Intelligent power module and overcurrent detection circuit thereof and household appliance

Abstract

The application discloses an intelligent power module, an overcurrent detection circuit thereof and household electrical appliances, wherein the overcurrent detection circuit comprises an overcurrent detection unit, which is used for outputting an overcurrent detection signal when detecting that overcurrent occurs in the intelligent power module; a filtering unit, which is connected with the overcurrent detection unit and is used for filtering out interference signals in the overcurrent detection signal; and an anti-interference enhancement unit, which is connected with the filtering unit, is used for generating an anti-interference enhancement signal according to an upper tube switch action interval and / or a lower tube switch action interval of the intelligent power module, and is used for improving the filtering interference ability of the filtering unit according to the anti-interference enhancement signal. Thus, the overcurrent detection circuit of the intelligent power module of the embodiment can sufficiently improve the stability of overcurrent detection, effectively reduces the probability of faults caused by false triggering in overcurrent detection, and guarantees the overcurrent detection sensitivity under normal interference conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of detection circuit, in particular to an overcurrent detection circuit of an intelligent power module, an intelligent power module and a household appliance. BACKGROUND

[0002] The intelligent power module is an advanced power switching device, which is essentially a module integrating power devices and driving circuit chips, mainly realizing power conversion, real-time protection and communication functions. The intelligent power module can play an important role in the field of energy management that other integrated circuits cannot achieve, and the performance of the device can directly affect the utilization efficiency of the energy system, and the overcurrent detection performance is one of the parameters that reflect the performance of the device.

[0003] In the related art, the overcurrent detection is generally to compare the sampling current through the comparator first, if the sampling current is greater than the protection threshold, the current is transmitted to the filter circuit to filter out noise and other interference, usually a filter time is set, if the pulse width of the sampling current greater than the protection threshold is less than the filter time, it is filtered out and normal work is maintained, if the pulse width of the sampling current greater than the protection threshold is greater than the filter time, it is not filtered out, then the output end changes logic, and then the chip in the intelligent power module stops working to protect the intelligent power module.

[0004] However, in the related art, at the moment of opening or closing of the power device, the current will oscillate, so the current sampling signal will also oscillate, and the change of the current sampling signal is easy to cause the output end of the detection circuit to be mis-triggered, which may cause the entire system (such as air conditioner, washing machine, etc.) to stop. Taking a three-phase six-way inverter module as an example, the interval of the switching signals of different phases is variable, if the interval of the switching signals of two upper bridges or lower bridges is small, the interval of the switching of the corresponding two power devices will be small, which will easily cause the current oscillation to be intensified, and thus the current sampling signal will also be intensified, thereby increasing the probability of mis-triggering of the output end of the detection circuit. SUMMARY

[0005] The present application aims to at least solve one of the technical problems in the related art. To this end, one object of the present application is to provide an overcurrent detection circuit of an intelligent power module, which can sufficiently improve the stability of overcurrent detection, effectively reduce the probability of failure caused by mis-triggering in overcurrent detection, and at the same time ensure the overcurrent detection sensitivity under normal interference conditions.

[0006] A second object of the present application is to provide an intelligent power module.

[0007] A third object of the present application is to provide a household appliance.

[0008] To achieve the above object, the first aspect of the present application provides an overcurrent detection circuit of an intelligent power module, which comprises an overcurrent detection unit configured to output an overcurrent detection signal when detecting overcurrent of the intelligent power module; a filter unit connected with the overcurrent detection unit and configured to filter out interference signals in the overcurrent detection signal; and an anti-interference enhancement unit connected with the filter unit and configured to generate an anti-interference enhancement signal according to an upper tube switching action interval and / or a lower tube switching action interval of the intelligent power module, and to enhance the interference filtering capability of the filter unit according to the anti-interference enhancement signal.

[0009] The overcurrent detection circuit of the intelligent power module comprises the overcurrent detection unit, the filter unit and the anti-interference enhancement unit. Firstly, the overcurrent detection unit detects the sampling current of the intelligent power module and outputs an overcurrent detection signal when detecting overcurrent of the intelligent power module. Then, the filter unit receives the overcurrent detection signal and filters out interference signals in the overcurrent detection signal. The anti-interference enhancement unit is connected with the filter unit and generates an anti-interference enhancement signal according to the control signal of the intelligent power module. The interference filtering capability of the filter unit can be enhanced according to the anti-interference enhancement signal. Thus, the overcurrent detection circuit of the intelligent power module can improve the stability of overcurrent detection, effectively reduce the probability of malfunction caused by false triggering in overcurrent detection, and ensure the overcurrent detection sensitivity under normal interference conditions.

[0010] In some embodiments of the present application, the filter unit comprises a first filter part and a second filter part. The first filter part is configured to filter out interference signals in the overcurrent detection signal when the filter unit does not receive the anti-interference enhancement signal. The second filter part is configured to filter out interference signals in the overcurrent detection signal together with the first filter part when the filter unit receives the anti-interference enhancement signal.

[0011] In some embodiments of the present application, the first filter part comprises a first filter resistor, one end of which is connected with an output end of the overcurrent detection unit; and a first filter capacitor, one end of which is connected with the other end of the first filter resistor and has a first node, and the other end of which is grounded, the first node being connected with the second filter part.

[0012] In some embodiments of the present application, the second filter part comprises a first transmission gate, one end of which is connected with the first node, and an enable end of which is connected with an output end of the anti-interference enhancement unit; and a second filter capacitor, one end of which is connected with the other end of the first transmission gate, and the other end of which is grounded.

[0013] In some embodiments of the present application, the anti-interference enhancement unit controls the first transmission gate to be turned on when the interval of the upper switch signal and / or the interval of the lower switch signal of any two-phase bridge arm of the three-phase bridge arm of the smart power module is less than the first preset interval, so that the first filter capacitor and the second filter capacitor work in parallel.

[0014] In some embodiments of the present application, the anti-interference enhancement unit comprises a first edge interval detection sub-circuit, the output end of the first edge interval detection sub-circuit serving as the output end of the anti-interference enhancement unit, for simultaneously detecting the six-way switch tube control signals of the smart power module, and outputting an enable signal to the first transmission gate when the interval of the upper switch signal and / or the interval of the lower switch signal is less than the first preset interval.

[0015] In some embodiments of the present application, the anti-interference enhancement unit comprises a second edge interval detection sub-circuit for simultaneously detecting the three-way upper switch signals of the smart power module to output a first control signal when the interval of the upper switch signal is less than the first preset interval, a third edge interval detection sub-circuit for simultaneously detecting the three-way lower switch control signals of the smart power module to output a second control signal when the interval of the lower switch signal is less than the first preset interval, and a first OR gate, a first input end of the first OR gate being connected with the output end of the second edge interval detection sub-circuit, a second input end of the first OR gate being connected with the output end of the third edge interval detection sub-circuit, the output end of the first OR gate serving as the output end of the anti-interference enhancement unit, and the first OR gate outputting an enable signal to the first transmission gate according to the first control signal and the second control signal.

