A voltage reference circuit and an overcurrent protection circuit

Abstract

This utility model relates to the field of switching power supply technology, and discloses a voltage reference circuit and an overcurrent protection circuit. The voltage reference circuit includes a peak reference circuit and a trough reference circuit. The first input terminal of the peak reference circuit is connected to the bus voltage of the device to be protected, and the second input terminal is connected to the supply voltage. Similarly, the first input terminal of the trough reference circuit is connected to the bus voltage of the device to be protected, and the second input terminal is connected to the supply voltage. In this utility model, the peak reference circuit adjusts the peak reference voltage according to the bus voltage of the device to be protected, and the trough reference circuit adjusts the trough reference voltage according to the bus voltage of the device to be protected. This allows for setting different threshold values ​​according to different bus voltages, thus addressing the stress problem of the tube under high voltage conditions.

Description

Technical Field

[0001] This utility model relates to the field of switching power supply technology, specifically to a voltage reference circuit and an overcurrent protection circuit. Background Technology

[0002] In the field of new energy photovoltaic energy storage inverters, when the inverter is in off-grid mode and drives loads such as motors that require high current to start, overcurrent protection faces a dilemma: if the overcurrent protection value is set too low, the protection will be easily triggered at the moment of load start-up, resulting in the inability to carry the load normally; if the protection value is increased to cope with impact loads, the protection function will be ineffective under normal operating conditions, and it will also increase the stress on the switching transistors. Moreover, it is difficult to accurately define the characteristics of different loads, making it difficult to balance impact loads and reliable protection. At the same time, existing inverters generally set fixed protection values ​​based on rated current, and operate according to the hardware protection current under any bus voltage. This is not a problem under low bus voltage conditions, but under high bus voltage conditions, the stress risk on the switching transistors increases dramatically. Utility Model Content

[0003] In view of this, the present invention provides a voltage reference circuit and an overcurrent protection circuit to solve the problem of how to adjust the overcurrent protection value according to the required operating conditions.

[0004] In a first aspect, this utility model provides a voltage reference circuit, comprising: a peak reference circuit and a trough reference circuit, wherein the first input terminal of the peak reference circuit is connected to the bus voltage of the device to be protected, and the second input terminal of the peak reference circuit is connected to the supply voltage, and the peak reference circuit is used to adjust the peak reference voltage according to the bus voltage of the device to be protected; the first input terminal of the trough reference circuit is connected to the bus voltage of the device to be protected, and the second input terminal of the trough reference circuit is connected to the supply voltage, and the trough reference circuit is used to adjust the trough reference voltage according to the bus voltage of the device to be protected.

[0005] In this invention, the peak reference circuit adjusts the peak reference voltage according to the bus voltage of the device to be protected, and the trough reference circuit adjusts the trough reference voltage according to the bus voltage of the device to be protected, thereby setting different thresholds according to different bus voltages, satisfying the stress problem of the tube under high voltage under different voltages.

[0006] In one optional implementation, the peak reference circuit includes: a negative subtractor, a first comparator circuit, and a second comparator circuit. The first input terminal of the negative subtractor is connected to the bus voltage of the device to be protected, the second input terminal of the negative subtractor is connected to the power supply voltage, and the output terminal of the negative subtractor is connected to the input terminal of the first comparator circuit. The input terminal of the second comparator circuit is connected to the power supply voltage, and the output terminal of the second comparator circuit is connected to the output terminal of the first comparator circuit at a single point and leads out to the output terminal of the peak reference circuit.

[0007] In one optional embodiment, the negative subtractor includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a first comparator, and a second comparator. The positive input terminal of the first comparator is connected to the first terminal of the first capacitor and the first terminal of the first resistor via the second resistor. The positive input terminal of the first comparator is also grounded via the third resistor. The negative input terminal of the first comparator is connected to the output terminal of the second comparator via the sixth resistor. The negative input terminal of the first comparator is also connected to its output terminal via the seventh resistor. The output terminal of the first comparator is connected to the first input terminal of the first comparator sub-circuit. The positive input terminal of the second comparator is connected to the power supply voltage via the fourth resistor. The positive input terminal of the second comparator is also grounded via the fifth resistor. The negative input terminal of the second comparator is connected to its output terminal. The second terminal of the first resistor is connected to the bus voltage. The second terminal of the first capacitor is grounded.

[0008] In one optional implementation, the first comparator circuit includes a third comparator, a tenth resistor, and a first diode, wherein the positive input terminal of the third comparator is connected to the output terminal of the negative subtractor, the negative input terminal of the third comparator is connected to the cathode of the first diode, and the output terminal of the third comparator is connected to the anode of the first diode through the tenth resistor; the cathode of the first diode is connected to the output terminal of the second comparator circuit at a single point and leads out to the output terminal of the peak reference circuit.

[0009] In one optional embodiment, the second comparator circuit includes a fourth comparator, an eighth resistor, a ninth resistor, an eleventh resistor, and a second diode. The positive input terminal of the fourth comparator is connected to the power supply voltage through the eighth resistor, and the positive input terminal of the fourth comparator is also grounded through the ninth resistor. The negative input terminal of the fourth comparator is connected to the cathode of the second diode, and the output terminal of the fourth comparator is connected to the anode of the second diode through the eleventh resistor. The cathode of the second diode is connected to the output terminal of the first comparator circuit at a single point and leads out to the output terminal of the peak reference circuit.

[0010] In one optional implementation, the trough reference circuit includes: a positive adder, a third comparator circuit, and a fourth comparator circuit. The first input terminal of the positive adder is connected to the bus voltage, the second input terminal of the positive adder is connected to the supply voltage, and the output terminal of the positive adder is connected to the input terminal of the third comparator circuit. The input terminal of the fourth comparator circuit is connected to the supply voltage, and the output terminal of the fourth comparator circuit is connected to the output terminal of the third comparator circuit at a single point and leads out to the output terminal of the trough reference circuit.

[0011] In one optional embodiment, the positive adder includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a second capacitor, a fifth comparator, and a sixth comparator. The positive input terminal of the fifth comparator is connected to the output terminal of the sixth comparator via the sixteenth resistor, and the positive input terminal of the fifth comparator is grounded via the seventeenth resistor. The negative input terminal of the fifth comparator is connected to the first terminal of the twelfth resistor and the first terminal of the second capacitor via the thirteenth resistor, and the negative input terminal of the fifth comparator is connected to its output terminal and the input terminal of the third comparator sub-circuit via the eighteenth resistor. The positive input terminal of the sixth comparator is connected to the power supply voltage via the fourteenth resistor, and the positive input terminal of the sixth comparator is grounded via the fifteenth resistor. The negative input terminal of the sixth comparator is connected to its output terminal. The second terminal of the twelfth resistor is connected to the bus voltage. The second terminal of the second capacitor is grounded.

[0012] In one optional implementation, the third comparator circuit includes: a seventh comparator, a twenty-first resistor, a twenty-third resistor, a third diode, and a fourth diode. The positive input terminal of the seventh comparator is connected to the output terminal of the positive adder, the negative input terminal of the seventh comparator is connected to the cathode of the fourth diode, and the output terminal of the seventh comparator is connected to the cathode of the third diode and the anode of the fourth diode through the twenty-first resistor. The anode of the third diode is connected to the cathode of the fourth diode through the twenty-third resistor, and the anode of the third diode is connected to the output terminal of the fourth comparator circuit at a single point, leading to the output terminal of the trough reference circuit.

