Switching power supply circuit and charger

Abstract

The invention provides a switching power supply circuit and a charger. The switching power supply circuit comprises a voltage conversion circuit, a temperature acquisition circuit, a first comparison circuit and a first control circuit, the output end of the voltage conversion circuit is connected with a charging interface of a charging load; the output end of the temperature acquisition circuit is connected with the input end of the first comparison circuit, and the output end of the first comparison circuit is connected with the first control circuit; the first control circuit is connected with the output end of the voltage conversion circuit; the voltage conversion circuit is used for providing required charging voltage and charging current for a charging interface of a charging load according to external power supply voltage output by an external power supply; the temperature acquisition circuit is used for acquiring the temperature of a preset detection point of the switching power supply circuit and generating a corresponding analog voltage based on the acquired temperature; the first comparison circuit is used for comparing the analog voltage with a pre-configured first reference voltage; the first control circuit is used for adjusting the charging voltage and / or the charging current output by the voltage conversion circuit according to the first comparison result.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a switching power supply circuit and a charger. Background Art

[0002] When using a charger to charge loads such as mobile phones, tablets, smart wearable devices, computers, routers and other electronic devices, if the charging temperature is too high, it will not only damage the charger and affect the life of the electrical equipment, but may also cause safety accidents and pose certain safety hazards. Summary of the invention

[0003] The present application provides a switching power supply circuit and a charger.

[0004] The embodiment of the present application provides a switching power supply circuit, which includes: a voltage conversion circuit, a temperature acquisition circuit, a first comparison circuit and a first control circuit; the input end of the voltage conversion circuit is connected to an external power supply, and the output end of the voltage conversion circuit is connected to a charging interface of a charging load; the output end of the temperature acquisition circuit is connected to the input end of the first comparison circuit, and the output end of the first comparison circuit is connected to the first control circuit; the first control circuit is connected to the output end of the voltage conversion circuit;

[0005] The voltage conversion circuit is used to provide the required charging voltage and charging current for the charging interface of the charging load according to the external power supply voltage output by the external power supply;

[0006] The temperature acquisition circuit is used to acquire the temperature of a preset detection point of the switching power supply circuit, generate a corresponding analog voltage based on the acquired temperature, and output the analog voltage to the first comparison circuit;

[0007] The first comparison circuit is used to compare the analog voltage with a preconfigured first reference voltage and output a corresponding first comparison result to the first control circuit;

[0008] The first control circuit is used to adjust the charging voltage and / or charging current output by the voltage conversion circuit according to the first comparison result.

[0009] An embodiment of the present application provides a charger, comprising the switching power supply circuit provided in the above embodiment.

[0010] According to the switching power supply circuit and charger of the embodiment of the present application, the switching power supply circuit collects the temperature of the preset detection point through the temperature collection circuit and converts it into a corresponding analog voltage, compares the analog voltage corresponding to the temperature of the preset detection point detected with the preset first reference voltage through the first comparison circuit to determine whether the current charging temperature of the switching power supply circuit has reached the preset temperature, and adjusts the charging voltage and / or charging current output by the voltage conversion circuit according to the first comparison result output by the first comparison circuit through the first control circuit to reduce the charging voltage and / or charging current, reduce the charging power, and thus reduce the charging temperature, which can effectively prevent the charging safety problem caused by the excessively high charging temperature. In practical applications, while effectively preventing the charging temperature of the charger from being too high and ensuring the charging safety of the charger, the adjustment process of the charging temperature of the charger is effectively simplified, the delay time of the charging temperature adjustment of the charger is effectively reduced, and the adjustment response speed of the charging temperature of the charger is improved.

[0011] With regard to the above embodiments and other aspects of the present application and their implementation, further description is provided in the accompanying drawings, detailed description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In the accompanying drawings of the embodiments of the present application:

[0013] Figure 1 A schematic diagram of the structure of a switching power supply circuit provided in an embodiment of the present application is shown.

[0014] Figure 2 A schematic diagram of the composition structure of another switching power supply circuit provided in an embodiment of the present application is shown.

[0015] Figure 3 A schematic diagram of the structure of another switching power supply circuit provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0017] The present application will be described more fully below with reference to the accompanying drawings, but the embodiments shown may be embodied in different forms, and the present application should not be construed as being limited to the embodiments set forth below. On the contrary, the purpose of providing these embodiments is to make the present application thorough and complete, and to enable those skilled in the art to fully understand the scope of the present application.

[0018] The accompanying drawings of the embodiments of the present application are used to provide a further understanding of the embodiments of the present application, and constitute a part of the specification. Together with the detailed embodiments, they are used to explain the present application, and do not constitute a limitation of the present application. By describing the detailed embodiments with reference to the accompanying drawings, the above and other features and advantages will become more obvious to those skilled in the art.

[0019] The present application may be described with reference to plan views and / or cross-sectional views by means of ideal schematic views of the present application. Therefore, the exemplary illustrations may be modified according to manufacturing techniques and / or tolerances.

[0020] In the absence of conflict, the embodiments of the present application and the features therein may be combined with each other.