[0016] In some embodiments of the present application, the anti-interference enhancement unit further comprises a first MOS (Metal-Oxide-Semiconductor) tube, a first end of the first MOS tube being connected with one end of the second filter capacitor and the other end of the first transmission gate respectively, and a second end of the first MOS tube being grounded; and an inverter, an input end of the inverter being connected with the enable end of the first transmission gate, and an output end of the inverter being connected with the control end of the first MOS tube.

[0017] In some embodiments of the present application, the second filter unit comprises a second transmission gate, one end of the second transmission gate being connected with one end of the first filter resistor, and the enable end of the second transmission gate being connected with the output end of the anti-interference enhancement unit; and a second filter resistor, one end of the second filter resistor being connected with the other end of the second transmission gate, and the other end of the second filter resistor being connected with the first node.

[0018] In some embodiments of the present application, the anti-interference enhancement unit controls the second transmission gate to be turned off when the interval of the upper switch signal and / or the interval of the lower switch signal of any two phase bridge arms of the three-phase bridge arm of the intelligent power module is less than the first preset interval, so that the first filter resistor works.

[0019] In some embodiments of the present application, the anti-interference enhancement unit comprises a fourth edge interval detection sub-circuit, the output end of the fourth edge interval detection sub-circuit serving as the output end of the anti-interference enhancement unit, for simultaneously detecting the six-way switch tube control signals of the intelligent power module, and outputting a turn-off signal to the first transmission gate when the interval of the upper switch signal and / or the interval of the lower switch signal is less than the first preset interval.

[0020] In some embodiments of the present application, the anti-interference enhancement unit comprises a fifth edge interval detection sub-circuit for simultaneously detecting the three-way upper switch signals of the intelligent power module, to output a first control signal when the interval of the upper switch signal is less than the first preset interval; a sixth edge interval detection sub-circuit for simultaneously detecting the three-way lower switch signals of the intelligent power module, to output a second control signal when the interval of the lower switch signal is less than the first preset interval; a first NOR gate, the first input end of the first NOR gate being connected with the output end of the fifth edge interval detection sub-circuit, the second input end of the first NOR gate being connected with the output end of the sixth edge interval detection sub-circuit, the output end of the first NOR gate serving as the output end of the anti-interference enhancement unit, the first NOR gate outputting a turn-off signal to the second transmission gate according to the first control signal and the second control signal.

[0021] In some embodiments of the present application, the overcurrent detection unit comprises a current sampling end for sampling a current signal; a comparator, the positive input end of the comparator being connected with the current sampling end, the negative input end of the comparator being connected with a reference power supply, for outputting an overcurrent signal when the current signal is greater than the current protection threshold value provided by the reference power supply; and a shaping circuit, the input end of the shaping circuit being connected with the output end of the comparator, for shaping the overcurrent signal to output the overcurrent detection signal.

[0022] To achieve the above object, the second aspect of the embodiments of the present application provides an intelligent power module, which comprises the overcurrent detection circuit in the above embodiments.

[0023] The intelligent power module of the present embodiment can sufficiently improve the stability of overcurrent detection, effectively reduce the probability of malfunction caused by false triggering in overcurrent detection, and ensure the sensitivity of overcurrent detection under normal interference conditions, through the overcurrent detection circuit in the above embodiments.

[0024] To achieve the above object, the third aspect of the present application provides a household appliance, which comprises the intelligent power module in the above embodiments.

[0025] The household appliance in the embodiment can improve the stability of overcurrent detection, effectively reduce the probability of malfunction caused by false triggering in overcurrent detection, and ensure the sensitivity of overcurrent detection under normal interference conditions.

[0026] Additional aspects and advantages of the present application will be described in the following description, become apparent from the following description, or be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic diagram of an overcurrent detection circuit of an intelligent power module according to an embodiment of the present application;

[0028] Figure 2 is a schematic diagram of an overcurrent detection circuit of an intelligent power module according to an embodiment of the present application;

[0029] Figure 3 is a schematic diagram of an overcurrent detection circuit of an intelligent power module according to an embodiment of the present application;

[0030] Figure 4 is a schematic diagram of an overcurrent detection circuit of an intelligent power module according to an embodiment of the present application;

[0031] Figure 5 is a structural block diagram of an intelligent power module according to an embodiment of the present application;

[0032] Figure 6 is a structural block diagram of a household appliance according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0034] The overcurrent detection circuit of the intelligent power module, the intelligent power module and the household appliance of the embodiments of the present application are described below with reference to the drawings.

[0035] Figure 1 is a schematic diagram of an overcurrent detection circuit of an intelligent power module according to an embodiment of the present application.

[0036] As Figure 1As shown, the application provides an overcurrent detection circuit which can be applied to a power module.

[0037] The detection circuit comprises an overcurrent detection unit 10, a filtering unit 20 and an anti-interference enhancement unit 30.

[0038] The detection unit 10 can be used to detect whether the current flowing through the power module is overcurrent, and output a corresponding detection signal when overcurrent occurs; the filtering unit 20 can be connected with the detection unit 10, and then filter the overcurrent detection signal when the detection unit 10 detects the overcurrent signal, to filter out the interference signal; the enhancement unit 30 can be connected with the filtering unit 20, and then improve the interference filtering capability of the filtering unit 20 according to the enhancement signal generated in the interval of the switching action of the corresponding switch of the power module.

[0039] Specifically, in this embodiment, the current flowing through the power module can be detected by the detection unit 10, and a corresponding detection signal can be generated when the current exceeds the defined current, and then the filtering unit 20 connected with the detection unit 10 can receive the detection signal and filter it when it is received. The enhancement unit 30 is also provided in this embodiment, which can determine whether the power module generates an enhancement signal according to the interval of the switching action of the upper tube or the interval of the switching action of the lower tube, and then control the filtering unit 20 to improve the interference filtering capability when the corresponding enhancement signal is detected. The detection circuit of this embodiment can improve the interference filtering capability of the filtering unit 20 when the power module generates an enhancement signal, thereby fully improving the stability of overcurrent detection, effectively reducing the probability of failure due to false triggering in overcurrent detection, and ensuring the overcurrent detection sensitivity under normal interference conditions.

[0040] For example, since the interval between the switching signals of different phases of the power device is variable, if the switching signal interval of two upper bridges or two lower bridges is small, it will lead to a small switching interval of the corresponding two power devices, which is very easy to cause the current oscillation to intensify. For example, when the switching interval of the two power devices is less than or equal to 10 microseconds, the current oscillation will intensify, so the current detected by the detection unit 10 will also oscillate, and therefore the detection unit 10 is likely to be false triggered due to the intensified current oscillation, thereby causing the device to work unstably, for example, causing the air conditioner to stop working when it is powered on, which greatly reduces the user's experience.

