Load short circuit protection circuit and electronic device

Abstract

The embodiment of the application provides a load short circuit protection circuit and electronic equipment, including: load tube unit, sampling unit, load short circuit protection trigger unit, control unit, processing unit; the load tube unit is used for external load and power supply, to supply power to the load; the sampling unit is used for collecting load current information in the load tube unit, generating a sampling signal according to the collected load current information and sending to the load short circuit protection trigger unit; the load short circuit protection trigger unit is used for generating a short circuit protection trigger signal according to the sampling signal when the load short circuit occurs, and sending the short circuit protection trigger signal to the control unit; the control unit is used for stopping sending the drive signal of opening the load tube to the load tube unit according to the control signal sent by the processing unit and the short circuit protection trigger signal; the load tube unit is also used for closing the load tube when the drive signal of opening the load tube is not received, to disconnect the connection between the load tube unit and the load.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic circuit, in particular to a load short circuit protection circuit and electronic equipment. BACKGROUND

[0002] In the electronic circuit, generally by the battery or other power supply to the load power. Load in the running process may occur short circuit phenomenon, resulting in the current in the circuit increases sharply, burn the electronic devices in the circuit, and even damage the power supply, so need to set short circuit protection mechanism in the circuit. Because the voltage across the resistance will increase with the increase of current, therefore, usually in series between the battery and the load sampling resistance, when the current in the circuit increases sharply, the voltage across the sampling resistance also increases accordingly, through the sampling resistance can detect the circuit short circuit fault information, and take appropriate measures to protect the short circuit.

[0003] For example, in a photovoltaic power generation system, a photovoltaic charge and discharge controller is a device for controlling charging and discharging of a storage battery. The controller controls on and off of the storage battery to a load device through a load tube. The controller is externally connected with the load device at a load end. When the load device fails or a short circuit occurs, a load current will sharply rise, which will burn the load tube and other electronic devices in the circuit. In order to detect the short circuit failure in time, a sampling resistor is connected in series between the storage battery and the load. A short circuit protection circuit collects discharge information such as the load current through the sampling resistor and determines whether the load exists short circuit. The short circuit protection circuit includes the sampling resistor, the load tube, a comparator, an optocoupler and a self-locking control circuit composed of a plurality of NAND gates. The optocoupler is an electronic device in which a light emitting diode and a photoresistor are packaged in a tube shell. One end of the load tube is externally connected with a power supply through the sampling resistor, and the other end of the load tube is externally connected with the load. The control end of the load tube is connected with the self-locking control circuit. The load short circuit protection circuit can collect the load current through the sampling resistor. When the load is turned on and no short circuit occurs, the load current is normal, the self-locking control circuit outputs a drive signal for turning on the load tube, the load tube is turned on, and the power supply supplies power to the load through the sampling resistor and the load tube. When the load has a short circuit, the load short circuit protection circuit collects the load current through the sampling resistor. It can be determined through the comparator that the load current exceeds a preset threshold, which indicates that the load has a short circuit failure. That is, when the load short circuit protection circuit collects a too large load current through the sampling resistor, it can be determined that there is a short circuit failure. At this time, the comparator in the circuit generates a short circuit protection trigger signal, and provides the short circuit protection trigger signal to the self-locking control circuit through the optocoupler. After receiving the short circuit protection trigger signal, the self-locking control circuit stops sending the drive signal for turning on the load tube to the load tube, so as to turn off the load tube and disconnect the circuit from the load, thereby playing a role of short circuit protection. However, in the existing load short circuit protection circuit, the transmission of the short circuit trigger signal from the comparator to the self-locking control circuit through the optocoupler will cause transmission delay of the short circuit trigger signal, which will reduce the reliability of the short circuit protection. SUMMARY

[0004] Therefore, the application provides a load short circuit protection circuit and an electronic device to solve the problem of transmission delay of the short circuit trigger signal caused by the optocoupler in the prior art.

[0005] In a first aspect, an embodiment of the application provides a load short circuit protection circuit, including a load tube unit, a sampling unit, a load short circuit protection trigger unit, a control unit and a processing unit. The load tube unit is connected with the sampling unit and the control unit. The sampling unit is connected with the load short circuit protection trigger unit and the processing unit. The load short circuit protection trigger unit is connected with the control unit and the processing unit. The control unit is connected with the processing unit. The load tube unit includes a load tube.

[0006] The load pipe unit is configured to externally connect a load and a power supply to supply power to the load.

[0007] The sampling unit is configured to collect load current information in the load pipe unit, generate a sampling signal according to the collected load current information, and send the sampling signal to the load short-circuit protection triggering unit.

[0008] The processing unit is configured to determine whether to supply power to the load, and generate a control signal according to a determination result, and send the control signal to the control unit.

[0009] The load short-circuit protection triggering unit is configured to generate a short-circuit protection triggering signal when a load short circuit occurs according to the sampling signal, and send the short-circuit protection triggering signal to the control unit.

[0010] The control unit is configured to stop sending a load pipe opening driving signal to the load pipe unit according to the control signal and the short-circuit protection triggering signal when a load short circuit occurs.

[0011] The load pipe unit is further configured to close the load pipe to disconnect the load pipe unit from the load when the load pipe opening driving signal is not received.

[0012] Preferably, the circuit further comprises a self-locking unit; the self-locking unit is connected to the processing unit, the self-locking unit is connected to the load short-circuit protection triggering unit, and the self-locking unit is connected to the control unit.

[0013] The self-locking unit is configured to lock a short-circuit protection triggering signal output by the load short-circuit protection unit when a load short circuit occurs.

[0014] Preferably, the control signal comprises a first control signal or a second control signal; the first control signal is a signal for indicating that the load is supplied with power, and the second control signal is a signal for indicating that the load is stopped from being supplied with power.

[0015] The processing unit is specifically configured to determine that the load is supplied with power when a load power supply instruction is received, and generate a first control signal.

[0016] Alternatively, when a load power supply stop instruction is received, it is determined that the load is stopped from being supplied with power, and a second control signal is generated.

[0017] Alternatively, when it is detected that a load short circuit occurs, it is determined that the load is stopped from being supplied with power, and a second control signal is generated.

[0018] Preferably, the processing unit is specifically configured to determine that the load is short-circuited when the signal output by the load short-circuit protection trigger unit and the self-locking unit is converted from the first level signal to the second level signal.

[0019] Preferably, the sampling unit comprises a sampling operational amplifier and a sampling resistor, wherein one end of the sampling resistor is connected to a power supply, the other end of the sampling resistor is connected to the first end of the load tube, the positive input end of the sampling operational amplifier is connected to the one end of the sampling resistor, the negative input end of the sampling operational amplifier is connected to the other end of the sampling resistor, the power supply input end of the sampling operational amplifier is connected to the first power supply, and the ground end of the sampling operational amplifier is grounded.

[0020] Preferably, the control unit comprises a diode, a first comparator, and a load driver.

[0021] Preferably, the negative electrode of the diode is connected to the load short-circuit protection trigger unit, the positive electrode of the diode is connected to the negative input end of the first comparator, the negative input end of the first comparator is connected to the processing unit, the power supply pin of the first comparator is connected to the first power supply, the ground pin of the first comparator is grounded, the output end of the first comparator is connected to the first input end of the load driver, the second input end of the load driver is connected to the first power supply, the power supply input end of the load driver is connected to the second power supply, the output end of the load driver is connected to the control end of the load tube, and the ground end of the load driver is connected to the second end of the load tube.

[0022] Preferably, the control unit further comprises a first resistor and a second resistor, wherein the second input end of the load driver is connected to the first power supply through the first resistor, and the negative input end of the first comparator is connected to the processing unit through the second resistor.

[0023] Preferably, the load short-circuit protection trigger unit is specifically configured to determine whether the load current exceeds a first preset threshold according to the sampling signal, and generate a first short-circuit protection trigger signal and send the first short-circuit protection trigger signal to the control unit when it is determined that the load current exceeds the first preset threshold.

[0024] Preferably, the load short-circuit protection trigger unit comprises a third resistor, a fourth resistor, and a second comparator, wherein one end of the third resistor is connected to the first power supply, the other end of the third resistor is connected to one end of the fourth resistor and the positive input end of the second comparator, the other end of the fourth resistor is grounded, the negative input end of the second comparator is connected to the output end of the sampling operational amplifier, the output end of the second comparator is connected to the negative electrode of the diode, the power supply pin of the second comparator is connected to the first power supply, and the ground pin of the second comparator is grounded.

[0025] Preferably, the load short-circuit protection triggering unit further comprises a fifth resistor and a first capacitor, wherein

[0026] The negative input end of the second comparator is connected with the output end of the sampling operational amplifier, comprising:

[0027] One end of the fifth resistor is connected with the output end of the sampling operational amplifier, and the other end of the fifth resistor is connected with the negative input end of the second comparator and one end of the first capacitor, and the other end of the first capacitor is grounded.

[0028] Preferably, the load short-circuit protection triggering unit comprises a first load short-circuit protection triggering module and a second load short-circuit protection triggering module.

[0029] The first load short-circuit protection triggering module is configured to determine whether the load current exceeds a second preset threshold according to the sampling signal, and generate a first short-circuit protection triggering signal when it is determined that the load current exceeds the second preset threshold.

[0030] The second load short-circuit protection triggering module is configured to determine whether the load current exceeds a third preset threshold according to the sampling signal, and generate a second short-circuit protection triggering signal when it is determined that the load current exceeds the third preset threshold, wherein the second preset threshold is greater than the third preset threshold.

[0031] The load short-circuit protection triggering unit is specifically configured to combine the first short-circuit protection triggering signal and the second short-circuit protection triggering signal into the short-circuit protection triggering signal, and send the short-circuit protection triggering signal to the control unit.

