Charging control method and device of switching power supply converter

Abstract

The invention discloses a charging control method and device for a switching power supply converter, and belongs to the technical field of switching power supplies. The method comprises the following steps: when a battery is in a trickle charging mode and an output voltage of a switching power supply converter is detected to be smaller than a target voltage threshold value, obtaining an output voltage of the switching power supply converter in a target stage based on an input voltage and an output voltage of the switching power supply converter and a duration of entering the target stage in a plurality of timing stages; the charging current of the battery changes along with time; adjusting the charging current of the battery based on the target function relation and the duration of entering the target stage, and enabling the charging current to be preposed to zero at the end of the current switching period; and in the trickle charging mode, when it is detected that the output voltage of the switching power supply converter is larger than or equal to a target voltage threshold value, the input current of the switching power supply converter is adjusted by adopting the power conservation principle of the switching power supply converter, so that the charging current of the battery is adjusted to a target charging current value.

Description

Technical Field

[0001] The present application belongs to the technical field of switching power supplies, and in particular relates to a charging control method and device for a switching power converter. Background Art

[0002] In the field of battery charging technology, the charging process is usually divided into three stages: trickle charging, constant current charging and constant voltage charging. When the battery voltage is lower than a certain threshold, in order to protect the battery and extend its service life, the battery management chip will use a smaller current to charge the battery, that is, trickle charging. Figure 1 The control circuit shown in the figure controls the charging current. This method requires the introduction of a current-sense resistor at the battery end and the addition of two pins to the chip, which increases the number of peripheral devices and chip pins and increases the system cost. In addition, the open-loop control method requires fixing the switching time of the power tube in the switching power converter to regulate the charging current, resulting in low control accuracy and a limited control range. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems existing in the related art. To this end, this application proposes a charging control method and device for a switching power converter, which simplifies the circuit structure, reduces the number of peripheral components and chip pin requirements, reduces system costs, improves control accuracy, and broadens the control range.

[0004] In a first aspect, the present application provides a charging control method for a switching power converter, wherein the output end of the switching power converter is connected to a battery; the method comprises:

[0005] When the battery is in a trickle charging mode and the output voltage of the switching power converter is detected to be less than a target voltage threshold, an objective function relationship of a charging current of the battery over time in the target stage is obtained based on the input voltage and the output voltage of the switching power converter and the duration of entering a target stage among multiple timing stages; the objective function relationship is used to characterize a positive correlation or negative correlation change of the charging current over time;

[0006] Based on the objective function relationship and the duration of entering the target phase, adjusting the charging current of the battery and setting the charging current to zero before the end of the current switching cycle; the switching cycle includes a plurality of consecutive different timing phases;

[0007] In the trickle charging mode, when it is detected that the output voltage of the switching power converter is greater than or equal to the target voltage threshold, the power conservation principle of the switching power converter is adopted to adjust the input current of the switching power converter to adjust the charging current of the battery to the target charging current value.

[0008] According to the charging control method of the switching power converter provided in the embodiment of the present application, when the battery is in trickle charging mode, open-loop control or closed-loop control of the battery charging current is selected according to the size of the output voltage. When the output voltage is lower than the target voltage threshold, the charging current is controlled by open-loop control. When the output voltage is greater than or equal to the target voltage threshold, it is switched to closed-loop control mode. The charging current is controlled by closed-loop control of the input current, which simplifies the circuit structure, reduces the number of peripheral devices used and the chip pin requirements, reduces the system cost, improves the control accuracy, and widens the control range.

[0009] A charging control method for a switching power converter according to an embodiment of the present application, wherein the objective function relationship of the charging current of the battery over time in the target stage is obtained based on the input voltage and the output voltage of the switching power converter and the duration of entering a target stage among multiple timing stages, includes:

[0010] Based on the input voltage and the output voltage, and the duration of entering the first stage of the multiple timing stages, a first functional relationship corresponding to the first stage is obtained; the first functional relationship is used to represent that the charging current changes positively with time;

[0011] Based on the output voltage and the duration of entering the second stage of the multiple timing stages, a second functional relationship corresponding to the second stage is obtained; the second functional relationship is used to characterize the negative correlation change of the charging current over time, and the start time of the second stage is after the end time of the first stage.

[0012] A charging control method for a switching power converter according to an embodiment of the present application is provided.

[0013] The obtaining, based on the input voltage and the output voltage, and the duration of entering the first stage of the multiple timing stages, a first functional relationship corresponding to the first stage includes:

[0014] Obtaining a first rate of change based on a ratio of a difference between the input voltage and the output voltage to an inductance of an inductor in the switching power converter;

[0015] Obtaining a first functional relationship corresponding to the first stage based on the first change rate and the duration of entering the first stage;

[0016] The obtaining, based on the output voltage and the duration of entering the second stage of the plurality of timing stages, a second functional relationship corresponding to the second stage includes:

[0017] obtaining a second rate of change based on a ratio of the output voltage to the inductance value;

[0018] A second functional relationship corresponding to the second stage is obtained based on the second change rate, the inductor current at the end of the first stage, and the duration of entering the second stage.

[0019] In a charging control method for a switching power converter according to an embodiment of the present application, the multiple timing stages include a third stage, where the start time of the third stage is after the end time of the second stage; and obtaining a target function relationship of the battery charging current over time in the target stage based on the input voltage and the output voltage of the switching power converter and the duration of entering the target stage among the multiple timing stages, including:

[0020] A third rate of change is obtained based on a ratio of a sum of the output voltage and a parasitic diode conduction voltage drop corresponding to a power tube in the switching power converter to an inductance value of an inductor in the switching power converter; the third rate of change is greater than a second rate of change corresponding to the second functional relationship;

[0021] A third functional relationship corresponding to the third stage is obtained based on the third change rate, the inductor current at the end of the second stage, and the duration of entering the third stage; the third functional relationship is used to characterize the negative correlation change of the charging current over time.

[0022] A charging control method for a switching power converter according to an embodiment of the present application, wherein the method utilizes the power conservation principle of the switching power converter to adjust the input current of the switching power converter to adjust the charging current of the battery to a target charging current value, includes:

[0023] Adopting the power conservation principle and based on the target charging current value, obtaining a first reference signal;

[0024] Based on the magnitude relationship between the first reference signal and the target multiple of the input current, the input current is adjusted to adjust the charging current of the battery to the target charging current value.

[0025] In a charging control method for a switching power converter according to an embodiment of the present application, adjusting the input current based on a magnitude relationship between the first reference signal and the input current at a target multiple includes:

[0026] When the input current of the target multiple is greater than the first reference signal, reducing the input current until the input current of the target multiple is equal to the first reference signal;

[0027] In a case where the input current of the target multiple is smaller than the first reference signal, the input current is increased until the input current of the target multiple is equal to the first reference signal.

[0028] In one embodiment of the present application, a charging control method for a switching power converter is provided. The switching power converter selectively configures a first power tube, a second power tube, a third power tube, and a fourth power tube based on device type. When the switching power converter is a buck-boost switching power converter, the buck-boost switching power converter is configured to include the first power tube, the second power tube, the third power tube, and the fourth power tube. When the switching power converter is a buck-boost switching power converter, the buck-boost switching power converter is configured to include the first power tube and the second power tube. The multiple timing stages include a first stage, a second stage, and a third stage. The start time of the second stage is after the end time of the first stage, and the start time of the third stage is after the end time of the second stage. Adjusting the charging current of the battery includes:

[0029] In the first stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned on, the second power tube is turned off, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned on and the second power tube is turned off;

[0030] In the second stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned off, the second power tube is turned on, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned off and the second power tube is turned on;

[0031] In the third stage, the first power tube, the second power tube, the third power tube and the fourth power tube corresponding to the buck-boost switching power converter are controlled to be turned off, or the first power tube and the second power tube corresponding to the buck switching power converter are controlled to be turned off to adjust the charging current of the battery.

