Overvoltage protection system and method

Abstract

Provided in the embodiments of the present application are an overvoltage protection system and method. The overvoltage protection system comprises a controller and an overvoltage protection circuit. The controller is configured to generate a control signal, the control signal being used for controlling the overvoltage protection circuit to work normally or stop working. The overvoltage protection circuit comprises: an input stage, which is configured to generate, on the basis of the control signal, a first voltage signal and a second voltage signal from a power supply voltage; a comparison stage, which is configured to compare the first voltage signal and the second voltage signal, and generate a comparison stage output signal on the basis of a comparison result; and an output stage, which is configured to generate an overvoltage protection circuit output signal on the basis of the comparison stage output signal.

Description

Overvoltage protection system and method Technical Field

[0001] The present application relates to the field of integrated circuits, and more particularly, to an overvoltage protection system and method. Background Art

[0002] With the rapid development of new energy vehicles, electric vehicles have become an inevitable trend in future development. However, the development of electric vehicles faces various challenges, such as damage to electronic components, explosion, or spontaneous combustion caused by power short circuits, overheating, or power overvoltage / overcurrent. Therefore, effective overvoltage protection is necessary. Currently, overvoltage protection is mainly implemented in two ways: one is a hardware protection solution, such as installing a hardware overvoltage protection circuit at the vehicle power supply end. The circuit uses the voltage at each input terminal of the comparator to make a judgment. When an overvoltage is determined, the output of the subsequent circuit is cut off through a control signal to achieve overvoltage protection of the circuit; the other is a software protection solution. By collecting the system voltage value and comparing it with a module equipped with software voltage detection, if the value exceeds the system-set threshold, the program enters a fault state through an interrupt, closes the corresponding port, and cuts off the output of the subsequent circuit.

[0003] However, in practical applications, software protection schemes require first collecting voltage values ​​and then making judgments through internal comparisons within the program. This can lead to damage to subsequent circuits due to a delayed response. Furthermore, the application of currently used hardware overvoltage protection circuits is limited because they require different voltage divider circuits, and the power supply can fluctuate, resulting in inaccurate standard voltage signals. Furthermore, with increasing demands for vehicle safety, circuit redundancy is required, increasing the cost of hardware overvoltage protection circuits. Therefore, a low-cost, efficient, and reliable overvoltage protection solution is needed.

[0004] Summary of the Invention

[0005] An embodiment of the present application provides an overvoltage protection system, comprising: a controller and an overvoltage protection circuit, wherein the controller is configured to generate a control signal, the control signal being used to control the overvoltage protection circuit to operate normally or stop operating; and wherein the overvoltage protection circuit comprises: an input stage, configured to generate a first voltage signal and a second voltage signal from a power supply voltage based on the control signal; a comparison stage, configured to compare the first voltage signal and the second voltage signal and generate a comparison stage output signal based on a result of the comparison; and an output stage, configured to generate an overvoltage protection circuit output signal based on the comparison stage output signal.

[0006] An embodiment of the present application also provides an overvoltage protection method, which is applied to an overvoltage protection system. The overvoltage protection system includes a controller and an overvoltage protection circuit. The overvoltage protection method includes: generating a control signal through the controller, the control signal is used to control the overvoltage protection circuit to work normally or stop working; generating a first voltage signal and a second voltage signal from the power supply voltage based on the control signal through the input stage of the overvoltage protection circuit; comparing the first voltage signal and the second voltage signal through the comparison stage of the overvoltage protection circuit and generating a comparison stage output signal based on the comparison result; and generating an overvoltage protection circuit output signal based on the comparison stage output signal through the output stage of the overvoltage protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly describes the drawings involved in the embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0008] FIG1 shows a schematic structural diagram of an overvoltage protection circuit;

[0009] FIG2 shows a schematic structural diagram of an overvoltage protection system according to an embodiment of the present application;

[0010] FIG3 shows another schematic structural diagram of an overvoltage protection system according to an embodiment of the present application;

[0011] FIG4 is a schematic diagram showing the interaction between a controller and an overvoltage protection circuit in an overvoltage protection system according to an embodiment of the present application; and

[0012] FIG5 shows a schematic flow chart of an overvoltage protection method according to an embodiment of the present application. DETAILED DESCRIPTION

[0013] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, scheme, and advantages of the present application clearer, the details of the present application are further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. For those skilled in the art, the present application can be implemented without some of the details in these specific details. The following description of the embodiments is only for providing a better understanding of the present application by illustrating the examples of the present application.

[0014] It should be noted that, in this article, relational terms such as first, second, third, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. In addition, the terms "comprise", "include" and any other variants thereof are intended to cover non-exclusive inclusion, and the process, method, article or equipment comprising a series of elements includes not only these elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "comprise..." do not exclude the presence of additional elements in the process, method, article or equipment comprising the elements.