[0041] In this embodiment, as shown in Figure 1As shown, the detection unit 10 includes a sampling end 11, a comparator 12 and a shaping circuit 13.

[0042] The sampling end 11 can sample the current of the power module, and the sampling end 11 is connected to the positive input end of the comparator 12. The negative input end of the comparator 12 is connected to a reference power supply, which provides a current protection threshold to the comparator 12. When the current signal collected by the sampling end 11 is greater than the protection threshold, the comparator 12 outputs an overcurrent signal. The shaping circuit 13 shapes the overcurrent signal and outputs a detection signal of overcurrent.

[0043] Specifically, the positive input end of the comparator 12 is connected to the sampling end 11, that is, the sampling end 11 inputs the collected current signal to the comparator 12 through the positive input end of the comparator 12. The negative input end of the comparator 12 is also connected to a reference power supply, wherein the positive electrode of the reference power supply is connected to the negative input end of the comparator 12, and the negative electrode of the reference power supply is grounded. The reference power supply provides a current protection threshold to the comparator 12. The comparator 12 compares the current signal collected by the sampling end 11 with the protection threshold, and outputs an overcurrent signal when the current signal is greater than the protection threshold. In order to make the overcurrent signal more stable for subsequent circuit control, the detection unit 10 further includes a shaping circuit 13. Figure 1 As shown, the shaping circuit 13 includes two inverters. After the overcurrent signal is shaped by the two inverters, a relatively stable detection signal is generated. It should be noted that a resistor is arranged between the sampling end 11 and the negative electrode of the reference power supply, which can further prevent the circuit from oscillating. Figure 1 As shown, the shaping circuit 13 includes two inverters. After the overcurrent signal is shaped by the two inverters, a relatively stable detection signal is generated. It should be noted that a resistor is arranged between the sampling end 11 and the negative electrode of the reference power supply, which can further prevent the circuit from oscillating.

[0044] After the detection unit 10 outputs the detection signal, a filtering unit 20 connected to the detection unit 10 filters the detection signal, and then outputs the filtered signal to the output end of the detection circuit. The circuit connected to the output end of the detection circuit can respond according to the signal output by the output end of the detection circuit.

[0045] As shown, the filtering unit 20 can include a first filtering part 21 and a second filtering part 22. Figure 1

[0046] The first filtering part 21 can filter out the interference signal carried in the detection signal when the filtering unit 20 does not receive the enhancement signal. When the filtering unit 20 receives the enhancement signal, the first filtering part 21 and the second filtering part 22 can be used together to filter out the interference signal carried in the detection signal. ​

[0047] In particular, referring to Figure 1 , the detection unit 10 is connected with the filter unit 20, more specifically, the detection unit 10 is connected with the first filter part 21, when the filter unit 20 does not receive the enhancement signal, then the second filter part 22 is disconnected with the first filter part 21, that is to say, the second filter part 22 is not connected into the filter circuit and does not participate in the filtering process of the detection signal, and only the first filter part 21 filters the detection signal to filter out the interference signal carried in the detection signal. When the filter unit 20 receives the enhancement signal, the second filter part 22 is connected with the first filter part 21, that is to say, the second filter part 22 is connected into the filter circuit and participates in the filtering process of the detection signal, so that the first filter part 21 and the second filter part 22 can filter the detection signal together.

[0048] It can be understood that the first filter part 21 and the second filter part 22 have a delay function in addition to the filtering function in the filter unit. In particular, in order to filter out the noise interference in the signal, a filtering time is usually set, if the pulse width of the detection signal greater than the protection threshold is less than the filtering time, then the detection signal is filtered out. If the pulse width of the detection signal greater than the protection threshold is greater than the filtering time, then the detection signal is retained and output through the output end in the detection circuit, and the device can be controlled to stop or other responses to protect the safety of the device.

[0049] In this embodiment, in order to prevent false triggering, such as when the interval between the opening or closing actions of two or more power modules is small, the oscillation of the detection signal can also cause the device to be miscontrolled. Therefore, in order to solve this problem, the first filter part 21 and the second filter part 22 are provided, and when the enhancement signal is received, the first filter part 21 and the second filter part 22 can be controlled to work together, thereby increasing the filtering time and preventing the device from being miscontrolled in the case of the enhancement signal.

[0050] More specifically, as shown in Figure 1 , the first filter part 21 includes a first filter resistor R1 and a first filter capacitor C1.

[0051] One end of the filter resistor R1 is connected to the output end of the detection unit 10, one end of the filter capacitor C1 is connected to the other end of the filter resistor R1 and is provided with a first node P1, the first node P1 is connected with the second filter part 22, and the other end of the filter capacitor C1 is connected with the ground.

[0052] In particular, as shown in Figure 1As shown, the first filter unit 21 includes a filter resistor R1 and a filter capacitor C1. One end of the filter resistor R1 is connected to the output end of the detection unit 10, for processing the detection signal output by the detection unit 10. The other end of the filter resistor R1 is connected to one end of the filter capacitor C1, and forms a first node P1, which can be connected to the second filter unit 22. The other end of the filter capacitor C1 is connected to ground. The resistance value of the filter resistor R1 and the capacitance value of the filter capacitor C1 in this embodiment can be set according to different devices, and are not limited in detail herein.

[0053] In one embodiment of the present application, as shown in Figure 1 The second filter unit 22 includes a first transmission gate TG1 and a second filter capacitor C2.

[0054] The one end of the first transmission gate TG1 is connected to the first node P1, the enable end of the first transmission gate TG1 is connected to the output end of the enhancement unit 30, one end of the filter capacitor C2 is connected to the other end of the first transmission gate TG1, and the other end of the filter capacitor C2 is connected to ground.

[0055] Specifically, in this embodiment, the first transmission gate TG1 can control the connection or disconnection of the one end and the other end of the first transmission gate TG1 according to the signal received by the enable end. It can be understood that when the one end and the other end of the first transmission gate TG1 are connected, the filter capacitor C2 in the second filter unit 22 can be connected to the first filter unit 21, and thus can filter the detection signal output by the detection unit 10 together with the first filter unit 21. It should be noted that when the enhancement signal is received by the filter unit 20, the one end and the other end of the first transmission gate TG1 can be connected, so that the filter capacitor C2 can be connected to the first node P1, i.e., the filter capacitor C2 can be connected in parallel with the filter capacitor C1. At this time, the filter resistor R1, the filter capacitor C1 and the filter capacitor C2 can together perform delay filtering processing on the detection signal output by the detection unit 10. When the enhancement signal is not received by the filter unit 20, the one end and the other end of the first transmission gate TG1 can be disconnected, so that the filter capacitor C2 is not connected to the first node P1, i.e., the filter capacitor C2 is not connected to the first filter unit 21. At this time, only the filter resistor R1 and the filter capacitor C1 in the first filter unit 21 perform delay filtering processing on the detection signal output by the detection unit 10.