[0013] In one optional implementation, the fourth comparator circuit includes: an eighth comparator, a nineteenth resistor, a twentieth resistor, a twenty-second resistor, a twenty-fourth resistor, a fifth diode, and a sixth diode. The positive input terminal of the eighth comparator is connected to the power supply voltage through the nineteenth resistor, and the positive input terminal of the eighth comparator is also grounded through the twentieth resistor. The negative input terminal of the eighth comparator is connected to the cathode of the sixth diode. The output terminal of the eighth comparator is connected to the cathode of the fifth diode and the anode of the sixth diode through the twenty-second resistor. The anode of the fifth diode is connected to the cathode of the sixth diode through the twenty-fourth resistor. The anode of the fifth diode is connected to the output terminal of the third comparator circuit as a single point and leads out to the output terminal of the trough reference circuit.

[0014] Secondly, this utility model provides an overcurrent protection circuit, comprising: a voltage reference circuit, a positive comparator circuit, and a negative comparator circuit according to the first aspect and any optional embodiment thereof, wherein: the first input terminal of the peak reference circuit is connected to the bus voltage of the device to be protected, the second input terminal of the peak reference circuit is connected to the supply voltage, and the output terminal of the peak reference circuit is connected to the first input terminal of the positive comparator circuit; the peak reference circuit is used to adjust the peak reference voltage according to the bus voltage of the device to be protected; the first input terminal of the trough reference circuit is connected to the bus voltage of the device to be protected, the second input terminal of the trough reference circuit is connected to the supply voltage, and the output terminal of the trough reference circuit is connected to the first input terminal of the negative comparator circuit; the trough reference circuit is used to adjust the trough reference voltage according to the bus voltage of the device to be protected; the second input terminal of the positive comparator circuit is connected to the output voltage of the device to be protected; the positive comparator circuit is used to determine whether the output voltage of the device to be protected is overvoltage according to the peak reference voltage; the second input terminal of the negative comparator circuit is connected to the output voltage of the device to be protected, and the output terminal of the negative comparator circuit is connected to the output terminal of the positive comparator circuit; the negative comparator circuit is used to determine whether the output voltage of the device to be protected is overvoltage according to the trough reference voltage.

[0015] In one optional embodiment, the positive comparator circuit includes: a 25th resistor, a 29th resistor, a 30th resistor, a third capacitor, and a 9th comparator. The positive input terminal of the 9th comparator is connected to the output terminal of the peak reference circuit, and the negative input terminal of the 9th comparator is connected to the first terminal of the 25th resistor and the first terminal of the third capacitor. The output terminal of the 9th comparator is connected to its positive input terminal through the 29th resistor, and the output terminal of the 9th comparator is also connected to the power supply voltage through the 30th resistor. The second terminal of the 25th resistor is connected to the output voltage of the device to be protected. The second terminal of the third capacitor is grounded.

[0016] In one optional embodiment, the negative comparator circuit includes: a 26th resistor, a 27th resistor, a 28th resistor, a fourth capacitor, and a 10th comparator. The positive input terminal of the 10th comparator is connected to the first terminal of the 26th resistor and the first terminal of the fourth capacitor through the 27th resistor. The positive input terminal of the 10th comparator is also connected to its output terminal and the output terminal of the positive comparator circuit through the 28th resistor. The negative input terminal of the 10th comparator is connected to the output terminal of the trough reference circuit. The second terminal of the 26th resistor is connected to the output voltage of the device to be protected. The second terminal of the fourth capacitor is grounded. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a circuit structure diagram of the overcurrent protection circuit of the relevant technology;

[0019] Figure 2 This is a diagram showing the composition of the voltage reference circuit and the overcurrent protection circuit according to an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the peak reference circuit according to an embodiment of the present invention;

[0021] Figure 4 This is a circuit structure diagram of the peak reference circuit according to an embodiment of the present invention;

[0022] Figure 5 This is a diagram illustrating the composition of the valley reference circuit according to an embodiment of the present invention;

[0023] Figure 6 This is a circuit structure diagram of the valley reference circuit according to an embodiment of the present utility model;

[0024] Figure 7 This is a circuit structure diagram of the positive comparison circuit and the negative comparison circuit according to an embodiment of the present utility model. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] Figure 1 The schematic diagram for existing hardware overcurrent protection is shown below. 29 R 30 R 31 The reference value and hysteresis protection value that constitute the forward comparison are, under normal circumstances, comparator U 3A Output high level, R 29 R 30 Parallel and R 31 The corresponding reference value U is obtained by voltage division.ref1 When the input current acquisition signal exceeds U ref1 At that time, the corresponding comparator U 3A Output low level, R 29 R 31 Parallel and R 30 The corresponding reference value U is obtained by voltage division. ref2 U ref2 Less than U ref1 This causes the current acquisition signal to exceed U ref1 When the comparator outputs a low level, the current acquisition signal is less than U. ref2 The comparator only returns to its initial state after a while.

[0027] R 32 R 33 The reference value U that constitutes the negative comparator ref3 Under normal circumstances, comparator U 3B Output high level, current acquisition signal passes through R 26 and 3.3V through R 28 The superposition of these values ​​forms the comparison value U3 at the non-inverting input. When the negative value of the current acquisition signal increases, the corresponding I... o The size decreases, making the comparator U 3B The output is low, at which point the current acquisition signal passes through R. 26 and 0V through R 28 The superimposed components form the in-phase comparator U3, since the reference value U ref3 The value remains unchanged, but the value superimposed on the positive terminal decreases, so the current acquisition signal decreases at the reverse terminal, I. o Only by increasing the size can the comparator U 3B Restore to the original state.

[0028] The above describes the working principle of the voltage signal obtained after AC current passes through the bias voltage, which provides overcurrent protection with hysteresis at both positive and negative peak values. However, this circuit has a problem: once the hardware circuit parameters are determined, the corresponding protection value is unique and cannot be adjusted according to the required operating conditions.

[0029] Based on this, this embodiment provides a voltage reference circuit, aiming to solve the problem that the protection value of traditional overcurrent protection circuits cannot be adjusted online, such as... Figure 2 As shown, it includes: peak reference circuit 1 and trough reference circuit 2.

[0030] like Figure 1 As shown, the first input terminal of the peak reference circuit 1 is connected to the bus voltage V of the device to be protected. BUS The second input terminal of the peak reference circuit 1 is connected to the power supply voltage V. CC The peak reference circuit 1 is used to determine the bus voltage V of the device to be protected. BUSAdjusting the peak reference voltage REF UP .

[0031] Specifically, the first input terminal of the peak reference circuit 1 is directly connected to the bus voltage V of the device to be protected. BUS Bus voltage V BUS As a key parameter reflecting the operating conditions of equipment, its changes directly affect the stability and safety of the system. The peak reference circuit 1 integrates a sophisticated voltage sampling and signal processing unit, capable of sensing the bus voltage V in real time. BUS The fluctuation situation. Through complex and efficient algorithms and circuit logic, based on the bus voltage V of the equipment to be protected. BUS The actual values ​​and trends of the peak reference voltage REF Up Make precise adjustments.