[0015] With the rapid development of new energy vehicles, electric vehicles have become an inevitable trend in future development. However, the development of electric vehicles faces various challenges, such as damage to electronic components, explosion, or spontaneous combustion caused by power short circuits, overheating, or power overvoltage / overcurrent. Therefore, effective overvoltage protection is necessary. Overvoltage protection generally refers to a protection strategy that disconnects the power supply or reduces the voltage of the controlled circuit when the voltage of the protected circuit exceeds a predetermined maximum value, thereby ensuring the safety of circuit components.

[0016] At present, overvoltage protection is mainly achieved in two ways: one is a hardware protection solution, such as setting a hardware overvoltage protection circuit at the vehicle power supply end, using the voltage of each input terminal of the comparator for judgment, and when it is determined that overvoltage occurs, the output of the subsequent circuit is cut off through the control signal to achieve overvoltage protection of the circuit; the other is a software protection solution, by collecting the system voltage value and comparing it with a module with software voltage detection. When it exceeds the system-set threshold, the program enters a fault state through an interrupt, closes the corresponding port, and cuts off the output of the subsequent circuit.

[0017] FIG1 shows a schematic structural diagram of an overvoltage protection circuit in the prior art.

[0018] As shown in FIG1 , the overvoltage protection circuit includes a system power supply V_FLTR and a vehicle power supply V_FLTR_BATT, wherein the system power supply V_FLTR is used to power the overvoltage protection circuit.

[0019] The overvoltage protection circuit shown in Figure 1 also includes a comparator U1. The power supply input VCC and first input IN- of comparator U1 can be coupled to the system power supply V_FLTR via resistor R1. Furthermore, the second input IN+ of comparator U1 can be coupled to the vehicle power supply V_FLTR_BATT via a voltage divider circuit formed by resistors R6 and R4. As shown in Figure 1, the first end of resistor R6 can be coupled to the vehicle power supply V_FLTR_BATT, and the second end of resistor R6 can be coupled to the second input IN+ of comparator U1 and the first end of resistor R4. The second end of resistor R4 can be grounded. Furthermore, comparator U1 may include a ground terminal GND and an output terminal OUT.

[0020] As shown in Figure 1, the overvoltage protection circuit also includes a transistor Q1, which can be coupled to the output terminal OUT of the comparator U1 and can be coupled to the vehicle power supply V_FLTR_BATT via a voltage divider circuit composed of resistors R2 and R3. As shown in Figure 1, the first end of resistor R2 can be coupled to the vehicle power supply V_FLTR_BATT, and the second end of resistor R2 can be coupled to the transistor Q1 and the first end of resistor R3. The second end of resistor R3 can be used to generate an output signal of the overvoltage protection circuit, which is labeled PMIC_SS2 in Figure 1.

[0021] In the overvoltage protection circuit shown in FIG1 , the voltage values ​​VIN- and VIN+ at the first input terminal IN- and the second input terminal IN+ of the comparator U1 can be calculated by the following equations: VIN-=V_FLTR (1)

[0022] In addition, as shown in FIG1 , the power supply input terminal VCC and the first input terminal IN− of the comparator U1 are coupled to each other, so the voltage value of the power supply input terminal VCC may be equal to the voltage value VIN− of the first input terminal IN−.

[0023] When the system is operating normally, the voltage VIN- at the first input terminal IN- of comparator U1 is greater than the voltage VIN+ at the second input terminal IN+. Comparator U1 then outputs a low-level signal. This low-level signal turns off transistor Q1, and the output signal PMIC_SS2 is high and input to the system, enabling the system's subsequent circuits to operate normally.

[0024] When an overvoltage occurs in the system, the voltage VIN- at the first input terminal IN- of comparator U1 is lower than the voltage VIN+ at the second input terminal IN+. Comparator U1 then outputs a high-level signal. Transistor Q1, under the control of the high-level signal output by comparator U1, saturates and conducts. As a result, the output signal PMIC_SS2 is low and input to the system, shutting down the system's downstream circuits.

[0025] The overvoltage protection circuit shown in Figure 1 has some drawbacks. For example, a system power supply V_FLTR dedicated to powering the overvoltage protection circuit is required. This system power supply V_FLTR is also used to generate the voltage VIN- at the first input terminal IN- of comparator U1. This voltage VIN- is the standard voltage used for comparison. Therefore, it is necessary to ensure that the system power supply V_FLTR does not fluctuate significantly. Otherwise, the standard voltage value may deviate, resulting in inaccurate judgment of system overvoltage. Furthermore, resistors R6 and R4 must be appropriately set to ensure that the voltage VIN+ at the second input terminal IN+ of comparator U1 is less than the voltage VIN- at the first input terminal IN- during normal system operation. Therefore, the application of the overvoltage protection circuit shown in Figure 1 is limited.

