Power supply high-voltage input protection circuit, power supply and equipment

Abstract

The invention relates to a power supply high-voltage input protection circuit, a power supply and equipment, a power supply sampling circuit module detects a direct-current power supply, outputs a sampling signal of the direct-current power supply to a comparison circuit module, performs voltage division based on a power supply voltage provided by the direct-current power supply through a power supply module, and outputs a power supply voltage division signal. The power supply voltage division signal comprises a reference voltage signal, so that the comparison circuit module performs voltage comparison and outputs a comparison result signal, and the self-selection circuit module automatically selects a target input loop according to the comparison result signal, so as to electrically output a power supply input signal to a high-voltage input pin of the switching power supply chip through the target input loop; the high-voltage input pin can obtain matched power input signals under different direct-current power supply voltages, and the problems that in the prior art, a protection mechanism of the HV input pin of the switching power supply chip cannot adapt to wide-range voltage fluctuation due to a fixed threshold value, protection is triggered by mistake when the voltage is too high, and work cannot be carried out when the voltage is too low are solved.

Description

Technical Field

[0001] This application relates to the field of switching power supply technology, and in particular to a high-voltage input protection circuit, power supply, and device. Background Technology

[0002] In switching power supply design, the switching power supply chip is a crucial component. To reduce losses in the startup circuit of the switching power supply chip, most current switching power supply chips incorporate a high-voltage (HV) startup circuit. Once the switching power supply chip starts up normally, the HV startup circuit is automatically shut down, resulting in very low power consumption. In addition, the HV input pin of the switching power supply chip is also used as an input voltage detection circuit to implement high-voltage protection. That is, if the input voltage is below a certain input voltage threshold, the switching power supply chip can operate normally; when the input voltage exceeds the input voltage threshold, the switching power supply chip enters a protection state and stops working.

[0003] When the DC power supply voltage does not change significantly, a suitable input voltage threshold can be selected to ensure the normal operation of the switching power supply chip. However, when the DC power supply voltage changes significantly, such as in special applications like photovoltaic modules, the DC input voltage is often affected by factors such as light intensity and load variations, fluctuating drastically over a wide range. In such cases, the HV startup circuit of the switching power supply chip is prone to high-voltage protection, causing the switching power supply chip to malfunction. Summary of the Invention

[0004] In view of this, this application provides a high voltage input protection circuit, power supply, and device to solve the problem that the protection mechanism of the HV input pin of the switching power supply chip in the prior art cannot adapt to a wide range of voltage fluctuations due to a fixed threshold, resulting in false triggering of protection when the voltage is too high and failure to work when the voltage is too low.

[0005] In a first aspect, embodiments of this application provide a high-voltage input protection circuit for a power supply, comprising: a power sampling circuit module, a comparison circuit module, a power supply module, and a self-selection circuit module;

[0006] The self-selection circuit module includes at least two input loops, each of which has a different regulated voltage value, and the output terminal of each input loop is configured to be electrically connected to the high-voltage input pin of the switching power supply chip.

[0007] The power sampling circuit module is configured to: detect the DC power supply and output a sampling signal of the DC power supply;

[0008] The power module is configured to: perform voltage division based on the power supply voltage provided by the DC power supply, and output a power voltage division signal, wherein the power voltage division signal includes a reference voltage signal;

[0009] The comparison circuit module is configured to: perform a voltage comparison based on the reference voltage signal and the sampled signal, and output a comparison result signal;

[0010] The self-selection circuit module is configured to: select a target input circuit from the at least two input circuits based on the comparison result signal, so as to electrically output the power input signal corresponding to the DC power supply to the high-voltage input pin through the target input circuit.

[0011] Optionally, the sampling input terminal of the power sampling circuit module, the input terminal of the power module, the power input terminal of the self-selection circuit module, and the positive terminal of the DC power supply are electrically connected, and the power input terminal of each input circuit serves as the power input terminal of the self-selection circuit module.

[0012] The output terminal of the power sampling circuit module is electrically connected to the first input terminal of the comparison circuit module, the second input terminal of the comparison circuit module is electrically connected to the reference voltage output terminal of the power module, and the output terminal of the comparison circuit module is electrically connected to the control input terminal of the self-selection circuit module.

[0013] The output terminal of the power sampling circuit module is configured to output the sampling signal;

[0014] The reference voltage output terminal is configured to output the reference voltage signal;

[0015] The output of the comparison circuit module is configured to output the comparison result signal.

[0016] Optionally, the at least two input circuits include a first input circuit and a second input circuit, and the regulated voltage of the first input circuit is greater than the regulated voltage of the second input circuit;

[0017] The comparison result signal is divided into a first-level signal and a second-level signal;

[0018] The first input circuit is configured to transmit the power input signal to the high-voltage input pin under the control of the first level signal;

[0019] The second input circuit is configured to transmit the power input signal to the high-voltage input pin under the control of the second level signal.

[0020] Optionally, each of the input circuits includes a control switch, a power switch, a grounding resistor, and a voltage regulator.

[0021] The first end of the control switch is electrically connected to the drive output end of the power module, the second end of the control switch, the control end of the power switch and the first end of the grounding resistor are electrically connected, and the control end of the control switch serves as the control input end of the self-selection circuit module.

[0022] The first terminal of the power switch is electrically connected to the positive terminal of the DC power supply, and the second terminal of the power switch is electrically connected to the first terminal of the voltage regulator.

[0023] The second end of the grounding resistor is electrically connected to the reference ground of the input circuit;

[0024] The second terminal of the voltage regulator is electrically connected to the high-voltage input pin of the switching power supply chip.

[0025] Optionally, the power supply voltage divider signal further includes a drive voltage signal and a negative voltage signal, and the power supply module includes a first-stage voltage divider circuit, a second-stage voltage divider circuit, a third-stage voltage divider circuit, and a fourth-stage voltage divider circuit.

[0026] The first terminal of the first-stage voltage divider circuit is electrically connected to the positive terminal of the DC power supply, the second terminal of the first-stage voltage divider circuit is electrically connected to the reference ground of the power module, and the first-stage voltage divider circuit includes a first Zener diode.

[0027] The cathode of the first Zener diode is electrically connected to the first terminal of the second-stage voltage divider circuit, and the anode of the first Zener diode is electrically connected to the second terminal of the second-stage voltage divider circuit.

[0028] The third terminal of the second-stage voltage divider circuit, the first terminal of the third-stage voltage divider circuit, the first terminal of the fourth-stage voltage divider circuit, and the drive input terminal of each of the input loops are electrically connected, and the third terminal of the second-stage voltage divider circuit is configured to output the drive voltage signal.

[0029] The second terminal of the third-stage voltage divider circuit is electrically connected to the second power supply terminal of the comparator circuit module, and the second terminal of the third-stage voltage divider circuit is configured to output the negative voltage signal;

[0030] The third terminal of the third-stage voltage divider circuit and the second terminal of the fourth-stage voltage divider circuit are both electrically connected to the reference ground.

[0031] The third terminal of the fourth-stage voltage divider circuit is electrically connected to the second input terminal of the comparator circuit module, and the third terminal of the fourth-stage voltage divider circuit is configured to output the reference voltage signal.