[0056] It should be noted that the enhancement signal can be connected to the enable end of the first transmission gate TG1, so that the first transmission gate TG1 can control one end to be connected to the other end when receiving the enhancement signal, so as to connect the filter capacitor C2 and the filter capacitor C1 in parallel, so that the filter capacitor C2 participates in the delay filtering process; if there is no enhancement signal, the enable end of the first transmission gate TG1 does not receive the enhancement signal, and one end can be controlled to be disconnected from the other end, that is, the filter capacitor C2 does not participate in the delay filtering process, so as to ensure the sensitivity of the first filtering unit 21.

[0057] In this embodiment, when the interval of the switching action of the upper tube or the interval of the switching action of the lower tube in the power module is small, such as the interval of the switching action of the upper tube or the interval of the switching action of the lower tube is less than or equal to 20 microseconds, or 10 microseconds, the first transmission gate TG1 is controlled to be turned on, so that the filter capacitor C1 and the filter capacitor C2 work in parallel. It should be noted that the interval time of the switching action of the upper tube and the interval time of the switching action of the lower tube in this embodiment can be selected according to the actual circuit, such as 15 microseconds, 18 microseconds, etc. The above-mentioned examples of 20 microseconds and 10 microseconds are only for illustration and are not limited.

[0058] Specifically, the power module in this embodiment can include six switching tubes, which are controlled by six control signals, such as Figure 1 As shown in the figure, the six control signals include three upper bridge control signals and three lower bridge control signals. Optionally, a Schmitt trigger is connected behind each control signal, and the control signal can be waveform shaped through the Schmitt trigger. When the power module needs to be controlled, the control can be realized by sending control signals to the corresponding switching tubes of the power module. In this embodiment, the signal after the dead-time protection circuit can be selected as the collection point of the control signal, which can further ensure the accuracy of the signal. Moreover, Figure 1 Various drivers are also shown in the figure, which can include high-voltage side drivers and low-voltage side drivers. It can be understood that under the control of the control signal, each driver can drive other devices in the external circuit.

[0059] In this embodiment, when the interval of the upper tube switching signal and / or the interval of the lower tube switching signal in any two-phase bridge arm of the three-phase bridge arm is less than the interval corresponding to the first preset, the first transmission gate TG1 is controlled to be turned on, that is, the filter capacitor C2 can be connected to the first node P1, so that the filter capacitor C1 and the filter capacitor C2 can work in parallel.

[0060] It can be understood that when the interval of the upper tube switching signal in any two-phase bridge arm is less than the interval corresponding to the first preset, or the interval of the lower tube switching signal in any two-phase bridge arm is less than the interval corresponding to the first preset, it can be equivalent to that the enhanced signal appears in the power module, so the second filtering unit 22 needs to be involved in the filtering work. It should be noted that the first preset interval can be 10 microseconds, or 15 microseconds, 20 microseconds, etc. Therefore, in this embodiment, taking the first preset interval of 10 microseconds as an example, when the interval of the upper tube switching signal in any two-phase bridge arm is less than 10 microseconds, or the interval of the lower tube switching signal in any two-phase bridge arm is less than 10 microseconds, the first transmission gate TG1 is controlled to be turned on, so that the first filtering unit 21 and the second filtering unit 22 can perform filtering work together to improve the delay filtering time of the filtering unit 20. For example, when the equipment provided with the detection circuit is powered on, the interval of the switching signal of the upper tube or the lower tube of any two-phase bridge arm in the three-phase bridge arm is less than 10 microseconds, so when the equipment is powered on, the enhancement unit 30 can control the first transmission gate TG1 to be turned on, and then the filtering capacitor C2 can be connected in parallel with the filtering capacitor C1, and then the detection signal is filtered and delayed together, preventing false triggering.

[0061] It should be noted that since the switching signal is a very short process signal, optionally, in some embodiments, an edge interval detection sub-circuit 31 can also be arranged in the enhancement unit 30, so as to accurately detect the interval in the switching signal, thereby improving the control accuracy and preventing false triggering.

[0062] In this embodiment, as shown in Figure 1 The first edge interval detection sub-circuit 31 is included in the enhancement unit 30, the input end of the detection sub-circuit 31 can be connected to the control signals emitted by the six switching tubes on the power module, for simultaneously detecting the control signals emitted by the six switching tubes on the power module, and the output end can be used as the output end of the enhancement unit 30, and in the case that the interval of the upper tube switching signal is less than the interval corresponding to the first preset, or the interval of the lower tube switching signal is less than the interval corresponding to the first preset, the detection sub-circuit 31 can output an enable signal to the first transmission gate TG1.

[0063] Specifically, in this embodiment, as shown in Figure 1As shown, the control signals emitted by the six-way switch tubes are connected to the detection sub-circuit 31 of the enhancement unit 30 in three groups, each group can include an upper tube switching signal and a lower tube switching signal, wherein when the interval between any two of the three upper tube switching signals is less than the interval corresponding to the first preset, the detection sub-circuit 31 can output an enable signal to the first transmission gate TG1, which can control one end and the other end of the first transmission gate TG1 to be connected, so that both the second filter unit 22 and the first filter unit 21 participate in the filtering operation in the detection circuit, to ensure that the detection circuit can accurately detect the overcurrent signal and prevent false triggering. Of course, if the interval between any two of the three lower tube switching signals is less than the interval corresponding to the first preset, the detection sub-circuit 31 can also output an enable signal to the first transmission gate TG1, and the specific control process can be referred to the above example, which will not be described here.

[0064] In this embodiment, as shown in Figure 2 The enhancement unit 30 also includes a second edge interval detection sub-circuit 32, a third edge interval detection sub-circuit 33, and a first OR gate OR1.

[0065] The detection sub-circuit 32 can detect the switching signals of the corresponding three-way upper tube in the power module, and if the interval between any two switching signals is less than the interval of the first preset, the detection sub-circuit 32 can output a first control signal; the detection sub-circuit 33 can detect the switching signals of the corresponding three-way lower tube in the power module, and if the interval between any two switching signals is less than the interval of the first preset, the detection sub-circuit 33 can output a second control signal; the two input ends of the first OR gate OR1 are respectively connected to the output ends of the detection sub-circuit 32 and the detection sub-circuit 33, for receiving the first control signal and the second control signal, and outputting an enable signal to the first transmission gate TG1 according to the first control signal and the second control signal.