[0032] In a second aspect, the present application provides a charging control device for a switching power converter, wherein the output end of the switching power converter is used to connect to a battery; the device comprises:

[0033] a first processing module, configured to, when the battery is in a trickle charging mode and the output voltage of the switching power converter is detected to be less than a target voltage threshold, obtain, based on the input voltage and the output voltage of the switching power converter, and the duration of entering a target stage among multiple timing stages, an objective function relationship of a charging current of the battery over time in the target stage; the objective function relationship is used to characterize a positive correlation or negative correlation change of the charging current over time;

[0034] a second processing module, configured to adjust the charging current of the battery based on the objective function relationship and the duration of entering the target phase, and to set the charging current to zero before the end of a current switching cycle; wherein the switching cycle includes a plurality of consecutive different timing phases;

[0035] a third processing module, configured to, in the trickle charging mode, adjust the input current of the switching power converter by adopting the power conservation principle of the switching power converter when detecting that the output voltage of the switching power converter is greater than or equal to the target voltage threshold, so as to adjust the charging current of the battery to the target charging current value.

[0036] According to the charging control device of the switching power converter provided in the embodiment of the present application, when the battery is in trickle charging mode, open-loop control or closed-loop control of the battery charging current is selected according to the size of the output voltage. When the output voltage is lower than the target voltage threshold, the charging current is controlled by open-loop control. When the output voltage is greater than or equal to the target voltage threshold, it switches to closed-loop control mode and controls the charging current by closed-loop control of the input current. This simplifies the circuit structure, reduces the number of peripheral devices used and the chip pin requirements, reduces the system cost, improves the control accuracy, and widens the control range.

[0037] In a third aspect, the present application provides a switching power supply system, comprising:

[0038] A switching power converter, wherein the output end of the switching power converter is connected to a battery;

[0039] a closed-loop charging control circuit, wherein an input end of the closed-loop charging control circuit is connected to an input end of the switching power converter and an output end of the switching power converter respectively;

[0040] an open-loop charging control circuit, wherein an input end of the open-loop charging control circuit is connected to an input end of the switching power converter and an output end of the switching power converter respectively;

[0041] A logic and drive circuit, wherein the input end of the logic and drive circuit is respectively connected to the output end of the closed-loop charging control circuit and the output end of the open-loop charging control circuit, and the output end of the logic and drive circuit is connected to the switching power converter.

[0042] According to the switching power supply system provided in the embodiment of the present application, when the battery is in trickle charging mode, open-loop control or closed-loop control of the battery charging current is selected according to the size of the output voltage. When the output voltage is lower than the target voltage threshold, the charging current is controlled by the open-loop charging control circuit, and when the output voltage is greater than or equal to the target voltage threshold, it switches to the closed-loop control mode, and controls the input current to control the charging current through the closed-loop charging control circuit, which simplifies the circuit structure, reduces the number of peripheral devices used and the chip pin requirements, reduces the system cost, improves the control accuracy, and widens the control range.

[0043] In a switching power supply system according to an embodiment of the present application, the open-loop charging control circuit includes:

[0044] a first voltage-to-current conversion module, wherein an input terminal of the first voltage-to-current conversion module is connected to an input terminal of the switching power converter and an output terminal of the switching power converter respectively;

[0045] A trickle open-loop control circuit, wherein the input end of the trickle open-loop control circuit is connected to the output end of the first voltage-to-current conversion module, the output end of the trickle open-loop control circuit is connected to the input end of the logic and drive circuit, and the trickle open-loop control circuit is used to output an enable signal corresponding to each timing stage.

[0046] In a switching power supply system according to an embodiment of the present application, the switching power converter includes:

[0047] A plurality of power tubes, the gate of each power tube is respectively connected to the output end of the logic and drive circuit, and the working state of the power tube is determined based on the signal output by the logic and drive circuit.

[0048] In a fourth aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the charging control method for the switching power converter as described in the first aspect above is implemented.

[0049] In a fifth aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the charging control method for the switching power converter as described in the first aspect above.

[0050] In a sixth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the charging control method for the switching power converter as described in the first aspect above.

[0051] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0052] When the battery is in trickle charging mode, open-loop control or closed-loop control of the battery charging current is selected according to the output voltage. When the output voltage is lower than the target voltage threshold, the charging current is controlled by open-loop control. When the output voltage is greater than or equal to the target voltage threshold, it switches to closed-loop control mode and controls the charging current by closed-loop control of the input current. This simplifies the circuit structure, reduces the number of peripheral devices used and the chip pin requirements, reduces system costs, improves control accuracy, and broadens the control range.

[0053] Furthermore, by setting the first stage and the second stage, and based on the input voltage and the output voltage, as well as the time length of entering the first stage, the relationship between the change of the inductor current with time in the first stage is obtained, and based on the output voltage and the time length of entering the second stage, the relationship between the change of the inductor current with time in the second stage is obtained, so that the inductor current can be controlled to change based on the corresponding functional relationship, and the average charging current at the battery end can be accurately controlled.

[0054] Furthermore, by setting the third stage and setting the rate of decrease of the charging current in the third stage to be greater than the rate of decrease of the charging current in the second stage, it is possible to ensure that the charging current of the battery is equal to zero before the end of the current switching cycle, thereby avoiding the error superposition in the next switching cycle due to the charging current not being equal to zero, thereby avoiding the charging current from being out of control, ensuring the accuracy of the trickle charging current, improving the noise sensitivity of the open-loop control trickle charging, and improving the precision and accuracy of controlling the charging current.

[0055] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0057] Figure 1 It is a structural diagram of a trickle charging control circuit in the related art;

[0058] Figure 2 This is one of the structural diagrams of the switching power converter provided in the embodiment of the present application;

[0059] Figure 3 This is the second structural diagram of the switching power converter provided in the embodiment of the present application;

[0060] Figure 4 This is one of the structural diagrams of the switching power supply system provided in the embodiment of the present application;

[0061] Figure 5 This is the second structural diagram of the switching power supply system provided in an embodiment of the present application;

[0062] Figure 6 This is one of the principle schematic diagrams of the charging control method of the switching power converter provided in the embodiment of the present application;

[0063] Figure 7 This is the second principle schematic diagram of the charging control method of the switching power converter provided in the embodiment of the present application;

[0064] Figure 8 This is the third structural diagram of the switching power supply system provided in the embodiment of the present application;

[0065] Figure 9 This is the fourth structural diagram of the switching power supply system provided in an embodiment of the present application;

[0066] Figure 10 This is the third principle diagram of the charging control method for the switching power converter provided in the embodiment of the present application;

[0067] Figure 11 1 is a flow chart of a charging control method for a switching power converter provided in an embodiment of the present application;

[0068] Figure 12 1 is a schematic structural diagram of a charging control device for a switching power converter provided in an embodiment of the present application;

[0069] Figure 13 It is a structural diagram of an electronic device provided in an embodiment of the present application.

[0070] Reference numerals:

[0071] Switching power converter 100; closed-loop charging control circuit 110; open-loop charging control circuit 120;

[0072] Logic and drive circuit 130; first voltage-to-current conversion module 140; trickle open-loop control circuit 150;

[0073] Current division module 160; trickle current reference generation circuit 170; reference selection circuit 180; PWM generation module 190;

[0074] Second voltage-to-current conversion module 200; operational amplifier EA; first power tube M1; second power tube M2;

[0075] The third power tube M3; the fourth power tube M4. DETAILED DESCRIPTION

[0076] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0077] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0078] Below, in conjunction with the accompanying drawings, the charging control method for the switching power converter, the charging control device for the switching power converter, the electronic device and the readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0079] The charging control method for the switching power converter may be applied to a terminal, and may be specifically executed by hardware or software in the terminal.

[0080] The terminal includes, but is not limited to, a portable communication device such as a mobile phone or tablet computer having a touch-sensitive surface (e.g., a touch screen display and / or a touch pad). It should also be understood that, in some embodiments, the terminal may not be a portable communication device, but a desktop computer having a touch-sensitive surface (e.g., a touch screen display and / or a touch pad).

[0081] In the following embodiments, a terminal including a display and a touch-sensitive surface is described. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, a mouse, and a joystick.

