Overcurrent protection circuit and electronic product

Abstract

The utility model discloses an overcurrent protection circuit and an electronic product. The overcurrent protection circuit comprises a switching circuit, a sampling circuit, a comparison circuit and a control circuit. The comparison circuit is coupled with the sampling circuit, the comparison circuit outputs a first comparison signal when the sampling signal is larger than the reference signal, and the control circuit controls the switching circuit to be switched off until the control circuit receives an external abnormity clearing signal and controls the switching circuit to be switched on when receiving the first comparison signal output by the comparison circuit. According to the invention, power can be cut off in time when overcurrent occurs, a power device is prevented from being damaged, the overcurrent protection circuit can be recovered to a conducting state without power off, and the use and the operation are simpler.

Description

Technical Field

[0001] This application relates to the field of electronic technologies, and particularly to an overcurrent protection circuit and an electronic product. Background Art

[0002] During the operation of a chip or a circuit, the current may suddenly increase abnormally. When the current continuously exceeds a certain value, it may cause the chip or the circuit to burn out or malfunction. Summary of the Utility Model

[0003] The main technical problem to be solved by this application is to provide an overcurrent protection circuit and an electronic product, which can automatically monitor the magnitude of the current of the electronic product and cut off the current in time to reduce losses when the current magnitude is abnormal.

[0004] To solve the above technical problem, the technical solution adopted by this application is to provide an overcurrent protection circuit, which includes: a switching circuit; a sampling circuit coupled to the switching circuit, the sampling circuit being configured to sample the current flowing through the sampling circuit to obtain a sampling signal; a comparison circuit coupled to the sampling circuit, the comparison circuit being configured to compare the received sampling signal with a reference signal and output a first comparison signal when the sampling signal is greater than the reference signal; a control circuit including a first input terminal, a second input terminal, and an output terminal, the first input terminal being coupled to the comparison circuit, the second input terminal being configured to receive an external anomaly clearing signal, the output terminal being coupled to the switching circuit, when the control circuit receives the first comparison signal output by the comparison circuit, the control circuit controls the switching circuit to turn off until the control circuit receives the external anomaly clearing signal, and the control circuit controls the switching circuit to turn on.

[0005] In a possible implementation, the switching circuit has a first control terminal and a second control terminal, the first control terminal is coupled to the control circuit, the second control terminal is configured to receive an external control signal, the switching circuit is controlled to turn on and off by the control circuit, or the switching circuit is controlled to turn on and off by the external control signal.

[0006] In a possible implementation, the overcurrent protection circuit further includes: a conversion circuit, one end of the conversion circuit is coupled to the sampling circuit, and the other end of the conversion circuit is coupled to the comparison circuit. Wherein, the sampling signal sampled by the sampling circuit is a current signal, and the conversion circuit is configured to convert the current signal into a voltage signal.

[0007] In a possible implementation, the comparison circuit includes: a voltage comparator, an input end of the voltage comparator is coupled to the conversion circuit, and an output end of the voltage comparator is coupled to the control circuit. Wherein, the voltage comparator outputs a first comparison signal when the sampling signal is greater than the reference signal, and the voltage comparator outputs a second comparison signal when the sampling signal is not greater than the reference signal.

[0008] In a possible implementation, the control circuit is a logic gate circuit, and the logic gate circuit includes a first input end, a second input end, and an output end; wherein, the first comparison signal is a high-level signal, and the second comparison signal is a low-level signal; when the control circuit receives the high-level signal, it outputs a low-level signal to control the switch circuit to turn off, and when the control circuit receives an external abnormal clearing signal, the control circuit outputs a high-level signal to control the switch circuit to turn on.

[0009] In a possible implementation, the sampling circuit is any one of a sampling resistor, a Hall device, and a current transformer device.