[0032] Preferably, the first load short-circuit protection triggering module comprises a sixth resistor, a seventh resistor and a third comparator, and the second load short-circuit protection triggering module comprises an eighth resistor and a fourth comparator, wherein

[0033] One end of the sixth resistor is connected with the first power supply, the other end of the sixth resistor is connected with one end of the seventh resistor and the positive input end of the third comparator, the negative input end of the third comparator is connected with the output end of the sampling operational amplifier, the other end of the seventh resistor is connected with one end of the eighth resistor and the positive input end of the fourth comparator, the negative input end of the fourth comparator is connected with the output end of the sampling operational amplifier, the other end of the eighth resistor is grounded, the output end of the third comparator is connected with the output end of the fourth comparator and then connected with the negative electrode of the diode, the power supply pin of the third comparator is connected with the first power supply, the ground pin of the third comparator is grounded, the power supply pin of the fourth comparator is connected with the first power supply, and the ground pin of the fourth comparator is grounded.

[0034] Preferably, the first load short-circuit protection triggering module further comprises a ninth resistor and a second capacitor, and the second load short-circuit protection triggering module further comprises a tenth resistor and a third capacitor; wherein,

[0035] The negative input end of the third comparator is connected with the output end of the sampling operational amplifier, comprising:

[0036] One end of the ninth resistor is connected with the output end of the sampling operational amplifier, and the other end of the ninth resistor is connected with the negative input end of the third comparator and one end of the second capacitor, and the other end of the second capacitor is grounded.

[0037] The negative input end of the fourth comparator is connected with the output end of the sampling operational amplifier, comprising:

[0038] One end of the tenth resistor is connected with the output end of the sampling operational amplifier, and the other end of the tenth resistor is connected with the negative input end of the fourth comparator and one end of the third capacitor, and the other end of the third capacitor is grounded.

[0039] Preferably, the self-locking circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor and a fifth comparator; wherein,

[0040] One end of the eleventh resistor is connected with the processing unit, the other end of the eleventh resistor is connected with the negative input end of the fifth comparator and one end of the twelfth resistor, the other end of the twelfth resistor is grounded, the positive input end of the fifth comparator is connected with the first power supply through the thirteenth resistor, the output end of the fifth comparator is connected with the negative electrode of the diode, the power supply pin of the fifth comparator is connected with the first power supply, and the ground pin of the fifth comparator is grounded.

[0041] Preferably, the self-locking circuit further comprises a fourteenth resistor; wherein one end of the fourteenth resistor is connected with the other end of the thirteenth resistor and the positive input end of the fifth comparator, and the other end of the fourteenth resistor is connected with the output end of the third comparator and the output end of the fourth comparator.

[0042] Preferably, the self-locking unit is further configured to, after the load is short-circuited, release the locking of the short-circuit protection triggering signal output by the load short-circuit protection triggering unit according to the received second control signal sent by the processing unit.

[0043] Preferably, the processing unit is further configured to, when it is determined that the load is powered, turn on the first power supply, so that the first power supply supplies power to the sampling unit, the load short-circuit protection triggering unit, the control unit and the self-locking unit.

[0044] The processing unit is further configured to, when determining to stop supplying power to the load, turn off the first power supply, so that the first power supply stops supplying power to the sampling unit, the load short-circuit protection triggering unit, the control unit and the self-locking unit.

[0045] Preferably, the load short-circuit protection circuit further comprises a switching unit, wherein

[0046] A first end of the switching unit is connected to the first power supply, and a second end of the switching unit is connected to the sampling unit, the load short-circuit protection triggering unit, the control unit and the self-locking unit respectively, and a control end of the switching unit is connected to the processing unit.

[0047] The processing unit is specifically configured to, when determining to supply power to the load, control the switching unit to be turned on, so that the first power supply supplies power to the sampling unit, the load short-circuit protection triggering unit, the control unit and the self-locking unit.

[0048] The processing unit is specifically configured to, when determining to stop supplying power to the load, control the switching unit to be turned off, so that the first power supply stops supplying power to the sampling unit, the load short-circuit protection triggering unit, the control unit and the self-locking unit.

[0049] In a second aspect, an electronic device is provided, which comprises the load short-circuit protection circuit according to any one of the first aspect.

[0050] The load short-circuit protection circuit provided in the embodiment of the present application comprises a load tube unit, a sampling unit, a load short-circuit protection triggering unit, a control unit and a processing unit. The load tube unit is connected with the sampling unit, the sampling unit is connected with the load short-circuit protection triggering unit and the processing unit, the load short-circuit protection triggering unit is connected with the control unit and the processing unit, and the control unit is connected with the processing unit. The load tube unit comprises a load tube. The load tube unit is used for connecting with a load and a power supply to supply power to the load. The sampling unit is used for collecting load current information in the load tube unit, generating a sampling signal according to the collected load current information and sending the sampling signal to the load short-circuit protection triggering unit. The processing unit is used for determining whether to supply power to the load and generating a control signal according to the determination result and sending the control signal to the control unit. The load short-circuit protection triggering unit is used for generating a short-circuit protection triggering signal according to the sampling signal when a load short circuit occurs and sending the short-circuit protection triggering signal to the control unit. The control unit is used for stopping sending a driving signal for turning on the load tube to the load tube unit according to the control signal and the short-circuit protection triggering signal when the load short circuit occurs. The load tube unit is also used for turning off the load tube when the driving signal for turning on the load tube is not received, so as to disconnect the load tube unit and the load. In this way, when the load short circuit occurs, the load short-circuit protection triggering unit can determine that the load short circuit occurs according to the sampling signal and generate a corresponding short-circuit protection triggering signal sent to the control unit. The control unit stops sending the driving signal for turning on the load tube to the load tube unit according to the control signal and the short-circuit protection triggering signal, so that the load tube unit turns off the load tube when the driving signal for turning on the load tube is not received, thereby disconnecting the load tube unit and the load. In the above load short-circuit protection process, the short-circuit protection triggering signal does not need to be transmitted through an optical coupler, which reduces the transmission delay caused by the optical coupler to a certain extent and improves the reliability of the short-circuit protection. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0052] Figure 1 A structural schematic diagram of a load short-circuit protection circuit provided in the embodiment of the present application;

[0053] Figure 2 A structural schematic diagram of a sampling unit provided in the embodiment of the present application;

[0054] Figure 3 A structural schematic diagram of another sampling unit provided in the embodiment of the present application;

[0055] Figure 4 A structure schematic diagram of a control unit provided for an embodiment of the present application is shown in FIG. 1.

[0056] Figure 5 A structure schematic diagram of another control unit provided for an embodiment of the present application is shown in FIG. 2.

[0057] Figure 6 A structure schematic diagram of another control unit provided for an embodiment of the present application is shown in FIG. 3.

[0058] Figure 7 A structure schematic diagram of a load short-circuit protection triggering unit provided for an embodiment of the present application is shown in FIG. 4.

[0059] Figure 8 A structure schematic diagram of another load short-circuit protection triggering unit provided for an embodiment of the present application is shown in FIG. 5.

[0060] Figure 9 A structure schematic diagram of another load short-circuit protection triggering unit provided for an embodiment of the present application is shown in FIG. 6.

[0061] Figure 10 A structure schematic diagram of another load short-circuit protection triggering unit provided for an embodiment of the present application is shown in FIG. 7.

[0062] Figure 11 A structure schematic diagram of another load short-circuit protection circuit provided for an embodiment of the present application is shown in FIG. 8.

[0063] Figure 12 A structure schematic diagram of a self-locking unit provided for an embodiment of the present application is shown in FIG. 9.

[0064] Figure 13 A structure schematic diagram of another load short-circuit protection circuit provided for an embodiment of the present application is shown in FIG. 10.

[0065] Figure 14 A structure schematic diagram of another load short-circuit protection circuit provided for an embodiment of the present application is shown in FIG. 11. DETAILED DESCRIPTION

[0066] In order to better understand the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0067] It should be clear that the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0068] The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the description of the embodiments of the present application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0069] It should be understood that the term "and / or" used herein only describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B, which can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents that the front and rear associated objects have an "or" relationship.

[0070] In the related art, in a photovoltaic power generation system, a photovoltaic charge-discharge controller is a device for controlling the charging and discharging of a storage battery. The controller controls the on and off of the storage battery to a load device through a load tube. The load device is externally connected to the load end of the controller. When the load device fails or a short circuit occurs, the load current will rise sharply, which will burn out the electronic devices such as the load tube in the circuit. In order to detect the short circuit failure in time, a sampling resistor is connected in series between the storage battery and the load. The short circuit protection circuit collects the load current and other discharge information through the sampling resistor, and determines whether the load has a short circuit. The short circuit protection circuit includes a sampling resistor, a load tube, a comparator, an optocoupler, and a self-locking control circuit composed of a plurality of NAND gates. The optocoupler is an electronic device in which a light-emitting diode and a photoresistor are packaged in one shell. One end of the load tube is externally connected to the power supply through the sampling resistor, the other end of the load tube is externally connected to the load, and the control end of the load tube is connected to the self-locking control circuit. The load short circuit protection circuit can collect the load current through the sampling resistor. When the load is turned on and no short circuit occurs, the load current is normal, the self-locking control circuit outputs a drive signal to turn on the load tube, the load tube is turned on, and the power supply supplies power to the load through the sampling resistor and the load tube. When the load has a short circuit, the load short circuit protection circuit collects the load current through the sampling resistor. The comparator can determine that the load current exceeds the preset threshold, indicating that the load has a short circuit failure. That is, when the load short circuit protection circuit collects a large load current through the sampling resistor, it can be determined that there is a short circuit failure. At this time, the comparator in the circuit generates a short circuit protection trigger signal, and provides the generated short circuit protection trigger signal to the self-locking control circuit through the optocoupler. After receiving the short circuit protection trigger signal, the self-locking control circuit stops sending the drive signal to turn on the load tube to the load tube, so as to turn off the load tube and disconnect the circuit from the load, thereby playing a role in short circuit protection. However, in the existing load short circuit protection circuit, the transmission of the short circuit protection trigger signal is delayed due to the presence of the optocoupler in the process of providing the generated trigger signal to the self-locking control circuit through the optocoupler, which reduces the reliability of the short circuit protection.