[0082] The charging control method for a switching power converter provided in an embodiment of the present application may be executed by an electronic device or a functional module or functional entity in the electronic device that can implement the charging control method for the switching power converter. The electronic devices mentioned in the embodiment of the present application include but are not limited to mobile phones, tablet computers, computers, cameras, and wearable devices. The charging control method for the switching power converter provided in the embodiment of the present application is described below using an electronic device as an example of the execution subject.

[0083] like Figure 11 As shown, the charging control method of the switching power converter includes: step S1, step S2 and step S3.

[0084] It should be noted that the output terminal of the switching power converter is used to connect to the battery.

[0085] The output voltage of the switching power converter is the battery terminal voltage.

[0086] Step S1: When the battery is in a trickle charging mode and the output voltage of the switching power converter is detected to be less than a target voltage threshold, a target function relationship of the battery charging current versus time in the target stage is obtained based on the input voltage and output voltage of the switching power converter and the duration of entering a target stage among multiple timing stages.

[0087] In this step, in the trickle charge mode, the battery management chip uses a smaller current to charge the battery.

[0088] Trickle charge can be used for pre-charging when the battery voltage is low. The charging current in trickle charge mode is usually one tenth of the constant current charging current.

[0089] For example, a trickle current threshold may be set, and whether to perform trickle charging may be determined by comparing the set trickle current threshold with the battery voltage.

[0090] When the battery voltage is greater than the set trickle threshold, constant current charging can be performed; when the battery voltage is less than or equal to the set trickle threshold, trickle charging can be performed.

[0091] Among them, the value of the trickle threshold can be customized based on user needs, and different trickle thresholds can be set based on the battery type. For example, when the battery type is a lithium battery, the trickle threshold can be set to about 3V. When the battery type is a nickel-metal hydride battery, the trickle threshold can be set to about 1V. When the battery type is a lead-acid battery, the trickle threshold can be set to about 12V, or it can be set to other values, which is not limited in this application.

[0092] In the trickle charge mode, the method of controlling the charging current to be adopted can be determined based on the relationship between the output voltage of the switching power converter and the target voltage threshold.

[0093] Among them, the target voltage threshold is less than the set trickle current threshold. The value of the target voltage threshold can be set based on user needs and is not limited in this application.

[0094] The input voltage of a switching power converter can affect the output capability of the switching power converter.

[0095] The output voltage of the switching power converter can reflect the current voltage level of the battery. When the output voltage (battery voltage) is less than the target voltage threshold, the charging current can be controlled in an open-loop control manner.

[0096] A switching cycle consists of a number of consecutive, distinct timing phases.

[0097] The target phase is any one of the multiple timing phases.

[0098] After entering the timing phase, a timing circuit related to the timing phase may start working and timing to obtain a target function relationship corresponding to the target phase based on the input voltage and the output voltage, as well as the duration of entering the target phase.

[0099] The objective function relationship is a functional relationship of the battery charging current changing with time. The objective function relationship may include a positive correlation function relationship or a negative correlation function relationship, that is, the objective function relationship may be used to characterize the positive correlation change or negative correlation change of the charging current with time.

[0100] Step S2: Based on the objective function relationship and the duration of entering the target phase, adjust the charging current of the battery and set the charging current to zero before the end of the current switching cycle;

[0101] In this step, the duration of entering the target stage can be substituted into the objective function relationship to obtain the inductor current corresponding to the switching power converter at the current moment (i.e., the charging current of the battery), thereby adjusting the charging current of the battery based on the inductor current at the current moment.

[0102] By adjusting the battery charging current, the average charging current within a switching cycle can be controlled to a set value, and the charging current can be controlled to zero before the end of a switching cycle.

[0103] Step S3: In the trickle charge mode, when it is detected that the output voltage of the switching power converter is greater than or equal to the target voltage threshold, the power conservation principle of the switching power converter is used to adjust the input current of the switching power converter to adjust the charging current of the battery to the target charging current value.

[0104] In this step, when it is detected that the output voltage of the switching power converter is greater than or equal to the target voltage threshold, a closed-loop control method may be used to adjust the charging current of the battery.

[0105] The power conservation principle of the switching power converter is that at the current moment, the input power of the switching power converter is equal to the output power, that is, Vbus*Ibus=Vbat*Ibat, where Vbus is the input voltage of the switching power converter, Ibus is the input current of the switching power converter, Vbat is the output voltage of the switching power converter, Ibat is the output current of the switching power converter, and, at the current moment, the input voltage and output voltage of the switching power converter are fixed values.

[0106] During trickle charging, the output current (battery charging current) needs to be controlled to a target charging current value (eg, 0.1A to 0.4A), wherein the target charging current value can be customized based on user needs.

[0107] Based on the power conservation principle of the switching power converter, Ibus=Vbat*Ibat / Vbus can be obtained. The output current Ibat, that is, the battery charging current, can be adjusted by adjusting the input current Ibus until the battery charging current is adjusted to the target charging current value.

[0108] In the present application, when the output voltage is lower than the target voltage threshold, the charging current of the battery is controlled by open loop, thereby avoiding the failure of closed loop control and thus avoiding the situation where the charging current is out of control.

[0109] According to the charging control method of the switching power converter provided in the embodiment of the present application, when the battery is in trickle charging mode, open-loop control or closed-loop control of the battery charging current is selected according to the size of the output voltage. When the output voltage is lower than the target voltage threshold, the charging current is controlled by open-loop control. When the output voltage is greater than or equal to the target voltage threshold, it is switched to closed-loop control mode. The charging current is controlled by closed-loop control of the input current, which simplifies the circuit structure, reduces the number of peripheral devices used and the chip pin requirements, reduces the system cost, improves the control accuracy, and widens the control range.

[0110] like Figure 4 As shown, in some embodiments, the switching power supply system may include an open-loop charging control circuit.

[0111] In this embodiment, the open-loop charging control circuit may be configured to receive an input voltage and an output voltage, so as to control the charging circuit to enter different timing phases based on the input voltage and the output voltage.

[0112] In some embodiments, step S1 may include:

[0113] Based on the input voltage and the output voltage, and the duration of entering the first stage of the multiple timing stages, a first functional relationship corresponding to the first stage is obtained;

[0114] Based on the output voltage and the duration of entering the second stage of the multiple timing stages, a second functional relationship corresponding to the second stage is obtained.

[0115] In this embodiment, the first phase and the second phase can be set within a switching cycle, the duration of the switching cycle is equal to the sum of the durations of the first phase and the second phase, and the start time of the second phase is after the end time of the first phase.

[0116] The first functional relationship is a functional relationship of the charging current changing with time in the first stage. The first functional relationship is used to characterize a positive correlation change of the charging current with time.

[0117] In the first stage, the inductor current increases with time, and at the end of the first stage, the inductor current may generate a peak value.

[0118] The second functional relationship is a functional relationship of the charging current changing with time in the second stage. The second functional relationship is used to characterize the negative correlation change of the charging current with time.

[0119] In the second stage, the inductor current decreases with time.

[0120] By setting the first functional relationship and the second functional relationship, the inductor current in each stage is controlled to change based on the corresponding functional relationship, so as to control the average current in the switching cycle to reach a set value.

[0121] In some embodiments, obtaining a first functional relationship corresponding to the first stage based on the input voltage and the output voltage, and the duration of entering the first stage of the multiple timing stages may include:

[0122] Obtaining a first rate of change based on a ratio of a difference between an input voltage and an output voltage to an inductance of an inductor in the switching power converter;

[0123] Based on the first change rate and the duration of entering the first stage, a first functional relationship corresponding to the first stage is obtained.

[0124] In this embodiment, if Figure 2 The circuit schematic of the buck-boost converter is shown as an example. Figure 3 An example circuit diagram of a buck converter is shown.

[0125] The inductor in the switching power converter is as follows Figure 2 or Figure 3As shown in the inductance L in FIG, the ratio of the difference between the input voltage and the output voltage to the inductance value can be determined as the first change rate.

[0126] The time duration of entering the first stage can be used as an independent variable, and the charging current of the battery (inductor current) in the first stage can be used as a dependent variable to construct a first functional relationship corresponding to the first stage.