[0026] In addition, as mentioned above, software protection solutions can also be used for overvoltage protection. For example, a microcontroller unit (MCU) can be used to collect system voltage values ​​and compare them with a module equipped with software voltage detection. When the collected system voltage value exceeds the system-set threshold, the program enters a fault state through an interrupt, shuts down the corresponding port, and cuts off the output of the subsequent circuit. This software protection solution utilizes the comparator within the MCU to implement overvoltage protection. However, since the MCU takes a certain amount of time to collect the voltage signal, perform the comparison to determine whether an overvoltage has occurred, and initiate the interrupt, the overvoltage protection response time is too long, and there is a risk of untimely shutdown.

[0027] To address the above issues, embodiments of the present application provide an overvoltage protection system that combines hardware and software protection solutions. The overvoltage protection system of the present application can address the limited application of existing overvoltage protection circuits. Furthermore, if software overvoltage protection fails or exceeds the overvoltage specified in relevant standards and cannot provide effective protection, the hardware overvoltage protection circuit can be used to implement multiple overvoltage protections, preventing overvoltage protection failures caused by single-point failures and improving the reliability of overvoltage protection.

[0028] The embodiments of the present application will now be described with reference to the accompanying drawings. Please refer to Figures 2 and 3 , wherein Figure 2 shows a schematic structural diagram of an overvoltage protection system 100 according to an embodiment of the present application, and Figure 3 shows another schematic structural diagram of an overvoltage protection system 100 according to an embodiment of the present application.

[0029] As shown in FIG2 , in some embodiments, an overvoltage protection system 100 according to an embodiment of the present application may include a controller 110 and an overvoltage protection circuit 120. In some embodiments, the controller 110 may be configured to generate a control signal, and the control signal may be used to control the overvoltage protection circuit 120 to operate normally or stop operating. As shown in FIG2 , in some embodiments, the overvoltage protection circuit 120 may include: an input stage 121 configured to generate a first voltage signal and a second voltage signal from a power supply voltage based on the control signal; a comparison stage 122 configured to compare the first voltage signal and the second voltage signal and generate a comparison stage output signal based on the comparison result; and an output stage 123 configured to generate an overvoltage protection circuit output signal based on the comparison stage output signal.

[0030] In some embodiments, the controller 110 may be further configured to: sample the power supply voltage to generate a sampled value of the power supply voltage, and compare the sampled value of the power supply voltage with a set threshold value to generate a control signal. In some embodiments, for example, when the sampled value of the power supply voltage is lower than the set threshold value, the control signal may be used to control the overvoltage protection circuit 120 to operate normally; when the sampled value of the power supply voltage is higher than the set threshold value, the control signal may be used to control the overvoltage protection circuit 120 to stop operating, and the overvoltage protection system 100 enters an overvoltage fault state through the control signal.

[0031] As shown in Figure 3, in some embodiments, the overvoltage protection system 100 according to an embodiment of the present application may include a power supply voltage V_FLTR_BATT (similar to the vehicle power supply V_FLTR_BATT shown in Figure 1), and the controller 110 may include a microcontroller unit (MCU) or other similar controller.

[0032] In some embodiments, for example, a microcontroller unit (MCU) can be coupled to a power supply voltage V_FLTR_BATT via a voltage divider circuit composed of resistors R9 and R10, and can be configured to sample the power supply voltage V_FLTR_BATT to generate a sampled value of the power supply voltage, which is shown as V_FLTR_BATT_AD in FIG3 . As shown in FIG3 , a first end of resistor R9 can be coupled to the power supply voltage V_FLTR_BATT, a second end of resistor R9 can be coupled to a first end of resistor R10, and a second end of resistor R10 can be grounded. Specifically, the sampled value V_FLTR_BATT_AD of the power supply voltage V_FLTR_BATT can be extracted between resistors R9 and R10.

[0033] In addition, the microcontroller unit (MCU) can be configured to generate the above-mentioned control signal (shown as Enable in FIG3 ) to control the overvoltage protection circuit 120 to operate normally or stop operating. In some embodiments, for example, when the sampled value V_FLTR_BATT_AD of the power supply voltage V_FLTR_BATT is lower than the set threshold, it is determined that no overvoltage has occurred, and the microcontroller unit (MCU) can generate a low-level signal as the control signal Enable, and the low-level control signal Enable can be used to control the overvoltage protection circuit 120 to operate normally; when the sampled value V_FLTR_BATT_AD of the power supply voltage V_FLTR_BATT is higher than the set threshold, it is determined that an overvoltage has occurred, and the microcontroller unit (MCU) can generate a high-level signal as the control signal Enable, and the high-level control signal Enable can be used to control the overvoltage protection circuit 120 to stop operating, and the overvoltage protection system 100 can enter the overvoltage fault state through the high-level control signal Enable.