[0032] Optionally, the first-stage voltage divider circuit further includes: a first voltage divider resistor and a second voltage divider resistor;

[0033] The first end of the first voltage divider resistor is electrically connected to the positive terminal of the DC power supply, and the second end of the first voltage divider resistor, the cathode of the first Zener diode, and the first end of the second-stage voltage divider circuit are electrically connected.

[0034] The first end of the second voltage divider resistor, the anode of the first Zener diode, and the second end of the second-stage voltage divider circuit are electrically connected, and the second end of the second voltage divider resistor is electrically connected to the reference ground.

[0035] Optionally, the second-stage voltage divider circuit includes: a third voltage divider resistor and a fourth voltage divider resistor;

[0036] The first end of the third voltage divider resistor serves as the first end of the second-stage voltage divider circuit, the second end of the fourth voltage divider resistor serves as the second end of the second-stage voltage divider circuit, and the second end of the third voltage divider resistor and the first end of the fourth voltage divider resistor serve as the third end of the second-stage voltage divider circuit.

[0037] Optionally, the third-stage voltage divider circuit includes: a second Zener diode and a fifth voltage divider resistor;

[0038] The cathode of the second Zener diode serves as the first terminal of the third-stage voltage divider circuit;

[0039] The anode of the second Zener diode and the first terminal of the fifth voltage divider resistor serve as the third terminal of the third-stage voltage divider circuit.

[0040] The second terminal of the fifth voltage divider resistor serves as the second terminal of the third-stage voltage divider circuit.

[0041] Optionally, the fourth-stage voltage divider circuit includes: a sixth voltage divider resistor and a seventh voltage divider resistor;

[0042] The first end of the sixth voltage divider resistor serves as the first end of the fourth-stage voltage divider circuit, the second end of the seventh voltage divider resistor serves as the second end of the fourth-stage voltage divider circuit, and the second end of the sixth voltage divider resistor and the first end of the seventh voltage divider resistor serve as the third end of the fourth-stage voltage divider circuit.

[0043] Optionally, the comparison circuit module includes a comparator;

[0044] The non-inverting input of the comparator is electrically connected to the output of the power sampling circuit module. The inverting input of the comparator, the first power supply terminal of the comparator, and the reference voltage output of the power supply module are electrically connected. The output of the comparator is electrically connected to the control input of the self-selection circuit module. The second power supply terminal of the comparator is electrically connected to the negative power supply output of the power supply module.

[0045] The control input terminal of the self-selection circuit module is configured to receive the comparison result signal.

[0046] Secondly, embodiments of this application provide a switching power supply, including: a switching power supply chip and a power high voltage input protection circuit as described in any one of the first aspects of this application; the output terminal of the power high voltage input protection circuit is electrically connected to the high voltage pin of the switching power supply chip.

[0047] Secondly, embodiments of this application provide an electrical device, which is equipped with a switching power supply, and the switching power supply includes a high-voltage input protection circuit as described in any one of the first aspects of this application.

[0048] The high-voltage input protection circuit, power supply, and device provided in this application embodiment detect the DC power supply through a power sampling circuit module, outputs the sampling signal of the DC power supply to a comparison circuit module, and performs voltage division based on the power supply voltage provided by the DC power supply to output a power voltage division signal. This power voltage division signal includes a reference voltage signal, allowing the comparison circuit module to compare the voltage based on the reference voltage signal and the sampling signal, and outputs a comparison result signal to a self-selection circuit module. This allows the self-selection circuit module to select a target input circuit from at least two input circuits based on the comparison result signal, and then outputs the corresponding power supply input signal to the high-voltage input pin through the target input circuit. This ensures that the high-voltage input pin can obtain a matching power supply input signal under different DC power supply voltages, enabling the input voltage of the high-voltage input pin of the switching power supply chip to adapt to a wide range of DC power supply fluctuations. This overcomes the limitations of traditional fixed thresholds and solves the problem in the prior art where the protection mechanism of the HV input pin of the switching power supply chip cannot adapt to a wide range of voltage fluctuations due to a fixed threshold, resulting in false triggering of protection when the voltage is too high and failure to work when the voltage is too low. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0051] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0052] Figure 1 A schematic diagram illustrating the connection between a high-voltage input protection circuit and a switching power supply chip, provided in an embodiment of this application;

[0053] Figure 2 A schematic diagram of a high-voltage input protection circuit for a power supply provided in an optional embodiment of this application;

[0054] Figure 3 A schematic diagram showing the connection between a power supply module, a comparison circuit module, and a power sampling circuit module, provided as an optional embodiment of this application;

[0055] Figure 4 A schematic diagram illustrating a power supply high-voltage input protection circuit that autonomously selects the target input circuit, as provided in this application example;

[0056] Figure 5 This application provides a schematic diagram of the structure of a switching power supply according to an embodiment of the present application.

[0057] Figure 6 This is a schematic diagram of the structure of an electrical device provided in an embodiment of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0060] In switching power supplies, the switching power supply chip is the core component for power conversion and control. The HV input pin of the switching power supply chip is responsible for functions such as startup circuitry, input voltage detection, and high-voltage protection. However, the protection mechanism of the HV input pin of the switching power supply chip relies on a fixed threshold. When the external DC power supply voltage fluctuates significantly, the fixed threshold cannot adapt, resulting in protection being triggered when the voltage is too high and the chip failing to operate when the voltage is too low. For example, in units with large voltage fluctuations, such as photovoltaic module units, the high-voltage protection circuit of traditional switching power supply chips has limitations: when the input DC voltage fluctuates excessively, the high-voltage input pin of the switching power supply chip is prone to falsely triggering the high-voltage protection, causing the chip to stop working and affecting the normal operation of the unit.

[0061] Based on the above, this application provides a power supply high voltage input protection circuit, power supply and device. By detecting the magnitude of the DC power supply voltage, it adaptively selects a suitable high voltage input circuit to ensure that the switching power supply chip can still operate stably when the voltage changes significantly, so as to ensure that weak electrical signals can be generated normally, thereby ensuring the normal operation of the unit and improving the stability of the unit operation.

[0062] Figure 1 This is a structural block diagram of a high-voltage input protection circuit for a power supply provided in an embodiment of this application. Figure 1 As shown, the high-voltage input protection circuit provided in this application embodiment may specifically include: a power sampling circuit module 110, a comparison circuit module 120, a power module 130, and a self-selection circuit module 140; wherein, the self-selection circuit module 140 includes at least two input loops 141, and the voltage regulation value of each input loop 141 is different, and the output terminal of each input loop 141 is configured to be electrically connected to the high-voltage input pin HV of the switching power supply chip 150; the power sampling circuit module 110 is configured to: detect the DC power supply, output the sampling signal U+ of the DC power supply, so that the comparison circuit module 120 can receive the sampling signal U+ of the DC power supply, and according to the sampling signal U+... The power supply module 130 is configured to perform voltage division based on the power supply voltage provided by the DC power supply, and output a power supply voltage division signal, the power supply voltage division signal including the reference voltage signal U-, so that the comparison circuit module 120 can perform voltage comparison based on the reference voltage signal U- and the sampling signal U+, and output a comparison result signal U0 to the self-selection circuit module 140; the self-selection circuit module 140 is configured to select a target input circuit from the at least two input circuits 141 based on the comparison result signal U0, so as to output the power supply input signal UK corresponding to the DC power supply to the high voltage input pin HV through the target input circuit.