[0071] To solve the above problems, the embodiment of the present application provides a load short-circuit protection circuit, which comprises a load tube unit, a sampling unit, a load short-circuit protection trigger unit, a control unit and a processing unit. The load tube unit is connected with the sampling unit, the sampling unit is connected with the load short-circuit protection trigger unit and the processing unit, the load short-circuit protection trigger unit is connected with the control unit and the processing unit, and the control unit is connected with the processing unit. The load tube unit comprises a load tube. The load tube unit is used for connecting an external load and a power supply to supply power to the load. The sampling unit is used for collecting load current information in the load tube unit, generating a sampling signal according to the collected load current information and sending the sampling signal to the load short-circuit protection trigger unit. The processing unit is used for determining whether to supply power to the load and generating a control signal according to a determination result and sending the control signal to the control unit. The load short-circuit protection trigger unit is used for generating a short-circuit protection trigger signal according to the sampling signal when a load short circuit occurs and sending the short-circuit protection trigger signal to the control unit. The control unit is used for stopping sending a drive signal for turning on the load tube to the load tube unit according to the control signal and the short-circuit protection trigger signal. The load tube unit is also used for turning off the load tube when the drive signal for turning on the load tube is not received, so as to disconnect the load tube unit and the load. In this way, when a load short circuit occurs, the load short-circuit protection trigger unit can determine that the load short circuit occurs according to the sampling signal, generate a corresponding short-circuit protection trigger signal and send the short-circuit protection trigger signal to the control unit. The control unit stops sending the drive signal for turning on the load tube to the load tube unit according to the control signal and the short-circuit protection trigger signal, so that the load tube unit turns off the load tube when the drive signal for turning on the load tube is not received, thereby disconnecting the load tube unit and the load. In the above load short-circuit protection process, the short-circuit protection trigger signal does not need to be transmitted through an optical coupler, which reduces the transmission delay caused by the optical coupler to a certain extent and improves the reliability of short-circuit protection. The following will be described in detail.

[0072] Figure 1 A structure diagram of a load short-circuit protection circuit provided by the embodiment of the present application is shown in the figure. Figure 1 As shown in the figure, the load short-circuit protection circuit comprises a load tube unit 101, a sampling unit 102, a load short-circuit protection trigger unit 103, a control unit 104 and a processing unit 105. The load tube unit 101 is connected with the sampling unit 102 and the control unit 104, the sampling unit 102 is connected with the load short-circuit protection trigger unit 103 and the processing unit 105, the load short-circuit protection trigger unit 103 is connected with the control unit 104 and the processing unit 105, and the control unit 104 is connected with the processing unit 105. The load tube unit 101 comprises a load tube.

[0073] The load tube unit 101 is used for connecting an external load and a power supply to supply power to the load.

[0074] The sampling unit 102 is configured to collect load current information in the load tube unit, generate a sampling signal according to the collected load current information, and send the sampling signal to the load short-circuit protection triggering unit.

[0075] The processing unit 105 is configured to determine whether to supply power to the load, generate a control signal according to a determination result, and send the control signal to the control unit.

[0076] The load short-circuit protection triggering unit 103 is configured to generate a short-circuit protection triggering signal according to the sampling signal when a load short circuit occurs, and send the short-circuit protection triggering signal to the control unit.

[0077] The control unit 104 is configured to stop sending a load tube opening driving signal to the load tube unit 101 according to the control signal and the short-circuit protection triggering signal when the load short circuit occurs.

[0078] The load tube unit 101 is further configured to close the load tube to disconnect the load tube unit 101 from the load when the load tube opening driving signal is not received.

[0079] Specifically, in an electronic circuit, generally, a load is supplied with power by a battery or other power supply, but the load may be short-circuited during operation, causing the current in the circuit to increase sharply, burning the electronic devices in the circuit, and even damaging the power supply, thus a load short-circuit protection mechanism needs to be provided in the circuit, which can disconnect the circuit from the load when the load is short-circuited. In the embodiments of the present application, the load short-circuit protection circuit comprises a load tube unit 101, a sampling unit 102, a load short-circuit protection trigger unit 103, a control unit 104, and a processing unit 105. The load tube unit 101 comprises a load tube, and the load tube is connected with a load and a power supply. When the load tube is turned on, the load can be supplied with power, and when the load tube is turned off, the connection between the power supply and the load can be disconnected, and the power supply to the load can be stopped. That is, when the load is short-circuited, the load tube can be controlled to be turned off to disconnect the connection between the load tube unit and the load, thereby achieving short-circuit protection. The sampling unit 102 collects load current information in the load tube unit, generates a sampling signal according to the collected load current information, and sends the sampling signal to the load short-circuit protection trigger unit 103. As a possible implementation manner, the sampling signal is a voltage signal. The sampling unit 102 is connected with the processing unit 105, and the sampling unit 102 is also used to send the collected load current information to the processing unit 105, so that the processing unit 105 displays the load current information. The load short-circuit protection trigger unit 103 can determine whether the load is short-circuited according to the sampling signal, and generate a load short-circuit protection trigger signal when the load is short-circuited, and send the short-circuit protection trigger signal to the control unit 104. The processing unit 105 can determine whether to supply power to the load, and generate a control signal according to the determination result and send the control signal to the control unit 104. For example, when the load needs to be turned on or turned off, the processing unit 105 will receive an instruction to supply power to the load or an instruction to stop supplying power to the load, and according to the received instruction, the processing unit 105 generates different control signals. The control unit 104 can stop sending a drive signal for turning on the load tube to the load tube unit 101 according to the short-circuit protection trigger signal and the control signal when the load is short-circuited. The load tube unit 101 turns on the load tube when receiving the drive signal for turning on the load tube, so that the load tube unit 101 is connected with the load and supplies power to the load; and the load tube unit 101 turns off the load tube when not receiving the drive signal for turning on the load tube, so as to disconnect the connection between the load tube unit 101 and the load and stop supplying power to the load. Since the control unit 104 stops sending the drive signal for turning on the load tube to the load tube unit 101 according to the short-circuit protection trigger signal and the control signal when the load is short-circuited, the load tube unit 101 cannot receive the drive signal for turning on the load tube, so as to turn off the load tube and disconnect the connection between the load tube unit 101 and the load, thereby achieving short-circuit protection.

[0080] As a possible implementation manner, the control signal comprises a first control signal or a second control signal; the first control signal is a signal for indicating to supply power to the load, and the second control signal is a signal for indicating to stop supplying power to the load.

[0081] The processing unit 105 is specifically configured to determine to supply power to the load when the load power supply instruction is received, and generate the first control signal.

[0082] Alternatively, when the load power supply stop instruction is received, it is determined to stop supplying power to the load, and the second control signal is generated.

[0083] Specifically, the control signal generated by the processing unit comprises a first control signal or a second control signal. Wherein, the first control signal is a signal for indicating to supply power to the load, and the second control signal is a signal for indicating to stop supplying power to the load. Then, the processing unit 105 determines to supply power to the load when the load power supply instruction is received, and generates the first control signal at this time, so that the control unit 104 can generate the drive signal for turning on the load tube according to the first control signal, so as to make the load tube unit 101 connected with the load. The processing unit 105 determines to stop supplying power to the load when the load power supply stop instruction is received, and generates the second control signal at this time, so that the control unit 104 can stop sending the drive signal for turning on the load tube to the load tube unit 101 according to the second control signal, so as to disconnect the load tube unit 101 and the load.

[0084] It should be noted that the processing unit 105 can be a single-chip microcomputer, an advanced reduced instruction set computer (ARM) microprocessor, etc., and the present application does not limit this.

[0085] As a possible implementation manner, as shown in Figure 2 The sampling unit 102 comprises a sampling operational amplifier U1 and a sampling resistor RS1. One end of the sampling resistor RS1 is connected with a power supply, the other end of the sampling resistor RS1 is connected with a first end of a load tube Q, a second end of the load tube Q is connected with a load, a positive input end of the sampling operational amplifier U1 is connected with one end of the sampling resistor RS1, a negative input end of the sampling operational amplifier U1 is connected with the other end of the sampling resistor RS1, a power supply input end of the sampling operational amplifier U1 is connected with a first power supply, and a grounding end of the sampling operational amplifier U1 is grounded.

[0086] Specifically, the sampling unit 102 comprises a sampling operational amplifier U1 and a sampling resistor RS1. One end of the sampling resistor RS1 is connected to the power supply BAT+, and the other end of the sampling resistor RS1 is connected to the first end of the load tube Q. The sampling resistor RS1 and the load tube Q can supply power to the load. The positive input end of the sampling operational amplifier U1 is connected to one end of the sampling resistor RS1, the negative input end of the sampling operational amplifier U1 is connected to the other end of the sampling resistor RS1, the power input end of the sampling operational amplifier U1 is connected to the first power supply, and the ground end of the sampling operational amplifier U1 is grounded. When the load is short-circuited, the current in the circuit will increase sharply, so by collecting the current in the circuit, it can be determined whether a short circuit occurs. If the collected current is too large, it indicates that a load short circuit has occurred, and certain short circuit protection measures need to be taken to avoid damage to the electronic devices and power supply in the circuit. Because the voltage across the resistor increases with the increase of the current, the voltage across the sampling resistor RS1 can be collected by the sampling operational amplifier U1, so as to determine the load current. The output end of the sampling operational amplifier U1 outputs a sampling signal and transmits it to the load short circuit protection triggering unit 103, so that the load short circuit protection triggering unit 103 determines whether a load short circuit occurs according to the sampling signal.