[0034] In some embodiments, as shown in Figures 2 and 3, the input stage 121 of the overvoltage protection circuit 120 can be configured to generate a first voltage signal VIN- and a second voltage signal VIN+ from a power supply voltage V_FLTR_BATT based on a control signal Enable. As shown in Figure 3, the input stage 121 can include a first transistor Q1 and a voltage regulation module. The first transistor Q1 can be coupled to the power supply voltage V_FLTR_BATT and turned on or off under the control of the control signal Enable generated by a microcontroller unit (MCU), and the voltage regulation module can be coupled to the first transistor Q1.

[0035] In the present application, the type of the first transistor Q1 can be determined according to the specific design requirements of the system and is not limited here. In some embodiments, for example, the first transistor Q1 can be a PNP type transistor. In this case, as shown in Figure 3, the base of the first transistor Q1 can be coupled to the control signal Enable via the resistor R6, the emitter of the first transistor Q1 can be coupled to the power supply voltage V_FLTR_BATT, and the collector of the first transistor Q1 can be coupled to the voltage stabilization module. For example, when the control signal Enable is at a low level, the first transistor Q1 can be reversely saturated and turned on to supply power to the comparison stage 122 of the overvoltage protection circuit 120, so that the comparison stage 122 works. When the control signal Enable is at a high level, the first transistor Q1 is turned off, and the comparison stage 122 does not work.

[0036] In some embodiments, the voltage stabilization module may include a Zener diode D1, the cathode of which may be coupled to the first transistor Q1. Specifically, as shown in FIG3 , the cathode of the Zener diode D1 may be coupled to the collector of the first transistor Q1. In some embodiments, the voltage stabilization module may further include a first capacitor C1. As shown in FIG3 , the first end of the first capacitor C1 may be coupled to the cathode of the Zener diode D1, and the second end of the first capacitor C1 may be coupled to the anode of the Zener diode D1. For example, the first capacitor C1 may be used to absorb a reverse spike voltage of the Zener diode D1.

[0037] In some embodiments, as shown in Figures 2 and 3 , the comparison stage 122 of the overvoltage protection circuit 120 can be configured to compare a first voltage signal VIN- with a second voltage signal VIN+ and generate a comparison stage output signal based on the comparison result. This comparison stage output signal is shown as OUT in Figure 3 . As shown in Figure 3 , the comparison stage 122 may include a comparator U1. The comparator U1 may include a first input terminal IN- for receiving the first voltage signal VIN- and a second input terminal IN+ for receiving the second voltage signal VIN+. The comparator U1 may be configured to generate a low-level signal as the comparison stage output signal OUT when the voltage value of the first voltage signal VIN- is greater than the voltage value of the second voltage signal VIN+; and to generate a high-level signal as the comparison stage output signal OUT when the voltage value of the first voltage signal VIN- is less than the voltage value of the second voltage signal VIN+. Furthermore, the comparator U1 may also include a ground terminal GND.

[0038] In some embodiments, as shown in FIG3 , the first input terminal IN- of the comparator U1 of the overvoltage protection circuit 120 can be coupled to the first transistor Q1 and the voltage regulator module D1 via a first voltage divider circuit, wherein the first voltage divider circuit may include a first resistor R1 and a second resistor R3. The first end of the first resistor R1 can be coupled to the first transistor Q1 and the voltage regulator module D1, the second end of the first resistor R1 can be coupled to the first input terminal IN- of the comparator U1 and the first end of the second resistor R3, and the second end of the second resistor R3 can be grounded. Specifically, as shown in FIG3 , the first end of the first resistor R1 can be coupled to the collector of the first transistor Q1 and the cathode of the voltage regulator diode D1.

[0039] In some embodiments, as shown in FIG3 , the second input terminal IN+ of the comparator U1 of the overvoltage protection circuit 120 can be coupled to the voltage stabilization module via a second voltage divider circuit, wherein the second voltage divider circuit may include a third resistor R7 and a fourth resistor R4. A first end of the third resistor R7 can be coupled to the voltage stabilization module D1, a second end of the third resistor R7 can be coupled to the second input terminal IN+ of the comparator U1 and a first end of the fourth resistor R4, and a second end of the fourth resistor R4 can be grounded. Specifically, as shown in FIG3 , the first end of the third resistor R7 can be coupled to the anode of the voltage stabilization diode D1.

[0040] In some embodiments, the power supply input terminal VCC of the comparator U1 of the overvoltage protection circuit 120 can also be coupled to the first transistor Q1 and the voltage regulator module. Specifically, as shown in FIG3 , the power supply input terminal VCC of the comparator U1 can be coupled to the collector of the first transistor Q1 and the cathode of the voltage regulator diode D1.