[0066] Specifically, the switching signals in the present embodiment have six ways, which are connected to the detection sub-circuit 32 and the detection sub-circuit 33 through control signal collection points, respectively. Optionally, the switching signals of the upper tube can be connected to the input end of the detection sub-circuit 32, and the switching signals of the lower tube can be connected to the input end of the detection sub-circuit 33. It can be understood that the switching signals of the upper tube can also be connected to the input end of the detection sub-circuit 33, and the switching signals of the lower tube can also be connected to the input end of the detection sub-circuit 32, as long as each upper tube switching signal is connected to the same detection sub-circuit and each lower tube switching signal is connected to the same detection sub-circuit.

[0067] In this embodiment, the output terminals of the detection sub-circuit 32 and the detection sub-circuit 33 are also connected to the input terminals of the first OR gate OR1, and the output terminal of the first OR gate OR1 is taken as the output terminal of the enhancement unit 30, and the output terminal of the enhancement unit 30 is connected to the enable terminal of the first transmission gate TG1.

[0068] More specifically, for example, when the interval between the first low-voltage-side input signal LIN1 and the second low-voltage-side input signal LIN2 is less than the interval corresponding to the first preset, the detection sub-circuit 33 can output the second control signal, and since the output terminal of the detection sub-circuit 33 is the input terminal of the first OR gate OR1, at least one control signal is also input to the input terminal of the first OR gate OR1, so the first OR gate OR1 outputs the enable signal, which can be set as the enhancement signal, so the first transmission gate TG1 can be controlled to be turned on, and then the filter capacitor C2 and the filter capacitor C1 are connected in parallel to perform delay filtering processing on the detection signal of the detection unit 10.

[0069] For example, when the interval between the second low-voltage-side input signal LIN2 and the third low-voltage-side input signal LIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 33 can output the second control signal, and since the output terminal of the detection sub-circuit 33 is the input terminal of the first OR gate OR1, at least one control signal is also input to the input terminal of the first OR gate OR1, so the first OR gate OR1 can output the enable signal, which can be set as the enhancement signal, so the first transmission gate TG1 can be controlled to be turned on, and then the filter capacitor C2 and the filter capacitor C1 are connected in parallel to perform delay filtering processing on the detection signal of the detection unit 10.

[0070] For example, when the interval between the first low-voltage-side input signal LIN1 and the third low-voltage-side input signal LIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 33 can output the second control signal, and since the output terminal of the detection sub-circuit 33 is the input terminal of the first OR gate OR1, at least one control signal is also input to the input terminal of the first OR gate OR1, so the first OR gate OR1 can output the enable signal, which can be set as the enhancement signal, so the first transmission gate TG1 can be controlled to be turned on, and then the filter capacitor C2 and the filter capacitor C1 are connected in parallel to perform delay filtering processing on the detection signal of the detection unit 10. It should be noted that the low-voltage-side input signal in this embodiment can also be a lower bridge input signal in any two-phase bridge arm.

[0071] For example, when the interval between the first high-side input signal HIN1 and the second high-side input signal HIN2 is less than the interval corresponding to the first preset, the detection sub-circuit 32 can output the first control signal. Since the output terminal of the detection sub-circuit 32 is the input terminal of the first OR gate OR1, at least one control signal is input to the input terminal of the first OR gate OR1, so the first OR gate OR1 can output the enable signal. The enable signal output by the first OR gate OR1 can be set as the enhancement signal, so the first transmission gate TG1 can be controlled to be turned on, and the filter capacitor C2 and the filter capacitor C1 are connected in parallel, so that the detection signal of the detection unit 10 is subjected to the delay filtering process.

[0072] For example, when the interval between the second high-side input signal HIN2 and the third high-side input signal HIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 32 can output the first control signal. Since the output terminal of the detection sub-circuit 32 is the input terminal of the first OR gate OR1, at least one control signal is input to the input terminal of the first OR gate OR1, so the first OR gate OR1 can output the enable signal. The enable signal output by the first OR gate OR1 can be set as the enhancement signal, so the first transmission gate TG1 can be controlled to be turned on, and the filter capacitor C2 and the filter capacitor C1 are connected in parallel, so that the detection signal of the detection unit 10 is subjected to the delay filtering process.

[0073] For example, when the interval between the first high-side input signal HIN1 and the third high-side input signal HIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 32 can output the first control signal. Since the output terminal of the detection sub-circuit 32 is the input terminal of the first OR gate OR1, at least one control signal is input to the input terminal of the first OR gate OR1, so the first OR gate OR1 can output the enable signal. The enable signal output by the first OR gate OR1 can be set as the enhancement signal, so the first transmission gate TG1 can be controlled to be turned on, and the filter capacitor C2 and the filter capacitor C1 are connected in parallel, so that the detection signal of the detection unit 10 is subjected to the delay filtering process. It should be noted that the high-side input signal in the embodiment can also be the upper bridge input signal in any two-phase bridge arm.

[0074] In this embodiment, as shown in Figure 1 or Figure 2 The enhancement unit 30 further includes a first MOS tube Q1 and an inverter D1.

[0075] The first end of the first MOS Q1 is connected with the filter capacitor C2, and the first end of the first MOS Q1 is also connected with the other end of the first transmission gate TG1, the second end of the first MOS Q1 is connected with the ground, the input end of the inverter D1 is connected to the enable end of the first transmission gate TG1, and the output end of the inverter D1 is connected to the control end of the first MOS Q1.

[0076] Specifically, it needs to be explained that, referring to Figure 2 The signal of the control end of the first MOS Q1 in the embodiment is opposite to the signal of the enable end of the first transmission gate TG1.

[0077] More specifically, in the embodiment, by setting the first MOS Q1 and the inverter D1, it can be ensured that the filter capacitor C2 can work normally, thereby further ensuring that the detection circuit can work normally.

[0078] More specifically, since the filter capacitor C2 participates in the delay filtering process when the first transmission gate TG1 is turned on, after the filtering process is completed, a certain amount of electricity will be charged in the filter capacitor C2, if it is not discharged in time, then when the filter capacitor C2 participates in the filtering process next time after receiving the enhanced signal, the filter capacitor C2 cannot work normally.

[0079] Therefore, in the embodiment, by controlling the first MOS Q1 to be turned on, the non-ground end of the filter capacitor C2 can be discharged until the voltage of the non-ground end of the filter capacitor C2 is zero volts. And since the inverter D1 is also connected to the control end of the first MOS Q1, when the first OR gate OR1 does not output the enable signal, it means that there is no enhanced signal at present, the first transmission gate TG1 is turned off, and the filter capacitor C2 is disconnected from the first node P1. At this time, due to the action of the inverter D1, the control end of the first MOS Q1 can receive a high level, therefore, the first end and the second end of the first MOS Q1 are connected, thereby being able to control the non-ground end of the filter capacitor C2 to be discharged.