[0087] As a possible implementation manner, as shown in Figure 3 , the sampling operational amplifier U1 can be packaged in a chip. The first pin of the chip is a power supply pin (Vs), that is, the power input end of the sampling operational amplifier U1; the second pin of the chip is a null pin (NC) and does not need to be connected; the third pin of the chip is an output pin (OUT), that is, the output end of the sampling operational amplifier U1; the fourth pin of the chip is a ground pin (GND), that is, the ground end of the sampling operational amplifier U1; the fifth pin of the chip is a positive input end pin (IN+), that is, the positive input end of the sampling operational amplifier U1; and the sixth pin of the chip is a negative input end pin (IN-), that is, the negative input end of the sampling operational amplifier U1. The specific connection can refer to the above embodiments, and will not be described here in detail. Figure 2

[0088] As a possible implementation manner, as shown in Figure 4 , the control unit 104 comprises a diode D, a first comparator U2A and a load driver U3. The negative electrode of the diode D is connected to the load short circuit protection triggering unit 103, the positive electrode of the diode D is connected to the negative input end of the first comparator U2A, the negative input end of the first comparator U2A is connected to the processing unit 105, the power supply pin of the first comparator U2A is connected to the first power supply, the ground pin of the first comparator U2A is grounded, the output end of the first comparator U2A is connected to the first input end of the load driver U3, the second input end of the load driver U3 is connected to the first power supply, the power input end of the load driver U3 is connected to the second power supply, the output end of the load driver U3 is connected to the control end of the load tube Q, and the ground end of the load driver U3 is connected to the second end of the load tube Q.​

[0089] Specifically, the control unit 104 comprises a diode D, a first comparator U2A and a load driver U3. The cathode of the diode D is connected to the signal output by the load short-circuit protection triggering unit 103, the anode of the diode D is connected to the load short-circuit protection triggering unit 103, the cathode of the diode D is connected to the negative input terminal of the first comparator U2A, the negative input terminal of the first comparator U2A is connected to the processing unit 105, the power supply pin of the first comparator U2A is connected to the first power supply to supply power to the first comparator U2A, the ground pin of the first comparator U2A is grounded, the positive input terminal of the first comparator U2A inputs a reference voltage, and the output terminal of the first comparator U2A is connected to the first input terminal of the load driver U3. The second input terminal of the load driver U3 is connected to the first power supply, and the power supply input terminal of the load driver U3 is connected to the second power supply, wherein the second power supply can be 12V_LOAD+. When a load short circuit occurs, the control unit 104 stops outputting the drive signal for turning on the load tube, so that the load tube unit 101 turns off the load tube Q when it does not receive the drive signal for turning on the load tube, thereby disconnecting the load tube unit 101 and the load, and completing the short circuit protection.

[0090] It should be noted that the reference voltage connected to the positive input terminal of the first comparator U2A can be set according to actual needs, and the present application does not limit this.

[0091] Further, as shown in Figure 5 , the control unit 104 further comprises a first resistor R1 and a second resistor R2. The second input terminal of the load driver U3 is connected to the first power supply through the first resistor R1, and the negative input terminal of the first comparator U2A is connected to the processing unit through the second resistor R2.

[0092] Specifically, the control unit 104 further comprises a first resistor R1 and a second resistor R2. To avoid excessive current from damaging the load driver U3, the first resistor R1 is connected in series between the second input terminal of the load driver U3 and the first power supply. To avoid short circuit, the second resistor R2 is connected in series at the negative input terminal of the first comparator U2A to limit the current.

[0093] As a possible implementation, as shown in Figure 6As shown, the load driver U3 can be packaged in a chip, wherein a first pin of the chip is an anode pin, i.e., the second input terminal of the load driver U3; a second pin of the chip is a null pin (NC) and does not need to be connected; a third pin of the chip is a cathode pin (Cathode), i.e., the first input terminal of the load driver U3; a fourth pin of the chip is a power supply pin (Vcc), i.e., the power input terminal of the load driver U3; a fifth pin of the chip is an output pin (Vo), i.e., the output terminal of the load driver U3; and a sixth pin of the chip is a ground pin (GND), i.e., the ground terminal of the load driver U3. For details, refer to the above embodiment of the load driver U3, which will not be described herein again. Figure 5

[0094] As a possible implementation, the load short-circuit protection triggering unit 103 is specifically configured to determine whether the load current exceeds the first preset threshold according to the sampling signal, and generate a first short-circuit protection triggering signal when it is determined that the load current exceeds the first preset threshold, and send the first short-circuit protection triggering signal to the control unit.

[0095] As shown in Figure 7 , the load short-circuit protection triggering unit includes a third resistor R3, a fourth resistor R4, and a second comparator U2B; wherein one end of the third resistor R3 is connected with the first power supply, the other end of the third resistor R3 is connected with one end of the fourth resistor R4 and the positive input terminal of the second comparator U2B, the other end of the fourth resistor R4 is grounded, the negative input terminal of the second comparator U2B is connected with the output terminal of the sampling op-amp U1, the output terminal of the second comparator U2B is connected with the negative electrode of the diode D, the power supply pin of the second comparator U2B is connected with the first power supply, and the ground pin of the second comparator U2B is grounded.

[0096] In the embodiment of the present application, after receiving the sampling signal sent by the sampling unit 102, the load short-circuit protection triggering unit 103 determines whether the load current exceeds the first preset threshold according to the sampling signal. If it is determined that the load current exceeds the first preset threshold, it means that a load short-circuit occurs at this time. The load short-circuit protection triggering unit 103 generates a short-circuit protection triggering signal and sends the short-circuit protection triggering signal to the control unit 104, so that the control unit 104 stops sending the drive signal for turning on the load tube to the load tube unit 101, so that the load tube unit 101 turns off the load tube Q when it does not receive the drive signal for turning on the load tube, thereby disconnecting the load tube unit 101 and the load, and completing the short-circuit protection.

[0097] It should be noted that the first preset threshold can be set according to actual needs, and the present application does not limit this.

[0098] ​Specifically, the load short-circuit protection trigger unit 103 includes: a third resistor R3, a fourth resistor, and a second comparator U2B. One end of the third resistor R3 is connected to the first power supply; the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the positive input terminal of the second comparator U2B; the other end of the fourth resistor R4 is grounded; the negative input terminal of the second comparator U2B is connected to the output terminal of the sampling operational amplifier U1; the output terminal of the second comparator U2B is connected to the negative terminal of the diode D; the power supply pin of the second comparator U2B is connected to the first power supply; and the ground pin of the second comparator U2B is grounded. In other words, the positive input terminal of the second comparator U2B receives the voltage division value of the first power supply through the third resistor R3 and the fourth resistor R4, i.e., the first threshold voltage REF1. If the voltage value of the sampled signal is higher than the first threshold voltage REF1, it indicates that a load short circuit has occurred, and the second comparator U2B outputs a short-circuit protection trigger signal. That is, when the voltage value of the sampled signal is higher than the first threshold voltage REF1, it indicates that the load current exceeds a first preset threshold, and a load short circuit occurs.

[0099] It should be noted that the first preset threshold corresponds to the first threshold voltage REF1. The first threshold voltage REF1 can be set according to the preset first threshold. In the load protection circuit trigger unit 103, the value of the first threshold voltage REF1 can be adjusted by adjusting the resistance values ​​of the third resistor R3 and the fourth resistor R4.

[0100] Furthermore, such as Figure 8 As shown, the load short-circuit protection trigger unit 103 further includes: a fifth resistor R5 and a first capacitor C1. One end of the fifth resistor R5 is connected to the output terminal of the sampling operational amplifier U1, and the other end of the fifth resistor R5 is connected to the negative input terminal of the second comparator U2B and one end of the first capacitor C1. The other end of the first capacitor C1 is grounded.

[0101] Specifically, the load short-circuit protection trigger unit 103 also includes: a fifth resistor R5 and a first capacitor C1. One end of the fifth resistor R5 is connected to the output terminal of the sampling operational amplifier U1, and the other end of the fifth resistor R5 is connected to the negative input terminal of the second comparator U2B and one end of the first capacitor C1. The other end of the first capacitor C1 is grounded. In this way, voltage stability is ensured, filtering and voltage regulation are achieved, and the circuit's anti-interference capability is increased.

[0102] As one possible implementation, the load short-circuit protection triggering unit 103 includes a first load short-circuit protection triggering module and a second load short-circuit protection triggering module;

[0103] The first load short-circuit protection trigger module is used to determine whether the load current exceeds the second preset threshold based on the sampled signal, and to generate a second short-circuit protection trigger signal when it is determined that the load current exceeds the second preset threshold.

[0104] The second load short-circuit protection trigger module is used to determine whether the load current exceeds the third preset threshold based on the sampled signal, and to generate a third short-circuit protection trigger signal when it is determined that the load current exceeds the third preset threshold; wherein, the second preset threshold is greater than the third preset threshold.

[0105] The load short-circuit protection trigger unit 103 is specifically used to combine the first short-circuit protection trigger signal and the second short-circuit protection trigger signal into a short-circuit protection trigger signal, and send the short-circuit protection trigger signal to the control unit 104.

[0106] As one possible implementation, such as Figure 9 As shown, the first load short-circuit protection trigger module 901 includes a sixth resistor R6, a seventh resistor R7, and a third comparator U2C; the second load short-circuit protection trigger module 902 includes an eighth resistor R8 and a fourth comparator U2D; wherein,

[0107] One end of the sixth resistor R6 is connected to the first power supply. The other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and the positive input terminal of the third comparator U2C. The negative input terminal of the third comparator U2C is connected to the output terminal of the sampling operational amplifier U1. The other end of the seventh resistor R7 is connected to one end of the eighth resistor R8 and the positive input terminal of the fourth comparator U2D. The negative input terminal of the fourth comparator U2D is connected to the output terminal of the sampling operational amplifier U1. The other end of the eighth resistor R8 is grounded. The output terminal of the third comparator U2C is connected to the output terminal of the fourth comparator U2D and then connected to the negative terminal of the diode. The power supply pin of the third comparator U2C is connected to the first power supply. The ground pin of the third comparator U2C is grounded. The power supply pin of the fourth comparator U2D is connected to the first power supply. The ground pin of the fourth comparator U2D is grounded.

[0108] In this embodiment, to further ensure the reliability of short-circuit protection, the load short-circuit protection trigger unit includes a first load short-circuit protection trigger module 901 and a second load short-circuit protection trigger module 902, forming a two-stage load short-circuit protection trigger unit to achieve protection for different load current thresholds. By setting different preset thresholds, the first load short-circuit protection trigger module 901 outputs a first short-circuit protection trigger signal when the load current exceeds a second preset threshold; the second load short-circuit protection trigger module 902 generates a second short-circuit protection trigger signal when the load current exceeds a third preset threshold. Then, the first and second short-circuit protection trigger signals are combined to form a short-circuit protection trigger signal as the output signal of the load short-circuit protection trigger unit, and sent to the control unit 104.

[0109] It should be noted that the second and third preset thresholds can be preset, but the second preset threshold must be greater than the third preset threshold. This application does not impose any restrictions on this.