[0041] In some embodiments, assuming that the turn-on voltage of the first transistor Q1 is VQ1 and the stable voltage value of the Zener diode D1 is VD1, the voltage values ​​of the first voltage signal VIN- and the second voltage signal VIN+ can be calculated by the following equations:

[0042] In addition, the voltage value of the power supply input terminal VCC of the comparator U1 of the overvoltage protection circuit 120 can be calculated by the following equation: VCC=V_FLTR_BATT-VQ1 (5)

[0043] When the system is operating normally, no overvoltage occurs, and the overvoltage protection circuit 120 operates normally under the control of the low-level control signal Enable generated by the microcontroller unit (MCU). At this time, the first transistor Q1 is reverse saturated and turned on, supplying power to the comparator U1 to enable the comparator U1 to operate. The voltage value of the first voltage signal VIN- can be calculated by the above equation (3). Since V_FLTR_BATT-VQ1 is less than the stable voltage value VD1 of the Zener diode D1, the Zener diode D1 is not turned on, and the voltage value of the second voltage signal VIN+ is zero, as shown in the first case in the above equation (4). In this case, the voltage value of the first voltage signal VIN- is greater than the voltage value of the second voltage signal VIN+, and the comparator U1 generates a low-level signal as the comparison stage output signal OUT.

[0044] When overvoltage protection circuit 120 is operating normally and the system experiences an overvoltage, the power supply voltage V_FLTR_BATT is large, causing V_FLTR_BATT-VQ1 to be greater than the stable voltage VD1 of Zener diode D1. Zener diode D1 then conducts. At this point, the voltage value of second voltage signal VIN+ is calculated according to the second case in equation (4), while the voltage value of first voltage signal VIN- is still calculated according to equation (3). In this case, the voltage value of first voltage signal VIN- is less than the voltage value of second voltage signal VIN+, and comparator U1 generates a high-level signal as comparison stage output signal OUT.

[0045] Please note that when the overvoltage protection circuit 120 is operating normally, the controller 110 may still sample the power supply voltage V_FLTR_BATT and compare the sampled value V_FLTR_BATT_AD with a set threshold, as described above. For example, if a system overvoltage occurs and the power supply voltage V_FLTR_BATT is relatively high, the sampled value V_FLTR_BATT_AD may be higher than the set threshold. In this case, the controller 110 may also generate a high-level control signal Enable, causing the overvoltage protection system 100 to enter an overvoltage fault state.

[0046] In some embodiments, as shown in Figures 2 and 3 , the output stage 123 of the overvoltage protection circuit 120 can be configured to generate an overvoltage protection circuit output signal based on the comparison stage output signal OUT. This overvoltage protection circuit output signal is shown as PMIC_SS2 in Figure 3 . In some embodiments, as shown in Figure 3 , the output stage 123 can include a second transistor Q2 , which can be coupled to the comparison stage 122 and coupled to the power supply voltage V_FLTR_BATT via a third voltage divider circuit. As shown in Figure 3 , the third voltage divider circuit can include a fifth resistor R2 and a sixth resistor R5 . A first end of the fifth resistor R2 can be coupled to the power supply voltage V_FLTR_BATT, a second end of the fifth resistor R2 can be coupled to the second transistor Q2 and the first end of the sixth resistor R5 , and a second end of the sixth resistor R5 can be used to output the overvoltage protection circuit output signal PMIC_SS2 .

[0047] In the present application, the type of the second transistor Q2 can be determined based on the specific design requirements of the system and is not limited here. In some embodiments, for example, the first transistor Q2 can be an NPN transistor. In this case, as shown in FIG3 , the base of the second transistor Q2 can be coupled to the comparison output signal OUT generated by the comparator U1, the collector of the second transistor Q2 can be coupled to the power supply voltage V_FLTR_BATT via the third voltage divider circuit, and the emitter of the second transistor Q2 can be grounded.

[0048] In some embodiments, as shown in Figures 2 and 3, the output stage 123 of the overvoltage protection circuit 120 can also be configured to: when the comparison stage output signal OUT is a low level signal, generate a high level signal as the overvoltage protection circuit output signal PMIC_SS2; and when the comparison stage output signal OUT is a high level signal, generate a low level signal as the overvoltage protection circuit output signal PMIC_SS2.

[0049] When the system is operating normally, the comparator U1 generates a low-level signal as the comparison-level output signal OUT, and as shown in FIG3 , the base of the second transistor Q2 is coupled to the comparison-level output signal OUT, and the second transistor Q2 is turned off under the control of the low-level comparison-level output signal OUT. At this time, the output stage 123 generates a high-level overvoltage protection circuit output signal PMIC_SS2, so that the subsequent circuits of the system operate normally; when an overvoltage occurs in the system, the comparator U1 generates a high-level signal as the comparison-level output signal OUT, and the second transistor Q2 is saturated and turned on under the control of the high-level comparison-level output signal OUT. At this time, the output stage 123 generates a low-level overvoltage protection circuit output signal PMIC_SS2, so that the subsequent circuits of the system are cut off.