[0127] For example, when the output voltage is lower than the target voltage threshold, the trickle open-loop enable signal changes from low level to high level, and the timing circuit corresponding to the first stage starts to work and counts. The timing time is ton = C*vref_ton / I3 (where C is Figure 9 The capacitance value of the capacitor shown, vref_ton is the reference signal of the first stage, I3 is the proportional current corresponding to the difference between the input voltage and the output voltage, I3 = K3*(Vbus-Vbat), where K3 is the proportional coefficient, Vbus is the input voltage, and Vbat is the output voltage). In the first stage, the inductor current increases.

[0128] When the initial inductor current is 0, the first functional relationship can be determined as: iL = (Vbus-Vbat)*t / L, where iL is the battery charging current, Vbus is the input voltage, Vbat is the output voltage, t is the time to enter the first stage, and L is the inductance value.

[0129] In some embodiments, obtaining a second functional relationship corresponding to the second stage based on the output voltage and the duration of entering the second stage of the multiple timing stages may include:

[0130] A second rate of change is obtained based on a ratio of the output voltage to the inductance value;

[0131] Based on the second change rate, the inductor current at the end of the first stage, and the time duration of entering the second stage, a second functional relationship corresponding to the second stage is obtained.

[0132] In this embodiment, the ratio of the output voltage to the inductance value may be determined as the second change rate.

[0133] The time duration of entering the second stage can be used as an independent variable, and the charging current of the battery (inductor current) in the second stage can be used as a dependent variable to construct a second functional relationship corresponding to the second stage.

[0134] The starting moment of the second stage is the ending moment of the first stage, and the inductor current at the ending moment of the first stage can be determined as the starting value of the second functional relationship.

[0135] For example, Figure 10As shown, at the end of the first stage, the enable signal corresponding to the first stage can be set low, and the enable signal corresponding to the second stage can be set high, and the timing circuit corresponding to the second stage starts to work and count, and the timing time is toff = C*vref_toff / I4 (where C is Figure 9 The capacitance value of the capacitor shown, vref_toff is the reference signal of the second stage, I4 is the proportional current of the output voltage, I4=K3*Vbat, where K3 is the proportional coefficient and Vbat is the output voltage). In the second stage, the inductor current decreases.

[0136] At the end of the first stage, the inductor current generates a peak value Ipeak=(Vbus-Vbat)*ton / L, where Vbus is the input voltage, Vbat is the output voltage, ton is the total duration of the first stage, and L is the inductance value.

[0137] The second functional relationship can be determined as: iL=Ipeak-Vbat*t / L, where Ipeak is the inductor current at the end of the first stage, Vbat is the output voltage, t is the time to enter the second stage, and L is the inductance value.

[0138] In the actual implementation process, when only the first stage and the second stage are set in one switching cycle, the inductor current is set to 0 at the end of the second stage, that is, the average inductor current in one switching cycle is: iavg = Ipeak / 2, where Ipeak is the inductor current at the end of the first stage; the parameters Vref_ton (reference signal of the first stage), Vref_toff (reference signal of the second stage), C (capacitance value), L (inductance value) and K3 (proportional coefficient) can be set to satisfy the equation Ibat = Vref_ton*C / (2*L*K3) = Vref_toff*C / (2*L*K3), thereby controlling the trickle charging current.

[0139] According to the charging control method for a switching power converter provided in an embodiment of the present application, by setting a first stage and a second stage, and based on the input voltage and the output voltage, as well as the time length of entering the first stage, obtaining the relationship between the change of the inductor current with time in the first stage, and based on the output voltage and the time length of entering the second stage, obtaining the relationship between the change of the inductor current with time in the second stage, the inductor current can be controlled to change based on the corresponding functional relationship, thereby being able to accurately control the average charging current at the battery end.

[0140] In some embodiments, step S1 may include:

[0141] A third rate of change is obtained based on a ratio of a sum of an output voltage and a parasitic diode conduction voltage drop corresponding to a power tube in the switching power converter to an inductance value of an inductor in the switching power converter;

[0142] Based on the third change rate, the inductor current at the end of the second stage, and the duration of entering the third stage, a third functional relationship corresponding to the third stage is obtained.

[0143] In this embodiment, a power tube is provided in the switching power converter, and a parasitic diode is formed by a PN junction between the drain and source of the power tube. The anode of the parasitic diode is connected to the source, and the cathode is connected to the drain. When the drain voltage of the power tube is lower than the source voltage, the parasitic diode is turned on.

[0144] The forward voltage drop of a parasitic diode is the voltage drop across the diode when it is conducting in the forward direction. When the parasitic diode is forward biased, current will flow through the diode, and the voltage across the diode at this time is the forward voltage drop.

[0145] The ratio of the sum of the output voltage and the conduction voltage drop of the parasitic diode to the inductance value can be determined as the third change rate.

[0146] The third change rate is greater than the second change rate corresponding to the second functional relationship, which can ensure that the inductor current is reduced to 0 after the third stage ends.

[0147] The duration of entering the third stage can be determined as the independent variable, and the charging current (inductor current) of the battery in the third stage can be used as the dependent variable to construct a third functional relationship corresponding to the third stage.

[0148] The start time of the third stage is after the end time of the second stage. The start time of the third stage may be the end time of the second stage, and the inductor current at the end time of the second stage may be determined as the start value of the third functional relationship.

[0149] For example, Figure 10 As shown, at the end of the second stage, the enable signal corresponding to the second stage can be set low, and the enable signal corresponding to the third stage can be set high, and the timing circuit corresponding to the third stage starts to work and count, and the timing time is treset=C*vref_treset / I5 (where C is Figure 9 The capacitance value of the capacitor shown, vref_treset is the reference signal of the third stage, I5 is the proportional current of the output voltage, I5=K3*Vbat, where K3 is the proportional coefficient and Vbat is the output voltage). In the third stage, the inductor current decreases.

[0150] At the end of the second stage, the inductor current is: Ipeak-Vbat*toff / L, where Ipeak is the inductor current at the start of the second stage, Vbat*toff / L is the value of the inductor current drop during the second stage, toff is the total duration of the second stage, L is the inductance value, and Vbat is the output voltage.

[0151] The third functional relationship can be determined as: iL=Ipeak-Vbat*toff / L-(Vbat+vdiode) / L*t, where vdiode is the conduction voltage drop of the parasitic diode, Vbat is the output voltage, L is the inductance value, Ipeak is the inductor current at the starting moment of the second stage, and toff is the total duration of the second stage.

[0152] The third functional relationship is used to characterize the negative correlation between the charging current and time. In the third stage, the charging current decreases as time increases.

[0153] In the actual implementation process, Figure 8 As shown, the input end of the timing circuit corresponding to the first stage (ton stage) is used to receive the proportional current I3 of the input voltage minus the output voltage (I3 = K3*(Vbus-Vbat), where K3 is the proportional coefficient, Vbus is the input voltage, and Vbat is the output voltage), the open-loop ton stage reference signal vref_ton, the ton stage enable signal ton_en, and the trickle open-loop enable signal trickle_open_en. The timing circuit corresponding to the ton stage is used to output the ton stage control signal ton and the toff stage start timing enable signal toff_en.

[0154] Among them, the ton stage timing circuit enable signal can be obtained by performing a logical "OR" operation on the high level state of ton_en and the rising edge of trickle_open_en.

[0155] The input end of the timing circuit corresponding to the second stage (toff stage) is used to receive the proportional current I4 of the output voltage (I4 = K3*Vbat, where K3 is the proportional coefficient and Vbat is the output voltage), the reference signal vref_toff of the open-loop toff stage, the start timing enable signal toff_en of the toff stage, and the trickle open-loop enable signal trickle_open_en. The timing circuit corresponding to the toff stage is used to output the toff stage control signal toff and the treset stage start timing enable signal treset_en.

[0156] The enable signal of the timing circuit in the toff phase can be obtained by performing a logic AND operation on the high level of toff_en and the high level of trickle_open_en.