[0021] The terms used in this application are only used to describe specific embodiments and are not intended to limit the application. The term "and / or" as used in this application includes any and all combinations of one or more related enumerated items. The singular forms "one" and "the" as used in this application are also intended to include plural forms, unless the context clearly indicates otherwise. The terms "including", "made of..." as used in this application specify the presence of the features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof.

[0022] Unless otherwise defined, all terms (including technical and scientific terms) used in this application have the same meaning as those commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this application, and will not be interpreted as having an idealized or overly formal meaning unless explicitly defined in this application.

[0023] The present application is not limited to the embodiments shown in the drawings, but includes modifications of the configurations formed based on the manufacturing process. Therefore, the regions illustrated in the drawings have schematic properties, and the shapes of the regions shown in the drawings illustrate the specific shapes of the regions of the elements, but are not intended to be limiting.

[0024] In related technologies, the charging temperature is usually sensed at the charger end. When the temperature is too high, an over-temperature reminder is sent to the load. The load then replies with a corresponding charging power adjustment signal to the charger. The control chip at the charger end adjusts the charging parameters according to the signal, thereby reducing the charging power to achieve the purpose of cooling.

[0025] However, this method requires two-way communication between the charger and the load, and the charger needs to go through a series of processes including sensing high temperature, sending over-temperature reminders to the load, and adjusting charging parameters according to the load response signal, which increases the complexity of temperature control and the delay time of charging temperature adjustment is longer.

[0026] The present application provides a switching power supply circuit and a charger, aiming to solve the technical problems existing in the above-mentioned related technologies.

[0027] Figure 1 A schematic diagram of the structure of a switching power supply circuit provided in an embodiment of the present application is shown. Figure 1 As shown, an embodiment of the present application provides a switching power supply circuit 100, which includes a voltage conversion circuit 101, a temperature acquisition circuit 102, a first comparison circuit 103 and a first control circuit 104; the input end of the voltage conversion circuit 101 is connected to an external power supply, and the output end of the voltage conversion circuit 101 is connected to a charging interface of a charging load 200; the output end of the temperature acquisition circuit 102 is connected to the input end of the first comparison circuit 103, and the output end of the first comparison circuit 103 is connected to the first control circuit 104; the first control circuit 104 is connected to the output end of the voltage conversion circuit 101.

[0028] Among them, the voltage conversion circuit 101 is used to provide the required charging voltage and charging current for the charging interface of the charging load 200 according to the external power supply voltage output by the external power supply; the temperature acquisition circuit 102 is used to collect the temperature of a preset detection point of the switching power supply circuit 100, and generate a corresponding analog voltage based on the collected temperature, and output the analog voltage to the first comparison circuit 103; the first comparison circuit 103 is used to compare the analog voltage with a pre-configured first reference voltage, and output the corresponding first comparison result to the first control circuit 104; the first control circuit 104 is used to adjust the charging voltage and / or charging current output by the voltage conversion circuit 101 according to the first comparison result.

[0029] In an embodiment of the present application, the analog voltage can be used to characterize the temperature of a preset detection point of the switching power supply circuit 100 collected by the temperature collection circuit 102. The higher the temperature, the larger the corresponding converted analog voltage. The first reference voltage can be configured according to a preset first preset standard temperature. The first reference voltage at least includes a voltage value corresponding to the preset first preset standard temperature. The first comparison result can at least be used to represent the comparison result between the collected temperature of the preset detection point and the first preset standard temperature.

[0030] When the first comparison result includes a comparison result indicating that the analog voltage is greater than or equal to the first reference voltage corresponding to the first preset standard temperature, it means that the temperature corresponding to the analog voltage is greater than or equal to the first preset standard temperature corresponding to the pre-configured first reference voltage, that is, the current charging temperature is too high and has reached or exceeded the first preset standard temperature; when the first comparison result includes a comparison result indicating that the analog voltage is less than the first reference voltage corresponding to the first preset standard temperature, it means that the temperature corresponding to the analog voltage is less than the first preset standard temperature corresponding to the pre-configured first reference voltage, that is, the current charging temperature is low and has not reached the first preset standard temperature.

[0031] Based on this, when it is determined according to the first comparison result that the temperature of the preset detection point is greater than or equal to the first preset standard temperature, the first control circuit 104 can adjust the charging voltage and / or charging current output by the voltage conversion circuit 101, reduce the charging voltage and / or charging current, thereby reducing the charging power and achieving the purpose of reducing the charging temperature; on the contrary, when it is determined according to the first comparison result that the temperature of the preset detection point is less than the first preset standard temperature, there is no need to adjust the charging power output by the voltage conversion circuit 101, that is, there is no need to adjust the output charging voltage and / or charging current.