[0110] Specifically, the first load short-circuit protection trigger module 901 comprises a sixth resistor R6, a seventh resistor R7 and a third comparator U2C, and the second load short-circuit protection trigger module 902 comprises an eighth resistor R8 and a fourth comparator U2D; wherein one end of the sixth resistor R6 is connected with the first power supply, the other end of the sixth resistor R6 is connected with one end of the seventh resistor R7 and the positive input end of the third comparator U2C, the negative input end of the third comparator U2C is connected with the output end of the sampling operational amplifier U1, the other end of the seventh resistor R7 is connected with one end of the eighth resistor R8 and the positive input end of the fourth comparator U2D, the negative input end of the fourth comparator U2D is connected with the output end of the sampling operational amplifier U1, and the other end of the eighth resistor R8 is grounded. The output end of the third comparator U2C is connected with the output end of the fourth comparator U2D and then connected with the negative electrode of the diode D, the power supply pin of the third comparator U2C is connected with the first power supply to supply power for the third comparator U2C, and the grounding pin of the third comparator U2C is grounded. The power supply pin of the fourth comparator U2D is connected with the first power supply to supply power for the fourth comparator U2D, and the grounding pin of the fourth comparator U2D is grounded.

[0111] That is, the negative input end of the third comparator U2C inputs the sampling signal, the positive input end of the third comparator U2C inputs the voltage value divided by the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 of the first power supply, that is, the second threshold voltage REF2. When the voltage value of the sampling signal exceeds the second threshold voltage REF2, it indicates that the load current exceeds the second preset threshold value, and the load is short-circuited. At this time, the third comparator U2C outputs the first short-circuit protection trigger signal. The negative input end of the fourth comparator U2D inputs the sampling signal, and the positive input end of the fourth comparator U2D inputs the voltage value divided by the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 of the first power supply, that is, the third threshold voltage REF3. When the voltage value of the sampling signal exceeds the third threshold voltage REF3, it indicates that the load current exceeds the third preset threshold value, and the load is short-circuited. At this time, the fourth comparator U2D outputs the second short-circuit protection trigger signal. Then the first short-circuit protection trigger signal and the second short-circuit protection trigger signal are combined and output as the short-circuit protection trigger signal, and are transmitted to the negative electrode of the diode D in the control unit 104.

[0112] It should be noted that the second preset threshold value corresponds to the second threshold voltage REF2, and the third preset threshold value corresponds to the third threshold voltage REF3. The second threshold voltage REF2 can be set according to the pre-set second preset threshold value, and the third threshold voltage REF3 can be set according to the pre-set third preset threshold value. The values of the second threshold voltage REF2 and the third threshold voltage REF3 can be adjusted by adjusting the resistance values of the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8.

[0113] Further, as shown in FIG. 6, the control unit 104 further comprises a first short-circuit protection trigger module 901 and a second short-circuit protection trigger module 902.Figure 10 The first load short-circuit protection trigger module 901 further comprises a ninth resistor R9 and a second capacitor C2, and the second load short-circuit protection trigger module 902 further comprises a tenth resistor R10 and a third capacitor C3.

[0114] One end of the ninth resistor R9 is connected to the output terminal of the sampling operational amplifier U1, the other end of the ninth resistor R9 is connected to the negative input terminal of the third comparator U2C and one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

[0115] One end of the tenth resistor R10 is connected to the output terminal of the sampling operational amplifier U1, the other end of the tenth resistor R10 is connected to the negative input terminal of the fourth comparator U2D and one end of the third capacitor C3, and the other end of the third capacitor C3 is grounded.

[0116] Specifically, the first load short-circuit protection trigger module 901 further comprises a ninth resistor R9 and a second capacitor C2, and the second load short-circuit protection trigger module 902 further comprises a tenth resistor R10 and a third capacitor C3. One end of the ninth resistor R9 is connected to the output terminal of the sampling operational amplifier U1, the other end of the ninth resistor R9 is connected to the negative input terminal of the third comparator U2C and one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded. One end of the tenth resistor R10 is connected to the output terminal of the sampling operational amplifier U1, the other end of the tenth resistor R10 is connected to the negative input terminal of the fourth comparator U2D and one end of the third capacitor C3, and the other end of the third capacitor C3 is grounded. In this way, the ninth resistor R9 and the tenth resistor R10 ensure the stability of the input voltage of the negative input terminals of the third comparator U2C and the fourth comparator U2D. Since the second capacitor C2 and the third capacitor C3 are added in the circuit, the filtering and voltage stabilizing effects are achieved, and the anti-interference performance of the circuit is improved.

[0117] The load short-circuit protection circuit provided by the embodiment of the application does not need to transmit the short-circuit protection trigger signal through an optical coupler, avoids the transmission delay caused by the optical coupler, and improves the reliability of short-circuit protection. When a two-stage short-circuit trigger protection circuit is used, two different short-circuit protection trigger conditions are provided, different threshold voltages are set, the characteristics of fast protection for large current and slow protection for small current are met, and the reliability of short-circuit protection is maximized.

[0118] In summary, Figure 11Another structure schematic diagram of the load protection circuit provided by the embodiment of the present application is shown in FIG. 3. In the diagram, the output signal of the load short-circuit protection triggering unit 103 is LOAD_SC, that is, when the load is short-circuited, the output signal LOAD_SC is a short-circuit protection triggering signal, and when the load is normally operated, the output signal LOAD_SC is a normal output signal; the positive input end of the first comparator U2A in the control unit 104 is connected to one end of the eighth resistor R8, that is, the reference voltage inputted by the positive input end of the first comparator U2A is provided by the third threshold voltage, that is, the reference voltage inputted by the positive input end of the first comparator U2A is the voltage value of the eighth resistor R8.

[0119] For example, assuming that the first power supply is a 3.3V power supply, by reasonably setting the resistance values of the sixth resistor, the seventh resistor and the eighth resistor, the values of the second threshold voltage REF2 and the third threshold voltage REF3 can be adjusted, and the second threshold voltage REF2 is higher than the third threshold voltage REF3. When the load is turned on and no short-circuit occurs, the first power supply is turned on, and the sampling op-amp U1, the first comparator U2A, the third comparator U2C, the fourth comparator U2D and the load driver U3 are powered on. At this time, the processing unit 105 determines that the load is powered, and determines the control signal as the first control signal, that is, high level. The negative input end of the third comparator U2C inputs the sampling signal, the positive input end of the third comparator U2C is connected to the second threshold voltage REF2, the negative input end of the fourth comparator U2D inputs the sampling signal, and the positive input end of the fourth comparator U2D is connected to the third threshold voltage REF3. Since the load is normally operated and no short-circuit occurs, the voltage value of the sampling signal outputted by the sampling op-amp U1 is lower than the second threshold voltage REF2 and the third threshold voltage REF3. Then, the third comparator U2C outputs high level, the fourth comparator U2D outputs high level, the output signal LOAD_SC of the load short-circuit protection triggering unit 103 is high level, the negative input end of the first comparator U2A is connected to the first control signal, that is, high level, so the positive and negative electrodes of the diode D are both connected to high level, the diode D does not work, the positive input end of the first comparator U2A is connected to the third threshold voltage REF3, since the voltage of the first control signal is higher than the third threshold voltage REF3, the first comparator U2A outputs low level, the first input end Cathode of the load driver U3 inputs low level, the second input end Anode of the load driver U3 is connected to the first power supply through the first resistor R1, and the load driver U3 is turned on. Therefore, the load driver U3 outputs a 12V_LOAD+ high level signal (indicating that the voltage between the 12V_LOAD+ and LOAD+ is 12V), that is, the driving signal for turning on the load tube, the control end of the load tube Q is connected to the driving signal for turning on the load tube, the load tube Q is turned on, and the load has output.

[0120] When the load is normal, the load is closed, at this time, the processing unit 105 determines to stop supplying power to the load, the processing unit 105 determines the control signal as the second control signal, that is, low level. The negative input end of the third comparator U2C inputs the sampling signal, the positive input end of the third comparator U2C is connected to the second threshold voltage REF2, the negative input end of the fourth comparator U2D inputs the sampling signal, and the positive input end of the fourth comparator U2D is connected to the third threshold voltage REF3. Since the load is normal and no short circuit occurs, the voltage value of the sampling signal output by the sampling operational amplifier U1 is lower than the second threshold voltage REF2 and the third threshold voltage REF3, so the third comparator U2C outputs high level, the fourth comparator U2D outputs high level, and the output signal LOAD_SC of the load short circuit protection triggering unit 103 is high level. The negative input end of the first comparator U2A is connected to the second control signal, that is, low level, so the positive electrode of the diode is connected to low level and the negative electrode is connected to high level, the diode D does not work, the positive input end of the first comparator U2A is connected to the third threshold voltage REF3, and since the voltage of the second control signal is lower than the third threshold voltage REF3, the first comparator U2A outputs high level, the first input end Cathode of the load driver U3 inputs high level, the second input end Anode of the load driver U3 is connected to the first power supply through the first resistor R1, the input end of the load driver U3 is cut off, the load driver U3 stops outputting high level signal, that is, stops outputting the driving signal of the opening load tube, so the load tube Q is closed, and the load has no output.