[0010] In a possible implementation, the comparison circuit further includes: a signal amplification circuit, the signal amplification circuit is coupled to the sampling circuit, and the signal amplification circuit is used to amplify the sampling signal output by the sampling circuit; preferably, the signal amplification circuit is a signal amplifier.

[0011] In a possible implementation, the switch circuit has one of a current input end and a current output end, and the sampling circuit has the other of a current input end and a current output end.

[0012] In a possible implementation, the switch circuit is any one of a field effect transistor device, a triode device, and a gallium nitride semiconductor device.

[0013] To solve the above technical problems, another technical solution adopted by this application is to provide an electronic product, and the electronic product includes: an overcurrent protection circuit, and the overcurrent protection circuit is the above-mentioned overcurrent protection circuit; a power device, and the power device is connected to the overcurrent protection circuit.

[0014] The beneficial effects of this application are as follows: Different from the prior art, this application provides an overcurrent protection circuit and an electronic product. When an overcurrent problem occurs due to an increase in current, the collected signal is greater than the reference signal, and the comparison circuit outputs a first comparison signal. After receiving the first comparison signal, the control circuit controls the switch circuit to turn off, and the overcurrent protection circuit enters a self-locking state. In the self-locking state, the overcurrent protection circuit stops supplying power to the subsequent power device, avoiding damage to the power device. In the self-locking state, the user can input an abnormal clearing signal through the second input terminal to make the overcurrent protection circuit return to the conducting state. As described above, it can cut off the power in time when an overcurrent occurs, avoid damaging the power device, and the overcurrent protection circuit can return to the conducting state without power-off, making the operation simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic block diagram of the structure of an embodiment of the overcurrent protection circuit of this application;

[0017] Figure 2 It is a schematic block diagram of the structure of an embodiment of the electronic product of this application.

[0018] Among them, 100 / 300, overcurrent protection circuit; 10, switch circuit; 1l, first control terminal; 12, second control terminal; 20, sampling circuit; 30, conversion circuit; 40, comparison circuit; 41, signal amplification circuit; 42, voltage comparator; 50, control circuit; 51, first input terminal; 52, second input terminal; 200, electronic product; 400, power device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0020] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "the", and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless clearly indicated otherwise in the context. The term "a plurality" generally includes at least two, but does not exclude the case of including at least one.

[0021] It should be understood that the term "and / or" used herein is only an associative relationship describing associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0022] It should be understood that the terms "include", "comprise", or any other variants used herein are intended to cover non-exclusive inclusion, such that a process, method, article, or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article, or device. Without further limitation, elements defined by the statement "including..." do not exclude the existence of additional identical elements in the process, method, article, or device including the said elements.

[0023] During the operation of a chip or a circuit, when an abnormality occurs, the current will suddenly increase. When the current continuously exceeds a certain value, it may cause the chip or the circuit to burn out or malfunction.

[0024] Based on the above problems, the present application provides an overcurrent protection circuit and an electronic product. By comparing a sampling signal with a reference signal through a comparison circuit, when the sampling signal is greater than the reference signal, the control circuit controls the switching circuit to turn off, which can cut off the current in time when the current abnormally increases and avoid the electronic product from burning out.

[0025] The following describes in detail an overcurrent protection circuit and an electronic product provided by the present application with reference to the accompanying drawings and embodiments.

[0026] The present application provides an overcurrent protection circuit. Please refer to Figure 1 , Figure 1 which is a schematic block diagram of a structure of an embodiment of the overcurrent protection circuit of the present application. In some embodiments, the overcurrent protection circuit 100 includes a switching circuit 10, a sampling circuit 20, a comparison circuit 40, and a control circuit 50.