[0080] It can be understood that when the third OR gate OR3 outputs a high level, the filter capacitor C2 and the filter capacitor C1 are connected in parallel to perform delay filtering work, at this time, the first MOS Q1 is disconnected and does not discharge the filter capacitor C2. It can be seen that the discharge of the filter capacitor and the filtering can be well separated, thereby being able to ensure that the filter capacitor C2 can work normally.

[0081] Specifically, for example, as Figure 2As shown, the input end of the detection unit 10 can sample the current flowing through the power module, and also collect the switch tube control signal on the power module after the dead zone protection circuit. When the interval corresponding to the switch signal is less than the interval corresponding to the first preset, that is, the enhancement signal appears, the detection sub-circuit 32, the detection sub-circuit 33 and the first OR gate OR1 can output from the first OR gate OR1, and at this time the detection unit 10 also generally samples the overcurrent detection signal. The signal output from the first OR gate OR1 can control the first transmission gate TG1 to be turned on, so that the filter capacitor C2 and the first node P1 are connected, and then the filter capacitor C1 and the filter capacitor C2 are connected in parallel, and the detection signal is processed by the filter resistor R1, the filter capacitor C1 and the filter capacitor C2 for delay filtering, so as to fully improve the stability of the overcurrent detection, and effectively reduce the probability of malfunction caused by false triggering in the overcurrent detection. When the control signal returns to normal, the first MOS tube Q1 can be turned on to discharge the filter capacitor C2, so that the voltage of the non-ground end of the filter capacitor C2 is reduced to zero volt, and the filter capacitor C2 does not participate in the delay filtering process of the first filtering part 21, so as to ensure the overcurrent detection sensitivity of the detection circuit under normal interference conditions.

[0082] In another embodiment of the present application, as shown in Figure 3 The second filtering part 22 includes a second transmission gate TG2 and a filter resistor R2.

[0083] The one end of the second transmission gate TG2 is connected to the filter resistor R1, and the enable end of the second transmission gate TG2 is connected to the output end of the enhancement unit 30; one end of the filter resistor R2 is connected to the other end of the second transmission gate TG2, and the other end of the filter resistor R2 is connected to the first node P1.

[0084] Specifically, the enable end of the second transmission gate TG2 is connected to the output end of the enhancement unit 30, and after the enhancement signal is output from the output end of the enhancement unit 30, the enable end of the second transmission gate TG2 can receive the enhancement signal, and then according to the enhancement signal, the one end of the filter resistor R2 can be disconnected from the one end of the filter resistor R1, so that the filter resistor R1 is not connected in parallel with the second resistor R2, and then the resistance value is increased, the filtering time of the filter unit 20 is increased, and the detection signal detected by the detection unit 10 can be processed by the delay filtering.

[0085] In this embodiment, when the signal interval of the upper and lower tube switches in any two-phase bridge arm of the power module is less than the interval of the first preset, the enhancement unit 30 controls the second transmission gate TG2 to be turned off, so that the filter resistor R1 works.

[0086] It can be understood that when the interval of the upper tube switching signal in any two-phase bridge arm is less than the interval corresponding to the first preset, or the interval of the lower tube switching signal in any two-phase bridge arm is less than the interval corresponding to the first preset, it can be equivalent to that the enhanced signal occurs in the power module, so the second filtering unit 22 does not need to participate in the filtering work. It should be noted that the first preset interval can be 10 microseconds, or 15 microseconds, 20 microseconds, etc. Therefore, in this embodiment, taking the first preset interval of 10 microseconds as an example, when the interval of the upper tube switching signal in any two-phase bridge arm is less than 10 microseconds, or the interval of the lower tube switching signal in any two-phase bridge arm is less than 10 microseconds, the second transmission gate TG2 is controlled to be turned off, so that the second filtering unit 22 does not participate in the filtering work, so as to improve the resistance value of the filtering resistor in the filtering unit 20, and further improve the delay filtering time of the filtering unit 20. For example, when the equipment provided with the detection circuit is powered on, the interval of the upper tube or lower tube switching signal of any two-phase bridge arm in the three-phase bridge arm is less than 10 microseconds, so when the equipment is powered on, the enhancement unit 30 can control the second transmission gate TG2 to be turned off, and further make the filtering resistor R2 can be disconnected with the parallel relationship of the filtering resistor R1, so as to improve the total filtering resistor of the filtering unit 20, and further prolong the filtering processing of the detection signal, and prevent the occurrence of false triggering.

[0087] It should be noted that since the switching signal is a very short process signal, optionally, in some embodiments, an edge interval detection sub-circuit 31 can also be arranged in the enhancement unit 30, so as to accurately detect the interval in the switching signal, and further improve the control accuracy and prevent false triggering.

[0088] In this embodiment, as shown in Figure 3 The fourth edge interval detection sub-circuit 34 in the enhancement unit 30, the input end of the detection sub-circuit 34 can be connected to the control signals of the six switching tubes on the power module, for simultaneously detecting the control signals of the six switching tubes on the power module, and the output end can be used as the output end of the enhancement unit 30, and in the case that the interval of the upper tube switching signal is less than the interval corresponding to the first preset, or the interval of the lower tube switching signal is less than the interval corresponding to the first preset, the detection sub-circuit 34 can output an enable signal to the second transmission gate TG2.

[0089] Specifically, in this embodiment, as shown in Figure 3As shown, the control signals of the six-way switch tubes are connected to the detection sub-circuit 34 of the enhancement unit 30 in three groups, each group can include one upper tube switching signal and one lower tube switching signal, wherein when the interval between any two of the three upper tube switching signals is less than the interval corresponding to the first preset, the detection sub-circuit 34 can output an enable signal to the second transmission gate TG2, which can control one end and the other end of the second transmission gate TG2 to be connected, so that the second filter unit 22 and the first filter unit 21 both participate in the filtering operation in the detection circuit, to ensure that the detection circuit can accurately detect the overcurrent signal and prevent false triggering. Of course, if the interval between any two of the three lower tube switching signals is less than the interval corresponding to the first preset, the detection sub-circuit 34 can also output an enable signal to the second transmission gate TG2, and the specific control process can be referred to the above example, which will not be described here.

[0090] In this embodiment, as shown in Figure 4 The enhancement unit 30 includes a fifth edge interval detection sub-circuit 35, a sixth edge interval detection sub-circuit 36, and a first OR gate OR'.

[0091] The detection sub-circuit 35 can be used to simultaneously detect the switching signals of the three upper tubes in the power module, and when the interval between any two switching signals of the three upper tubes is less than the first preset interval, the detection sub-circuit 35 outputs a first control signal; the detection sub-circuit 36 can be used to simultaneously detect the switching signals of the three lower tubes in the power module, and when the interval between any two switching signals of the three lower tubes is less than the first preset interval, the detection sub-circuit 36 outputs a second control signal; the two input ends of the first OR gate OR' are connected with the output ends of the detection sub-circuit 35 and the detection sub-circuit 36 respectively, for receiving the first control signal and the second control signal, and outputting an enable signal to the second transmission gate TG2 according to the first control signal and the second control signal.