[0032] In an embodiment of the present application, the switching power supply circuit collects the temperature of a preset detection point through a temperature acquisition circuit and converts it into a corresponding analog voltage. The first comparison circuit compares the analog voltage corresponding to the detected temperature of the preset detection point with a preset first reference voltage to determine whether the current charging temperature of the switching power supply circuit has reached the preset temperature. The first control circuit adjusts the charging voltage and / or charging current output by the voltage conversion circuit according to the first comparison result output by the first comparison circuit to reduce the charging voltage and / or charging current, reduce the charging power, and thus reduce the charging temperature, which can effectively prevent charging safety problems caused by excessively high charging temperature.

[0033] In the embodiment of the present application, the switching power supply circuit can be applied to the charger. When it is detected at the charger end that the temperature of the charger itself is greater than or equal to the first preset standard temperature, the charging voltage and / or charging current output by the charger can be adjusted directly at the charger end through the internal first control circuit, thereby realizing the control and adjustment of the charging voltage and / or charging current, and reducing the charging power to reduce the heat generated by the charger itself, thereby achieving the purpose of reducing the charging temperature, effectively preventing the charging temperature from being too high, and effectively ensuring charging safety; in the process of adjusting the output charging voltage and / or charging current at the charger end, since the charger does not need to interact and communicate with the charging load, there is no need to sense the high temperature at the charger end and send a reminder to the charging load. , and wait for the charging load to reply to the signal before adjusting the charging parameters. The charging temperature can be adjusted and controlled by directly detecting the temperature and adjusting it at the charger end, which can effectively prevent the charging temperature of the charger from being too high and ensure the charging safety of the charger. At the same time, it effectively simplifies the charging temperature adjustment process of the charger, effectively reduces the delay time of the charging temperature adjustment of the charger, and improves the charging temperature adjustment response speed of the charger; for the charging load, the charging load can adjust its own working mode accordingly by sensing the adjustment of the charging voltage and / or charging current of the charger to adapt to the charging voltage and charging current currently output by the charger, thereby effectively avoiding affecting the normal charging process and improving the charging efficiency.

[0034] In some embodiments, the number of first reference voltages can be configured as one, and the first reference voltage can be a voltage value obtained by converting a preset first preset standard temperature into an analog voltage. In the first comparison circuit 103, comparing the analog voltage with the pre-configured first reference voltage is equivalent to comparing the temperature of the preset detection point of the switching power supply circuit 100 collected by the temperature collection circuit 102 and the first preset standard temperature. Accordingly, the first comparison result can be used to represent the comparison result of the collected temperature of the preset detection point and the first preset standard temperature; when the analog voltage is greater than or equal to the pre-configured first reference voltage, it means that the temperature corresponding to the analog voltage is greater than or equal to the first preset standard temperature corresponding to the pre-configured first reference voltage; when the analog voltage is less than the pre-configured first reference voltage, it means that the temperature corresponding to the analog voltage is less than the first preset standard temperature corresponding to the pre-configured first reference voltage. In the first control circuit 104, it can be determined based on the first comparison result whether the temperature of the preset detection point collected is greater than or equal to the first preset standard temperature. When it is determined that the temperature of the preset detection point collected is greater than or equal to the first preset standard temperature, the first control circuit 104 adjusts the charging voltage and / or charging current output by the voltage conversion circuit 101, reduces the charging voltage and / or charging current, thereby reducing the charging power, and then achieving the purpose of reducing the charging temperature.

[0035] In some embodiments, in order to achieve more accurate regulation of the charging voltage and / or charging current, multiple temperature regulation levels may be pre-divided according to actual needs, and different charging voltage and / or charging current adjustments may be performed at different temperature regulation levels, and the higher the level, the greater the amplitude of the adjustment. Accordingly, in order to determine the temperature regulation level to which the currently collected temperature belongs, the number of first reference voltages may be configured to be multiple, and a first reference voltage may be set corresponding to each temperature regulation level. The higher the temperature regulation level, the greater the voltage value of the correspondingly configured first reference voltage, and each first reference voltage is greater than or equal to the voltage corresponding to the first preset standard temperature. For example, the multiple first reference voltages are respectively a first reference voltage vref11, a first reference voltage vref12, a first reference voltage vref13,..., a first reference voltage vref1n, where n is an integer greater than or equal to 2, and the first reference voltage vref11 can be configured as a voltage corresponding to a first preset standard temperature, and the first reference voltage vref11, the first reference voltage vref12, the first reference voltage vref13,..., the first reference voltage vref1n are set in ascending order, that is, vref11<vref12<vref13<……<vref1n, wherein each first reference voltage can correspond to a temperature adjustment level.

[0036] In some embodiments, when there are multiple first reference voltages, the number of first comparison results may also be multiple, and the first comparison results correspond to the first reference voltages one by one, and each first comparison result includes a comparison result of the analog voltage and the corresponding first reference voltage. The first comparison circuit 103 obtains multiple first comparison results after comparing the analog voltage corresponding to the temperature of the preset detection point currently detected with multiple first reference voltages, and outputs them to the first control circuit 104. The first control circuit 104 may determine whether the currently detected temperature is greater than or equal to the first preset standard temperature and the temperature adjustment level corresponding to the temperature according to the multiple first comparison results, and adjust the charging voltage and / or charging current output by the voltage conversion circuit according to the adjustment amount of the charging voltage and / or charging current according to the adjustment amount of the charging voltage and / or charging current when it is determined that the temperature is greater than or equal to the first preset standard temperature.