[0032] For example, when the current is in the positive half-axis, if the actual voltage output by the device to be protected is lower than the set voltage threshold, the protection value output by the peak reference circuit 1 remains unchanged, i.e., the peak reference voltage REF remains unchanged. Up The voltage remains unchanged, but when the actual voltage output by the device to be protected is higher than the set voltage threshold, the protection value output by the peak reference circuit 1 changes with the bus voltage V. BUS It shows a linear decrease.

[0033] Specifically, when the current waveform is in the positive half-axis operating state, the peak reference circuit 1 and the overcurrent protection mechanism work together to exhibit intelligent and precise dynamic response characteristics. When the actual voltage of the protected equipment is lower than the preset threshold, the system is in a relatively safe operating range, and the corresponding threshold remains constant to ensure stable operation of the equipment under normal conditions and avoid affecting the normal operation of the system due to unnecessary protection actions. However, once the actual voltage exceeds the set threshold, it means that the operating conditions of the equipment have changed and may face higher risks. At this time, the threshold will be adjusted according to the bus voltage V. BUS The threshold value is dynamically adjusted based on the changing trend of the bus voltage V. BUS The relationship between them is linearly decreasing, that is, as the bus voltage V... BUS As the voltage increases, the threshold gradually decreases according to a strict linear law. The ingenuity of this design lies in the fact that when the voltage rises, appropriately lowering the threshold can enhance the system's sensitivity to overcurrent conditions, triggering the protection mechanism in advance, thereby effectively avoiding equipment damage or system failure caused by overcurrent, and providing more rigorous protection for equipment under high-voltage conditions.

[0034] like Figure 1 As shown, the first input terminal of the valley reference circuit 2 is connected to the bus voltage V of the device to be protected. BUS The second input terminal of the trough reference circuit 2 is connected to the supply voltage V. CCThe trough reference circuit 2 is used to determine the bus voltage V of the device to be protected. BUS Adjusting the trough reference voltage REF DOWN .

[0035] Specifically, the first input terminal of the trough reference circuit 2 is also connected to the bus voltage V of the device to be protected. BUS This allows for the acquisition of voltage change information during equipment operation. The trough reference circuit 2 possesses a unique voltage analysis and processing mechanism, capable of in-depth analysis of the bus voltage V. BUS The changing characteristics, especially when the voltage is at a low level, need to be carefully analyzed. Based on the bus voltage V BUS For accurate analysis, the trough reference circuit 2 can determine the bus voltage V of the equipment to be protected. BUS The system adaptively adjusts the trough reference voltage REFDOWN according to the situation.

[0036] For example, when the current is in the negative half-axis, if the actual voltage output by the device to be protected is lower than the set voltage threshold, the protection value output by the peak reference circuit 1 remains unchanged, that is, the trough reference voltage REFDOWN remains unchanged. However, when the actual voltage output by the device to be protected is higher than the set voltage threshold, the protection value output by the peak reference circuit 1 changes with the bus voltage V. BUS It increases linearly.

[0037] Specifically, when the current waveform enters the negative half-axis operating phase, the system's overcurrent protection logic also demonstrates a high degree of adaptability and flexibility. When the actual voltage is below the set threshold, the system remains in a stable and controllable operating state, and the corresponding threshold remains unchanged, ensuring continuous and stable operation of the equipment. However, when the actual voltage exceeds the set threshold, it indicates a change in the system's operating state and an increase in potential risks. At this point, the threshold will be related to the bus voltage V. BUS It exhibits a linear increasing relationship. As the bus voltage V... BUS As the voltage increases, the threshold gradually increases in a precise linear proportion. This linear increase allows the system to dynamically adjust the protection threshold according to voltage changes during high-voltage operation on the negative half-axis, ensuring timely protection while avoiding false triggering caused by improper threshold settings. In this way, the system's ability to handle overcurrent risks during negative-axis operation is effectively improved, ensuring safe and reliable operation of the equipment under complex and changing conditions.

[0038] In some alternative implementations, such as Figure 3 As shown, the peak reference circuit 1 includes: a negative subtractor 11, a first comparator circuit 12, and a second comparator circuit 13.

[0039] like Figure 3As shown, the first input terminal of the negative subtractor 11 is connected to the bus voltage V of the equipment to be protected. BUS The second input terminal of the negative subtractor 11 is connected to the power supply voltage V. CC The output of the negative subtractor 11 is connected to the input of the first comparator circuit 12.

[0040] Specifically, the negative subtractor 11, as the front-end signal processing unit of the peak reference circuit 1, undertakes the critical voltage signal processing task. Its first input terminal is directly connected to the bus voltage V of the equipment to be protected. BUS Bus voltage V BUS As a core parameter reflecting the operating status of equipment, its real-time changes can intuitively reflect changes in equipment operating conditions. The negative subtractor 11, based on a precise operational amplifier and resistor network architecture, subtracts the input bus voltage V... BUS With supply voltage V CC Perform precise subtraction. This subtraction operation allows for the effective extraction of the bus voltage V. BUS Relative to the supply voltage V CC The difference in the change will affect the bus voltage V. BUS The fluctuation information is converted into a more easily processed electrical signal, and the processed signal is transmitted to the first comparator circuit 12 through the output terminal for subsequent signal analysis and peak reference voltage REF. Up Adjustments lay the foundation.

[0041] like Figure 3 As shown, the input terminal of the second comparator circuit 13 is connected to the power supply voltage V. CC The output terminal of the second comparator circuit 13 is connected to the output terminal of the first comparator circuit 12 at one point and the output terminal of the peak reference circuit 1 is led out.

[0042] Specifically, the second comparator circuit 13 is used to generate a threshold. Both the output of the first comparator circuit 12 and the output of the second comparator circuit 13 have built-in unidirectional conduction devices. When the voltage output of the first comparator circuit 12 is higher than the output voltage V of the second comparator circuit 13... OUT When the voltage output by the first comparator circuit 12 is used as the peak reference voltage REF, then... Up When the voltage output by the first comparator circuit 12 is lower than the output voltage V of the second comparator circuit 13 OUT When the voltage output by the second comparator circuit 13 is used as the peak reference voltage REF, then... Up .

[0043] In some alternative implementations, such as Figure 4As shown, the negative subtractor 11 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first capacitor C1, and a first comparator U. 1A and the second comparator U 1B .

[0044] like Figure 4 As shown, the first comparator U 1A The positive input terminal of the first comparator U is connected to the first terminal of the first capacitor C1 and the first terminal of the first resistor R1 through the second resistor R2. 1A The positive input terminal is also grounded through the third resistor R3, and the first comparator U 1A The negative input terminal is connected to the second comparator U through the sixth resistor R6. 1B The output terminal is connected to the first comparator U. 1A The negative input terminal is also connected to its output terminal through the seventh resistor R7, and the first comparator U 1A The output terminal is connected to the first input terminal of the first comparator circuit 12; the second terminal of the first resistor R1 is connected to the bus voltage V. BUS The second terminal of the first capacitor C1 is grounded.