[0063] Specifically, after the self-selection circuit module 140 obtains the comparison result signal U0 output by the comparison circuit module 120, it can automatically select an input circuit 141 with a suitable regulated voltage value from each of its included input circuits 141 based on the comparison result signal U0, as the target input circuit. Through the target input circuit, the power input signal UK corresponding to the DC power supply is output to the high-voltage input pin HV of the switching power supply chip 150, thereby ensuring that the high-voltage input pin HV can obtain a matching power input signal UK under different DC power supply voltages. This allows the input voltage of the high-voltage input pin HV of the switching power supply chip 150 to adapt to the wide range of DC power supply fluctuations, breaking through the limitations of the traditional fixed threshold. It solves the problem in the prior art that the protection mechanism of the HV input pin of the switching power supply chip cannot adapt to the wide range of voltage fluctuations due to the fixed threshold, resulting in false triggering of protection when the voltage is too high and failure to work when the voltage is too low.

[0064] The comparison circuit module 120 is configured to perform voltage comparison based on the reference voltage signal U- and the sampling signal U+, and output a comparison result signal U0. This allows the self-selection circuit module 140 to select a target input circuit from the at least two input circuits 141 based on the comparison result signal U0. The target input circuit then outputs the power input signal UK corresponding to the DC power supply to the high-voltage input pin HV. This ensures that the input voltage of the high-voltage input pin HV of the switching power supply chip 150 can adapt to the wide range of fluctuations in the DC power supply, thereby solving the problem of insufficient adaptability of the HV input pin protection mechanism and ensuring the normal operation of the switching power supply chip 150.

[0065] In some optional embodiments of this application, the sampling input terminal of the power sampling circuit module 110, the input terminal of the power module 130, the power input terminal of the self-selection circuit module 140, and the positive terminal of the DC power supply are electrically connected; and the power input terminal of each input circuit 141 serves as the power input terminal of the self-selection circuit module 140 and is electrically connected to the positive terminal of the DC power supply; the output terminal of each input circuit 141 is electrically connected to the high-voltage input pin HV of the switching power supply chip 150, so that the self-selection circuit module 140 can automatically select the target input circuit from its various input circuits 141 according to the comparison result signal U0, so as to transmit the power input signal UK corresponding to the DC power supply through the target input circuit.

[0066] In this embodiment, the output terminal of the power sampling circuit module 110 is electrically connected to the first input terminal of the comparison circuit module 120, and the second input terminal of the comparison circuit module 120 is electrically connected to the reference voltage output terminal of the power module 130, so that the comparison circuit module 120 can perform voltage comparison based on the reference voltage signal U- and the sampling signal U+. The output terminal of the comparison circuit module 120 is electrically connected to the control input terminal of the self-selection circuit module 140, so that the comparison circuit module 120 can output the comparison result signal U0 to the self-selection circuit module 140.

[0067] Specifically, the output terminal of the power sampling circuit module 110 is configured to output the sampling signal U+, so that the comparison circuit module 120 can acquire the sampling signal U+ of the DC power supply output by the power sampling circuit module 110; the reference voltage output terminal is configured to output the reference voltage signal U-, so that the comparison circuit module 120 can acquire the reference voltage signal U- output by the power module 130; the output terminal of the comparison circuit module 120 is configured to output the comparison result signal U0, so that the self-selection circuit module 140 can automatically select the target input circuit according to the comparison result signal U0, thereby realizing the automatic selection of the target input circuit.

[0068] Specifically, to avoid the HV startup circuit of the switching power supply chip 150 easily experiencing high-voltage protection failure due to large DC power supply voltage fluctuations, causing the switching power supply chip 150 to malfunction, the power sampling circuit module 110 in this embodiment can serve as a DC power supply voltage sampling circuit. It detects the DC power supply voltage value and generates a DC power supply sampling signal U+ based on the detected voltage value. This signal is then output to the comparison circuit module 120, allowing the comparison circuit module 120 to perform a voltage comparison based on the reference voltage signal U- and the sampling signal U+, outputting a comparison result signal U0. This enables the selection circuit module to select the appropriate circuit based on the voltage value. Based on the comparison result signal U0, an input circuit 141 with a suitable regulated voltage value is automatically selected from its various input circuits 141 as the target input circuit. This target input circuit then outputs a power input signal UK to the high-voltage input pin HV of the switching power supply chip 150. This ensures that the high-voltage input pin HV receives a matching power input signal UK under different DC power supply voltages, allowing the input voltage of the high-voltage input pin HV of the switching power supply chip 150 to adapt to a wide range of DC power supply fluctuations. This overcomes the limitations of traditional fixed thresholds and ensures the stability of the normal operating state of the switching power supply chip 150. The comparison circuit module 120 is configured to perform a voltage comparison based on the reference voltage signal U- and the sampling signal U+, and output a comparison result signal U0.

[0069] Optionally, the power sampling circuit module 110 in this embodiment can be used as a DC power sampling circuit, such as a DC power voltage sampling circuit, specifically including a first resistor R1 and a second resistor R2, for example. Figure 2 As shown, the voltage of the DC power supply P is detected using a first resistor R1 and a second resistor R2. The first end of the second resistor R2 serves as the sampling input terminal of the power supply sampling circuit module 110 and is electrically connected to the positive terminal of the DC power supply P. The second ends of the second resistor R2 and the second ends of the first resistor R1 serve as the output terminals of the power supply sampling circuit module 110 and are electrically connected to the first input terminal of the comparator circuit module 120. The first end of the first resistor R1 is electrically connected to the reference ground GND. Through the voltage division effect of the first resistor R1 and the second resistor R2, the voltage of the DC power supply P is converted into a smaller sampling signal U+, which is then input to the comparator circuit module 120, achieving real-time detection of the DC power supply P voltage.

[0070] In some optional embodiments of this application, the comparison circuit module 120 serves as a comparison circuit, and may specifically include a comparator U11, such as... Figure 2 As shown, the non-inverting input of comparator U11 can serve as the first input of comparator circuit module 120, electrically connected to the output of power supply sampling circuit module 110, so that comparator U11 can acquire the sampling signal U+ of the DC power supply P output by power supply sampling circuit module 110; the inverting input of comparator U11 can serve as the second input of comparator circuit module 120, electrically connected to the reference voltage output of power supply module 130, so that comparator U11 can acquire the reference voltage signal U- output by power supply module 130; the output of comparator U11 can serve as the output of comparator circuit module 120, connected to the self-selection circuit module 14. The control input terminal 0 is electrically connected, enabling comparator U11 to compare the sampled signal U+ and the reference voltage signal U-. If the voltage value of the sampled signal U+ is greater than the voltage value of the reference voltage signal U-, it outputs a first level signal U5 as the comparison result signal U0, which is transmitted to the self-selection circuit module 140. If the voltage value of the sampled signal U+ is not greater than the voltage value of the reference voltage signal U-, it outputs a first level signal U5 as the comparison result signal U0, which is also transmitted to the self-selection circuit module 140. This allows the self-selection circuit module 140 to automatically select a suitable target input circuit based on the comparison result signal U0, thus achieving automatic selection of the target input circuit.

[0071] The voltage values ​​of the first level signal U5 and the second level signal U6 are different. For example, the first level signal U5 can be a high level signal, while the second level signal U6 can be a low level signal. This application embodiment does not impose specific restrictions on this.