[0037] For example, when it is determined according to multiple first comparison results that the analog voltage corresponding to the currently detected temperature is greater than the first reference voltage vref11 but less than the first reference voltage vref12, it can be determined that the currently detected temperature is greater than the first preset standard temperature corresponding to the first reference voltage vref11, and the temperature adjustment level corresponding to the temperature is determined to be the temperature adjustment level corresponding to the first reference voltage vref11. For another example, when it is determined according to multiple first comparison results that the analog voltage corresponding to the currently detected temperature is greater than the first reference voltage vref12 but less than the first reference voltage vref13, it can be determined that the currently detected temperature is greater than the temperature corresponding to the first reference voltage vref12, and the temperature adjustment level corresponding to the temperature is determined to be the temperature adjustment level corresponding to the first reference voltage vref12, and the first reference voltage vref12 is greater than the first reference voltage vref11, so it is determined that the currently detected temperature is naturally greater than the first preset standard temperature.

[0038] In some embodiments, the corresponding relationship between the temperature adjustment level and the adjustment amount of the charging parameter (charging voltage and / or charging current) can be configured according to actual test experience. The higher the temperature adjustment level, the larger the corresponding adjustment amount. After determining the temperature adjustment level to which the currently detected temperature belongs, the adjustment amount of the charging voltage and / or charging current corresponding to the temperature adjustment level can be determined from the corresponding relationship between the pre-configured temperature adjustment level and the adjustment amount of the charging parameter (charging voltage and / or charging current).

[0039] It can be understood that when the first control circuit 104 determines that the analog voltage is less than the first reference voltage corresponding to the first preset standard temperature based on multiple first comparison results, it determines that the currently detected temperature is less than the first preset standard temperature, that is, the current charging temperature is low and does not exceed the first preset standard temperature. Therefore, there is no need to adjust the charging voltage and / or charging current output by the voltage exchange circuit 101.

[0040] In some embodiments, by dividing the temperature adjustment level and configuring multiple first reference voltages, a relatively accurate temperature range of the currently detected temperature can be determined by analysis according to the comparison results of the currently detected temperature and the multiple first reference voltages, thereby determining the current temperature adjustment level, thereby determining the adjustment amount of the charging voltage and / or charging current, so as to achieve accurate adjustment of the charging parameters, so as to maximize the charging efficiency. For example, when the first control circuit 104 determines that the currently detected temperature is much higher than the first preset standard temperature according to multiple first comparison results, the adjustment amount of the charging voltage and / or charging current is large to reduce the charging temperature as soon as possible; when the first control circuit 104 determines that the currently detected temperature is less than the first preset standard temperature according to multiple first comparison results, the adjustment amount of the charging voltage and / or charging current can be relatively small, so as to maximize the charging efficiency.

[0041] Figure 2 A schematic diagram showing the structure of another switching power supply circuit provided in an embodiment of the present application is shown. Figure 2 As shown, in some embodiments, the switching power supply circuit 100 further includes: a second comparison circuit 105 and a second control circuit 106, the input end of the second comparison circuit 105 is connected to the output end of the temperature acquisition circuit 102, the output end of the second comparison circuit 105 is connected to the second control circuit 106, and the second control circuit 106 is connected to the input end of the voltage conversion circuit 101;

[0042] Among them, the second comparison circuit 105 is used to compare the analog voltage output by the temperature acquisition circuit 102 and the pre-configured second reference voltage, and output the corresponding second comparison result to the second control circuit 106, and the second reference voltage is greater than the first reference voltage; the second control circuit 106 is used to determine whether the currently detected temperature is greater than or equal to the second preset standard temperature based on the second comparison result, and when it is determined that the currently detected temperature is greater than or equal to the second preset standard temperature, the voltage conversion circuit 101 is controlled to stop outputting the charging voltage and / or charging current.

[0043] The analog voltage is compared with the second reference voltage through the second comparison circuit, and the second comparison result is output to the second controller 106, so that the second controller 106 determines, based on the second comparison result, that when the currently detected temperature is higher than the second preset standard temperature, it indicates that the charging temperature is too high at this time. Therefore, the second control circuit 106 controls the voltage conversion circuit 101 to stop the output of electric energy (charging voltage and / or charging current), that is, stops charging the charging load, so as to protect the charging load and the charger.

[0044] It can be understood that the second comparison result can be used to represent the comparison result between the collected temperature of the preset detection point and the second preset standard temperature; when the analog voltage is greater than or equal to the pre-configured second reference voltage, it means that the temperature corresponding to the analog voltage is greater than or equal to the first preset standard temperature corresponding to the pre-configured second reference voltage; when the analog voltage is less than the pre-configured second reference voltage, it means that the temperature corresponding to the analog voltage is less than the second preset standard temperature corresponding to the pre-configured second reference voltage.