[0045] Specifically, the first resistor R1 serves as the bus voltage V. BUS The access bridge has its second end directly connected to the busbar of the equipment to be protected, and the busbar voltage V is collected in real time. BUS Sample the value and transmit it to the first comparator U. 1A In the signal processing link, the first comparator U... 1A The positive input terminal is connected to the first terminal of the first capacitor C1 through the second resistor R2, forming an RC filter circuit structure. The second terminal of the first capacitor C1 is grounded, and together with the second resistor R2, they form a low-pass filter network, which can effectively filter out the bus voltage V. BUS High-frequency noise in the sampled values ​​is eliminated to ensure a pure and stable input signal. Meanwhile, the first comparator U... 1A The positive input terminal is also grounded through a third resistor R3 to provide a stable reference potential for the input signal, so that the sampled signal can be processed under a reliable reference.

[0046] First comparator U 1A The negative input terminal is also connected to its output terminal through the seventh resistor R7, forming a deep negative feedback loop. Based on the "virtual short" and "virtual open" characteristics of the operational amplifier, and combined with the proportional relationship set by the resistance values ​​of each resistor, when the bus voltage V BUS When the sampled value increases, the first comparator U 1A As the voltage at the inverting input increases, and with the reference voltage remaining relatively stable, the first comparator U is adjusted via negative feedback. 1AThe output voltage of the first comparator U will decrease accordingly. By precisely designing the parameters of each resistor, the output voltage of the first comparator U can be strictly controlled. 1A The output voltage varies with the bus voltage V BUS The magnitude and trend of the change cause the first comparator U 1A The output forms a precise line that follows the bus voltage V. BUS The curve rises and then monotonically decreases. This curve provides crucial information for the subsequent signal processing of the first comparator circuit 12, enabling the entire peak reference circuit 1 to dynamically adjust the peak reference voltage REF according to the actual operating conditions of the equipment. Up This enables precise overcurrent protection.

[0047] like Figure 4 As shown, the second comparator U 1B The positive input terminal is connected to the supply voltage V through the fourth resistor R4. CC Second comparator U 1B The positive input terminal is also grounded through the fifth resistor R5, and the second comparator U 1B The negative input terminal is connected to its output terminal.

[0048] Specifically, the reference voltage is passed through the second comparator U 1B The circuit constructed from its surrounding resistors is generated. The second comparator U... 1B The positive input terminal is connected to the supply voltage V through the fourth resistor R4. CC Simultaneously, it is grounded through the fifth resistor R5, forming a stable voltage divider circuit to divide the supply voltage V. CC This voltage is converted to a suitable reference voltage. Its negative input is connected to its output, forming a voltage follower structure. This not only serves as a signal buffer and isolation but also ensures a stable output of the reference voltage. This reference voltage is connected to the first comparator U through the sixth resistor R6. 1A The negative input terminal.

[0049] In some alternative implementations, such as Figure 4 As shown, the first comparator circuit 12 includes: a third comparator U 1C The tenth resistor R 10 and the first diode D1, wherein the third comparator U 1C The positive input terminal is connected to the output terminal of the negative subtractor 11, and the third comparator U 1C The negative input terminal of the third comparator is connected to the cathode of the first diode D1. 1C The output terminal is connected to the tenth resistor R 10 The cathode of the first diode D1 is connected to the anode of the second comparator circuit 13 at a single point and leads out to the output of the peak reference circuit 1.

[0050] Specifically, the third comparator U1C The positive input terminal is directly connected to the output terminal of the negative subtractor 11, and is used to receive the bus voltage V after processing by the negative subtractor 11. BUS The difference signal between the voltage and the reference voltage. This signal carries the bus voltage V. BUS The real-time changes in voltage and the comparison results with the reference voltage are crucial for the decision-making of the first comparator circuit 12. The third comparator U... 1C The negative input terminal is connected to the cathode of the first diode D1. Through this connection, the third comparator U... 1C It can acquire the output signal from the second comparator circuit 13 and use it as a comparison reference. Meanwhile, the third comparator U... 1C The output terminal is connected to the tenth resistor R 10 The tenth resistor R is connected to the anode of the first diode D1. 10 This serves a dual purpose: current limiting and signal conditioning. It prevents excessive current from damaging components and also regulates the signal of the third comparator U. 1C The output signal is adjusted appropriately to ensure the stability and reliability of signal transmission.

[0051] Specifically, the first diode D1, as a key device for signal filtering and transmission, utilizes its unidirectional conduction characteristic to achieve selective signal output in the first comparator circuit 12. Its cathode is connected to the output terminal of the second comparator circuit 13 at a single point, thereby leading to the output terminal of the peak reference circuit 1. This design allows the first comparator circuit 12 to selectively output signals based on the third comparator U. 1C The comparison results allow for flexible control of the peak reference voltage REF. Up The output path of the third comparator U. 1C When the voltage at the positive input terminal is higher than the voltage at the negative input terminal, that is, when the signal voltage output by the negative subtractor 11 is higher than the signal voltage output by the second comparator circuit 13, the third comparator U... 1C When the output is high, the anode potential of the first diode D1 increases. Since the anode potential is higher than the cathode potential, the first diode D1 conducts, causing the third comparator U to... 1C The output voltage signal can pass smoothly through the first diode D1 and serve as the peak reference voltage REF. Up The output is sent to the output terminal of the peak reference circuit 1. Conversely, when the third comparator U... 1C When the voltage at the positive input terminal is lower than the voltage at the negative input terminal, the third comparator U 1C When the output is low, the anode potential of the first diode D1 decreases, becoming lower than the cathode potential, and the first diode D1 is cut off. At this time, the voltage signal output by the second comparator circuit 13 is directly used as the peak reference voltage REF through the connection point. Up Output.

[0052] Through the third comparator U 1C The tenth resistor R 10 With the close cooperation of the first diode D1, the first comparator circuit 12 can quickly and accurately compare and filter the input signal, and dynamically select a suitable voltage signal as the peak reference voltage REF according to the actual operating conditions. Up Output. This intelligent signal processing mechanism ensures that the peak reference circuit 1 can adapt to changes in the operating status of the equipment in real time, providing an accurate and reliable reference for the overcurrent protection system, thereby effectively improving the stability and safety of the entire system.

[0053] In some alternative implementations, such as Figure 4 As shown, the second comparator circuit 13 includes: a fourth comparator U 1D Eighth resistor R8, Ninth resistor R9, Eleventh resistor R 11 and the second diode D2, wherein the fourth comparator U 1D The positive input terminal is connected to the supply voltage V through the eighth resistor R8. CC Fourth comparator U 1D The positive input terminal is also grounded through the ninth resistor R9, and the fourth comparator U 1D The negative input terminal of the fourth comparator is connected to the cathode of the second diode D2. 1D The output terminal is connected to the eleventh resistor R 11 The cathode of the second diode D2 is connected to the anode of the first comparator circuit 12 at a single point and leads out to the output of the peak reference circuit 1.

[0054] Specifically, the fourth comparator U 1D As the core operational unit of this sub-circuit, its integrated differential input stage can respond quickly to minute voltage differences. Fourth comparator U 1D The positive input terminal is connected to the supply voltage V through the eighth resistor R8. CC Simultaneously, it is grounded through the ninth resistor R9, forming a typical resistor voltage divider network. By precisely selecting the resistance ratio of R8 and R9, the supply voltage V can be... CC The voltage is proportionally attenuated to the required threshold. This voltage divider structure exhibits good linearity and temperature stability, effectively suppressing the supply voltage V. CC The impact of fluctuations on the benchmark value. Fourth comparator U 1D The negative input terminal of the first comparator is connected to the cathode of the second diode D2, forming a feedback comparison node. When the output voltage changes, the voltage at this node is fed back to the comparator input in real time and continuously compared with the threshold. The fourth comparator U... 1D The output terminal is connected to the eleventh resistor R 11It is connected to the anode of the second diode D2, forming a typical pull-up structure. The eleventh resistor R... 11 This serves a dual purpose: limiting current peak and buffering signal. On the one hand, it limits the current peak and protects the comparator output stage; on the other hand, it forms an RC time constant with the circuit distributed capacitance, optimizing the signal rise time characteristics and avoiding high-frequency oscillation.

