charging circuit according to claim 2, wherein: The charging circuit also includes a constant current control circuit; The constant current control circuit is arranged between the controller and the adjustment circuit, and is used to control the current size of the constant current output of the charge pump.

6. The charging circuit according to claim 5, characterized in that: The constant current control circuit includes a second MOS tube; The drain and gate of the second MOS transistor are respectively connected to the controller, and the source of the second MOS transistor is connected to the gate of the first MOS transistor.

7. The charging circuit according to claim 1, wherein: The charging circuit also includes a protection circuit; The protection circuit is provided between the input end of the charge pump and the external power supply, and is used to control the connection and disconnection between the charge pump and the external power supply.

8. A charging method, characterized in that: The charging circuit according to any one of claims 1 to 7 comprises: When it is detected that an external power source is connected, the voltage of the battery to be charged is detected; When it is detected that the voltage of the battery to be charged is less than or equal to the first voltage, requesting the external power supply to input a first power into the charge pump, controlling the charge pump to enter a first working state, and controlling the adjustment circuit to output a constant current with a first current magnitude; When it is detected that the voltage of the battery to be charged is greater than the first voltage and less than or equal to the second voltage, requesting the external power supply to input a second power into the charge pump, controlling the charge pump to enter a second working state, and controlling the adjustment circuit to output a constant current with a second current magnitude; When it is detected that the voltage of the battery to be charged is greater than the second voltage, requesting the external power supply to input a third power into the charge pump, controlling the charge pump to enter the first working state, and controlling the adjustment circuit to output a constant voltage; Among them, the second power and the third power are both greater than the first power, the first current magnitude is smaller than the second current magnitude, the voltage adjustment ratio of the charge pump in the first working state is smaller than the voltage adjustment ratio in the second working state, and the voltage adjustment ratio is the ratio between the input voltage and the output voltage of the charge pump.

9. The charging method according to claim 8, characterized in that: The control adjustment circuit outputs a constant current with a first current magnitude, comprising: The voltage input to the gate of the first MOS tube of the adjustment circuit is controlled to be in the constant current output region of the first MOS tube, so that the source of the first MOS tube outputs a constant current with a first current magnitude.

10. The charging method according to claim 8, characterized in that: The control adjustment circuit outputs a constant current with a first current magnitude, comprising: Controlling the drain and source of the first MOS tube of the adjustment circuit to be fully turned on; The current operational amplifier in the operational amplifier module of the adjustment circuit is turned on to enable the source of the first MOS tube to output a constant current with a first current magnitude.

11. The charging method according to claim 8, wherein: The step of controlling the adjustment circuit to output a constant current with a second current magnitude includes: The drain and source of the first MOS tube of the adjustment circuit are controlled to be fully turned on, so that the source of the first MOS tube outputs a constant current with a second current magnitude.

12. The charging method according to claim 8, wherein: The controlling the constant voltage output of the adjustment circuit includes: Controlling the drain and source of the first MOS tube of the adjustment circuit to be fully turned on; The voltage operational amplifier in the operational amplifier module of the adjustment circuit is turned on to enable the source of the first MOS tube to output a constant voltage.

13. An electronic device, characterized in that: The charging circuit comprises the charging circuit according to any one of claims 1 to 7.

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