[0045] In some embodiments, when the first comparison circuit 103 and the first control circuit 104 detect that the current charging temperature is slightly higher than the first preset standard temperature, it means that a charging safety accident is not likely to occur at this time. Therefore, the charging parameters (charging voltage and / or charging current) can be adjusted by the first control circuit 104 to effectively avoid affecting the normal charging process; when the first comparison circuit 103 and the first control circuit 104 detect that the current charging temperature is too high, higher than the second preset standard temperature, it means that the risk of a charging safety accident is relatively high at this time. Therefore, the second control circuit 106 controls the voltage conversion circuit 101 to stop charging the charging load, which can help improve charging safety.

[0046] Figure 3 FIG. 1 shows a schematic diagram of the structure of another switching power supply circuit provided in an embodiment of the present application. In some embodiments, for example, Figure 3 As shown, the first comparison circuit 103 includes at least one first voltage comparator 1031, each first voltage comparator 1031 corresponds to a pre-configured first reference voltage, and the first reference voltages corresponding to different first voltage comparators 1031 have different magnitudes; when one first reference voltage is configured, the first comparison circuit 103 includes one first voltage comparator 1031. When multiple first reference voltages are configured, the first comparison circuit 103 includes multiple first voltage comparators 1031, and the first voltage comparators 1031 correspond to the first reference voltages one by one.

[0047] For example, Figure 3 As shown, the first comparison circuit 103 includes multiple first voltage comparators 1031, and the correspondingly configured multiple first reference voltages include a first reference voltage vref11, a first reference voltage vref12, a first reference voltage vref13, ... a first reference voltage vref1n, wherein the first first voltage comparator 1031 corresponds to the first reference voltage vref11, the second first voltage comparator 1031 corresponds to the first reference voltage vref12, the third first voltage comparator 1031 corresponds to the first reference voltage vref13, and the nth first voltage comparator 1031 corresponds to the first reference voltage vref1n. For the description of the multiple first reference voltages, please refer to the above-mentioned related description, which will not be repeated here.

[0048] Among them, one input end of the first voltage comparator 1031 is connected to the output end of the temperature acquisition circuit 102, the other input end is connected to the corresponding first reference voltage providing end, and the output end is connected to the first control circuit 104; the first voltage comparator 1031 is used to compare the analog voltage output by the temperature acquisition circuit 102 and the corresponding first reference voltage, obtain the corresponding first comparison result, and output the corresponding first comparison result to the first control circuit 104; the first control circuit 104 adjusts the charging voltage and / or charging current output by the voltage conversion circuit 101 according to the first comparison result output by at least one first voltage comparator 1031.

[0049] It should be noted that Figure 3 The case where the first comparison circuit 103 includes multiple first voltage comparators 1031 and correspondingly configured first reference voltages is only shown as an example. The embodiments of the present application include but are not limited to this case. The embodiments of the present application can also set the number of first voltage comparators 1031 and the correspondingly configured first reference voltages according to actual needs.

[0050] In some embodiments, Figure 3 As shown, the first control circuit 104 includes a first controller 1041 and a first control switch tube Q1; the output end of the first comparison circuit 103 is connected to the first controller 1041, the first control switch tube Q1 is connected in series to the path of the output end of the voltage conversion circuit 101, and the control electrode of the first control switch tube Q1 is connected to the first controller 1041. Among them, the output end of each first voltage comparator 1031 in the first comparison circuit 103 is connected to the first controller 1041.

[0051] Among them, the first controller 1041 is used to determine whether the currently detected temperature is greater than or equal to the first preset standard temperature according to the first comparison result, and determine the temperature adjustment level corresponding to the currently detected temperature; when it is determined that the currently detected temperature is greater than or equal to the first preset standard temperature, adjust the charging voltage and / or charging current corresponding to the temperature adjustment level; according to the adjustment amount of the charging voltage and / or charging current, adjust the on-off time or on-off frequency of the first control switch tube Q1, thereby adjusting the charging voltage and / or charging current output by the voltage conversion circuit 101, reducing the charging voltage and / or charging current, so as to reduce the charging temperature.

[0052] In some embodiments, the corresponding relationship between the adjustment amount of the charging voltage and / or charging current and the on-off time or on-off frequency of the first control switch tube Q1 can be configured according to actual test experience. The adjustment amount of the charging voltage and / or charging current is determined according to the temperature adjustment level corresponding to the currently detected temperature. The on-off time or on-off frequency of the first control switch tube Q1 can be determined according to the corresponding relationship. By adjusting the on-off time or on-off frequency of the first control switch tube Q1, the charging voltage and / or charging current output by the voltage conversion circuit 101 are adjusted, and the charging voltage and / or charging current are reduced to reduce the charging temperature.