[0055] Specifically, the second diode D2, as a key component for signal selection, has its cathode connected at a single point to the output terminal of the first comparator circuit 12. When the fourth comparator U... 1D When it is determined that the reference voltage generated by itself is more suitable for the current operating condition (i.e., the voltage at the positive input terminal is higher than that at the negative input terminal), the output is high to turn on the second diode D2 and transmit the reference voltage to the output terminal of the peak reference circuit 1; otherwise, it is turned off, allowing the output signal of the first comparator circuit 12 to pass through.

[0056] In actual operation, when the power supply voltage V CC Stable and bus voltage V BUS When within the normal range, the reference voltage output by the second comparator circuit 13 provides the basic protection threshold; while when the bus voltage V BUS When significant fluctuations or shocks occur, the dynamically adjusted voltage generated by the first comparator circuit 12 will be output first through a competition mechanism. This redundant design of dual comparator circuits enables the peak reference circuit 1 to achieve a balance between steady-state accuracy and dynamic response, ensuring protection reliability under normal operating conditions while improving the system's robustness in the face of sudden faults.

[0057] For example, Figure 4 In the middle, the bus voltage V BUS and reference voltage through U 1A This forms a negative subtractor 11, resulting in a curve where the output decreases as the voltage increases. 1D The reference voltage is divided by R8 and R9, and this value is the preset voltage inflection point (i.e., the positive threshold). This is achieved through U... 1C and U 1D By comparing the two, the minimum of the two is the final value, obtained through R. 10 R 11 Current limiting is implemented, and D1 and D2 are switched. This ensures that when the voltage is below the positive threshold, the protection threshold remains unchanged; when the voltage is above the positive threshold, the protection threshold adjusts according to the bus voltage V. BUS It rises and then falls.

[0058] For example, the corresponding peak reference voltage REF Up Value and bus voltage V BUS The relationship is shown in equation (1).

[0059]

[0060] In some alternative implementations, such as Figure 5 As shown, the trough reference circuit 2 includes: a positive adder 21, a third comparator circuit 22, and a fourth comparator circuit 23.

[0061] like Figure 5 As shown, the first input terminal of the positive adder 21 is connected to the bus voltage V. BUS The second input terminal of the positive adder 21 is connected to the power supply voltage V. CC The output of the positive adder 21 is connected to the input of the third comparator circuit 22.

[0062] Specifically, the output of the positive adder 21 changes with the bus voltage V BUS The voltage curve increases as it rises. The first input terminal of the positive adder 21 is directly connected to the bus voltage V of the equipment to be protected. BUS Real-time acquisition of bus voltage V BUS The signal contains a wealth of operating information about the equipment; the second input terminal is connected to a stable power supply voltage V. CC This provides a stable reference signal source for addition operations. The positive adder 21 circuit operates on the superposition principle, applying the input bus voltage V... BUS With supply voltage V CC Perform precise addition operations. By rationally designing the resistor value ratio, the weights of the two input signals can be precisely controlled, thus adjusting the bus voltage V. BUS With supply voltage V CC They are superimposed according to a specific ratio to generate a signal containing the bus voltage V. BUS A composite signal of variation characteristics and stable reference information.

[0063] like Figure 5 As shown, the input terminal of the fourth comparator circuit 23 is connected to the power supply voltage V. CC The output terminal of the fourth comparator circuit 23 is connected to the output terminal of the third comparator circuit 22 at one point, and the output terminal of the valley reference circuit 2 is led out.

[0064] The fourth comparator circuit 23 operates with a stable supply voltage V. CC Using this as the input source, a stable threshold is generated through a sophisticated internal voltage divider and signal processing mechanism. This signal serves as a reference scale, possessing extremely strong stability and anti-interference capabilities, and can provide a reference voltage REF for the trough during device operation. DOWN The selection process provides a reliable reference. The output of the fourth comparator circuit 23 is connected to the output of the third comparator circuit 22 through a specific node, forming the "intersection point" for intelligent decision-making.

[0065] In the voltage screening stage, the output signals of the two comparator circuits are compared in real time: when the output voltage of the third comparator circuit 22 is less than the output voltage of the fourth comparator circuit 23, it means that based on the supply voltage V... CC The generated threshold is more in line with the current operating conditions, so the output voltage of the fourth comparator circuit 23 will be preferentially selected as the trough reference voltage REF. DOWN This ensures the reliability of the protection threshold; conversely, if the output voltage of the third comparator circuit 22 is higher, it indicates that the bus voltage V transmitted by the positive adder 21 is not as high as expected. BUS Change information is given higher priority, and its output voltage will be used as the trough reference voltage REF. DOWN Output.

[0066] In some alternative implementations, such as Figure 6 As shown, the forward adder 21 includes: a twelfth resistor R 12 The thirteenth resistor R 13 Fourteenth resistor R 14 The fifteenth resistor R 15 The sixteenth resistor R 16 The seventeenth resistor R 17 The eighteenth resistor R 18 Second capacitor C2, fifth comparator U 2A and the sixth comparator U 2B .

[0067] like Figure 6 As shown, the fifth comparator U 2A The positive input terminal is connected to the sixteenth resistor R. 16 With the sixth comparator U 2B The output terminal is connected to the fifth comparator U. 2A The positive input terminal is connected to the seventeenth resistor R. 17 Ground, fifth comparator U 2A The negative input terminal is connected to the thirteenth resistor R. 13 With the twelfth resistor R 12 The first terminal of the first capacitor C2 is connected to the first terminal of the second capacitor C2, and the fifth comparator U is connected to the first terminal of the second capacitor C2. 2A The negative input terminal is connected to the eighteenth resistor R. 18 It is connected to its output terminal and the input terminal of the third comparator circuit 22; the twelfth resistor R 12 The second terminal is connected to the bus voltage V BUS The second terminal of the second capacitor C2 is grounded.

[0068] Specifically, in the signal input and conditioning stage, the bus voltage V BUS Through the twelfth resistor R 12 Transmitted to the thirteenth resistor R 13The low-pass filter network formed by the second capacitor C2 effectively filters out high-frequency noise and improves signal quality. The filtered bus voltage V... BUS Signal input to the fifth comparator U 2A The negative input terminal serves as the dynamic input component for addition operations.

[0069] like Figure 6 As shown, the sixth comparator U 2B The positive input terminal is connected to the fourteenth resistor R. 14 Connected power supply voltage V CC The sixth comparator U 2B The positive input terminal is connected to the fifteenth resistor R. 15 Ground, sixth comparator U 2B The negative input terminal is connected to its output terminal.