[0050] Those skilled in the art should understand that although the various modules included in the overvoltage protection system 100 according to the embodiment of the present application are shown in dotted boxes in FIG3, this is only schematic, and these dotted boxes do not limit the specific structure of each module. For example, the first voltage divider circuit and the second voltage divider circuit can be regarded as part of the input stage or as part of the comparison stage. In addition, for example, the overvoltage protection circuit 120 may also include a resistor R8, as shown in FIG3, the resistor R8 can be used as a feedback resistor to prevent circuit oscillation, and the resistor R8 can be coupled between the second voltage divider circuit and the comparison stage output signal OUT. In addition, it should be understood that the resistance value of each resistor included in the overvoltage protection system 100 can be set according to the specific design requirements of the system and is not limited here.

[0051] As described above, the overvoltage protection system 100 according to an embodiment of the present application includes a controller 110 and an overvoltage protection circuit 120. The controller 110 is capable of sampling the power supply voltage V_FLTR_BATT and determining whether an overvoltage has occurred by comparing the sampled value V_FLTR_BATT_AD of the power supply voltage V_FLTR_BATT with a set threshold. If an overvoltage has occurred, a control signal generated by the controller 110 causes the overvoltage protection circuit 120 to stop operating, and the overvoltage protection system 100 enters an overvoltage fault state through the control signal. If an overvoltage has not occurred, a control signal generated by the controller 110 causes the overvoltage protection circuit 120 to operate normally. Furthermore, when the overvoltage protection circuit 120 is operating normally, a comparator U1 in the overvoltage protection circuit 120 is used to determine whether an overvoltage has occurred, and if an overvoltage has occurred, the subsequent circuits of the system are disconnected.

[0052] FIG4 is a schematic diagram illustrating the interaction between the controller 110 and the overvoltage protection circuit 120 in the overvoltage protection system 100 according to an embodiment of the present application. It should be understood that FIG4 merely briefly illustrates the interaction between the controller 110 and the overvoltage protection circuit 120. For details, please refer to the above description of the embodiment of the present application.

[0053] According to the overvoltage protection system 100 of the embodiment of the present application, multiple overvoltage protections are achieved through the controller 110 and the overvoltage protection circuit 120. On the one hand, the overvoltage protection system 100 of the present application can perform software overvoltage protection through the controller 110. On the other hand, the overvoltage protection circuit 120 therein does not need to set up a separate system power supply. The standard voltage for comparison can be obtained through the vehicle power supply. Therefore, it is only necessary to adjust the withstand voltage value of the voltage regulator diode D1 to achieve overvoltage protection for different circuits. Therefore, according to the overvoltage protection system 100 of the embodiment of the present application, a hardware protection solution and a software protection solution are provided, which solves the problem of limited application of existing overvoltage protection circuits. In addition, when the software overvoltage protection fails or exceeds the overvoltage specified by the relevant standards and cannot provide effective protection, the hardware overvoltage protection circuit can be used to achieve multiple overvoltage protections, thereby preventing the failure of overvoltage protection caused by a single point fault and improving the reliability of overvoltage protection.

[0054] FIG5 shows a schematic flow chart of an overvoltage protection method 200 according to an embodiment of the present application. The overvoltage protection method 200 according to an embodiment of the present application can be applied to the overvoltage protection system 100 described above, and the overvoltage protection system 100 can include the controller 110 and the overvoltage protection circuit 120 described above. Specific details of the overvoltage protection system 100 can be found in the above description and will not be repeated here.

[0055] As shown in FIG5 , the overvoltage protection method 200 according to an embodiment of the present application may include the following steps:

[0056] Step S201: Generate a control signal through a controller, where the control signal is used to control the overvoltage protection circuit to work normally or stop working;

[0057] Step S202: generating a first voltage signal and a second voltage signal from a power supply voltage based on a control signal through an input stage of the overvoltage protection circuit;

[0058] Step S203: comparing the first voltage signal and the second voltage signal through a comparison stage of the overvoltage protection circuit and generating a comparison stage output signal based on a result of the comparison; and

[0059] Step S204 : generating an overvoltage protection circuit output signal based on the comparison stage output signal by the output stage of the overvoltage protection circuit.

[0060] In some embodiments, the overvoltage protection method 200 according to an embodiment of the present application further includes: sampling the power supply voltage V_FLTR_BATT via the controller 110 to generate a sampled value V_FLTR_BATT_AD of the power supply voltage V_FLTR_BATT, and comparing the sampled value V_FLTR_BATT_AD with a set threshold to generate a control signal Enable. In some embodiments, for example, when the sampled value V_FLTR_BATT_AD of the power supply voltage is lower than the set threshold, the control signal Enable can be used to control the overvoltage protection circuit 120 to operate normally; when the sampled value V_FLTR_BATT_AD of the power supply voltage is higher than the set threshold, the control signal Enable can be used to control the overvoltage protection circuit 120 to stop operating, and the overvoltage protection system 100 enters an overvoltage fault state via the control signal.