[0092] Specifically, the switching signals in the present embodiment have six ways, which are connected to the detection sub-circuit 35 and the detection sub-circuit 36 through the control signal collection points respectively, and optionally, the switching signals of the upper tubes can be connected to the input ends of the detection sub-circuit 35, and the switching signals of the lower tubes can be connected to the input ends of the detection sub-circuit 36. It can be understood that the switching signals of the upper tubes can also be connected to the input ends of the detection sub-circuit 36, and the switching signals of the lower tubes can also be connected to the input ends of the detection sub-circuit 35, as long as each switching signal of the upper tubes is connected to the same detection sub-circuit, and each switching signal of the lower tubes is connected to the same detection sub-circuit.

[0093] In this embodiment, the output terminals of the detection sub-circuit 35 and the detection sub-circuit 36 are also connected to the input terminals of the first NOR gate OR', and the output terminal of the first NOR gate OR' is taken as the output terminal of the enhancement unit 30, and the output terminal of the enhancement unit 30 is connected to the enable terminal of the second transmission gate TG2.

[0094] More specifically, for example, when the interval between the first low-voltage-side input signal LIN1 and the second low-voltage-side input signal LIN2 is less than the interval corresponding to the first preset, the detection sub-circuit 36 can output the second control signal, and since the output terminal of the detection sub-circuit 36 is the input terminal of the first NOR gate OR', at least one control signal is also input to the input terminal of the first NOR gate OR', so the first NOR gate OR' does not output the enable signal, and it can be set that when the first NOR gate OR' does not output the enable signal, it is the enhancement signal, so the second transmission gate TG2 can be controlled to be turned off, and the filter resistor R2 and the filter resistor R1 are not connected, and the detection signal of the detection unit 10 is subjected to the delay filtering process.

[0095] For example, when the interval between the second low-voltage-side input signal LIN2 and the third low-voltage-side input signal LIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 36 can output the second control signal, and since the output terminal of the detection sub-circuit 36 is the input terminal of the first NOR gate OR', at least one control signal is also input to the input terminal of the first NOR gate OR', so the first NOR gate OR' does not output the enable signal, and it can be set that when the first NOR gate OR' does not output the enable signal, it is the enhancement signal, so the second transmission gate TG2 can be controlled to be turned off, and the filter resistor R2 and the filter resistor R1 are not connected, and the detection signal of the detection unit 10 is subjected to the delay filtering process.

[0096] For example, when the interval between the first low-voltage-side input signal LIN1 and the third low-voltage-side input signal LIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 36 can output the second control signal, and since the output terminal of the detection sub-circuit 36 is the input terminal of the first NOR gate OR', at least one control signal is also input to the input terminal of the first NOR gate OR', so the first NOR gate OR' does not output the enable signal, and it can be set that when the first NOR gate OR' does not output the enable signal, it is the enhancement signal, so the second transmission gate TG2 can be controlled to be turned off, and the filter resistor R2 and the filter resistor R1 are not connected, and the detection signal of the detection unit 10 is subjected to the delay filtering process. It should be noted that the low-voltage-side input signal in this embodiment can also be the lower bridge input signal in any two-phase bridge arm.

[0097] For example, when the interval between the first high-voltage side input signal HIN1 and the second high-voltage side input signal HIN2 is less than the interval corresponding to the first preset, the detection sub-circuit 35 can output the first control signal, since the output end of the detection sub-circuit 35 is the input end of the first OR NOT gate OR', the input end of the first OR NOT gate OR' also has at least one control signal, so the first OR NOT gate OR' does not output the enable signal, which can be set as the enhancement signal when the first OR NOT gate OR' does not output the enable signal, so the second transmission gate TG2 can be controlled to be turned off, and the filter resistor R2 and the filter resistor R1 are disconnected, for the delay filtering processing of the detection signal of the detection unit 10.

[0098] For example, when the interval between the second high-voltage side input signal HIN2 and the third high-voltage side input signal HIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 35 can output the first control signal, since the output end of the detection sub-circuit 35 is the input end of the first OR NOT gate OR', the input end of the first OR NOT gate OR' also has at least one control signal, so the first OR NOT gate OR' does not output the enable signal, which can be set as the enhancement signal when the first OR NOT gate OR' does not output the enable signal, so the second transmission gate TG2 can be controlled to be turned off, and the filter resistor R2 and the filter resistor R1 are disconnected, for the delay filtering processing of the detection signal of the detection unit 10.

[0099] For example, when the interval between the first high-voltage side input signal HIN1 and the third high-voltage side input signal HIN3 is less than the interval corresponding to the first preset, the detection sub-circuit 35 can output the first control signal, since the output end of the detection sub-circuit 35 is the input end of the first OR NOT gate OR', the input end of the first OR NOT gate OR' also has at least one control signal, so the first OR NOT gate OR' does not output the enable signal, which can be set as the enhancement signal when the first OR NOT gate OR' does not output the enable signal, so the second transmission gate TG2 can be controlled to be turned off, and the filter resistor R2 and the filter resistor R1 are disconnected, for the delay filtering processing of the detection signal of the detection unit 10. It should be noted that the high-voltage side input signal in the embodiment can also be the upper bridge input signal in any two-phase bridge arm.

[0100] It should be noted that, Figure 4 The specific embodiments of other specific embodiments of the embodiments shown can be seen in Figure 2 The specific embodiments of the same part of the embodiments shown are not repeated here.

[0101] In summary, the detection circuit of the embodiment of the application can sufficiently improve the stability of the overcurrent detection, effectively reduce the probability of faults caused by false triggering in overcurrent detection, and ensure the overcurrent detection sensitivity under normal interference conditions.

[0102] Figure 5 is a structural block diagram of the intelligent power module according to the embodiment of the present application.

[0103] Further, as shown in Figure 5 , the present application proposes an intelligent power module 100, which comprises the detection circuit in the above embodiment.

[0104] The power module in the embodiment can sufficiently improve the stability of overcurrent detection, effectively reduce the probability of malfunction due to false triggering in overcurrent detection, and ensure the overcurrent detection sensitivity under normal interference conditions.

[0105] Figure 6 is a structural block diagram of the household appliance according to the embodiment of the present application.

[0106] Further, as shown in Figure 6 , the present application proposes a household appliance 200, which comprises the intelligent power module 100 in the above embodiment.

[0107] The household appliance in the embodiment can sufficiently improve the stability of overcurrent detection, effectively reduce the probability of malfunction due to false triggering in overcurrent detection, and ensure the overcurrent detection sensitivity under normal interference conditions.

[0108] In addition, other configurations and functions of the household appliance according to the embodiment of the present application are known to those skilled in the art, and are not described herein to avoid redundancy.