[0070] Supply voltage V CC Through the fourteenth resistor R 14 With the fifteenth resistor R 15 After voltage division, the signal is connected to the sixth comparator U. 2B The positive input terminal of the sixth comparator U 2B The output terminal is connected to the negative input terminal to form a voltage follower structure, ensuring that the reference voltage after voltage division has low output impedance and can stably drive subsequent circuits. This reference voltage is connected through the sixteenth resistor R. 16 Transmitted to the fifth comparator U 2A The positive input terminal provides a stable reference component for addition operations.

[0071] Fifth comparator U 2A As the core component for addition operations, its positive input terminal is connected to the seventeenth resistor R. 17 Grounded, and connected to the sixteenth resistor R 16 Together they form a voltage divider network, precisely controlling the weight of the reference voltage; its negative input terminal is connected to the eighteenth resistor R. 18 Deep negative feedback is introduced to make the comparator operate in the linear amplification region. Based on the "virtual short" and "virtual open" characteristics of the operational amplifier, the fifth comparator U... 2A The output voltage can be expressed as (V) BUS ×R 18 / R 13 )+(Vref×R 18 / R 16 ), where V BUS Bus voltage V BUS Vref is the reference voltage. Through precise matching of R... 13 R 16 With R 18 The resistance value ensures that the output voltage strictly follows the bus voltage V. BUS It increases linearly as it rises.

[0072] Compared to traditional operational amplifier circuits, comparator-based adder designs can quickly track the bus voltage V. BUS The dynamic changes of the output voltage curve are ensured by selecting comparators with low offset voltage and low bias current, and employing a precisely matched resistor network. BUS The change maintains a highly linear relationship. The output signal is directly transmitted to the third comparator circuit 22, which is the trough reference voltage REF. DOWN The generation provides an accurate dynamic reference, enabling the entire protection circuit to respond in real time to the bus voltage V. BUS The changes effectively improve the stability and reliability of the system under complex operating conditions.

[0073] In some alternative implementations, such as Figure 6 As shown, the third comparator circuit 22 includes: a seventh comparator U 2C The twenty-first resistor R 21 The twenty-third resistor R 23 The third diode D3 and the fourth diode D4, wherein the seventh comparator U 2C The positive input terminal is connected to the output terminal of the positive adder 21, and the seventh comparator U 2C The negative input terminal is connected to the cathode of the fourth diode D4, and the seventh comparator U 2C The output terminal is connected to the twenty-first resistor R 21 It is connected to the cathode of the third diode D3 and the anode of the fourth diode D4; the anode of the third diode D3 is connected to the twenty-third resistor R. 23 The cathode of the fourth diode D4 is connected to the cathode of the third diode D3, and the anode of the third diode D3 is connected to the output of the fourth comparator circuit 23 at a single point and the output of the valley reference circuit 2 is led out.

[0074] Specifically, the seventh comparator U 2C The positive input terminal is directly connected to the output terminal of the positive adder 21 to receive the bus voltage V in real time. BUS The dynamic signal superimposed on the reference voltage. Seventh comparator U 2C The negative input terminal is connected to the reference voltage through the cathode of the fourth diode D4, which originates from the output of the fourth comparator circuit 23. When the voltage signal output by the positive adder 21 is higher than the reference voltage, the seventh comparator U... 2C Output a high level if the output is high, and vice versa. When the seventh comparator U... 2C When the output is high, the twenty-first resistor R... 21 The current provides driving capability for the subsequent diode network; while in the seventh comparator U 2C When the output is low, the twenty-first resistor R 21 This limits the reverse current and protects the comparator output stage from damage.

[0075] Specifically, the third diode D3 and the fourth diode D4 utilize their unidirectional conductivity to construct the voltage selection logic. When the seventh comparator U... 2C When the output is high, the third diode D3 is turned on while the fourth diode D4 is turned off, thus turning the seventh comparator U... 2C The output signal is transmitted to the output node; otherwise, the fourth diode D4 is turned on while the third diode D3 is turned off, so that the output node is connected to the reference voltage of the fourth comparator circuit 23.

[0076] Specifically, when the output voltage of the positive adder 21 gradually increases and exceeds the reference voltage, the seventh comparator U... 2C The output flips from low to high, and the third diode D3 begins to conduct. At this time, the twenty-third resistor R... 23 Working together with the third diode D3, it ensures a smooth transition of the output voltage from the reference voltage to the voltage division value of the output voltage of the forward adder 21, preventing voltage jumps from impacting subsequent circuits. This design allows the trough reference voltage REF to... DOWN Able to determine the bus voltage V BUS The changes enable continuous and smooth adjustment.

[0077] In some alternative implementations, such as Figure 6 As shown, the fourth comparator circuit 23 includes: an eighth comparator U 2D Nineteenth resistor R 19 The twentieth resistor R 20 The twenty-second resistor R 22 The twenty-fourth resistor R 24 Diodes D5 and D6 are the fifth and sixth diodes, respectively. The eighth comparator is U. 2D The positive input terminal is connected to the nineteenth resistor R. 19 Connected power supply voltage V CC Eighth comparator U 2D The positive input terminal is also connected to the twentieth resistor R. 20 Grounded, eighth comparator U 2D The negative input terminal is connected to the cathode of the sixth diode D6, and the eighth comparator U 2D The output terminal is connected to the twenty-second resistor R 22 It is connected to the cathode of the fifth diode D5 and the anode of the sixth diode D6; the anode of the fifth diode D5 is connected to the twenty-fourth resistor R. 24 The cathode of the sixth diode D6 is connected to the cathode of the fifth diode D5, and the anode of the fifth diode D5 is connected to the output of the third comparator circuit 22 at one point and the output of the valley reference circuit 2 is led out.

[0078] Specifically, the eighth comparator U 2D The positive input terminal is connected to the nineteenth resistor R.19 A stable power supply voltage is connected, and the positive input terminal is connected to the twentieth resistor R. 20 Grounding forms a stable voltage divider circuit. Through precise design of R... 19 With R 20 The resistance ratio can be used to convert the supply voltage into a threshold voltage, which is unaffected by the bus voltage V. BUS Fluctuations provide a stable protection threshold basis for the system.

[0079] Specifically, the twenty-second resistor R 22 Connected to the eighth comparator U 2D The output terminal of the circuit is connected to the cathode of the fifth diode D5 and the anode of the sixth diode D6. This connection serves to limit current (preventing excessive current from damaging the comparator when the diodes are conducting) and optimizes the signal edges by cooperating with the circuit's parasitic capacitance, thus avoiding high-frequency oscillations.

[0080] Specifically, the fifth diode D5 and the sixth diode D6 construct a selection network based on their unidirectional conduction characteristics: when the eighth comparator U... 2D When the output is high, the fifth diode D5 is turned on and the sixth diode D6 is turned off, passing the threshold to the output node; when the output is low, the sixth diode D6 is turned on and the sixth diode D6 is turned off, blocking the threshold output and making way for the dynamic signal of the third comparator circuit 22.

[0081] For example, Figure 6 In the middle, the bus voltage V BUS and reference voltage through U 2A This forms a positive adder 21, resulting in a curve where the output increases as the voltage rises. 2D The reference voltage is obtained through R 19 R 20 Voltage division is performed; this value is the preset voltage inflection point (i.e., the negative threshold), through U 2C and U 2D The comparison shows that the maximum of the two values ​​is the final value, obtained through R. 23 R 24 Current limiting is implemented. This ensures that when the voltage is below the negative threshold, the protection threshold remains unchanged; when the voltage is above the negative threshold, the protection threshold adjusts according to the bus voltage V. BUS It rises and rises.