[0121] When the load is on and a short circuit occurs, the processing unit 105 determines to supply power to the load since the load is still running at this time, and the control signal is the first control signal, i.e., high level. The negative input end of the third comparator U2C inputs the sampling signal, the positive input end of the third comparator U2C is connected to the second threshold voltage REF2, the negative input end of the fourth comparator U2D inputs the sampling signal, and the positive input end of the fourth comparator U2D is connected to the third threshold voltage REF3. Since a short circuit occurs in the load, the voltage value of the sampling signal output by the sampling op-amp U1 rises. Since the second threshold voltage REF2 is greater than the third threshold voltage REF3, there may be a case that the voltage value of the sampling signal output by the sampling op-amp U1 is higher than the third threshold voltage REF3 but lower than the second threshold voltage REF2, or a case that the voltage value of the sampling signal output by the sampling op-amp U1 is higher than the second threshold voltage REF2 and the third threshold voltage REF3. When the voltage value of the sampling signal output by the sampling op-amp U1 is higher than the third threshold voltage REF3 but lower than the second threshold voltage REF2, the third comparator U2C outputs high level, and the fourth comparator U2D outputs low level, i.e., the second short circuit protection triggering module triggers short circuit protection, and the output signal LOAD_SC of the load short circuit protection triggering unit 103 is low level. When the voltage value of the sampling signal output by the sampling op-amp U1 is higher than the second threshold voltage REF2 and the third threshold voltage REF3, the third comparator U2C outputs low level, and the fourth comparator U2D outputs low level, i.e., the first load short circuit protection triggering module and the second load short circuit protection triggering module both trigger short circuit protection, and the output signal LOAD_SC of the load short circuit protection triggering unit 103 is low level. That is, when a short circuit occurs in the load and the load current is small, only one short circuit protection triggering signal can be generated; when a short circuit occurs in the load and the load current rises sharply, two short circuit protection triggering signals can be generated, triggering short circuit protection quickly, thereby improving the reliability of load short circuit protection. Based on this, since only one of the third comparator U2C and the fourth comparator U2D outputs low level, the load short circuit protection triggering unit 103 outputs low level, so when a short circuit occurs in the load, as long as the voltage value of the sampling signal output by the sampling op-amp U1 is higher than the third threshold voltage REF3, the output signal LOAD_SC of the load short circuit protection triggering unit 103 is low level. Then the negative electrode of the diode D inputs low level, and since the positive electrode of the diode is connected to the second resistor, the positive electrode of the diode is connected to the first control signal, i.e., high level, and the diode D is turned on.In this way, the voltage value inputted at the negative input terminal of the first comparator U2A is the junction voltage drop 0.7V of the diode D, the positive input terminal of the first comparator U2A is connected with the third threshold voltage REF3, and the first comparator U2A outputs a high level because the third threshold voltage REF3 is higher than the junction voltage drop 0.7V of the diode D. The first input terminal Cathode of the load driver U3 inputs a high level, the second input terminal Anode of the load driver U3 is connected with the first power supply through the first resistor R1, the input terminal of the load driver U3 is cut off, the load driver U3 stops outputting a high level signal, i.e., stops outputting the driving signal for turning on the load tube, and thus the load tube Q is turned off, and the load has no output.

[0122] As a possible implementation manner, the load short-circuit protection circuit further comprises a self-locking unit 106; the self-locking unit 106 is connected with the processing unit 105, the self-locking unit 106 is connected with the load short-circuit protection triggering unit 103, and the self-locking unit 106 is connected with the control unit 104; the self-locking unit 106 is configured to lock the short-circuit protection triggering signal outputted by the load short-circuit protection triggering unit 103 when the load is short-circuited.

[0123] In the embodiment of the present application, if the load is short-circuited, the control unit 104 stops outputting the driving signal for turning on the load tube when the short-circuit protection triggering signal is received, and the load tube unit 101 turns off the load tube Q when the driving signal for turning on the load tube is not received, so as to disconnect the load tube unit 101 from the load. However, because the current can be an unsteady current, a large current forms a short circuit at a certain moment, and the current can return to normal at the next moment. The control unit 104 stops outputting the driving signal for turning on the load tube, and the load tube unit 101 turns off the load tube Q when the driving signal for turning on the load tube is not received. This process needs a certain time, and thus there can be a case that the load tube Q is not turned off in time when the load is short-circuited. Therefore, in order to realize reliable turning off of the load tube Q when the load is short-circuited, the self-locking unit 106 is arranged. The self-locking unit 106 is configured to lock the short-circuit protection triggering signal even if the current returns to normal before the load tube Q is turned off after the load is short-circuited, so as to make the control unit 104 stop outputting the driving signal for turning on the load tube, and the load tube unit 101 can turn off the load tube Q when the driving signal for turning on the load tube is not received. In this way, when the load is short-circuited, the self-locking unit 106 locks the short-circuit protection triggering signal, so as to ensure reliable turning off of the load tube Q, avoid damage of the load tube Q caused by frequent turning on and off of the load tube Q when the load current decreases, and prolong the service life of the load tube Q.

[0124] As a possible implementation manner, the load short-circuit protection circuit further comprises a self-locking unit 106; the self-locking unit 106 is connected with the processing unit 105, the self-locking unit 106 is connected with the load short-circuit protection triggering unit 103, and the self-locking unit 106 is connected with the control unit 104; the self-locking unit 106 is configured to lock the short-circuit protection triggering signal outputted by the load short-circuit protection triggering unit 103 when the load is short-circuited. Figure 12As shown, the self-locking circuit 106 comprises an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a fifth comparator U2E. One end of the eleventh resistor R11 is connected to the processing unit 105, the other end of the eleventh resistor R11 is connected to the negative input terminal of the fifth comparator U2E and one end of the twelfth resistor R12, the other end of the twelfth resistor R12 is grounded, the positive input terminal of the fifth comparator U2E is connected to the first power supply through the thirteenth resistor R13, the output terminal of the fifth comparator U2E is connected to the negative electrode of the diode D, the power supply pin of the fifth comparator U2E is connected to the first power supply, and the grounding pin of the fifth comparator U2E is grounded.

[0125] Specifically, the self-locking circuit 106 comprises an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a fifth comparator U2E. One end of the eleventh resistor R11 is connected to the processing unit 105, i.e. connected to the control signal output terminal of the processing unit 105, the other end of the eleventh resistor R11 is connected to the negative input terminal of the fifth comparator U2E and one end of the twelfth resistor R12, the other end of the twelfth resistor R12 is grounded, the positive input terminal of the fifth comparator U2E is connected to the first power supply through the thirteenth resistor R13, and the output terminal of the fifth comparator U2E is connected to the negative electrode of the diode D, i.e. connected to the control unit 104. The power supply pin of the fifth comparator U2E is connected to the first power supply to supply power to the fifth comparator U2E, and the grounding pin of the fifth comparator U2E is grounded.

[0126] As a possible implementation manner, as shown in Figure 13 As shown, the self-locking circuit 106 further comprises a fourteenth resistor R14, wherein the connection between the positive input terminal of the fifth comparator U2E and the first power supply through the thirteenth resistor R13 comprises:

[0127] One end of the thirteenth resistor R13 is connected to the first power supply, and the other end of the thirteenth resistor R13 is connected to the positive input terminal of the fifth comparator U2E and one end of the fourteenth resistor R14.

[0128] The connection between the output terminal of the third comparator U2C and the output terminal of the fourth comparator U2D and the negative electrode of the diode comprises:

[0129] The output terminal of the third comparator U2C is connected to the output terminal of the fourth comparator U2D, and then connected to the other end of the fourteenth resistor R14 and the negative electrode of the diode D.

[0130] Specifically, since the output of the comparator has two ways of push-pull output and open drain output, when the internal circuit of the comparator is of the push-pull output architecture, the comparator can directly output a high level, but the output terminals of the two comparators of the push-pull output architecture cannot be directly connected; when the internal circuit of the comparator is of the open drain output architecture, if a pull-up resistor is not added to the output terminal of the comparator, when the voltage value input by the positive input terminal of the comparator is lower than the voltage value input by the negative input terminal, the comparator outputs a low level signal, when the voltage value input by the positive input terminal of the comparator is higher than the voltage value input by the negative input terminal, the output of the comparator is open drain, that is, no voltage signal is output, at this time, a pull-up resistor needs to be added to the output terminal of the comparator to output a high level. Since the third comparator U2C and the fourth comparator U2D need to merge the output signals and output a high level signal when the load is turned on and no short circuit occurs, the third comparator U2C and the fourth comparator U2D are both comparators of the open drain output, and a pull-up resistor needs to be added to the output terminal of the third comparator U2C and the fourth comparator U2D, so that the third comparator U2C and the fourth comparator U2D can output a high level signal. Based on this, the fourteenth resistor R14 is added in the self-locking circuit, one end of the thirteenth resistor R13 is connected to the first power supply, the other end of the thirteenth resistor R13 is connected to the positive input terminal of the fifth comparator U2E and one end of the fourteenth resistor R14; the output terminals of the third comparator U2C and the fourth comparator U2D are connected to the other end of the fourteenth resistor R14 and are connected to the negative electrode of the diode D. In this way, the output terminals of the third comparator U2C and the fourth comparator U2D are connected to the first power supply through the fourteenth resistor R14 and the thirteenth resistor R13, so that the third comparator U2C and the fourth comparator U2D can output a high level.

[0131] As a possible implementation manner, the processing unit 105 is further configured to determine to stop power supply for the load when detecting the load short circuit, and generate a second control signal.

[0132] In the embodiment of the present application, the processing unit 105 determines to stop power supply for the load when detecting the load short circuit, and generates a second control signal, for example, a low level signal.

[0133] Further, the processing unit 105 is specifically configured to determine that the load short circuit occurs when the signal merged and output by the load short circuit protection triggering unit and the self-locking unit is converted from the first level signal to the second level signal.

[0134] Specifically, referring to the above examples, when the load is turned on and no short circuit occurs, the signal output by the load short circuit protection trigger unit is a first level signal, i.e., high level, and when the load is short-circuited, the signal output by the load short circuit protection trigger unit is a second level signal, i.e., low level. Then, when the processing unit 105 detects that the signal output by the combination of the load short circuit protection trigger unit and the self-locking unit changes from the first level signal to the second level signal, it can be determined that a load short circuit occurs.

[0135] As a possible implementation, the self-locking unit 106 is further configured to, after the load is short-circuited, release the locking of the short circuit protection trigger signal output by the load short circuit protection trigger unit 103 according to the received second control signal sent by the processing unit 105.

[0136] Specifically, after the circuit returns to normal, it needs to return to the normal working state. If the locking of the short circuit protection trigger signal is maintained all the time, the control unit 104 will not send the driving signal for turning on the load tube to the load tube unit 101, so that the load tube Q remains in the closed state and the normal operation of the circuit cannot be realized. Therefore, after the load tube Q is closed, the locking of the short circuit protection trigger signal needs to be released. After the load is short-circuited, the processing unit 105 can detect that the load is short-circuited and determine to stop supplying power to it. At this time, the second control signal is generated and sent to the self-locking unit 106. According to the second control signal, the self-locking unit 106 can release the locking of the short circuit protection trigger signal to ensure that the load can work normally subsequently.

[0137] As a possible implementation, the processing unit 105 is further configured to, when determining to supply power to the load, turn on the first power supply to supply power to the sampling unit 102, the load short circuit protection trigger unit 103, the control unit 104, and the self-locking unit 106 by the first power supply.