[0072] In a specific implementation, the first level signal U5 and the second level signal U6 can be used to select different input circuits 141 as target input circuits. For example, when the self-selection circuit module 140 contains two input circuits, the first level signal U5 can be used to select the first input circuit 1411 as the target input circuit, while the second level signal U6 is used to select the second input circuit 1412 as the target input circuit. Here, the first input circuit 1411 refers to input circuit one of the two input circuits, and the second input circuit 1412 refers to input circuit two of the two input circuits.

[0073] In some optional embodiments of this application, the comparison result signal U0 can be divided into a first level signal U5 and a second level signal U6. The at least two input circuits 141 include a first input circuit 1411 and a second input circuit 1412, and the regulated voltage value of the first input circuit 1411 is greater than the regulated voltage value of the second input circuit 1412. The first input circuit 1411 is configured to transmit the power input signal UK to the high-voltage input pin HV under the control of the first level signal U5. The second input circuit 1412 is configured to transmit the power input signal UK to the high-voltage input pin HV under the control of the second level signal U6.

[0074] Specifically, the power input terminals of the first input circuit 1411 and the second input circuit 1412 serve as the power input terminals of the self-selection circuit module 140, and are electrically connected to the positive terminal of the DC power supply P, respectively; the output terminals of the second input circuit 1412 serve as the output terminals of the comparator circuit module 120, and are electrically connected to the high-voltage input pin HV, respectively; the control input terminals of the first input circuit 1411 and the second input circuit 1412 serve as the control input terminals of the self-selection circuit module 140, and are electrically connected to the output terminal of the comparator circuit module 120, so that when the comparison result signal U0 output by the comparator circuit module 120 is a first level signal U5, the first level signal U5 controls the first input circuit 1411 to conduct, and the first input... When input circuit 1411 is disconnected, the first input circuit 1411, which is automatically turned on, is used as the target input circuit. When the comparison result signal U0 output by the comparison circuit module 120 is the second level signal U6, the second input circuit 1412 is turned on by the second level signal U6, and the first input circuit 1411 is disconnected. The second input circuit 1412, which is automatically turned on, is used as the target input circuit, thereby realizing the automatic switching of input circuit 141. This ensures that the HV input pin of the switching power supply chip 150 can obtain the matching power input signal UK under different DC power supply voltages, meeting the working requirements of the switching power supply chip 150. This solves the problem in the prior art that the protection mechanism of the HV pin of the switching power supply chip cannot adapt to a wide range of voltage fluctuations due to a fixed threshold, resulting in false triggering of protection when the voltage is too high and failure to work when the voltage is too low.

[0075] In some optional embodiments of this application, each input circuit 141 in the self-selection circuit module 140 includes a control switch, a power switch, a grounding resistor, and a voltage regulator. The first terminal of the control switch is electrically connected to the drive output terminal of the power module 130, and the second terminal of the control switch, the control terminal of the power switch, and the first terminal of the grounding resistor are electrically connected. The control terminal of the control switch is electrically connected to the output terminal of the comparator circuit module 120, so that the control terminal of the control switch serves as the control input terminal of the input circuit 141 and can receive the comparison result signal U0 output by the comparator circuit module 120. The first terminal of the power switch is electrically connected to the positive terminal of the DC power supply P, the second terminal of the power switch is electrically connected to the first terminal of the voltage regulator, and the second terminal of the grounding resistor is electrically connected to the reference ground GND of the input circuit 141, so that the power switch can output the power input signal UK corresponding to the DC power supply P through the voltage regulator under the control of the control switch. The second terminal of the voltage regulator is electrically connected to the high-voltage input pin HV of the switching power supply chip 150, and the voltage of the power input signal UK can be determined by the voltage regulation value of the voltage regulator. The voltage regulator can be a Zener diode, and this embodiment does not impose specific limitations on it.

[0076] For example, in the case where the self-selection circuit module 140 includes a first input circuit 1411 and a second input circuit 1412, such as Figure 2 As shown, the first transistor Q1 serves as the control switch of the first input circuit 1411, the second transistor Q2 serves as the power switch of the first input circuit 1411, the third Zener diode D3 serves as the voltage regulator of the first input circuit 1411, and the tenth resistor R10 serves as the grounding resistor of the first input circuit 1411. The first input circuit 1411 is formed by the first transistor Q1, the second transistor Q2, the third Zener diode D3, and the tenth resistor R10, thus enabling the first input circuit 1411 to function as the high-voltage input circuit in the self-selection circuit module 140. The third transistor Q3 serves as the control switch for the second input circuit 1412, the fourth transistor Q4 serves as the power switch for the second input circuit 1412, the fourth Zener diode D4 serves as the voltage regulator for the second input circuit 1412, and the eleventh resistor R11 serves as the grounding resistor for the second input circuit 1412. The third transistor Q3, the fourth transistor Q4, the fourth Zener diode D4, and the eleventh resistor R11 together form the second input circuit 1412, which can then be used as the second high-voltage input circuit in the self-selection circuit module 140. By selecting different input circuits to activate through the self-selection circuit module, the stability of the high-voltage input pin HV can be ensured even when the DC power supply P varies significantly, thereby guaranteeing the stable operation of the switching power supply.

[0077] Specifically, the voltage regulation value of the voltage regulator in each input circuit 141 is different. In this embodiment, the voltage value of the DC power supply P is detected by the power sampling circuit module 110. The detected voltage value is sampled and used as the sampling signal U+ of the DC power supply P, which is then input to the comparison circuit module 120. After comparison by the comparison circuit module 120, the comparison result signal U0 is output to the self-selection circuit module 140. The self-selection circuit module 140 selects different input circuits 141 of the high voltage pin of the switching power supply chip 150 according to the comparison result signal U0. That is, it selects different input circuits 141 according to the comparison result signal U0 as the target input circuits to input the power input signal UK to the high voltage input pin HV of the switching power supply chip 150. This ensures that the switching power supply chip 150 can still be in normal working state when the external power supply voltage changes greatly, avoiding the impact on the working state of the unit.

[0078] Furthermore, the power module 130 in this embodiment is configured to perform voltage division based on the power supply voltage provided by the DC power supply P, so as to output various power supply signals through voltage division, thereby ensuring that the entire circuit system can work normally. For example, the power module 130 may include two or more stages of voltage divider circuits, so as to output the power supply signals required by each circuit device and module through each stage of voltage division, thereby providing a suitable power supply for each circuit device and module, so that the entire system can work normally.

[0079] In some optional embodiments of this application, the power supply signal output by the power module 130 may include not only the reference voltage signal U-, but also other types of power supply signals, such as driving voltage signal U2, reference voltage signal U-, etc. This application does not limit this. Figure 3 As shown, the power module 130 may include a four-stage voltage divider circuit, namely a first-stage voltage divider circuit 131, a second-stage voltage divider circuit 132, a third-stage voltage divider circuit 133, and a fourth-stage voltage divider circuit 134. The first terminal of the first-stage voltage divider circuit 131 is electrically connected to the positive terminal of the DC power supply P, and the second terminal of the first-stage voltage divider circuit 131 is electrically connected to the reference ground GND of the power module 130. The first-stage voltage divider circuit 131 includes a first Zener diode D1. The first-stage voltage divider circuit 131 is configured to output a fixed voltage signal U1 to the second-stage voltage divider circuit 132, the voltage value of which is determined by the characteristics of the first Zener diode D1.