[0053] In some embodiments, the first controller 1041 may adjust the charging voltage and / or charging current output by the voltage conversion circuit 101 once according to the adjustment amount of the charging voltage and / or charging current, so as to adjust the charging voltage and / or charging current output by the voltage conversion circuit 101 to the required charging voltage and / or charging current; the first controller 1041 may also adjust the charging voltage and / or charging current output by the voltage conversion circuit 101 multiple times according to the adjustment amount of the charging voltage and / or charging current, so as to adjust the charging voltage and / or charging current output by the voltage conversion circuit 101 to the required charging voltage and / or charging current;

[0054] For example, the charging voltage currently output by the voltage conversion circuit 101 is 9V, the charging current currently output is 2A, and the adjustment amount of the charging current determined according to the currently detected temperature adjustment level is 1A. The first controller 1041 can adjust the charging voltage and / or charging current output by the voltage conversion circuit 101 once according to the adjustment amount of the charging current 1A, and directly adjust the charging current output by the voltage conversion circuit 101 to 2A-1A=1A, or, adjust the adjustment amount of 1A in two times, each adjustment amount is 0.5A, and in the first adjustment, the charging current output by the voltage conversion circuit 101 is adjusted to 2A-0.5A=1.5A, and in the second adjustment, the charging current output by the voltage conversion circuit 101 is adjusted to 1.5A-0.5A=1A.

[0055] In some embodiments, Figure 3 As shown, the second comparison circuit 105 includes a second voltage comparator 1051; one input end of the second voltage comparator 1051 is connected to the output end of the temperature acquisition circuit 102, the other input end is connected to the supply end of the second reference voltage vref2, and the output end is connected to the second control circuit 106. The second reference voltage vref2 is greater than the first reference voltage, and when multiple first reference voltages are configured, the second reference voltage vref2 is greater than the maximum value of the multiple first reference voltages.

[0056] In some embodiments, Figure 3As shown, the second control circuit 106 includes a second controller 1061 and a second control switch tube Q2; the output end of the second comparison circuit 105 is connected to the second controller 106, the second control switch tube Q2 is connected in series to the path of the input end of the voltage conversion circuit 101, and the control electrode of the second control switch tube Q2 is connected to the second controller 1061; wherein, the output end of the second voltage comparator 1051 in the second comparison circuit 105 is connected to the second controller 106.

[0057] The second controller 1061 is used to control the second control switch tube Q2 to be disconnected when it is determined that the currently detected temperature is greater than or equal to the second preset standard temperature, so that the voltage conversion circuit 101 stops outputting the charging voltage and / or charging current.

[0058] When it is determined that the currently detected temperature is greater than or equal to the second preset standard temperature, it means that the current charging temperature is too high, which may cause charging safety problems. Therefore, the second controller 1061 controls the second control switch tube Q2 to remain disconnected to control the voltage conversion circuit 101 to stop the output of electrical energy (charging voltage and / or charging current), that is, stop charging the charging load to protect the charging load and the charger and improve charging safety.

[0059] In some embodiments, the regulation of the charging voltage and / or charging current output by the voltage conversion circuit 101 is achieved based on a pulse width modulation (PWM) method and a synchronous rectification method of a switching power supply, or based on a pulse frequency modulation (PFM) method and a synchronous rectification method of a switching power supply.

[0060] In the synchronous rectification mode based on the pulse width modulation (PWM) mode and the switching power supply, the on-off frequency (also referred to as the switching frequency) of the first control switch tube Q1 and the second control switch tube Q2 is kept unchanged. At the output end of the voltage conversion circuit 101, the first controller 1041 adjusts the on-off time of the first control switch tube Q1, for example, adjusts the duty cycle of the first control switch tube Q1. Due to the effect of synchronous rectification, correspondingly, at the input end of the voltage conversion circuit 101, the second controller 1061 adjusts the on-off time of the second control switch tube Q2 to adjust the voltage and / or current at the input end of the voltage conversion circuit 101, thereby changing the charging voltage and / or charging current outputted from the output end of the voltage conversion circuit 101. Generally speaking, by increasing the duty cycle of the switch tube, that is, extending the conduction time of the switch tube, the voltage conversion circuit 101 can have more energy transmitted to the output end during the conduction period of the switch tube, thereby increasing the output voltage and / or current. Conversely, reducing the duty cycle of the switch tube will reduce the output voltage and / or current.

[0061] In the synchronous rectification method based on the pulse frequency modulation (PFM) method and the switching power supply, at the output end of the voltage conversion circuit 101, the first controller 1041 adjusts the on-off frequency of the first control switch tube Q1. Due to the effect of synchronous rectification, correspondingly, at the input end of the voltage conversion circuit 101, the second controller 1061 adjusts the on-off frequency of the second control switch tube Q2 to adjust the voltage and / or current at the input end of the voltage conversion circuit 101, thereby changing the charging voltage and / or charging current outputted from the output end of the voltage conversion circuit 101. Generally speaking, by increasing the on-off frequency of the switch tube, the voltage conversion circuit 101 can complete more energy conversion cycles per unit time, thereby increasing the average value of the voltage and / or current outputted from the output end. Conversely, by reducing the on-off frequency of the switch tube, the output voltage and / or current will be reduced.