[0082] For example, the corresponding REF Down Value and U BUS The relationship is shown in equation (2).

[0083]

[0084] This embodiment provides an overcurrent protection circuit, such as Figure 1As shown, it includes: the voltage reference circuit, the positive comparison circuit 3, and the negative comparison circuit 4 of the above embodiments and any optional embodiments thereof.

[0085] The first input terminal of the peak reference circuit 1 is connected to the bus voltage V of the device to be protected. BUS The second input terminal of the peak reference circuit 1 is connected to the power supply voltage V. CC The output terminal of the peak reference circuit 1 is connected to the first input terminal of the positive comparator circuit 3. The peak reference circuit 1 is used to measure the bus voltage V of the device to be protected. BUS Adjusting the peak reference voltage REF Up .

[0086] The first input terminal of the valley reference circuit 2 is connected to the bus voltage V of the device to be protected. BUS The second input terminal of the trough reference circuit 2 is connected to the supply voltage V. CC The output of the trough reference circuit 2 is connected to the first input of the negative comparator circuit 4. The trough reference circuit 2 is used to measure the bus voltage V of the device to be protected. BUS Adjusting the trough reference voltage REF DOWN .

[0087] The second input terminal of the forward comparator circuit 3 is connected to the output voltage V of the device to be protected. OUT The forward comparator circuit 3 is used to compare the peak reference voltage REF. Up Determine the output voltage V of the device to be protected in the positive direction. OUT Is there an overvoltage?

[0088] The second input terminal of the negative comparator circuit 4 is connected to the output voltage V of the device to be protected. OUT The output of the negative comparator circuit 4 is connected to the output of the positive comparator circuit 3. The negative comparator circuit 4 is used to compare the output of the trough reference voltage REF. DOWN Determine the output voltage V of the negative-biased device to be protected. OUT Is there an overvoltage?

[0089] Specifically, when the current is in the positive half-axis, the second input terminal of the positive comparator circuit 3 is directly connected to the output voltage V of the device to be protected. OUT Its first input terminal is connected to the dynamic reference voltage generated by the peak reference circuit 1. This reference voltage varies with the bus voltage V. BUS It dynamically adjusts to changes, reflecting the normal upper limit range of equipment operation in real time. When the output voltage V of the equipment to be protected changes... OUT Exceeding the peak reference voltage REF Up At this time, the forward comparator circuit 3 triggers the overvoltage protection signal. This comparison mechanism based on a dynamic reference can adapt to voltage fluctuations under different operating conditions, avoiding false protection or protection failure caused by unreasonable static threshold settings.

[0090] Specifically, when the current is in the negative half-axis, the second input terminal of the negative comparator circuit 4 is also connected to the output voltage V of the device to be protected. OUT However, its first input terminal is connected to the output terminal of the valley reference circuit 2, and receives the valley reference voltage REF. DOWN The reference voltage is based on the bus voltage V. BUS With supply voltage V CC Dynamically generated, for the device output voltage V OUT Set a safety lower limit. When the output voltage V of the device to be protected... OUT Below the trough reference voltage REF DOWN When the negative comparator circuit 4 flips its output state, it indicates a negative overvoltage state.

[0091] In some alternative implementations, such as Figure 7 As shown, the forward comparator circuit 3 includes: the twenty-fifth resistor R 25 The twenty-ninth resistor R 29 The thirtieth resistor R 30 The third capacitor C3 and the ninth comparator U 3A Among them, the ninth comparator U 3A The positive input terminal is connected to the output terminal of the peak reference circuit 1, and the ninth comparator U 3A The negative input terminal and the 25th resistor R 25 The first terminal of the first capacitor C3 is connected to the first terminal of the third capacitor C3; the ninth comparator U 3A The output terminal is connected to the twenty-ninth resistor R 29 Connected to its positive input, the ninth comparator U 3A The output terminal is also connected to the thirtieth resistor R 30 Connected power supply voltage V CC ; Twenty-fifth resistor R 25 The second terminal is connected to the output voltage V of the device to be protected. OUT The second terminal of the third capacitor is grounded.

[0092] When the output voltage V of the device to be protected OUT Gradually rise and exceed the peak reference voltage REF Up At that time, the ninth comparator U 3A The output state is quickly toggled from low to high, triggering an overvoltage protection signal.

[0093] In some alternative implementations, such as Figure 7 As shown, the negative comparator circuit 4 includes: a twenty-sixth resistor R 26 The twenty-seventh resistor R 27 The twenty-eighth resistor R 28 The fourth capacitor C4 and the tenth comparator U3B Among them, the tenth comparator U 3B The positive input terminal is connected to the 27th resistor R. 27 With the twenty-sixth resistor R 26 The first terminal of the first capacitor C4 is connected to the first terminal of the tenth comparator U. 3B The positive input terminal is also connected to its output terminal and the output terminal of the positive comparator circuit 3 through the twenty-eighth resistor, and the tenth comparator U 3B The negative input terminal is connected to the output terminal of the trough reference circuit 2; the twenty-sixth resistor R 26 The second terminal is connected to the output voltage V of the device to be protected. OUT The second terminal of the fourth capacitor C4 is grounded.

[0094] When the output voltage V of the device to be protected OUT The voltage drops to the trough reference voltage REF due to sudden load changes, power failures, or other reasons. DOWN The following is the tenth comparator U 3B The system responds quickly, flipping its output from low to high, triggering an overvoltage protection signal.

[0095] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A voltage reference circuit, characterized by, include: Peak reference circuit and trough reference circuit, among which, The first input terminal of the peak reference circuit is connected to the bus voltage of the device to be protected, and the second input terminal of the peak reference circuit is connected to the power supply voltage. The peak reference circuit is used to adjust the peak reference voltage according to the bus voltage of the device to be protected. The first input terminal of the valley reference circuit is connected to the bus voltage of the device to be protected, and the second input terminal of the valley reference circuit is connected to the power supply voltage. The valley reference circuit is used to adjust the valley reference voltage according to the bus voltage of the device to be protected.

2. The voltage reference circuit according to claim 1, characterized in that, The peak reference circuit includes: a negative subtractor, a first comparator subcircuit, and a second comparator subcircuit, wherein... The first input terminal of the negative subtractor is connected to the bus voltage of the equipment to be protected, the second input terminal of the negative subtractor is connected to the power supply voltage, and the output terminal of the negative subtractor is connected to the input terminal of the first comparator circuit. The input terminal of the second comparator circuit is connected to the power supply voltage, and the output terminal of the second comparator circuit is connected to the output terminal of the first comparator circuit at a single point and leads out to the output terminal of the peak reference circuit.

3. The voltage reference circuit according to claim 2, characterized in that, The negative subtractor includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a first comparator, and a second comparator, wherein... The positive input terminal of the first comparator is connected to the first terminal of the first capacitor and the first terminal of the first resistor through the second resistor. The positive input terminal of the first comparator is also grounded through the third resistor. The negative input terminal of the first comparator is connected to the output terminal of the second comparator through the sixth resistor. The negative input terminal of the first comparator is also connected to its output terminal through the seventh resistor. The output terminal of the first comparator is connected to the first input terminal of the first comparator sub-circuit. The positive input terminal of the second comparator is connected to the power supply voltage through the fourth resistor, and the positive input terminal of the second comparator is also grounded through the fifth resistor. The negative input terminal of the second comparator is connected to its output terminal. The second terminal of the first resistor is connected to the bus voltage; The second terminal of the first capacitor is grounded.