[0080] In a specific implementation, the cathode of the first Zener diode D1 is electrically connected to the first terminal of the second-stage voltage divider circuit 132, and the anode of the first Zener diode D1 is electrically connected to the second terminal of the second-stage voltage divider circuit 132. The third terminal of the second-stage voltage divider circuit 132, the first terminal of the third-stage voltage divider circuit 133, the first terminal of the fourth-stage voltage divider circuit 134, and the drive input terminal of each of the input circuits 141 are electrically connected to output a drive voltage signal U2 to the drive input terminal of the input circuit 141 through the third terminal of the second-stage voltage divider circuit 132. That is, the third terminal of the second-stage voltage divider circuit 132 is configured to output the drive voltage signal U2 to drive the control switch in the input circuit 141, thereby ensuring that the control switch in the input circuit 141 can work normally.

[0081] The second terminal of the third-stage voltage divider circuit 133 is electrically connected to the second power supply terminal of the comparator circuit module 120, and the second terminal of the third-stage voltage divider circuit 133 is configured to output the negative voltage signal U3, such as... Figure 3 As shown, the second terminal of the third-stage voltage divider circuit 133 is electrically connected to the anode of the first Zener diode D1 and the second terminal of the second-stage voltage divider circuit 132, serving as the negative power supply output terminal of the power supply module 130. It is also electrically connected to the second power supply terminal of the comparator circuit module 120. That is, the anode of the first Zener diode D1 is electrically connected to the second terminal of the second-stage voltage divider circuit 132, the second terminal of the third-stage voltage divider circuit 133, and the second power supply terminal of the comparator circuit module 120. The third terminal of the third-stage voltage divider circuit 133 and the second terminal of the fourth-stage voltage divider circuit 134 are both electrically connected to the reference ground GND. Thus, a negative voltage signal U3 can be output through the second terminal of the third-stage voltage divider circuit 133, serving as the negative power supply of the comparator circuit module 120.

[0082] In this embodiment, the third terminal of the second-stage voltage divider circuit 132 serves as the drive output terminal of the power module 130, so as to output the drive voltage signal U2 through the third terminal of the second-stage voltage divider circuit 132. The first terminals of the third-stage voltage divider circuit 133 and the first terminals of the fourth-stage voltage divider circuit 134 are electrically connected to serve as the drive output terminal of the power module 130, and are electrically connected to the drive input terminal of each input circuit 141. That is, the third terminal of the second-stage voltage divider circuit 132, the first terminal of the third-stage voltage divider circuit 133, the first terminal of the fourth-stage voltage divider circuit 134, and the drive input terminal of each input circuit 141 are electrically connected, so that the drive voltage signal U2 can be output through the drive output terminal of the power module 130 to provide a suitable drive voltage for the drive input terminal of the input circuit 141. For example, the new drive voltage signal can be used to drive the control switch in the input circuit 141 to ensure that the control switch can work normally.

[0083] Furthermore, the third terminal of the third-stage voltage divider circuit 133 and the second terminal of the fourth-stage voltage divider circuit 134 are electrically connected to the reference ground GND. The third terminal of the fourth-stage voltage divider circuit 134 serves as the reference voltage output terminal of the power supply module 130 and is electrically connected to the second input terminal of the comparator circuit module 120. That is, the third terminal of the fourth-stage voltage divider circuit 134 is electrically connected to the second input terminal of the comparator circuit module 120, so that the reference voltage signal U- can be output to the comparator circuit module 120 through the third terminal of the fourth-stage voltage divider circuit 134, so that the comparator circuit module 120 can perform voltage comparison based on the reference voltage signal U-.

[0084] The third terminal of the fourth-stage voltage divider circuit 134 is configured to output the reference voltage signal U-. Optionally, the third terminal of the fourth-stage voltage divider circuit 134 can be electrically connected to both the first power supply terminal and the first power supply terminal of the comparator circuit module 120, to provide a corresponding power supply voltage to the first power supply of the comparator circuit module 120, ensuring that the comparator circuit module 120 can operate normally.

[0085] Of course, in addition to the first voltage divider diode D1, the first-stage voltage divider circuit 131 module in this application embodiment may also include other voltage divider components, such as the first voltage divider resistor and the second voltage divider resistor, etc. This application embodiment does not limit this.

[0086] For example, such as Figure 3 As shown, the first voltage divider resistor R3, the first Zener diode D1, and the second voltage divider resistor R4 together form the first-stage voltage divider circuit 131 in the power supply module 130. The first Zener diode D1 can be connected to the circuit in reverse. After being broken down by the DC power supply voltage, a fixed voltage value will exist across the first Zener diode D1, and this fixed voltage value is determined by the characteristics of the first Zener diode D1.

[0087] Specifically, when the first voltage divider resistor R3, the first Zener diode D1, and the second voltage divider resistor R4 together form the first-stage voltage divider circuit 131 in the power module 130, the first end of the first voltage divider resistor R3 is electrically connected to the positive terminal of the DC power supply P, the second end of the first voltage divider resistor R3, the cathode of the first Zener diode D1, and the first end of the second-stage voltage divider circuit 132 are electrically connected, the anode of the first Zener diode D1, the first end of the second voltage divider resistor, the second end of the second-stage voltage divider circuit 132, the second end of the third-stage voltage divider circuit 133, and the second power supply terminal of the comparator circuit module 120 are electrically connected, and the second end of the second voltage divider resistor is electrically connected to the reference ground GND of the power module 130.

[0088] As can be seen, in this embodiment, the first Zener diode D1 is connected to the circuit in reverse. After being broken down by the DC power supply voltage, the voltage across the first Zener diode D1 has a fixed value. This fixed voltage value can then be used to divide the voltage through the second-stage voltage divider circuit 132 and the third-stage voltage divider circuit 133 to output the drive voltage signal U2. The drive voltage signal U2 can be used to drive the control switch in the input circuit 141, thereby ensuring that the control switch can work normally.

[0089] In some optional embodiments of this application, the second-stage voltage divider circuit 132 of the power supply module 130 includes: a third voltage divider resistor R5 and a fourth voltage divider resistor R6; the first end of the third voltage divider resistor R5 serves as the first end of the second-stage voltage divider circuit 132 and is electrically connected to the cathode of the first Zener diode D1; the second end of the fourth voltage divider resistor R6 serves as the second end of the second-stage voltage divider circuit 132 and is electrically connected to the anode of the first Zener diode D1, the second end of the third-stage voltage divider circuit 133, and the second power supply terminal of the comparator circuit module 120; and the second end of the third voltage divider resistor R5 is electrically connected to the first end of the fourth voltage divider resistor R6 as... The third terminal of the second-stage voltage divider circuit 132 is electrically connected to the first terminal of the third-stage voltage divider circuit 133, the first terminal of the fourth-stage voltage divider circuit 134, and the drive input terminal of each input circuit 141. That is, the third voltage divider resistor R5 and the fourth voltage divider resistor R6 are connected in series, and the series-connected third-stage voltage divider resistor and fourth voltage divider resistor R6 are connected across the first Zener diode D1. Therefore, the voltage across the third voltage divider resistor R5 and the fourth voltage divider resistor R6 is a constant value. The drive voltage signal U2 can be obtained by resistor voltage division, so that the drive voltage signal U2 can be used to drive each input circuit 141 in the self-selection circuit module 140.