[0062] In some embodiments, Figure 3 As shown, the switching power supply circuit 100 may further include a current feedback circuit 107; one end of the current feedback circuit 107 is connected to the output end of the voltage conversion circuit 101, and the other end is connected to the first control circuit 104. The first control circuit 104 is also used to obtain the charging current actually output by the voltage conversion circuit 101 through the current feedback circuit 107.

[0063] In some embodiments, the other end of the current feedback circuit 107 is connected to the first controller 1041 , and the first controller 1041 obtains the charging current actually output by the voltage conversion circuit 101 through the current feedback circuit 107 .

[0064] In some embodiments, the current feedback circuit 107 may include one or more resistors connected in series (not shown in the figure); the first control circuit 104 is used to collect the voltage values ​​across the one or more resistors connected in series, and determine the charging current actually output by the voltage conversion circuit 101 based on the collected voltage values ​​and the resistance values ​​of the one or more resistors connected in series.

[0065] In some embodiments, Figure 3 As shown, the switching power supply circuit 100 may further include a voltage feedback circuit 108; one end of the voltage feedback circuit 108 is connected to the output end of the voltage conversion circuit 101, and the other end is connected to the first control circuit 104; wherein the first control circuit 104 is also used to obtain the charging voltage actually output by the voltage conversion circuit 101 through the voltage feedback circuit 108.

[0066] In some embodiments, the other end of the voltage feedback circuit 108 is connected to the first controller 1041 , and the first controller 1041 obtains the charging voltage actually output by the voltage conversion circuit 101 through the voltage feedback circuit 108 .

[0067] The embodiments of the present application do not impose any special restrictions on the specific implementation form of the voltage feedback circuit, and any suitable voltage acquisition circuit can be used according to actual needs, including but not limited to the implementation form of voltage acquisition through an operational amplifier.

[0068] In some embodiments, when adjusting the charging voltage and / or charging current output by the voltage conversion circuit 101, the first controller 1041 can make adjustments in combination with the detected charging voltage and / or charging current actually output by the voltage conversion circuit 101 to facilitate accurate adjustment of the charging voltage and / or charging current.

[0069] In some embodiments, Figure 3 As shown, the voltage conversion circuit 101 includes a transformer T, the input end of the voltage conversion circuit 101 includes the primary winding of the transformer T, and the output end of the voltage conversion circuit 101 includes the secondary winding of the transformer T.

[0070] Among them, the first end of the primary winding of the transformer T is connected to the external power supply for receiving the external power supply voltage provided by the external power supply, the second end of the primary winding of the transformer T is connected to the first pole of the second control switch tube Q2, and the second pole of the second control switch tube Q2 is connected to the ground end through the resistor R0.

[0071] The first end of the secondary winding of the transformer T is connected to one end of the charging interface of the charging load 200, the second end of the secondary winding of the transformer T is connected to the first pole of the first control switch tube Q1, and the second pole of the first control switch tube Q1 is connected to the other end of the charging interface of the charging load 200.

[0072] In some embodiments, the switching power supply circuit 100 may further include a capacitor C0, one end of the capacitor C0 is connected to the first end of the secondary winding of the transformer T, and the other end of the capacitor C0 is connected to the second electrode of the first control switch tube Q1.

[0073] In some embodiments, one end of the current feedback circuit 107 is connected to the second pole of the first control switch tube Q1, and the other end is connected to the first controller 1041; one end of the voltage feedback circuit 108 is connected to the first end of the secondary winding of the transformer T, and the other end is connected to the first controller 1041.

[0074] In some embodiments, the preset detection points in the switching power supply circuit 100 may include one or more of a charging interface of a charging load, a location of the first control switch tube Q1 , and a location of the second control switch tube Q2 .

[0075] Among them, since the charging interface of the charging load and the power switching devices in the switching power supply circuit are prone to heat up during the charging process and the temperature is usually high, the accuracy of temperature detection can be improved by arranging preset detection points at these locations.

[0076] In some embodiments, when there are multiple preset detection points, after the temperature acquisition circuit 102 acquires the temperatures of the multiple preset detection points, it may output the highest temperature among the temperatures of the multiple preset detection points as the currently detected temperature.

[0077] An embodiment of the present application also provides a charger, which includes the switching power supply circuit provided by any of the above embodiments. For the description of the switching power supply circuit, please refer to the description in the above embodiments, which will not be repeated here.

[0078] The charger provided in the embodiment of the present application can be applicable to charging and power supply devices of electronic devices such as mobile phones, tablets, computer equipment, smart wearable devices, routers, etc.

[0079] By way of exemplary and non-limiting examples, a detailed description of exemplary embodiments of the present application has been provided above. However, various modifications and adjustments to the above embodiments will be apparent to those skilled in the art when considered in conjunction with the accompanying drawings and claims, but will not depart from the scope of the present application. Therefore, the proper scope of the present application will be determined according to the claims.