[0138] The processing unit is further configured to, when determining to stop supplying power to the load, turn off the first power supply to stop supplying power to the sampling unit 102, the load short circuit protection trigger unit 103, the control unit 104, and the self-locking unit 106 by the first power supply.

[0139] Specifically, in the load short-circuit protection circuit provided in the embodiments of the present application, the first power supply supplies power for the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106. When the load is turned on, the processing unit 105 receives a load power supply instruction and determines to supply power for the load. At this time, the first power supply is turned on, so that the first power supply supplies power for the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106. When the load is turned off, the processing unit 105 receives a load power supply stop instruction and determines to stop supplying power for the load. At this time, the first power supply is turned off, so that the first power supply stops supplying power for the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106, thereby reducing the power consumption of the load short-circuit protection circuit.

[0140] It should be noted that turning on the first power supply means controlling the circuit connection between the first power supply and the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106 to be conducted, so that the first power supply can supply power for the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106. Turning off the first power supply means controlling the circuit connection between the first power supply and the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106 to be disconnected, so that the first power supply stops supplying power for the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106.

[0141] As a possible implementation manner, as shown in Figure 14 The load short-circuit protection circuit further includes a switching unit 107, wherein

[0142] The first end of the switching unit 107 is connected with the first power supply, the second end of the switching unit 107 is connected with the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106 respectively, and the control end of the switching unit 107 is connected with the processing unit 105.

[0143] The processing unit 105 is specifically configured to control the switching unit 107 to be conducted when it is determined to supply power for the load, so that the first power supply supplies power for the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106.

[0144] The processing unit 105 is specifically configured to control the switching unit 107 to be disconnected when it is determined to stop supplying power for the load, so that the first power supply stops supplying power for the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106.

[0145] Specifically, the load short-circuit protection circuit further comprises a switching unit 107. The first end of the switching unit 107 is connected with the first power supply, the second end of the switching unit 107 is connected with the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106 respectively, and the control end of the switching unit 107 is connected with the processing unit. The processing unit 105 can control the connection between the first power supply and the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106 through the switching unit 107. When the processing unit 105 determines to supply power to the load, the switching unit 107 can be controlled to be turned on, so that the first power supply is connected with the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106, and the first power supply supplies power to the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106. When the processing unit 105 determines to stop supplying power to the load, the switching unit 107 is controlled to be turned off, so that the connection between the first power supply and the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106 is disconnected, and the first power supply stops supplying power to the sampling unit 102, the load short-circuit protection triggering unit 103, the control unit 104 and the self-locking unit 106. In this way, the power consumption of the load short-circuit protection circuit can be reduced.

[0146] As a possible way, the switching unit 107 can be a field effect transistor, a relay, or other electronic devices that can act as a switch, which is not limited in the present application.

[0147] For example, assuming that the first comparator U2A, the third comparator U2C, the fourth comparator U2D and the fifth comparator U2E in the load short-circuit protection circuit are all open-drain output comparators, the first power supply is a 3.3V power supply, and the values of the second threshold voltage REF2 and the third threshold voltage REF3 can be adjusted by reasonably setting the resistance values of the sixth resistor, the seventh resistor and the eighth resistor, and the second threshold voltage REF2 is higher than the third threshold voltage REF3. As shown in FIG. 6, the first power supply is turned on, and the sampling operational amplifier U1, the first comparator U2A, the third comparator U2C, the fourth comparator U2D, the fifth comparator U2E and the load driver U3 are powered on. At this time, the positive input end of the fifth comparator U2E is connected with the first power supply through the thirteenth resistor R13, and inputs a high level, i.e. the voltage value of the first power supply. Since the load is not started at this time, the processing unit 105 determines the control signal as the second control signal, i.e. a low level, so the negative input end of the fifth comparator U2E inputs a low level, and the fifth comparator U2E outputs in open-drain mode and is pulled up to a high level through the thirteenth resistor R13 and the fourteenth resistor R14. Figure 13

[0148] ​When no short circuit occurs, the processing unit 105 receives the load power supply instruction, determines to supply power to the load, and determines the control signal as the first control signal, i.e., high level. The voltage value input at the negative input end of the fifth comparator U2E is the voltage value of the first control signal divided by the eleventh resistor R11 and the twelfth resistor R12, i.e., the voltage value of the twelfth resistor R12. The positive input end of the fifth comparator U2E is connected to the first power supply through the thirteenth resistor R13, and the voltage value input at the positive input end of the fifth comparator U2E is the voltage value of the first power supply. Since the value of the first control signal is usually 3.3V, and the first power supply is also 3.3V, the voltage value of the twelfth resistor R12 is less than the voltage value of the first power supply, so the voltage input at the negative input end of the fifth comparator U2E is lower than the voltage input at the positive input end, the fifth comparator U2E is open-drain output, and is pulled up to high level through the thirteenth resistor R13 and the fourteenth resistor R14. The negative input end of the third comparator U2C inputs the sampling signal, the positive input end of the third comparator U2C is connected to the second threshold voltage REF2, and the negative input end of the fourth comparator U2D inputs the sampling signal. The positive input end of the fourth comparator U2D is connected to the third threshold voltage REF3. Since the load is running normally and no short circuit occurs, the voltage value of the sampling signal output by the sampling op-amp U1 is lower than the second threshold voltage REF2 and the third threshold voltage REF3, so the outputs of the third comparator U2C and the fourth comparator U2D are open-drain, connected to the first power supply through the thirteenth resistor R13 and the fourteenth resistor R14, and thus the outputs of the third comparator U2C and the fourth comparator U2D are pulled up to high level, so the output signal LOAD_SC is high level. The negative input end of the first comparator U2A is connected to the first control signal, i.e., high level, so the positive and negative electrodes of the diode D are both connected to high level, the diode D does not work, the positive input end of the first comparator U2A is connected to the third threshold voltage REF3, and since the voltage of the first control signal is higher than the third threshold voltage REF3, the first comparator U2A outputs low level, the first input end Cathode of the load driver U3 inputs low level, the second input end Anode of the load driver U3 is connected to the first power supply through the first resistor R1, and the load driver U3 is turned on, so the load driver U3 outputs a 12V_LOAD+ high level signal (indicating that the voltage between AND LOAD+ is 12V), i.e., the load tube driving signal is turned on, the control end of the load tube Q receives the load tube driving signal, the load tube Q is turned on, and the load has output.

[0149] When the load is normal, the load is closed, at this time, the processing unit 105 receives the instruction of stopping the power supply of the load, determines to stop the power supply of the load, and the processing unit 105 determines the control signal as the second control signal, i.e. low level. The negative input end of the fifth comparator U2E inputs the control signal, i.e. low level, through the eleventh resistor R11, the positive input end of the fifth comparator U2E is connected with the first power supply through the thirteenth resistor R13, and inputs high level, so that the output of the fifth comparator U2E is open-drain. The negative input end of the third comparator U2C inputs the sampling signal, the positive input end of the third comparator U2C is connected with the second threshold voltage REF2, the negative input end of the fourth comparator U2D inputs the sampling signal, and the positive input end of the fourth comparator U2D is connected with the third threshold voltage REF3. Since the load is normal, no short circuit occurs, and thus the voltage value of the sampling signal output by the sampling operational amplifier U1 is lower than the second threshold voltage REF2 and the third threshold voltage REF3, so that the outputs of the third comparator U2C and the fourth comparator U2D are open-drain, and the output signal LOAD_SC of the load short circuit protection triggering unit 103 is connected with the first power supply through the thirteenth resistor R13 and the fourteenth resistor R14, so that the output signal LOAD_SC is high level. The negative input end of the first comparator U2A is connected with the second control signal, i.e. low level, so that the anode of the diode D is connected with low level, the cathode of the diode D is connected with high level, the diode D does not work, the positive input end of the first comparator U2A is connected with the third threshold voltage REF3, and since the voltage of the second control signal is lower than the third threshold voltage REF3, the output of the first comparator U2A is open-drain, the second input end Anode of the load driver U3 is connected with the first power supply through the first resistor R1, and the input end of the load driver U3 is cut off. The load driver U3 stops outputting high level signal, i.e. stops outputting the driving signal of opening the load tube, so that the load tube Q is closed, and the load has no output. Then, the processing unit 105 disconnects the switch unit 107, so as to achieve the purpose of low power consumption.