[0090] Optionally, the third-stage voltage divider circuit 133 in this embodiment may include a second Zener diode D2 and a fifth voltage divider resistor R7; the cathode of the second Zener diode D2 serves as the first terminal of the third-stage voltage divider circuit 133, and is electrically connected to the third terminal of the second-stage voltage divider circuit 132, the first terminal of the fourth-stage voltage divider circuit 134, and the drive input terminal of each input circuit 141; the anode of the second Zener diode D2 is electrically connected to the first terminal of the fifth voltage divider resistor R7, serving as the third terminal of the third-stage voltage divider circuit 133, that is, the anode of the second Zener diode D2 and the first terminal of the fifth voltage divider resistor R7 are electrically connected to the reference ground GND; the fifth voltage divider... The second end of the voltage divider resistor R7 serves as the second end of the third-stage voltage divider circuit 133, and is electrically connected to the anode of the first Zener diode D1, the second end of the second-stage voltage divider circuit 132, and the second power supply terminal of the comparator circuit module 120. Since the connection point between the anode of the second Zener diode D2 and the first end of the fifth voltage divider resistor R7 is connected to the reference ground GND, the potential of this connection point is 0V, and the voltage at the second end of the fifth voltage divider resistor R7 is a negative voltage. Based on this negative voltage, a negative voltage signal U3 can be output to the second power supply terminal of the comparator circuit module 120 through the second end of the fifth voltage divider resistor R7, serving as the negative power supply for the comparator circuit module 120.

[0091] Optionally, the fourth-stage voltage divider circuit 134 in this embodiment includes: a sixth voltage divider resistor R8 and a seventh voltage divider resistor R9; the first end of the sixth voltage divider resistor R8 serves as the first end of the fourth-stage voltage divider circuit 134 and is electrically connected to the third end of the second-stage voltage divider circuit 132 and the drive input end of each input loop 141; the second end of the seventh voltage divider resistor R9 serves as the second end of the fourth-stage voltage divider circuit 134 and is electrically connected to the reference ground GND; and the second end of the sixth voltage divider resistor R8 and the first end of the seventh voltage divider resistor R9 serve as the third end of the fourth-stage voltage divider circuit 134, thereby allowing the voltage divider circuit 134 to be used for comparison. The circuit module 120 outputs a reference voltage signal U-, that is, the third terminal of the fourth-stage voltage divider circuit 134 is configured to output the reference voltage signal U-. For example, the third terminal of the fourth-stage voltage divider circuit 134 can be used as the reference voltage output terminal of the power supply module 130. The reference voltage signal U- is output to the comparison circuit module 120 through the third terminal of the fourth-stage voltage divider circuit 134, so that the comparison circuit module 120 can compare the voltage based on the reference voltage signal U- and the sampling signal U+ of the DC power supply P, and output the comparison result signal U0. This allows the self-selection circuit module 140 to automatically select the target input circuit based on the comparison result signal U0, thereby realizing the automatic selection of the target input circuit.

[0092] The following description uses the example of a self-selection circuit module 140 containing two input loops to illustrate the embodiments of this application, but this exemplary description does not constitute a limitation on the embodiments of this application.

[0093] As an example of this application, the power supply sampling circuit module 110 can be composed of a first resistor R1 and a second resistor R2 connected in series to serve as a voltage sampling circuit for the DC power supply P, such as... Figure 4 As shown, the power supply voltage is sampled by the power supply sampling circuit module 110, which converts the DC power supply P voltage into a smaller voltage value and inputs it to the comparator U11 in the comparison circuit module 120. That is, the power supply sampling circuit module 110, based on the voltage division effect of the first resistor R1 and the second resistor R2, outputs a sampling signal U+ proportional to the DC power supply P voltage to the comparator U11. The comparator U11 then compares the voltage value of the sampling signal U+ with the voltage value of the reference voltage signal U-, determining whether the voltage value of the sampling signal U+ is greater than the voltage value of the reference voltage signal U-. This allows the self-selection circuit module 140 to select different input circuits 141 based on the comparison result signal U0 output by the comparator U11, serving as the target input circuit for inputting the power input signal UK to the high-voltage input pin HV of the switching power supply chip 150. For example, the first transistor Q1 is an NPN transistor, the third transistor Q3 is a PNP transistor, and the second transistor Q2 and the fourth transistor Q4 are both Metal-Oxide-Semiconductor (MOTS) transistors. In the case of a Field-Effect Transistor (MOSFET), if the voltage value of the sampled signal U+ is greater than the voltage value of the reference voltage signal U-, the comparator U11 outputs a high-level signal, the first transistor Q1 turns on, the third transistor Q3 turns off, and the high-voltage input circuit one is turned on. That is, the selection circuit module 140 automatically selects the first input circuit 1411 as the target input circuit. If the voltage value of the sampled signal U+ is not greater than the voltage value of the reference voltage signal U-, the comparator U11 outputs a low-level signal, the first transistor Q1 turns off, the third transistor Q3 turns on, and the high-voltage input circuit two is turned on. That is, the selection circuit module 140 automatically selects the second input circuit 1412 as the target input circuit. This can avoid the influence of external power supply voltage changes on the unit's operating state. That is, even when the external power supply voltage changes greatly, the switching power supply chip 150 can still be kept in a normal operating state, thereby ensuring the stability of the unit's operating state.

[0094] The power module 130 circuit consists of four voltage divider circuits, providing power to the entire system for normal operation. Specifically, the first voltage divider resistor R3, the first Zener diode D1, and the second voltage divider resistor R4 together form the first-stage voltage divider circuit 131 of the power module 130. The first Zener diode D1 is connected in reverse polarity, and after being broken down by the DC power supply voltage, a fixed voltage value exists across its terminals. The third voltage divider resistor R5 and the fourth voltage divider resistor R6 form the second-stage voltage divider circuit 132 of the power module 130. These two voltage divider resistors are connected across the first Zener diode D1, so the voltage across these two series-connected voltage divider resistors is a fixed voltage value. The driving voltage signal U2 in the subsequent circuit can be obtained through resistor voltage division. The second Zener diode D2 and the fifth voltage divider resistor R7 form the third-stage voltage divider circuit 133 of the power module 130. The second Zener diode D2 and the fifth voltage divider resistor R7 are connected in parallel across the fourth voltage divider resistor R6. The voltage across the fourth voltage divider resistor R6 is a constant value, but because the anode of the second Zener diode D2 is connected to the reference ground GND, the potential at that point is 0V. Therefore, the voltage across the other end of the fifth voltage divider resistor R7 is negative. The sixth voltage divider resistor R8 and the seventh voltage divider resistor R9 form the fourth-stage voltage divider circuit 134 of the power module 130. These two resistors are connected in parallel across the second Zener diode D2. The voltage across the second Zener diode D2 is a constant value. After being divided by the sixth voltage divider resistor R8 and the seventh voltage divider resistor R9, a reference voltage U4 is obtained. Based on this reference voltage U4, a reference voltage signal U- is output.