[0061] In some embodiments, the calculation of the first voltage signal VIN- and the second voltage signal VIN+ can refer to the above equations (3) and (4), and the overvoltage protection method 200 according to the embodiment of the present application also includes: when the voltage value of the first voltage signal VIN- is greater than the voltage value of the second voltage signal VIN+, a low-level signal is generated as the comparison level output signal OUT through the comparison level 122 of the overvoltage protection circuit 120; and when the voltage value of the first voltage signal VIN- is less than the voltage value of the second voltage signal VIN+, a high-level signal is generated as the comparison level output signal OUT through the comparison level 122 of the overvoltage protection circuit 120.

[0062] In some embodiments, the overvoltage protection method 200 according to the embodiment of the present application also includes: when the comparison level output signal OUT is a low-level signal, a high-level signal is generated through the output stage 123 of the over-protection circuit 120 as the overvoltage protection circuit output signal PMIC_SS2, so that the subsequent circuit operates normally; and when the comparison level output signal OUT is a high-level signal, a low-level signal is generated through the output stage 123 of the overvoltage protection circuit 120 as the overvoltage protection circuit output signal PMIC_SS2, so that the subsequent circuit is cut off.

[0063] According to the overvoltage protection method 200 of the embodiment of the present application, multiple overvoltage protection is achieved through the controller 110 and the overvoltage protection circuit 120. On the one hand, the overvoltage protection method 200 of the present application can perform software overvoltage protection through the controller 110. On the other hand, the overvoltage protection circuit 120 therein does not need to set up a separate system power supply. The standard voltage for comparison can be obtained through the vehicle power supply. Therefore, it is only necessary to adjust the withstand voltage value of the voltage regulator diode D1 to achieve overvoltage protection for different circuits. Therefore, according to the overvoltage protection method 200 of the embodiment of the present application, an overvoltage protection solution that combines hardware protection solutions and software protection solutions is provided, which solves the problem of limited application of existing overvoltage protection circuits, and can also use hardware overvoltage protection circuits to achieve multiple overvoltage protection when the software overvoltage protection fails or exceeds the overvoltage specified by the relevant standards and cannot effectively protect, thereby preventing the failure of overvoltage protection caused by single-point failure and improving the reliability of overvoltage protection.

[0064] Those skilled in the art will understand that the present application is not limited to the specific structures and steps described above and shown in the accompanying drawings. For the sake of simplicity, the description of known structures and methods is omitted herein. In the above embodiments, several specific steps are described and shown as examples. However, the method of the present application is not limited to the specific steps described and shown, and without departing from the scope of the present application, those skilled in the art can make various changes, modifications and additions to the embodiments of the present application, or change the order between the steps.

[0065] The functional blocks shown in the above structured block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, the functional blocks can be, for example, electronic circuits, application specific integrated circuits (ASICs), suitable firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. These programs or code segments can be stored in machine-readable media, or transmitted on a transmission medium or communication link via a data signal carried in a carrier wave. Machine-readable media can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0066] The above disclosures are only some specific implementation methods of the present application. Those skilled in the art will understand that for the convenience and brevity of description, the specific working processes of the above systems, modules and units can refer to the corresponding processes in the method embodiments, and will not be repeated here. In addition, it should be understood that the scope of protection of the present application is not limited thereto. Those skilled in the art can think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these equivalent modifications or replacements are all covered by the scope of protection of the present application.

Claims

1. An overvoltage protection system, comprising: controller and overvoltage protection circuit, Wherein, the controller is configured to generate a control signal, and the control signal is used to control the overvoltage protection circuit to work normally or stop working; and Wherein, the overvoltage protection circuit comprises: an input stage configured to generate a first voltage signal and a second voltage signal from a power supply voltage based on the control signal; a comparison stage configured to compare the first voltage signal and the second voltage signal and generate a comparison stage output signal based on a result of the comparison; and The output stage is configured to generate an overvoltage protection circuit output signal based on the comparison stage output signal.

2. The overvoltage protection system according to claim 1, wherein: The controller is further configured to: sample the power supply voltage to generate a sampled value of the power supply voltage, and compare the sampled value of the power supply voltage with a set threshold to generate the control signal.

3. The overvoltage protection system according to claim 2, wherein: When the sampled value of the power supply voltage is lower than the set threshold, the control signal is used to control the overvoltage protection circuit to operate normally.

4. The overvoltage protection system according to claim 2, wherein: When the sampled value of the power supply voltage is higher than the set threshold, the control signal is used to control the overvoltage protection circuit to stop working.