4. The voltage reference circuit according to claim 3, characterized in that, The first comparator circuit includes: a third comparator, a tenth resistor, and a first diode, wherein, The positive input terminal of the third comparator is connected to the output terminal of the negative subtractor, the negative input terminal of the third comparator is connected to the cathode of the first diode, and the output terminal of the third comparator is connected to the anode of the first diode through the tenth resistor. The cathode of the first diode is connected to the output of the second comparator circuit at a single point, and the output of the peak reference circuit is led out.

5. The voltage reference circuit according to claim 3, characterized in that, The second comparator circuit includes: a fourth comparator, an eighth resistor, a ninth resistor, an eleventh resistor, and a second diode, wherein, The positive input terminal of the fourth comparator is connected to the power supply voltage through the eighth resistor, and the positive input terminal of the fourth comparator is also grounded through the ninth resistor. The negative input terminal of the fourth comparator is connected to the cathode of the second diode, and the output terminal of the fourth comparator is connected to the anode of the second diode through the eleventh resistor. The cathode of the second diode is connected to the output of the first comparator circuit at a single point and leads out to the output of the peak reference circuit.

6. The voltage reference circuit according to claim 1, characterized in that, The trough reference circuit includes: a positive adder, a third comparator sub-circuit, and a fourth comparator sub-circuit, wherein... The first input terminal of the positive adder is connected to the bus voltage, the second input terminal of the positive adder is connected to the supply voltage, and the output terminal of the positive adder is connected to the input terminal of the third comparator circuit. The input terminal of the fourth comparator circuit is connected to the power supply voltage, and the output terminal of the fourth comparator circuit is connected to the output terminal of the third comparator circuit at a single point and leads out to the output terminal of the trough reference circuit.

7. The voltage reference circuit according to claim 6, characterized in that, The forward adder includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a second capacitor, a fifth comparator, and a sixth comparator, wherein... The positive input terminal of the fifth comparator is connected to the output terminal of the sixth comparator through the sixteenth resistor. The positive input terminal of the fifth comparator is grounded through the seventeenth resistor. The negative input terminal of the fifth comparator is connected to the first terminal of the twelfth resistor and the first terminal of the second capacitor through the thirteenth resistor. The negative input terminal of the fifth comparator is connected to its output terminal and the input terminal of the third comparator sub-circuit through the eighteenth resistor. The positive input terminal of the sixth comparator is connected to the power supply voltage through the fourteenth resistor, the positive input terminal of the sixth comparator is grounded through the fifteenth resistor, and the negative input terminal of the sixth comparator is connected to its output terminal. The second terminal of the twelfth resistor is connected to the bus voltage; The second terminal of the second capacitor is grounded.

8. The voltage reference circuit according to claim 6, characterized in that, The third comparator sub-circuit includes: a seventh comparator, a twenty-first resistor, a twenty-third resistor, a third diode, and a fourth diode, wherein... The positive input terminal of the seventh comparator is connected to the output terminal of the positive adder, the negative input terminal of the seventh comparator is connected to the cathode of the fourth diode, and the output terminal of the seventh comparator is connected to the cathode of the third diode and the anode of the fourth diode through the twenty-first resistor. The anode of the third diode is connected to the cathode of the fourth diode through the twenty-third resistor. The anode of the third diode is connected to the output terminal of the fourth comparator circuit at a single point and leads out to the output terminal of the trough reference circuit.

9. The voltage reference circuit according to claim 6, characterized in that, The fourth comparator sub-circuit includes: an eighth comparator, a nineteenth resistor, a twentieth resistor, a twenty-second resistor, a twenty-fourth resistor, a fifth diode, and a sixth diode, wherein... The positive input terminal of the eighth comparator is connected to the power supply voltage through the nineteenth resistor, and the positive input terminal of the eighth comparator is also grounded through the twentieth resistor. The negative input terminal of the eighth comparator is connected to the cathode of the sixth diode, and the output terminal of the eighth comparator is connected to the cathode of the fifth diode and the anode of the sixth diode through the twenty-second resistor. The anode of the fifth diode is connected to the cathode of the sixth diode through the twenty-fourth resistor. The anode of the fifth diode is connected to the output terminal of the third comparator circuit at a single point and leads out to the output terminal of the trough reference circuit.

10. An overcurrent protection circuit, characterized in that, include: The voltage reference circuit, positive comparator circuit, and negative comparator circuit according to any one of claims 1-9, wherein, The first input terminal of the peak reference circuit is connected to the bus voltage of the device to be protected, the second input terminal of the peak reference circuit is connected to the supply voltage, and the output terminal of the peak reference circuit is connected to the first input terminal of the positive comparator circuit. The peak reference circuit is used to adjust the peak reference voltage according to the bus voltage of the device to be protected. The first input terminal of the valley reference circuit is connected to the bus voltage of the device to be protected, the second input terminal of the valley reference circuit is connected to the supply voltage, and the output terminal of the valley reference circuit is connected to the first input terminal of the negative comparator circuit. The valley reference circuit is used to adjust the valley reference voltage according to the bus voltage of the device to be protected. The second input terminal of the positive comparator circuit is connected to the output voltage of the device to be protected. The positive comparator circuit is used to determine whether the output voltage of the device to be protected is overvoltage based on the peak reference voltage. The second input terminal of the negative comparison circuit is connected to the output voltage of the device to be protected, and the output terminal of the negative comparison circuit is connected to the output terminal of the positive comparison circuit. The negative comparison circuit is used to determine whether the output voltage of the device to be protected is overvoltage based on the trough reference voltage.

11. The overcurrent protection circuit according to claim 10, characterized in that, The forward comparator circuit includes: a 25th resistor, a 29th resistor, a 30th resistor, a 3rd capacitor, and a 9th comparator, wherein... The positive input terminal of the ninth comparator is connected to the output terminal of the peak reference circuit, and the negative input terminal of the ninth comparator is connected to the first terminal of the twenty-fifth resistor and the first terminal of the third capacitor; the output terminal of the ninth comparator is connected to its positive input terminal through the twenty-ninth resistor, and the output terminal of the ninth comparator is also connected to the power supply voltage through the thirtieth resistor; The second terminal of the 25th resistor is connected to the output voltage of the device to be protected; The second terminal of the third capacitor is grounded.

12. The overcurrent protection circuit according to claim 10, characterized in that, The negative comparator circuit includes: a 26th resistor, a 27th resistor, a 28th resistor, a 4th capacitor, and a 10th comparator, wherein... The positive input terminal of the tenth comparator is connected to the first terminal of the twenty-sixth resistor and the first terminal of the fourth capacitor through the twenty-seventh resistor. The positive input terminal of the tenth comparator is also connected to its output terminal and the output terminal of the positive comparator circuit through the twenty-eighth resistor. The negative input terminal of the tenth comparator is connected to the output terminal of the trough reference circuit. The second terminal of the 26th resistor is connected to the output voltage of the device to be protected; The second terminal of the fourth capacitor is grounded.

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