[0109] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0110] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0111] In addition, the terms "first", "second", and the like used in the embodiments of the present application are only for the purpose of description, and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of technical features referred to in the embodiments. Therefore, the features defined with "first", "second" and the like in the embodiments of the present application can be explicitly or implicitly indicated to include at least one of the features. In the description of the present application, the meaning of the word "plurality" is at least two or two or more, such as two, three, four, etc., unless otherwise specifically limited in the embodiments.

[0112] In the present application, unless otherwise specifically provided or limited in the embodiments, the terms "mounting", "connecting", "connecting" and "fixing" and the like appearing in the embodiments should be understood broadly, for example, the connection can be fixed connection, or detachable connection, or integral, which can be understood, or can be mechanical connection, electrical connection, etc. Of course, it can also be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements, or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific implementation situation.

[0113] In the present application, unless otherwise specifically provided and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0114] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. An overcurrent detection circuit for an intelligent power module, characterized in that, include: The overcurrent detection unit is used to output an overcurrent detection signal when an overcurrent is detected in the intelligent power module; A filtering unit, which is connected to the overcurrent detection unit, is used to filter out interference signals in the overcurrent detection signal; An anti-interference enhancement unit, which is connected to the filtering unit, is used to generate an anti-interference enhancement signal based on the upper tube switching action interval and / or lower tube switching action interval of the intelligent power module, and to enhance the interference filtering capability of the filtering unit based on the anti-interference enhancement signal. The filtering unit includes a first filtering section and a second filtering section. The first filtering section is used to filter out interference signals in the overcurrent detection signal when the filtering unit does not receive the anti-interference enhancement signal. The second filtering section is used to work with the first filtering section to filter out interference signals in the overcurrent detection signal when the filtering unit receives the anti-interference enhancement signal. The overcurrent detection unit includes: The current sampling terminal is used to sample the current signal; A comparator, wherein the positive input terminal of the comparator is connected to the current sampling terminal and the negative input terminal of the comparator is connected to a reference power supply, and is used to output an overcurrent signal when the current signal is greater than the current protection threshold provided by the reference power supply; A shaping circuit, the input of which is connected to the output of the comparator, is used to shape the overcurrent signal and output the overcurrent detection signal.

2. The overcurrent detection circuit according to claim 1, characterized in that, The first filter section includes: A first filter resistor, one end of which is connected to the output terminal of the overcurrent detection unit; A first filter capacitor, one end of which is connected to the other end of the first filter resistor and has a first node, the other end of which is grounded, and the first node is connected to the second filter section.

3. The overcurrent detection circuit according to claim 2, characterized in that, The second filter section includes: A first transmission gate, one end of which is connected to the first node, and the enable terminal of the first transmission gate is connected to the output terminal of the anti-interference enhancement unit; The second filter capacitor has one end connected to the other end of the first transmission gate, and the other end grounded.

4. The overcurrent detection circuit according to claim 3, characterized in that, When the interval between the upper switch signal and / or the lower switch signal of any two phases in the three-phase bridge arm of the intelligent power module is less than a first preset interval, the anti-interference enhancement unit controls the first transmission gate to open, so that the first filter capacitor and the second filter capacitor can work in parallel.

5. The overcurrent detection circuit according to claim 4, characterized in that, The anti-interference enhancement unit includes: The first edge interval detection sub-circuit, whose output terminal serves as the output terminal of the anti-interference enhancement unit, is used to simultaneously detect the six switching control signals of the intelligent power module, and outputs an enable signal to the first transmission gate when the upper switch signal interval and / or the lower switch signal interval is less than a first preset interval.

6. The overcurrent detection circuit according to claim 4, characterized in that, The anti-interference enhancement unit includes: The second edge interval detection sub-circuit is used to simultaneously detect the three upper-side switch signals of the intelligent power module, so as to output a first control signal when the interval between the upper-side switch signals is less than a first preset interval. The third edge interval detection sub-circuit is used to simultaneously detect the three down-tube control signals of the intelligent power module, so as to output a second control signal when the down-tube switching signal interval is less than the first preset interval. The first OR gate has its first input connected to the output of the second edge spacing detection sub-circuit, its second input connected to the output of the third edge spacing detection sub-circuit, and its output serving as the output of the anti-interference enhancement unit. The first OR gate outputs an enable signal to the first transmission gate based on the first control signal and the second control signal.

7. The overcurrent detection circuit according to claim 5 or 6, characterized in that, The anti-interference enhancement unit further includes: The first MOSFET has its first terminal connected to one end of the second filter capacitor and the other end of the first transmission gate, and its second terminal is grounded. An inverter, the input terminal of which is connected to the enable terminal of the first transmission gate, and the output terminal of which is connected to the control terminal of the first MOS transistor.

8. The overcurrent detection circuit according to claim 2, characterized in that, The second filter section includes: The second transmission gate has one end connected to one end of the first filter resistor, and the enable terminal of the second transmission gate is connected to the output terminal of the anti-interference enhancement unit. The second filter resistor has one end connected to the other end of the second transmission gate and the other end connected to the first node.

9. The overcurrent detection circuit according to claim 8, characterized in that, When the interval between the upper switch signal and / or the lower switch signal of any two phases in the three-phase bridge arm of the intelligent power module is less than a first preset interval, the anti-interference enhancement unit controls the second transmission gate to turn off, so that the first filter resistor can work.

10. The overcurrent detection circuit according to claim 9, characterized in that, The anti-interference enhancement unit includes: The fourth edge interval detection sub-circuit, whose output terminal serves as the output terminal of the anti-interference enhancement unit, is used to simultaneously detect the six switching control signals of the intelligent power module, and outputs a shutdown signal to the second transmission gate when the upper switch signal interval and / or the lower switch signal interval is less than the first preset interval.

11. The overcurrent detection circuit according to claim 9, characterized in that, The anti-interference enhancement unit includes: The fifth edge interval detection sub-circuit is used to simultaneously detect the three upper-side switch signals of the intelligent power module, so as to output a first control signal when the interval between the upper-side switch signals is less than a first preset interval; The sixth edge interval detection sub-circuit is used to simultaneously detect the three lower-channel control signals of the intelligent power module, so as to output a second control signal when the lower-channel switch signal interval is less than the first preset interval; The first NOR gate has its first input connected to the output of the fifth edge spacing detection sub-circuit, its second input connected to the output of the sixth edge spacing detection sub-circuit, and its output serving as the output of the anti-interference enhancement unit. The first NOR gate outputs a shutdown signal to the second transmission gate based on the first control signal and the second control signal.

12. A smart power module, characterized in that, Includes the overcurrent detection circuit according to any one of claims 1-11.

13. A household appliance, characterized in that, Includes the intelligent power module according to claim 12.

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