[0027] The sampling circuit 20 is coupled to the switching circuit 10. The sampling circuit 20 is configured to sample the current flowing through the sampling circuit 20 to obtain a sampling signal. The comparison circuit 40 is coupled to the sampling circuit 20. The comparison circuit 40 is configured to compare the received sampling signal with a reference signal and output a first comparison signal when the sampling signal is greater than the reference signal. The control circuit 50 includes a first input terminal 51, a second input terminal 52, and an output terminal (not labeled). The first input terminal 51 is coupled to the comparison circuit 40. The second input terminal 52 is configured to receive an external abnormal clearing signal. The output terminal is coupled to the switching circuit 10. When the control circuit 50 receives the first comparison signal output by the comparison circuit 40, the control circuit 50 controls the switching circuit 10 to turn off until the control circuit 50 receives the external abnormal clearing signal, and then the control circuit 50 controls the switching circuit 10 to turn on. Specifically, the overcurrent protection circuit 100 of the present application can be disposed on the pre-stage circuit for supplying power to the power device. The power device refers to the device that requires overcurrent protection. The power device can specifically be a semiconductor device, a resistor device, etc. Among them, the switching circuit 10 and the sampling circuit 20 are serially coupled. The current flows through the switching circuit 10 and the sampling circuit 20 to supply power to the power device. The sampling circuit 20 is configured to sample the current flowing through the sampling circuit 20 to obtain a sampling signal. Among them, the signal sampled by the sampling circuit 20 is a current signal, and the current signal also needs to be converted into a voltage signal, and the sampling signal that is a voltage signal is output to the comparison circuit 40. The comparison circuit 40 determines whether there is overcurrent by comparing the magnitudes of the sampling signal and the reference signal. Among them, the magnitude of the reference signal can be adjusted according to the rated current magnitude of the power device. The larger the rated current of the power device, the larger the value of the reference signal; the smaller the rated current of the power device, the smaller the value of the reference signal. When the sampling signal is greater than the reference signal, there is an overcurrent phenomenon in the current. Then the comparison circuit 40 outputs the first comparison signal to the control circuit 50, and the control circuit 50 controls the switching circuit 10 to turn off to avoid damaging the power device due to the overcurrent.

[0028] In a specific application scenario, after the overcurrent protection circuit 100 is powered on and the power device connected to the overcurrent protection circuit 100 is operating normally, the sampling signal sampled by the sampling circuit 20 does not exceed the reference signal. At this time, the comparison circuit 40 outputs a second comparison signal, and the control circuit 50 controls the switch circuit 10 to turn on. When the current suddenly increases, the sampling signal sampled by the sampling circuit 20 increases. If the sampling signal is greater than the reference signal, the comparison circuit 40 outputs a first comparison signal, and the control circuit 50 controls the switch circuit 10 to turn off. The overcurrent protection circuit 100 enters a self-locking state, and the overcurrent protection circuit 100 stops supplying power to the power device connected to the overcurrent protection circuit 100. In the self-locking state, the sampling signal sampled by the sampling circuit 20 is 0. At this moment, the sampling signal is less than the reference signal, and the comparison circuit 40 outputs a second comparison signal. When the overcurrent protection circuit 100 is in the self-locking state, the control circuit 50 keeps the switch circuit 10 in the off state even after receiving the second comparison signal. The control circuit 50 has a second input terminal 52. If the user determines that there is no overcurrent risk, the user can input an abnormality clearing signal through the second input terminal 52 to enable the control circuit 50 to control the switch circuit 10 to turn on, thereby releasing the self-locking state of the overcurrent protection circuit 100 and allowing the overcurrent protection circuit 100 to supply power to the power device normally.

[0029] Different from the prior art, the present application provides an overcurrent protection circuit 100. When the current increases and an overcurrent problem occurs, the acquisition signal is greater than the reference signal, the comparison circuit 40 outputs a first comparison signal, and the control circuit 50 controls the switch circuit 10 to shut down after receiving the first comparison signal. The overcurrent protection circuit 100 enters a self-locking state. In the self-locking state, the overcurrent protection circuit 100 stops supplying power to the subsequent power device to avoid damage to the power device. In the self-locking state, the user can input an abnormality clear signal through the second input terminal 52 to restore the overcurrent protection circuit 100 to the on state. As described above, the power can be cut off in time when an overcurrent occurs, avoiding damage to the power device. The overcurrent protection circuit 100 can be restored to the on state without cutting off the power, making it easier to use and operate.