Claims

1. A switching power supply circuit, comprising: A voltage conversion circuit, a temperature acquisition circuit, a first comparison circuit and a first control circuit; The input end of the voltage conversion circuit is connected to an external power supply, and the output end of the voltage conversion circuit is connected to a charging interface of a charging load; the output end of the temperature acquisition circuit is connected to the input end of the first comparison circuit, and the output end of the first comparison circuit is connected to the first control circuit; the first control circuit is connected to the output end of the voltage conversion circuit; The voltage conversion circuit is used to provide the required charging voltage and charging current for the charging interface of the charging load according to the external power supply voltage output by the external power supply; The temperature acquisition circuit is used to acquire the temperature of a preset detection point of the switching power supply circuit, generate a corresponding analog voltage based on the acquired temperature, and output the analog voltage to the first comparison circuit; The first comparison circuit is used to compare the analog voltage with a preconfigured first reference voltage and output a corresponding first comparison result to the first control circuit; The first control circuit is used to adjust the charging voltage and / or charging current output by the voltage conversion circuit according to the first comparison result.

2. The switching power supply circuit according to claim 1, wherein: The first comparison circuit includes at least one first voltage comparator, each of the first voltage comparators corresponds to a preconfigured first reference voltage, and different first voltage comparators correspond to first reference voltages of different magnitudes; One input end of the first voltage comparator is connected to the output end of the temperature acquisition circuit, the other input end is connected to the corresponding first reference voltage supply end, and the output end is connected to the first control circuit; The first voltage comparator is used to compare the analog voltage output by the temperature acquisition circuit with the corresponding first reference voltage to obtain a corresponding first comparison result, and output the corresponding first comparison result to the first control circuit.

3. The switching power supply circuit according to claim 1, wherein: The first control circuit includes a first controller and a first control switch tube; The output end of the first comparison circuit is connected to the first controller, the first control switch tube is connected in series to the path of the output end of the voltage conversion circuit, and the control electrode of the first control switch tube is connected to the first controller; The first controller is used to determine whether the temperature is greater than or equal to a first preset standard temperature and determine a temperature adjustment level corresponding to the temperature according to the first comparison result; When it is determined that the temperature is greater than or equal to the first preset standard temperature, the charging voltage and / or charging current are adjusted according to the temperature adjustment level; according to the adjustment amount of the charging voltage and / or charging current, the on-off time or on-off frequency of the first control switch tube is adjusted, thereby adjusting the charging voltage and / or charging current output by the voltage conversion circuit.

4. The switching power supply circuit according to claim 1, wherein: Also includes: a second comparison circuit and a second control circuit, wherein the input end of the second comparison circuit is connected to the output end of the temperature acquisition circuit, the output end of the second comparison circuit is connected to the second control circuit, and the second control circuit is connected to the input end of the voltage conversion circuit; The second comparison circuit is used to compare the analog voltage output by the temperature acquisition circuit with a pre-configured second reference voltage, and output a corresponding second comparison result to the second control circuit, wherein the second reference voltage is greater than the first reference voltage; The second control circuit is used to determine whether the temperature is greater than or equal to a second preset standard temperature based on the second comparison result, and when it is determined that the temperature is greater than or equal to the second preset standard temperature, control the voltage conversion circuit to stop outputting the charging voltage and / or charging current.

5. The switching power supply circuit according to claim 4, wherein: The second comparison circuit includes a second voltage comparator; one input end of the second voltage comparator is connected to the output end of the temperature acquisition circuit, the other input end is connected to the supply end of the second reference voltage, and the output end is connected to the second control circuit.

6. The switching power supply circuit according to claim 4, wherein: The second control circuit includes a second controller and a second control switch tube; The output end of the second comparison circuit is connected to the second controller, the second control switch tube is connected in series to the path of the input end of the voltage conversion circuit, and the control electrode of the second control switch tube is connected to the second controller; The second controller is used to control the second control switch tube to be disconnected when it is determined that the temperature is greater than or equal to a second preset standard temperature, so that the voltage conversion circuit stops outputting the charging voltage and / or charging current.

7. The switching power supply circuit according to claim 1, wherein: It also includes a current feedback circuit; one end of the current feedback circuit is connected to the output end of the voltage conversion circuit, and the other end is connected to the first control circuit; The first control circuit is further used to obtain the charging current actually output by the voltage conversion circuit through the current feedback circuit.

8. The switching power supply circuit according to claim 7, wherein: The current feedback circuit includes one or more resistors connected in series; The first control circuit is used to collect voltage values ​​across the one or more resistors connected in series, and determine the charging current actually output by the voltage conversion circuit based on the collected voltage values ​​and the resistance values ​​of the one or more resistors connected in series.

9. The switching power supply circuit according to claim 1, wherein: It also includes a voltage feedback circuit; one end of the voltage feedback circuit is connected to the output end of the voltage conversion circuit, and the other end is connected to the first control circuit; The first control circuit is further used to obtain the charging voltage actually output by the voltage conversion circuit through the voltage feedback circuit.

10. The switching power supply circuit according to claim 1, wherein: The voltage conversion circuit includes a transformer, the input end of the voltage conversion circuit includes a primary winding of the transformer, and the output end of the voltage conversion circuit includes a secondary winding of the transformer.

11. A charger, comprising the switching power supply circuit according to any one of claims 1 to 10.

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