[0157] The input end of the timing circuit corresponding to the third stage (treset stage) is used to receive the proportional current I5 of the output voltage (I5 = K3*Vbat, where K3 is the proportional coefficient and Vbat is the output voltage), the reference signal vref_treset of the open-loop treset stage, the start timing enable signal treset_en of the treset stage, and the trickle open-loop enable signal trickle_open_en. The output end of the timing circuit corresponding to the treset stage is used to output the treset stage control signal treset and the ton stage start timing enable signal ton_en, where the ton stage start timing enable signal ton_en is used to control entry into the first stage of the next switching cycle.

[0158] Among them, the enable signal of the timing circuit in the treset stage can be obtained by the high level of treset_en and the high level of trickle_open_en.

[0159] like Figure 9 The timing circuit corresponding to any timing stage in the first, second and third stages is illustrated. When the enable signal en is low, the enb signal is high, the switch tube MQ1 is turned on, the ramp voltage vsaw is cleared, the comparator comp is enabled at a low level, and the output out is low.

[0160] When the enable signal en changes from low level to high level, the switch tube MQ1 is turned off, the comparator comp starts working, the output out becomes high level, and the current I charges the capacitor C, the ramp voltage vsaw increases, and vsaw = I*t / C, where t is the timing time. When the ramp voltage vsaw increases to the reference voltage vref, the comparator output out becomes low level, that is, a period of timing is completed, and the timing time t = C*vref / I.

[0161] In the present application, when the first stage, the second stage and the third stage are set within a switching cycle, the Vref_ton (reference signal of the first stage), Vref_toff (reference signal of the second stage), Vref_treset (reference signal of the third stage), C (capacitance value), L (inductance value) and K3 (proportional coefficient) parameters can be set to satisfy the equation Ibat = Vref_ton*C / (2*L*K3) = (Vref_toff+Vref_treset)*C / (2*L*K3), thereby open-loop controlling the trickle charging current, and the trickle charging current value in the open-loop control mode can be adjusted by adjusting the above parameters according to actual needs.

[0162] By setting the reference signal corresponding to the second stage and the reference signal corresponding to the third stage, the accuracy of the trickle charging current can be guaranteed and the noise sensitivity of the open-loop controlled trickle charging can be improved.

[0163] According to the charging control method for a switching power converter provided in an embodiment of the present application, by setting a third stage and setting the rate of decrease of the charging current in the third stage to be greater than the rate of decrease of the charging current in the second stage, it is possible to ensure that the charging current of the battery is equal to zero before the end of the current switching cycle, thereby avoiding the error superposition in the next switching cycle due to the charging current not being equal to zero, thereby avoiding the loss of control of the charging current, ensuring the accuracy of the trickle charging current, improving the noise sensitivity of the open-loop control trickle charging, and improving the precision and accuracy of controlling the charging current.

[0164] During the research and development process, the inventor discovered that when the output voltage is low, the timing of the second and third stages is longer, the switching frequency of the switching power converter will be lower than 20KHz, and the circuit may produce a howling sound, thereby affecting the user experience. In this application, a pulse width judgment mechanism can be introduced in the second and third stages.

[0165] In some embodiments, when it is detected that the pulse widths of the second stage and the third stage exceed a set width threshold, the pulse widths of the second stage and the third stage may be adjusted to the set width threshold.

[0166] By automatically adjusting the pulse width of the second and third stages to the preset value for timing, it can ensure that the switching frequency is not lower than 20KHz, thereby effectively avoiding the howling phenomenon and improving the user experience.

[0167] In some embodiments, step S3 may include:

[0168] Adopting the power conservation principle and based on the target charging current value, obtaining a first reference signal;

[0169] Based on the magnitude relationship between the first reference signal and the target multiple of the input current, the input current is adjusted to adjust the charging current of the battery to the target charging current value.

[0170] In this embodiment, the principle of conservation of power shows that the product of the input current and the input voltage is equal to the product of the output current and the output voltage, and at the current moment, the input voltage and the output voltage of the switching power converter are fixed values. When it is known that the output current needs to be adjusted to a fixed value (target charging current value), the value that the input current needs to reach can be designed based on the target charging current value.

[0171] For example, by setting the first reference signal, the target multiple of the input current is adjusted to the first reference signal according to the first reference signal, so that the output current reaches the target charging current value.

[0172] In the actual implementation process, Figure 4 As shown, the input current of the switching power converter flows through the current sensing resistor Rcs, which will generate a voltage difference. The positive and negative terminals of the current sensing module CS can collect the voltage difference and output the input current sensing signal (i.e., the input current of the target multiple) vsen = K1*Ibus, where K1 is the current sensing proportional coefficient (i.e., the target multiple), Ibus is the input current, and the size of the target multiple K1 can be customized based on the user and is not limited in this application.

[0173] The switching power supply system includes a closed-loop charging control circuit, which may include a second voltage-to-current conversion module, a current division module, a trickle reference generation circuit, and a reference selection circuit.

[0174] Among them, the input end of the second voltage conversion current module is used to receive the input voltage and output voltage of the switching power converter, and output currents I1 = K2*Vbus and I2 = K2*Vbat proportional to the input voltage and output voltage, wherein K2 is the voltage conversion current proportional coefficient in the second voltage conversion current module, Vbus is the input voltage, and Vbat is the output voltage.

[0175] The current division module receives an input voltage proportional current I1 at a first input terminal, a reference current ib at a second input terminal, and an output voltage proportional current I2 at a third input terminal, and outputs a current idiv=ib*I2 / I1 having a division operation.

[0176] like Figure 5 As shown, idiv is mirrored through the current mirror into idiv1 and idiv2, with a current ratio of 1:n1:n2, where n1 and n2 are the current mirror ratio coefficients. ibat_set is the digital signal that sets the trickle charge current. ibat_set controls the on / off state of switch MN1, thereby controlling the current im flowing through resistor Rtrickle = m*idiv, where m is the multiplication ratio.

[0177] When ibat_set=0, the switch MN1 is turned off, im=n1*idiv, m=n1; when ibat_set=1, the switch MN1 is turned on, im=(n1+n2)*idiv, m=(n1+n2). The number of bits in ibat_set can be set based on actual needs and is not limited in this application.

[0178] The multiplied current im flows through the resistor Rtrickle, and a trickle reference voltage vref_trickle=im*Rtrickle can be obtained.

[0179] The reference selection current input trickle reference voltage vref_trickle and constant current reference voltage vref_cc, the system can determine whether to perform trickle charging based on the size relationship between the battery voltage and the set trickle threshold.

[0180] When the battery voltage is greater than the set trickle threshold, trickle = 0, constant current charging is performed; when the battery voltage is less than or equal to the set trickle threshold, trickle = 1, trickle charging is performed;

[0181] When trickle=1, the transmission gate TG2 is turned on, and vref=vref_trickle; when trickle=0, the transmission gate TG1 is turned on, and vref=vref_cc.

[0182] An operational amplifier can be set up, the non-inverting input terminal of the operational amplifier is used to receive a reference signal, and the negative input terminal of the operational amplifier is used to receive an input current of a target multiple (i.e., an input current detection signal). In the trickle charging mode, the non-inverting input terminal of the operational amplifier can be used to receive a first reference signal vref_trickle, and the input current is adjusted by comparing the input current of the target multiple with the first reference signal to adjust the input current to be equal to the first reference signal.

[0183] Among them, the first reference signal can be expressed as: vref_trickle = m*Vbat*ib*Rtrickle / Vbus, where m is the multiplication ratio of the current flowing through the resistor Rtrickle compared to the current flowing into the trickle reference generating circuit, Vbat is the output voltage, ib is the reference current input to the current division module, and Vbus is the input voltage.

[0184] In the case of closed-loop control of the charging current, the input current sensing signal can be adjusted to the first reference signal, that is, the equation can be established: K1*Ibus=m*Vbat*ib*Rtrickle / Vbus, and from Ibus=Vbat*Ibat / Vbus, it can be obtained that: K1*Ibat=m*ib*Rtrickle, that is, by designing the parameters m, ib, Rtrickle and K1 to satisfy the equation Ibat=m*ib*Rtrickle / K1, the closed-loop control of the battery charging current Ibat can be achieved.