[0030] In some embodiments, the switch circuit 10 is any one of a field effect transistor device, a triode device, and a gallium nitride semiconductor device.

[0031] In some embodiments, the switch circuit 10 has a first control terminal 11 and a second control terminal 12. The first control terminal 11 is coupled to the control circuit 50, and the second control terminal 12 is used to receive an external control signal. The switch circuit 10 is controlled to be turned on and off by the control circuit 50, or the switch circuit 10 is controlled to be turned on and off by an external control signal. Specifically, the switch circuit 10 can turn itself on and off by receiving a signal output by the control circuit 50. A user can also directly control the on and off of the switch circuit 10 through the second control terminal 12.

[0032] In some embodiments, the overcurrent protection circuit 100 further includes a conversion circuit 30. One end of the conversion circuit 30 is coupled to the sampling circuit 20, and the other end of the conversion circuit 30 is coupled to the comparison circuit 40. Among them, the sampling signal sampled by the sampling circuit 20 is a current signal, and the conversion circuit 30 is used to convert the current signal into a voltage signal. Specifically, the magnitude of the current signal is greatly affected by the impedance of the power device, while the magnitude of the voltage signal is stable, less affected by impedance fluctuations, and the voltage signal has less transmission attenuation and less interference. Voltage comparison devices and measurement devices are also more common. In this embodiment, by setting the conversion circuit 30 to convert the current signal into a voltage signal, it is convenient to monitor the change of the current magnitude subsequently. Among them, the conversion circuit 30 may specifically include one or more of an operational amplifier device, a Hall sensor, and a current transformer. The above devices can all convert the current signal into a voltage signal. In this embodiment, the conversion circuit 30 is specifically an operational amplifier.

[0033] In some embodiments, the comparison circuit 40 includes: a voltage comparator 42. The input end of the voltage comparator 42 is coupled to the conversion circuit 30, and the output end of the voltage comparator 42 is coupled to the control circuit 50. Among them, the voltage comparator 42 outputs a first comparison signal when the sampling signal is greater than the reference signal, and the voltage comparator 42 outputs a second comparison signal when the sampling signal is not greater than the reference signal. Specifically, the voltage comparator 42 can compare the input sampling signal with the set reference signal and output a corresponding electrical signal according to the comparison result. In this embodiment, the voltage comparator 42 is composed of an operational amplifier. The first comparison signal is a high-level signal, and the second comparison signal is a low-level signal. When the input sampling signal is not greater than the reference signal, the voltage comparator 42 outputs a low-level signal. When the input sampling signal is greater than the reference signal, the voltage comparator 42 outputs a high-level signal.