5. The overvoltage protection system according to any one of claims 1 to 4, wherein: The input stage includes a first transistor and a voltage regulation module, the first transistor is coupled to the power supply voltage and is turned on or off under the control of the control signal, and the voltage regulation module is coupled to the first transistor.

6. The overvoltage protection system according to claim 5, wherein: The comparison stage comprises a comparator, the comparator comprises a first input terminal for receiving the first voltage signal and a second input terminal for receiving the second voltage signal, and the comparator is configured as follows: When the voltage value of the first voltage signal is greater than the voltage value of the second voltage signal, generating a low level signal as the comparison stage output signal; and When the voltage value of the first voltage signal is smaller than the voltage value of the second voltage signal, a high level signal is generated as the comparison stage output signal.

7. The overvoltage protection system according to claim 6, wherein: The first input terminal of the comparator is coupled to the first transistor and the voltage stabilizing module through a first voltage divider circuit, and The first voltage divider circuit includes a first resistor and a second resistor, the first end of the first resistor is coupled to the first transistor and the voltage stabilizing module, the second end of the first resistor is coupled to the first input end of the comparator and the first end of the second resistor, and the second end of the second resistor is grounded.

8. The overvoltage protection system according to claim 6 or 7, wherein: The second input terminal of the comparator is coupled to the voltage stabilizing module through a second voltage divider circuit, and The second voltage divider circuit includes a third resistor and a fourth resistor, a first end of the third resistor is coupled to the voltage stabilizing module, a second end of the third resistor is coupled to the second input end of the comparator and a first end of the fourth resistor, and a second end of the fourth resistor is grounded.

9. The overvoltage protection system according to claim 5, wherein: The voltage stabilizing module includes a voltage stabilizing diode.

10. The overvoltage protection system according to claim 9, wherein: The voltage stabilizing module further includes a first capacitor, a first end of the first capacitor is coupled to the cathode of the voltage stabilizing diode, and a second end of the first capacitor is coupled to the anode of the voltage stabilizing diode.

11. The overvoltage protection system according to claim 6, wherein: The output stage is also configured as: When the comparison stage output signal is a low level signal, generating a high level signal as the overvoltage protection circuit output signal; and When the comparison stage output signal is a high level signal, a low level signal is generated as the overvoltage protection circuit output signal.

12. The overvoltage protection system according to claim 1, wherein: The output stage includes a second transistor coupled to the comparison stage and coupled to the supply voltage via a third voltage divider circuit.

13. The overvoltage protection system according to claim 12, wherein: The third voltage-dividing circuit includes a fifth resistor and a sixth resistor, the first end of the fifth resistor is coupled to the power supply voltage, the second end of the fifth resistor is coupled to the second transistor and the first end of the sixth resistor, and the second end of the sixth resistor is used to output the overvoltage protection circuit output signal.

14. An overvoltage protection method, applied to an overvoltage protection system, the overvoltage protection system comprising a controller and an overvoltage protection circuit, the overvoltage protection method comprising: Generate a control signal through the controller, wherein the control signal is used to control the overvoltage protection circuit to work normally or stop working; generating a first voltage signal and a second voltage signal from a power supply voltage based on the control signal through an input stage of the overvoltage protection circuit; comparing the first voltage signal and the second voltage signal by a comparison stage of the overvoltage protection circuit and generating a comparison stage output signal based on a result of the comparison; as well as An overvoltage protection circuit output signal is generated by the output stage of the overvoltage protection circuit based on the comparison stage output signal.

15. The overvoltage protection method according to claim 14, further comprising: The controller samples the power supply voltage to generate a sampled value of the power supply voltage, and compares the sampled value of the power supply voltage with a set threshold to generate the control signal.

16. The overvoltage protection method according to claim 15, wherein: When the sampled value of the power supply voltage is lower than the set threshold, the control signal is used to control the overvoltage protection circuit to operate normally.

17. The overvoltage protection method according to claim 15 or 16, wherein: When the sampled value of the power supply voltage is higher than the set threshold, the control signal is used to control the overvoltage protection circuit to stop working.

18. The overvoltage protection method according to claim 14, further comprising: When the voltage value of the first voltage signal is greater than the voltage value of the second voltage signal, a low level signal is generated as the comparison stage output signal through the comparison stage of the overvoltage protection circuit; as well as When the voltage value of the first voltage signal is less than the voltage value of the second voltage signal, a high level signal is generated by the comparison stage of the overvoltage protection circuit as the comparison stage output signal.

19. The overvoltage protection method according to claim 18, further comprising: When the comparison stage output signal is a low level signal, a high level signal is generated through the output stage of the over-protection circuit as the over-voltage protection circuit output signal; as well as When the comparison stage output signal is a high level signal, a low level signal is generated through the output stage of the over-protection circuit as the over-voltage protection circuit output signal.

Images