[0185] In some embodiments, adjusting the input current based on the magnitude relationship between the first reference signal and the target multiple of the input current may include:

[0186] When the input current of the target multiple is greater than the first reference signal, reducing the input current until the input current of the target multiple is equal to the first reference signal;

[0187] In a case where the target multiple input current is smaller than the first reference signal, the input current is increased until the target multiple input current is equal to the first reference signal.

[0188] In this embodiment, the magnitude of the input current may be adjusted based on the magnitude relationship between the target multiple input current and the first reference signal, so as to adjust the input current to a preset magnitude.

[0189] In the actual implementation process, Figure 4 As shown, the switching power supply system may include a PWM generation module, the input end of the PWM generation module is connected to the output end of the operational amplifier, and the operational amplifier may output an input current loop control signal Vc based on the magnitude relationship between the input current detection signal (the input current of the target multiple) and the first reference signal.

[0190] The PWM generation module can receive the input current loop control signal Vc to adjust the duty cycle based on the input current loop control signal Vc, thereby controlling the switching state of the power tube in the switching power converter to adjust the input current to a preset value.

[0191] For example, when the input current detection signal is smaller than the first reference signal, the input current loop control signal increases and the duty cycle increases, thereby controlling the input current to increase.

[0192] When the input current detection signal is greater than the first reference signal, the input current loop control signal decreases and the duty cycle is small, thereby controlling the input current to decrease.

[0193] In some embodiments, the switching power converter selectively configures the first power tube, the second power tube, the third power tube, and the fourth power tube based on device type.

[0194] In this embodiment, if Figure 2 As shown, in the case where the switching power converter is a buck-boost switching power converter, the buck-boost switching power converter can be configured to include a first power tube, a second power tube, a third power tube and a fourth power tube.

[0195] like Figure 3 As shown, in the case where the switching power converter is a step-down switching power converter, the step-down switching power converter is configured to include a first power tube and a second power tube.

[0196] In some embodiments, the switching power converter may include a logic and driver circuit.

[0197] In this embodiment, the input terminal of the logic and driving circuit is connected to the output terminal of the PWM generation module.

[0198] The PWM generation module can output pulse width modulation signals PWM_BUCK signal and PWM_BOOST signal, which can be input into the logic and drive circuit (wherein the PWM_BUCK signal is used to instruct the system to enter the buck mode, and the PWM_BOOST signal is used to instruct the system to enter the boost mode) so that the logic and drive circuit can generate drive signals HS1, LS1, HS2 and LS2, which are respectively used to control the switching states of the four power tubes M1 to M4 of the buck-boost converter, or the switching states of the first power tube M1 and the second power tube M2 of the buck converter.

[0199] like Figure 6 This diagram illustrates the working principle of the buck / boost-boost converter in BUCK mode (buck mode). In this mode, the HS1 and LS1 signals can control the switching states of the first power tube M1 and the second power tube M2 respectively. At this time, the inductor current is the battery charging current.

[0200] like Figure 7 The schematic diagram illustrates the working principle of the buck-boost converter in BOOST mode. In this mode, HS1 maintains a constant high level, so that the first power tube M1 is continuously turned on, and LS1 maintains a constant low level, so that the second power tube M2 is always in the off state. At this time, the LS2 and HS2 signals respectively control the switching states of the third power tube M3 and the fourth power tube M4. When the fourth power tube M4 is turned on, the battery terminal current is equal to the inductor current; when the fourth power tube M4 is turned off, the battery terminal current is zero. By adjusting the switching states of the third power tube M3 and the fourth power tube M4, the average charging current of the battery terminal can be accurately controlled.

[0201] In some embodiments, when the charging current is open-loop controlled, adjusting the charging current of the battery may include:

[0202] In the first stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned on, the second power tube is turned off, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned on and the second power tube is turned off;

[0203] In the second stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned off, the second power tube is turned on, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned off and the second power tube is turned on;

[0204] In the third stage, the first power tube, the second power tube, the third power tube and the fourth power tube corresponding to the buck-boost switching power converter are controlled to be turned off, or the first power tube and the second power tube corresponding to the buck switching power converter are controlled to be turned off to adjust the charging current of the battery.

[0205] In this embodiment, if Figure 10 As shown, in the first stage (ton stage), HS1 is a high level, LS1 is a low level, LS2 is a low level, and HS2 is a high level. In response to HS1, the first power tube can be controlled to be turned on; in response to LS1, the second power tube can be controlled to be turned off; in response to LS2, the third power tube can be controlled to be turned off; in response to HS2, the fourth power tube can be controlled to be turned on.

[0206] In the second stage (toff stage), HS1 is at a low level, LS1 is at a high level, LS2 is at a low level, and HS2 is at a high level. In response to HS1, the first power tube can be controlled to be turned off; in response to LS1, the second power tube can be controlled to be turned on; in response to LS2, the third power tube can be controlled to be turned off; in response to HS2, the fourth power tube can be controlled to be turned on.

[0207] In the third stage (treset stage), HS1 is at a low level, LS1 is at a low level, LS2 is at a low level, and HS2 is at a high level. In response to HS1, the first power tube can be controlled to be turned off; in response to LS1, the second power tube can be controlled to be turned off; in response to LS2, the third power tube can be controlled to be turned off; in response to HS2, the fourth power tube can be controlled to be turned on.

[0208] By controlling the conduction of different power tubes in different timing stages, the output current of the switching power converter, that is, the charging current of the battery, can be adjusted.

[0209] The charging control device of the switching power converter provided in the present application is described below. The charging control device of the switching power converter described below and the charging control method of the switching power converter described above can be referred to in correspondence with each other.

[0210] The charging control method for a switching power converter provided in the embodiments of the present application can be executed by a charging control device for the switching power converter. In the embodiments of the present application, the charging control device for a switching power converter executing the charging control method for the switching power converter is used as an example to illustrate the charging control device for the switching power converter provided in the embodiments of the present application.

[0211] An embodiment of the present application also provides a charging control device for a switching power converter.

[0212] like Figure 12As shown, the charging control device of the switching power converter has an output end of the switching power converter connected to a battery; the device includes: a first processing module 1210 , a second processing module 1220 and a third processing module 1230 .

[0213] The first processing module 1210 is configured to, when the battery is in a trickle charging mode and the output voltage of the switching power converter is detected to be less than a target voltage threshold, obtain an objective function relationship of the battery charging current over time in the target stage based on the input voltage and output voltage of the switching power converter and the duration of entering a target stage among multiple timing stages; the objective function relationship is used to represent a positive correlation or negative correlation change of the charging current over time;

[0214] The second processing module 1220 is configured to adjust the charging current of the battery based on the objective function relationship and the duration of entering the target phase, and to set the charging current to zero before the end of the current switching cycle; the switching cycle includes a plurality of consecutive different timing phases;

[0215] The third processing module 1230 is used to adjust the input current of the switching power converter to the target charging current value by adopting the power conservation principle of the switching power converter in the trickle charging mode when it is detected that the output voltage of the switching power converter is greater than or equal to the target voltage threshold.

[0216] According to the charging control device of the switching power converter provided in the embodiment of the present application, when the battery is in trickle charging mode, open-loop control or closed-loop control of the battery charging current is selected according to the size of the output voltage. When the output voltage is lower than the target voltage threshold, the charging current is controlled by open-loop control. When the output voltage is greater than or equal to the target voltage threshold, it switches to closed-loop control mode and controls the charging current by closed-loop control of the input current. This simplifies the circuit structure, reduces the number of peripheral devices used and the chip pin requirements, reduces the system cost, improves the control accuracy, and widens the control range.

[0217] In some embodiments, the first processing module 1210 may also be configured to:

[0218] Based on the input voltage and the output voltage, and the duration of the first stage of the multiple timing stages, a first functional relationship corresponding to the first stage is obtained; the first functional relationship is used to represent the positive correlation change of the charging current with time;

[0219] Based on the output voltage and the duration of entering the second stage of the multiple timing stages, a second functional relationship corresponding to the second stage is obtained; the second functional relationship is used to characterize the negative correlation change of the charging current with time, and the start time of the second stage is after the end time of the first stage.