[0034] Furthermore, in this embodiment, the control circuit 50 is a logic gate circuit, which includes a first input terminal 51, a second input terminal 52, and an output terminal (not labeled); wherein the first comparison signal is a high-level signal, and the second comparison signal is a low-level signal; when the control circuit 50 receives a high-level signal, it outputs a low-level signal to control the switch circuit 10 to be turned off; when the control circuit 50 receives an external abnormality clearing signal, the control circuit 50 outputs a high-level signal to control the switch circuit 10 to be turned on. Specifically, the first input terminal 51 is coupled to the comparison circuit 40, and the second input terminal 52 is used to receive the external abnormality clearing signal. When the overcurrent protection circuit 100 is normally powered on, the sampling signal is less than the reference signal, and the comparison circuit 40 outputs the second comparison signal. The second comparison signal is a low-level signal. The control circuit 50 inputs the low-level signal and outputs a high-level signal to control the switch circuit 10 to be turned on. When an overcurrent condition occurs and the sampling signal is greater than the reference signal, the comparison circuit 40 outputs a first comparison signal, which is a high-level signal. The control circuit 50 inputs a high-level signal and outputs a low-level signal to control the switch circuit 10 to turn off. After the switch circuit 10 is turned off, the overcurrent protection circuit 100 enters a self-locking state. In this self-locking state, even if the overcurrent condition disappears, the control circuit 50 inputs a low-level signal and the control circuit 50 still outputs a low-level signal to keep the switch circuit 10 off, causing the subsequent power devices to enter a protection state. If the user wishes to release the self-locking state of the overcurrent protection circuit 100, an abnormality clearing signal can be input externally through the second input terminal 52 of the control circuit 50, causing the control circuit 50 to output a high-level signal to restore the switch circuit 10 to a conductive state. In other embodiments, if the user wishes to release the self-locking state of the overcurrent protection circuit 100, the user can directly control the switch circuit 10 to turn on through the second control terminal 12 of the switch circuit 10, restoring it to a conductive state.

[0035] In some embodiments, the sampling circuit 20 can be any one of a sampling resistor, a Hall effect device, and a current transformer. Specifically, the sampling resistor can obtain a sampling signal based on Ohm's law, according to the relationship between voltage, current, and resistance. The Hall effect device can obtain a sampling signal based on the Hall effect principle. A current transformer can obtain a sampling signal based on the principle of electromagnetic induction. The specific structure of the sampling circuit 20 is not specifically limited.

[0036] In this embodiment, the comparison circuit 40 further includes: a signal amplification circuit 41. The signal amplification circuit 41 is coupled to the sampling circuit 20 and is configured to amplify the sampling signal output by the sampling circuit 20. Preferably, the signal amplification circuit 41 is a signal amplifier. Specifically, the signal amplification circuit 41 is configured to amplify the sampling signal before comparing the magnitudes of the sampling signals. The purpose of the amplification process is to improve the accuracy of the comparison. It is understandable that the sampled sampling signal may have the problem of weak signal. When the sampling signal fluctuates slightly, the comparison circuit 40 may not be able to recognize the change of the sampling signal. By setting the signal amplification circuit 41 to amplify the sampling signal, the monitoring effect of the current magnitude can be better.

[0037] In some embodiments, the switching circuit 10 has one of a current input terminal (not labeled) and a current output terminal (not labeled), and the sampling circuit 20 has the other. Specifically, in this embodiment, the switching circuit 10 has a current input terminal, and the sampling circuit 20 has a current output terminal. The current output terminal is connected to a power device, and the current flows through the switching circuit 10 and the sampling circuit 20 in sequence to supply power to the subsequent power device. In some other embodiments, the sampling circuit 20 may have a current input terminal, the switching circuit 10 may have a current output terminal, the current output terminal is connected to a power device, and the current passes through the sampling circuit 20 and the switching circuit 10 in sequence to supply power to the subsequent power device.

[0038] Different from the prior art, the present application provides an overcurrent protection circuit 100. When an overcurrent problem occurs due to an increase in current, the acquisition signal is greater than the reference signal, the comparison circuit 40 outputs a first comparison signal, and the control circuit 50 controls the switching circuit 10 to turn off after receiving the first comparison signal. The overcurrent protection circuit 100 enters a self-locking state. In the self-locking state, the overcurrent protection circuit 100 stops supplying power to the subsequent power device to avoid damage to the power device. In the self-locking state, the user can input an abnormal clearance signal through the second input terminal 52 to make the overcurrent protection circuit 100 return to the conducting state. As described above, it can cut off the power in time when overcurrent occurs to avoid damaging the power device, and the overcurrent protection circuit 100 can be restored to the conducting state without power-off, making the operation simpler.