[0095] The main function of comparator U11 is to compare the voltage sample value of DC power supply P with the reference voltage and output a comparison result signal based on the comparison value. This allows the self-selection circuit module to select which high-voltage input circuit as the target input circuit based on the comparison result signal. The positive power supply of comparator U11 is provided by the reference voltage U4, and the negative power supply is provided by the negative voltage signal U3. The non-inverting input terminal of comparator U11 receives the sampling signal U+ of DC power supply P, and the voltage value of the sampling signal U+ represents the voltage sample value of DC power supply P. The inverting input terminal of comparator U11 receives the reference voltage signal U-, and the voltage value of the reference voltage signal U- is the reference voltage U4.

[0096] When the voltage at the non-inverting input terminal of comparator U11 is greater than the voltage at the inverting input terminal of comparator U11, that is, when the voltage value of the DC power supply P is too high, i.e. when the voltage value of the sampling signal U+ is greater than the voltage value of the reference voltage signal U-, comparator U11 outputs a high-level signal as the first level signal U5, which is transmitted to the control input terminal of the self-selection circuit module 140. This causes the self-selection circuit module 140 to select the first input circuit to be turned on according to the first level signal U5, so as to limit the voltage value input to the high-voltage input pin HV of the switching power supply chip 150 through the third Zener diode D3 with a larger Zener voltage value, thereby avoiding the high-voltage protection of the high-voltage input pin HV of the switching power supply chip 150 from being falsely triggered.

[0097] When the voltage at the non-inverting input of comparator U11 is less than the voltage at the inverting input, i.e., when the voltage of the DC power supply P is relatively low (i.e., when the voltage of the sampled signal U+ is less than the voltage of the reference voltage signal U-), comparator U11 outputs a low-level signal as the second-level signal U6. This signal is transmitted to the control input of the self-selection circuit module 140, causing the self-selection circuit module 140 to select the second input circuit to be turned on based on the second-level signal U6. This limits the voltage value input to the high-voltage input pin HV of the switching power supply chip 150 through the low-regulation fourth Zener diode D4, thereby preventing the switching power supply chip 150 from malfunctioning due to excessively low voltage. The voltage at the inverting input of comparator U11 is equal to the voltage value of the reference voltage signal U-, which is determined by the voltage values ​​of the first resistor R1, the second resistor R2, and the DC power supply P.

[0098] This application example sets the voltage setting of the inverting input of comparator U11 based on the voltage division value of the DC power supply P by the first resistor R1 and the second circuit breaker R2. This allows the first input circuit to be activated when the DC power supply P voltage is too high, thus limiting the voltage input to the high-voltage input pin HV of the switching power supply chip 150 through the third Zener diode D3 with a larger regulated voltage, preventing the chip from overvoltage protection. Conversely, when the DC power supply P voltage is low, the second input circuit is activated, using the smaller fourth Zener diode D4 to limit the voltage input to the high-voltage input pin HV of the switching power supply chip 150. This avoids the chip malfunctioning due to excessively low input voltage, thus overcoming the limitations of traditional fixed thresholds. It solves the problem in the prior art where the protection mechanism of the HV input pin of the switching power supply chip 150 cannot adapt to a wide range of voltage fluctuations due to a fixed threshold, resulting in false triggering of protection when the voltage is too high and failure to operate when the voltage is too low.

[0099] In summary, this embodiment detects the DC power supply voltage value through a source sampling circuit module and compares it using comparator U11. This pure hardware circuitry compares the DC voltage values, and then adaptively selects different high-voltage input circuits based on the output signal of comparator U11. This ensures the switching power supply chip maintains normal operation even when the DC voltage value fluctuates significantly. Only the input circuit output terminal needs to be connected to the HV input pin of the switching power supply chip; no modification to the chip's internal structure is required. It is compatible with various switching power supply chips with built-in HV pins, exhibiting strong versatility. Furthermore, it can be implemented using pure hardware circuitry, eliminating the need for software control or transformer isolation. It does not rely on transformers to generate weak current for power supply and sampling, significantly differing from traditional comparator circuits. Through various graded circuits in the power supply module, it provides suitable power to the input circuits in the comparator circuit module and the self-selection circuit module, enabling the entire circuit system to operate normally. By automatically selecting the appropriate target input circuit, it ensures that the high-voltage input pin receives a matching power input signal under different DC power supply voltages. This solves the problem caused by the fixed threshold of existing switching power supply chip HV input pin protection mechanisms, which cannot adapt to wide-range voltage fluctuations.

[0100] In specific implementations, the high-voltage input protection circuit provided in this application is suitable for application scenarios with large DC power supply voltage fluctuations. For example, it can be integrated into a DC switching power supply, so that the DC switching power supply can automatically select a suitable target input circuit through the high-voltage input protection circuit, thereby ensuring that the high-voltage input pin of the switching power supply chip can obtain a matching power input signal under different DC power supply voltages, thus providing a guarantee for the stable operation of the switching power supply chip under wide voltage fluctuations, and thereby improving the working stability of the switching power supply.

[0101] like Figure 5 As shown in the figure, this application embodiment also provides a switching power supply 500, which includes a switching power supply chip 150 and a high-voltage input protection circuit 510 as described in any of the above embodiments. The output terminal of the high-voltage input protection circuit 510 is electrically connected to the high-voltage input pin of the switching power supply chip 150. The high-voltage input protection circuit 500 automatically selects a suitable target input circuit, thereby ensuring that the high-voltage input pin of the switching power supply chip 150 can obtain a matching power input signal under different DC power supply voltages. This allows the switching power supply 500 to work stably even when the DC input voltage fluctuates greatly, such as photovoltaic input, ensuring the stability of the switching power supply and thus ensuring that electrical equipment can work normally.

[0102] like Figure 6As shown in the figure, this application embodiment also provides an electrical device 601, which is equipped with a switching power supply 500. The switching power supply 500 includes a high-voltage input protection circuit 510 as described in any of the above embodiments. This allows the electrical device to detect the voltage value of the DC power supply through the high-voltage input protection circuit 510 and output a sampling signal of the detected voltage value. The voltage value of the sampling signal is compared with the voltage value of the reference voltage signal. Based on the comparison result, different high-voltage pin input circuits of the switching power supply chip are selected, enabling the high-voltage input pins of the switching power supply chip to adapt to a wide range of voltage fluctuations. This ensures the stable operation of the switching power supply and allows the electrical device to maintain stable operation even under wide-range voltage fluctuation scenarios, thereby improving the stability of the electrical device's operation.

[0103] In specific implementations, the electrical equipment in the embodiments of this application may include, but is not limited to, refrigeration equipment such as air conditioners and refrigerators, and may also include small electronic devices such as fans, washing machines and other small electronic devices. The embodiments of this application do not impose specific limitations on this.

[0104] The circuit and device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0105] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general-purpose hardware platform, or of course by hardware.

[0106] Based on this understanding, the above technical solutions, or the parts that contribute to the relevant technologies, can be embodied in the form of software products. These computer software products can be stored in computer-readable storage media, such as ROM / RAM, magnetic disks, optical disks, etc., and include several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments.