[0220] In some embodiments, the first processing module 1210 may also be configured to:

[0221] Obtaining a first rate of change based on a ratio of a difference between an input voltage and an output voltage to an inductance of an inductor in the switching power converter;

[0222] Based on the first change rate and the duration of entering the first stage, a first functional relationship corresponding to the first stage is obtained.

[0223] In some embodiments, the first processing module 1210 may also be configured to:

[0224] A second rate of change is obtained based on a ratio of the output voltage to the inductance value;

[0225] Based on the second change rate, the inductor current at the end of the first stage, and the time duration of entering the second stage, a second functional relationship corresponding to the second stage is obtained.

[0226] In some embodiments, the multiple timing stages include a third stage, where the start time of the third stage is after the end time of the second stage; the first processing module 1210 may further be configured to:

[0227] A third rate of change is obtained based on a ratio of a sum of an output voltage and a parasitic diode conduction voltage drop corresponding to a power tube in the switching power converter to an inductance value of the inductor in the switching power converter; the third rate of change is greater than a second rate of change corresponding to the second functional relationship;

[0228] Based on the third rate of change, the inductor current at the end of the second stage, and the duration of entering the third stage, a third functional relationship corresponding to the third stage is obtained; the third functional relationship is used to characterize the negative correlation change of the charging current with time.

[0229] In some embodiments, the third processing module 1230 may also be configured to:

[0230] Adopting the power conservation principle and based on the target charging current value, obtaining a first reference signal;

[0231] Based on the magnitude relationship between the first reference signal and the target multiple of the input current, the input current is adjusted to adjust the charging current of the battery to the target charging current value.

[0232] In some embodiments, the third processing module 1230 may also be configured to:

[0233] When the input current of the target multiple is greater than the first reference signal, reducing the input current until the input current of the target multiple is equal to the first reference signal;

[0234] In a case where the target multiple input current is smaller than the first reference signal, the input current is increased until the target multiple input current is equal to the first reference signal.

[0235] In some embodiments, the switching power converter selectively configures a first power tube, a second power tube, a third power tube, and a fourth power tube based on device type. When the switching power converter is a buck-boost switching power converter, the buck-boost switching power converter is configured to include the first power tube, the second power tube, the third power tube, and the fourth power tube; when the switching power converter is a buck-boost switching power converter, the buck-boost switching power converter is configured to include the first power tube and the second power tube; the multiple timing stages include a first stage, a second stage, and a third stage, the start time of the second stage is after the end time of the first stage, and the start time of the third stage is after the end time of the second stage; the second processing module 1220 may also be used to:

[0236] In the first stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned on, the second power tube is turned off, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned on and the second power tube is turned off;

[0237] In the second stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned off, the second power tube is turned on, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned off and the second power tube is turned on;

[0238] In the third stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned off, the second power tube is turned off, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned off and the second power tube is turned off to adjust the charging current of the battery.

[0239] The charging control device of the switching power converter in the embodiment of the present application can be an electronic device or a component in the electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other device other than a terminal. For example, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle electronic device, a mobile Internet device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook or a personal digital assistant (PDA), etc. It can also be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), a teller machine or a self-service machine, etc., and the embodiment of the present application does not specifically limit it.

[0240] The charging control device for the switching power converter in the embodiment of the present application may be a device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0241] The charging control device of the switching power converter provided in the embodiment of the present application can achieve Figures 1 to 11 To avoid repetition, the various processes implemented in the method embodiment are not described here.

[0242] like Figure 4 As shown, in some embodiments, the present application provides a switching power supply system, including: a switching power supply converter 100 , a closed-loop charging control circuit 110 , an open-loop charging control circuit 120 and a logic and drive circuit 130 .

[0243] In this embodiment, the output terminal of the switching power converter 100 is connected to a battery.

[0244] An input terminal of the closed-loop charging control circuit 110 is connected to an input terminal of the switching power converter 100 and an output terminal of the switching power converter 100 , respectively.

[0245] An input terminal of the open-loop charging control circuit 120 is connected to an input terminal of the switching power converter 100 and an output terminal of the switching power converter 100 , respectively.

[0246] The input end of the logic and driving circuit 130 is connected to the output end of the closed-loop charging control circuit 110 and the output end of the open-loop charging control circuit 120 , respectively. The output end of the logic and driving circuit 130 is connected to the switching power converter 100 .

[0247] According to the switching power supply system provided in the embodiment of the present application, when the battery is in trickle charging mode, open-loop control or closed-loop control of the battery charging current is selected according to the size of the output voltage. When the output voltage is lower than the target voltage threshold, the charging current is controlled by the open-loop charging control circuit 120, and when the output voltage is greater than or equal to the target voltage threshold, it switches to the closed-loop control mode, and controls the input current to control the charging current through the closed-loop charging control circuit 110, which simplifies the circuit structure, reduces the number of peripheral devices used and the chip pin requirements, reduces the system cost, improves the control accuracy, and widens the control range.

[0248] In some embodiments, the open-loop charging control circuit 120 may include: a first voltage-to-current conversion module 140 and a trickle open-loop control circuit 150 .

[0249] In this embodiment, the input end of the first voltage-to-current conversion module 140 is connected to the input end of the switching power converter 100 and the output end of the switching power converter 100 respectively.

[0250] The input end of the trickle open-loop control circuit 150 is connected to the output end of the first voltage-to-current conversion module 140, and the output end of the trickle open-loop control circuit 150 is connected to the input end of the logic and drive circuit 130. The trickle open-loop control circuit 150 is used to output the enable signal corresponding to each timing stage.

[0251] In some embodiments, the closed-loop charging control circuit 110 may include: a second voltage-to-current conversion module 200 , a current division module 160 , a trickle reference generation circuit 170 , and a reference selection circuit 180 .

[0252] In this embodiment, the input end of the second voltage-to-current conversion module 200 is connected to the input end of the switching power converter 100 and the output end of the switching power converter 100 respectively.

[0253] An input terminal of the current division module 160 is connected to an output terminal of the second voltage-to-current conversion module 200 .

[0254] An input terminal of the trickle reference generation circuit 170 is connected to an output terminal of the current division module 160 .

[0255] An input terminal of the reference selection circuit 180 is connected to an output terminal of the trickle reference generation circuit 170 .

[0256] In some embodiments, the switching power supply system may further include an operational amplifier EA and a PWM generation module 190 .

[0257] In this embodiment, the non-inverting input terminal of the operational amplifier EA is connected to the output terminal of the reference selection circuit 180, and the negative input terminal of the operational amplifier EA is connected to the input terminal of the switching power converter 100, for receiving the input current detection signal corresponding to the switching power converter 100.

[0258] An input terminal of the PWM generation module 190 is connected to an output terminal of the operational amplifier EA, and an output terminal of the PWM generation module 190 is connected to an input terminal of the logic and driving circuit 130 .

[0259] In some embodiments, the switching power converter 100 may include: a plurality of power transistors.

[0260] In this embodiment, the gate of each power tube is connected to the output terminal of the logic and driving circuit 130 , and the working state of the power tube is determined based on the signal output by the logic and driving circuit 130 .

[0261] In some embodiments, the switching power converter 100 selectively configures the first power transistor M1 , the second power transistor M2 , the third power transistor M3 , and the fourth power transistor M4 based on device types.

[0262] In this embodiment, if Figure 2 As shown, when the switching power converter 100 is a buck-boost switching power converter 100 , the buck-boost switching power converter 100 may be configured to include a first power tube M1 , a second power tube M2 , a third power tube M3 and a fourth power tube M4 .

[0263] like Figure 3 As shown, in the case where the switching power converter 100 is a step-down switching power converter 100 , the step-down switching power converter 100 is configured to include a first power tube M1 and a second power tube M2 .

[0264] In some embodiments, as Figure 13 As shown, an embodiment of the present application also provides an electronic device 1300, including a processor 1301, a memory 1302, and a computer program stored in the memory 1302 and executable on the processor 1301. When the program is executed by the processor 1301, each process of the above-mentioned charging control method embodiment of the switching power converter is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0265] It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and non-mobile electronic devices mentioned above.