[0039] Correspondingly, the present application also proposes an electronic product. Please refer to Figure 2 , Figure 2 which is a schematic block diagram of a structure of an embodiment of the electronic product of the present application. The electronic product 200 includes an overcurrent protection circuit 300 and a power device 400. Among them, the overcurrent protection circuit 300 is the overcurrent protection circuit of any one of the above; the power device 400 is connected to the overcurrent protection circuit 300.

[0040] The above are only embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent principle transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present application by the same token.

Claims

1. An overcurrent protection circuit, characterized in that, The overcurrent protection circuit includes: A switching circuit; A sampling circuit, the sampling circuit being coupled to the switching circuit, the sampling circuit being configured to sample the current flowing through the sampling circuit to obtain a sampling signal; A comparison circuit, the comparison circuit being coupled to the sampling circuit, the comparison circuit being configured to compare the received sampling signal with a reference signal and output a first comparison signal when the sampling signal is greater than the reference signal; A control circuit, the control circuit including a first input terminal, a second input terminal, and an output terminal, the first input terminal being coupled to the comparison circuit, the second input terminal being configured to receive an external anomaly clearing signal, the output terminal being coupled to the switching circuit, when the control circuit receives the first comparison signal output by the comparison circuit, the control circuit controls the switching circuit to turn off until the control circuit receives the external anomaly clearing signal, and the control circuit controls the switching circuit to turn on.

2. The overcurrent protection circuit according to claim 1, wherein The switching circuit has a first control terminal and a second control terminal, the first control terminal being coupled to the control circuit, the second control terminal being configured to receive an external control signal, the switching circuit is controlled to turn on and off by the control circuit, or the switching circuit is controlled to turn on and off by the external control signal.

3. The overcurrent protection circuit according to claim 1, wherein The overcurrent protection circuit further includes: A conversion circuit, one end of the conversion circuit being coupled to the sampling circuit, the other end of the conversion circuit being coupled to the comparison circuit, wherein the sampling signal sampled by the sampling circuit is a current signal, and the conversion circuit is configured to convert the current signal into a voltage signal.

4. The overcurrent protection circuit according to claim 3, wherein The comparison circuit includes: A voltage comparator, an input terminal of the voltage comparator being coupled to the conversion circuit, an output terminal of the voltage comparator being coupled to the control circuit, wherein the voltage comparator outputs a first comparison signal when the sampling signal is greater than the reference signal, and the voltage comparator outputs a second comparison signal when the sampling signal is not greater than the reference signal.

5. The overcurrent protection circuit according to claim 4, wherein The control circuit is a logic gate circuit, the logic gate circuit including a first input terminal, a second input terminal, and an output terminal; wherein, the first comparison signal is a high-level signal, the second comparison signal is a low-level signal; when the control circuit receives the high-level signal, it outputs a low-level signal to control the switching circuit to turn off, and when the control circuit receives the external anomaly clearing signal, the control circuit outputs a high-level signal to control the switching circuit to turn on.

6. The overcurrent protection circuit according to claim 1, wherein The sampling circuit is any one of a sampling resistor, a Hall device, and a current transformer device.

7. The overcurrent protection circuit according to claim 1, wherein The comparison circuit further includes: A signal amplification circuit, the signal amplification circuit being coupled to the sampling circuit, the signal amplification circuit being configured to amplify the sampling signal output by the sampling circuit; Preferably, the signal amplification circuit is a signal amplifier.

8. The overcurrent protection circuit according to claim 1, wherein The switching circuit has one of a current input terminal and a current output terminal, and the sampling circuit has the other of the current input terminal and the current output terminal.

9. The overcurrent protection circuit according to claim 1, wherein the switching circuit is any one of a field effect transistor device, a triode device, and a gallium nitride semiconductor device.

10. An electronic product, characterized in that, The electronic product includes: an overcurrent protection circuit, where the overcurrent protection circuit is the overcurrent protection circuit according to any one of claims 1-9; a power device, where the power device is connected to the overcurrent protection circuit.

Images