[0107] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0108] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A high-voltage input protection circuit for a power supply, characterized in that, include: Power sampling circuit module, comparator circuit module, power supply module and self-selection circuit module; The self-selection circuit module includes at least two input loops, each of which has a different regulated voltage value, and the output terminal of each input loop is configured to be electrically connected to the high-voltage input pin of the switching power supply chip. The power sampling circuit module is configured to: detect the DC power supply and output a sampling signal of the DC power supply; The power module is configured to: perform voltage division based on the power supply voltage provided by the DC power supply, and output a power voltage division signal, wherein the power voltage division signal includes a reference voltage signal; The comparison circuit module is configured to: perform a voltage comparison based on the reference voltage signal and the sampled signal, and output a comparison result signal; The self-selection circuit module is configured to: select a target input circuit from the at least two input circuits based on the comparison result signal, so as to electrically output the power input signal corresponding to the DC power supply to the high-voltage input pin through the target input circuit.

2. The high-voltage input protection circuit for power supply according to claim 1, characterized in that, The sampling input terminal of the power sampling circuit module, the input terminal of the power module, the power input terminal of the self-selection circuit module, and the positive terminal of the DC power supply are electrically connected, and the power input terminal of each input circuit serves as the power input terminal of the self-selection circuit module. The output terminal of the power sampling circuit module is electrically connected to the first input terminal of the comparison circuit module, the second input terminal of the comparison circuit module is electrically connected to the reference voltage output terminal of the power module, and the output terminal of the comparison circuit module is electrically connected to the control input terminal of the self-selection circuit module. The output terminal of the power sampling circuit module is configured to output the sampling signal. The reference voltage output terminal is configured to output the reference voltage signal; The output of the comparison circuit module is configured to output the comparison result signal.

3. The high-voltage input protection circuit for power supply according to claim 1, characterized in that, The at least two input circuits include a first input circuit and a second input circuit, and the regulated voltage of the first input circuit is greater than the regulated voltage of the second input circuit; The comparison result signal is divided into a first-level signal and a second-level signal; The first input circuit is configured to transmit the power input signal to the high-voltage input pin under the control of the first level signal; The second input circuit is configured to transmit the power input signal to the high-voltage input pin under the control of the second level signal.

4. The high-voltage input protection circuit for power supply according to any one of claims 1 to 3, characterized in that, Each of the input circuits includes a control switch, a power switch, a grounding resistor, and a voltage regulator. The first end of the control switch is electrically connected to the drive output end of the power module, the second end of the control switch, the control end of the power switch and the first end of the grounding resistor are electrically connected, and the control end of the control switch serves as the control input end of the self-selection circuit module. The first terminal of the power switch is electrically connected to the positive terminal of the DC power supply, and the second terminal of the power switch is electrically connected to the first terminal of the voltage regulator. The second end of the grounding resistor is electrically connected to the reference ground of the input circuit; The second terminal of the voltage regulator is electrically connected to the high-voltage input pin of the switching power supply chip.

5. The high-voltage input protection circuit for power supply according to claim 1, characterized in that, The power supply voltage divider signal also includes a drive voltage signal and a negative voltage signal. The power supply module includes a first-stage voltage divider circuit, a second-stage voltage divider circuit, a third-stage voltage divider circuit, and a fourth-stage voltage divider circuit. The first terminal of the first-stage voltage divider circuit is electrically connected to the positive terminal of the DC power supply, the second terminal of the first-stage voltage divider circuit is electrically connected to the reference ground of the power module, and the first-stage voltage divider circuit includes a first Zener diode. The cathode of the first Zener diode is electrically connected to the first terminal of the second-stage voltage divider circuit, and the anode of the first Zener diode is electrically connected to the second terminal of the second-stage voltage divider circuit. The third terminal of the second-stage voltage divider circuit, the first terminal of the third-stage voltage divider circuit, the first terminal of the fourth-stage voltage divider circuit, and the drive input terminal of each of the input loops are electrically connected, and the third terminal of the second-stage voltage divider circuit is configured to output the drive voltage signal. The second terminal of the third-stage voltage divider circuit is electrically connected to the second power supply terminal of the comparator circuit module, and the second terminal of the third-stage voltage divider circuit is configured to output the negative voltage signal; The third terminal of the third-stage voltage divider circuit and the second terminal of the fourth-stage voltage divider circuit are both electrically connected to the reference ground. The third terminal of the fourth-stage voltage divider circuit is electrically connected to the second input terminal of the comparator circuit module, and the third terminal of the fourth-stage voltage divider circuit is configured to output the reference voltage signal.

6. The high-voltage input protection circuit for power supply according to claim 5, characterized in that, The first-stage voltage divider circuit further includes: a first voltage divider resistor and a second voltage divider resistor; The first end of the first voltage divider resistor is electrically connected to the positive terminal of the DC power supply, and the second end of the first voltage divider resistor, the cathode of the first Zener diode, and the first end of the second-stage voltage divider circuit are electrically connected. The first end of the second voltage divider resistor, the anode of the first Zener diode, and the second end of the second-stage voltage divider circuit are electrically connected, and the second end of the second voltage divider resistor is electrically connected to the reference ground.

7. The high-voltage input protection circuit for power supply according to claim 5, characterized in that, The second-stage voltage divider circuit includes: a third voltage divider resistor and a fourth voltage divider resistor; The first end of the third voltage divider resistor serves as the first end of the second-stage voltage divider circuit, the second end of the fourth voltage divider resistor serves as the second end of the second-stage voltage divider circuit, and the second end of the third voltage divider resistor and the first end of the fourth voltage divider resistor serve as the third end of the second-stage voltage divider circuit.

8. The high-voltage input protection circuit for power supply according to any one of claims 5, characterized in that, The third-stage voltage divider circuit includes: a second Zener diode and a fifth voltage divider resistor; The cathode of the second Zener diode serves as the first terminal of the third-stage voltage divider circuit; The anode of the second Zener diode and the first terminal of the fifth voltage divider resistor serve as the third terminal of the third-stage voltage divider circuit. The second terminal of the fifth voltage divider resistor serves as the second terminal of the third-stage voltage divider circuit.

9. The high-voltage input protection circuit for power supply according to claim 5, characterized in that, The fourth-stage voltage divider circuit includes: a sixth voltage divider resistor and a seventh voltage divider resistor; The first end of the sixth voltage divider resistor serves as the first end of the fourth-stage voltage divider circuit, the second end of the seventh voltage divider resistor serves as the second end of the fourth-stage voltage divider circuit, and the second end of the sixth voltage divider resistor and the first end of the seventh voltage divider resistor serve as the third end of the fourth-stage voltage divider circuit.

10. The power supply high-voltage input protection circuit according to any one of claims 1 to 5, characterized in that, The comparison circuit module includes a comparator; The non-inverting input of the comparator is electrically connected to the output of the power sampling circuit module. The inverting input of the comparator, the first power supply terminal of the comparator, and the reference voltage output of the power supply module are electrically connected. The output of the comparator is electrically connected to the control input of the self-selection circuit module. The second power supply terminal of the comparator is electrically connected to the negative power supply output of the power supply module. The control input terminal of the self-selection circuit module is configured to receive the comparison result signal.

11. A switching power supply, characterized in that, include: Switching power supply chip and power high voltage input protection circuit as described in any one of claims 1 to 9; The output terminal of the high-voltage input protection circuit is electrically connected to the high-voltage pin of the switching power supply chip.

12. An electrical appliance, characterized in that, The electrical equipment is equipped with a switching power supply, and the switching power supply includes a high-voltage input protection circuit as described in any one of claims 1 to 9.

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