[0266] On the other hand, the present application also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the various processes of the above-mentioned charging control method embodiment of the switching power converter and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0267] On the other hand, the present application also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, it is implemented to perform the various processes of the above-mentioned charging control method embodiment of the switching power converter and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0268] On the other hand, an embodiment of the present application further provides a chip, which includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned charging control method embodiment of the switching power converter, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0269] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0270] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0271] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0272] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A charging control method for a switching power converter, characterized in that: The output end of the switching power converter is used to connect to a battery; the method includes: When the battery is in a trickle charging mode and the output voltage of the switching power converter is detected to be less than a target voltage threshold, an objective function relationship of a charging current of the battery over time in the target stage is obtained based on the input voltage and the output voltage of the switching power converter and the duration of entering a target stage among multiple timing stages; the objective function relationship is used to characterize a positive correlation or negative correlation change of the charging current over time; Based on the objective function relationship and the duration of entering the target phase, adjusting the charging current of the battery and setting the charging current to zero before the end of the current switching cycle; the switching cycle includes a plurality of consecutive different timing phases; In the trickle charging mode, when it is detected that the output voltage of the switching power converter is greater than or equal to the target voltage threshold, the power conservation principle of the switching power converter is adopted to adjust the input current of the switching power converter to adjust the charging current of the battery to the target charging current value.

2. The charging control method of the switching power converter according to claim 1, wherein: The objective function relationship of the charging current of the battery changing with time in the target stage is obtained based on the input voltage and the output voltage of the switching power converter and the duration of entering the target stage among the multiple timing stages, including: Based on the input voltage and the output voltage, and the duration of entering the first stage of the multiple timing stages, a first functional relationship corresponding to the first stage is obtained; the first functional relationship is used to represent that the charging current changes positively with time; Based on the output voltage and the duration of entering the second stage of the multiple timing stages, a second functional relationship corresponding to the second stage is obtained; the second functional relationship is used to characterize the negative correlation change of the charging current over time, and the start time of the second stage is after the end time of the first stage.

3. The charging control method for a switching power converter according to claim 2, wherein: The obtaining, based on the input voltage and the output voltage, and the duration of entering the first stage of the multiple timing stages, a first functional relationship corresponding to the first stage includes: Obtaining a first rate of change based on a ratio of a difference between the input voltage and the output voltage to an inductance of an inductor in the switching power converter; Obtaining a first functional relationship corresponding to the first stage based on the first change rate and the duration of entering the first stage; The obtaining of a second functional relationship corresponding to the second stage based on the output voltage and the duration of entering the second stage among the multiple timing stages includes: Obtaining a second rate of change based on a ratio of the output voltage to the inductance value; A second functional relationship corresponding to the second stage is obtained based on the second change rate, the inductor current at the end of the first stage, and the duration of entering the second stage.

4. The charging control method for a switching power converter according to claim 3, wherein: The multiple timing stages include a third stage, where the start time of the third stage is after the end time of the second stage; and the objective function relationship of the charging current of the battery varying with time in the target stage is obtained based on the input voltage and the output voltage of the switching power converter and the duration of entering the target stage among the multiple timing stages, including: A third rate of change is obtained based on a ratio of a sum of the output voltage and a parasitic diode conduction voltage drop corresponding to a power tube in the switching power converter to an inductance value of an inductor in the switching power converter; the third rate of change is greater than a second rate of change corresponding to the second functional relationship; A third functional relationship corresponding to the third stage is obtained based on the third change rate, the inductor current at the end of the second stage, and the duration of entering the third stage; the third functional relationship is used to characterize the negative correlation change of the charging current over time.

5. The charging control method for a switching power converter according to any one of claims 1 to 4, wherein: The step of using the power conservation principle of the switching power converter to adjust the input current of the switching power converter to adjust the charging current of the battery to a target charging current value includes: Adopting the power conservation principle and based on the target charging current value, obtaining a first reference signal; Based on the magnitude relationship between the first reference signal and the target multiple of the input current, the input current is adjusted to adjust the charging current of the battery to the target charging current value.

6. The charging control method for a switching power converter according to claim 5, wherein: The adjusting the input current based on a magnitude relationship between the first reference signal and the input current of a target multiple includes: When the input current of the target multiple is greater than the first reference signal, reducing the input current until the input current of the target multiple is equal to the first reference signal; In a case where the input current of the target multiple is smaller than the first reference signal, the input current is increased until the input current of the target multiple is equal to the first reference signal.

7. The charging control method for a switching power converter according to any one of claims 1 to 4, wherein: The switching power converter selectively configures a first power tube, a second power tube, a third power tube, and a fourth power tube based on device types. When the switching power converter is a buck-boost switching power converter, the buck-boost switching power converter is configured to include the first power tube, the second power tube, the third power tube, and the fourth power tube; when the switching power converter is a buck-boost switching power converter, the buck-boost switching power converter is configured to include the first power tube and the second power tube; the multiple timing stages include a first stage, a second stage, and a third stage, the start time of the second stage is after the end time of the first stage, and the start time of the third stage is after the end time of the second stage; The adjusting the charging current of the battery includes: In the first stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned on, the second power tube is turned off, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned on and the second power tube is turned off; In the second stage, the first power tube corresponding to the buck-boost switching power converter is controlled to be turned off, the second power tube is turned on, the third power tube is turned off, and the fourth power tube is turned on, or the first power tube corresponding to the buck switching power converter is controlled to be turned off and the second power tube is turned on; In the third stage, the first power tube, the second power tube, the third power tube and the fourth power tube corresponding to the buck-boost switching power converter are controlled to be turned off, or the first power tube and the second power tube corresponding to the buck switching power converter are controlled to be turned off to adjust the charging current of the battery.

8. A charging control device for a switching power converter, characterized in that: The output end of the switching power converter is used to connect to a battery; the device comprises: a first processing module, configured to, when the battery is in a trickle charging mode and the output voltage of the switching power converter is detected to be less than a target voltage threshold, obtain, based on the input voltage and the output voltage of the switching power converter, and the duration of entering a target stage among multiple timing stages, an objective function relationship of a charging current of the battery over time in the target stage; the objective function relationship is used to characterize a positive correlation or negative correlation change of the charging current over time; a second processing module, configured to adjust the charging current of the battery based on the objective function relationship and the duration of entering the target phase, and to set the charging current to zero before the end of a current switching cycle; wherein the switching cycle includes a plurality of consecutive different timing phases; a third processing module, configured to, in the trickle charging mode, adjust the input current of the switching power converter by adopting the power conservation principle of the switching power converter when detecting that the output voltage of the switching power converter is greater than or equal to the target voltage threshold, so as to adjust the charging current of the battery to the target charging current value.

9. A switching power supply system, characterized in that: include: A switching power converter, wherein the output end of the switching power converter is connected to a battery; a closed-loop charging control circuit, wherein an input end of the closed-loop charging control circuit is connected to an input end of the switching power converter and an output end of the switching power converter respectively; an open-loop charging control circuit, wherein an input end of the open-loop charging control circuit is connected to an input end of the switching power converter and an output end of the switching power converter respectively; A logic and drive circuit, wherein the input end of the logic and drive circuit is respectively connected to the output end of the closed-loop charging control circuit and the output end of the open-loop charging control circuit, and the output end of the logic and drive circuit is connected to the switching power converter.

10. The switching power supply system according to claim 9, wherein: The open-loop charging control circuit comprises: a first voltage-to-current conversion module, wherein an input terminal of the first voltage-to-current conversion module is connected to an input terminal of the switching power converter and an output terminal of the switching power converter respectively; A trickle open-loop control circuit, wherein the input end of the trickle open-loop control circuit is connected to the output end of the first voltage-to-current conversion module, the output end of the trickle open-loop control circuit is connected to the input end of the logic and drive circuit, and the trickle open-loop control circuit is used to output an enable signal corresponding to each timing stage.

11. The switching power supply system according to claim 9, wherein: The switching power converter comprises: A plurality of power tubes, the gate of each power tube is respectively connected to the output end of the logic and drive circuit, and the working state of the power tube is determined based on the signal output by the logic and drive circuit.

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