[0150] When the load is on and a short circuit occurs, the processing unit 105 determines to supply power to the load since the load is still running at this time, and the control signal is the first control signal, i.e., high level. The negative input end of the fifth comparator U2E inputs the control signal through the eleventh resistor R11, i.e., high level. That is, the voltage value input by the negative input end of the fifth comparator U2E is the voltage value of the twelfth resistor R12 through the voltage division of the eleventh resistor R11 and the twelfth resistor R12, i.e., the voltage value of the twelfth resistor R12. The positive input end of the fifth comparator U2E is connected with the first power supply through the thirteenth resistor R13, and the voltage value input by the positive input end of the fifth comparator U2E is the voltage value of the fourteenth resistor R14 through the voltage division of the thirteenth resistor R13 and the fourteenth resistor R14. Since the value of the first control signal is usually 3.3V, i.e., the first control signal and the first power supply are both 3.3V, the voltage value of the fourteenth resistor R14 can be set to be lower than the voltage value of the twelfth resistor R12 by reasonably setting the resistance values of the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13 and the fourteenth resistor R14. Therefore, the voltage value input by the positive input end of the fifth comparator U2E is lower than the voltage value input by the negative input end of the fifth comparator U2E, and the fifth comparator U2E outputs low level. The negative input end of the third comparator U2C inputs the sampling signal, the positive input end of the third comparator U2C is connected with the second threshold voltage REF2, and the negative input end of the fourth comparator U2D inputs the sampling signal, the positive input end of the fourth comparator U2D is connected with the third threshold voltage REF3. Since the load current rises due to the short circuit of the load, the voltage value of the sampling signal output by the sampling operational amplifier U1 rises. Since the second threshold voltage REF2 is greater than the third threshold voltage REF3, the voltage value of the sampling signal output by the sampling operational amplifier U1 may be higher than the third threshold voltage REF3 but lower than the second threshold voltage REF2, or the voltage value of the sampling signal output by the sampling operational amplifier U1 may be higher than the second threshold voltage REF2 and the third threshold voltage REF3. When the voltage value of the sampling signal output by the sampling operational amplifier U1 is higher than the third threshold voltage REF3 but lower than the second threshold voltage REF2, the third comparator U2C open-drain outputs, the fourth comparator U2D outputs low level, and the signal LOAD_SC output by the combination of the load short circuit protection triggering unit 103 and the self-locking unit 106 is low level. When the voltage value of the sampling signal output by the sampling operational amplifier U1 is higher than the second threshold voltage REF2 and the third threshold voltage REF3, the third comparator U2C outputs low level, the fourth comparator U2D outputs low level, and the signal LOAD_SC output by the combination of the load short circuit protection triggering unit 103 and the self-locking unit 106 is low level.Thus, when the load is short-circuited, the output signal LOAD_SC is low as long as the voltage of the sampling signal outputted by the sampling operational amplifier U1 is higher than the third threshold voltage REF3. Then, it can be determined that the negative electrode of the diode D is connected to the low level, and since the positive electrode of the diode D is connected to the first control signal, i.e. high level, through the second resistor, the diode D is turned on at this time. Thus, the voltage inputted to the negative input terminal of the first comparator U2A is the junction voltage drop 0.7V of the diode D, and the positive input terminal of the first comparator U2A is connected to the third threshold voltage REF3. Since the third threshold voltage REF3 is higher than the junction voltage drop 0.7V of the diode D, the output of the first comparator U2A is open-drain, the first input terminal Cathode of the load driver U3 has no input signal, the second input terminal Anode of the load driver U3 is connected to the first power supply through the first resistor R1, and the input terminal of the load driver U3 is cut off, thus the load driver U3 stops outputting the high level signal, i.e. stops outputting the driving signal for turning on the load tube, and thus the load tube Q is turned off, and the load has no output. In the above process, even if the load current returns to the normal value before the load tube Q is turned off, the outputs of the third comparator U2C and the fourth comparator U2D are open-drain, but since the fifth comparator U2E outputs the low level signal, the signal LOAD_SC outputted by the combination of the load short-circuit protection triggering unit 103 and the self-locking unit 106 will always remain low level, i.e. the short-circuit protection triggering signal is locked, and the self-locking is completed.

[0151] When the processing unit 105 detects that the signal LOAD_SC outputted by the combination of the load short-circuit protection triggering unit 103 and the self-locking unit 106 is converted from high level to low level, it is determined that the load is short-circuited, and at this time, the processing unit 105 generates the second control signal. After receiving the second control signal, the fifth comparator U2E is open-drain, and the unlocking is completed.

[0152] In this way, in the load short-circuit protection circuit provided by the embodiment of the present application, a plurality of NAND gates are not needed to form a control circuit, and a photo-coupler device is not needed to transmit the short-circuit trigger signal, and self-locking can be realized through a comparator, thereby greatly reducing the number of electronic devices in the circuit, saving cost, and reducing the size of the circuit board. Since there is no signal transmission delay caused by the photo-coupler device, the reliability of short-circuit protection is improved. In the load short-circuit protection trigger unit, by setting two-stage short-circuit protection trigger circuits, different threshold voltages can be set, large-current fast protection and small-current slow protection are realized, and the reliability of short-circuit protection is maximized. Moreover, when a load short-circuit occurs, the self-locking unit locks the short-circuit protection trigger signal, thereby ensuring the reliable closing of the load tube and avoiding damage caused by frequent switching of the load tube when the load current decreases.

[0153] The embodiment of the present application further provides an electronic device, which comprises the load short-circuit protection circuit described in any of the above embodiments.

[0154] Those skilled in the art can clearly understand that the technology in the embodiment of the present application can be realized by means of software and necessary general hardware platforms. Based on such understanding, the technical solutions in the embodiment of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the method described in the various embodiments or some parts of the embodiments of the present application.

[0155] The same or similar parts among the various embodiments in the specification can be referred to each other. Especially, for the device embodiments and the terminal embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the related parts can be referred to the description in the method embodiments.

Claims

1. A load short circuit protection circuit, characterized by, The circuit comprises a load tube unit, a sampling unit, a load short-circuit protection triggering unit, a control unit and a processing unit, wherein the load tube unit is connected with the sampling unit and the control unit, the sampling unit is connected with the load short-circuit protection triggering unit and the processing unit, the load short-circuit protection triggering unit is connected with the control unit and the processing unit, and the control unit is connected with the processing unit; the load tube unit comprises a load tube. The load tube unit is configured to be connected with an external load and a power supply to supply power to the load. The sampling unit is configured to collect load current information in the load tube unit, generate a sampling signal according to the collected load current information, and send the sampling signal to the load short-circuit protection triggering unit; the sampling unit comprises a sampling operational amplifier and a sampling resistor. The processing unit is configured to determine whether to supply power to the load, generate a control signal according to the determination result, and send the control signal to the control unit. The load short-circuit protection triggering unit is configured to generate a short-circuit protection triggering signal when a load short circuit occurs according to the sampling signal, and send the short-circuit protection triggering signal to the control unit; the load short-circuit protection triggering unit comprises a second comparator. The control unit is configured to stop sending a load tube opening driving signal to the load tube unit according to the control signal and the short-circuit protection triggering signal when a load short circuit occurs. The load tube unit is further configured to close the load tube to disconnect the load tube unit from the load when the load tube opening driving signal is not received. The control unit comprises a diode, a first comparator and a load driver. The negative electrode of the diode is connected with the load short-circuit protection triggering unit, the positive electrode of the diode is connected with the negative input end of the first comparator, the positive electrode of the diode is further connected with the control signal, the negative input end of the first comparator is connected with the processing unit, the positive input end of the first comparator inputs a reference voltage, and the output end of the first comparator is connected with the first input end of the load driver; the negative input end of the second comparator is connected with the output end of the sampling operational amplifier, the positive input end of the second comparator inputs a voltage divided value of a first power supply through a third resistor and a fourth resistor, the output end of the second comparator is connected with the negative electrode of the diode, the power supply pin of the second comparator is connected with the first power supply, and the ground pin of the second comparator is grounded. The circuit further comprises a self-locking unit connected with the processing unit, the load short-circuit protection triggering unit and the control unit. The self-locking unit is configured to lock the short-circuit protection triggering signal output by the load short-circuit protection triggering unit when a load short circuit occurs. The self-locking unit is further configured to release the locking of the short-circuit protection triggering signal output by the load short-circuit protection triggering unit according to a second control signal sent by the processing unit after a load short circuit occurs. ​ The processing unit is further configured to turn on the first power supply to supply power to the sampling unit, the load short-circuit protection triggering unit, the control unit and the self-locking unit when it is determined to supply power to the load. The processing unit is further configured to turn off the first power supply to stop supplying power to the sampling unit, the load short-circuit protection triggering unit, the control unit and the self-locking unit when it is determined to stop supplying power to the load.

2. The circuit of claim 1, wherein, The control signal comprises a first control signal or a second control signal; the first control signal is a signal for indicating to supply power to the load, and the second control signal is a signal for indicating to stop supplying power to the load. The processing unit is specifically configured to determine to supply power to the load and generate the first control signal when a load power supply instruction is received. Alternatively, the processing unit is specifically configured to determine to stop supplying power to the load and generate the second control signal when a load power supply stop instruction is received. Alternatively, the processing unit is specifically configured to determine to stop supplying power to the load and generate the second control signal when a load short circuit is detected.

3. The circuit according to claim 2, wherein The processing unit is specifically configured to determine that a load short circuit occurs when the signal output by the combination of the load short-circuit protection triggering unit and the self-locking unit is converted from the first level signal to the second level signal.

4. The circuit according to claim 3, wherein One end of the sampling resistor is externally connected to the power supply, the other end of the sampling resistor is connected to the first end of the load tube, the positive input end of the sampling operational amplifier is connected to the one end of the sampling resistor, the negative input end of the sampling operational amplifier is connected to the other end of the sampling resistor, the power supply input end of the sampling operational amplifier is connected to the first power supply, and the ground end of the sampling operational amplifier is grounded.

5. The circuit of claim 4, wherein, The power supply pin of the first comparator is connected to the first power supply, the ground pin of the first comparator is grounded, the second input end of the load driver is connected to the first power supply, the power supply input end of the load driver is connected to the second power supply, the output end of the load driver is connected to the control end of the load tube, and the ground end of the load driver is connected to the second end of the load tube.

6. The circuit of claim 5, wherein, The control unit further comprises a first resistor and a second resistor; the second input end of the load driver is connected to the first power supply through the first resistor, and the negative input end of the first comparator is connected to the processing unit through the second resistor.

7. The circuit according to claim 6, wherein The load short-circuit protection triggering unit is specifically configured to determine whether the load current exceeds a first preset threshold according to the sampling signal, and generate a short-circuit protection triggering signal and send the short-circuit protection triggering signal to the control unit when it is determined that the load current exceeds the first preset threshold.

8. The circuit of claim 7, wherein, The load short-circuit protection triggering unit comprises the third resistor and the fourth resistor; one end of the third resistor is connected to the first power supply, the other end of the third resistor is connected to one end of the fourth resistor and the positive input end of the second comparator, and the other end of the fourth resistor is grounded.

9. The circuit of claim 8, wherein, The load short-circuit protection triggering unit further comprises a fifth resistor and a first capacitor. The negative input end of the second comparator is connected with the output end of the sampling operational amplifier. One end of the fifth resistor is connected with the output end of the sampling operational amplifier, and the other end of the fifth resistor is connected with the negative input end of the second comparator and one end of the first capacitor, and the other end of the first capacitor is grounded.

10. The circuit of claim 6, wherein, The load short-circuit protection triggering unit comprises a first load short-circuit protection triggering module and a second load short-circuit protection triggering module. The first load short-circuit protection triggering module is configured to determine whether the load current exceeds a second preset threshold according to the sampling signal, and generate a first short-circuit protection triggering signal when it is determined that the load current exceeds the second preset threshold. The second load short-circuit protection triggering module is configured to determine whether the load current exceeds a third preset threshold according to the sampling signal, and generate a second short-circuit protection triggering signal when it is determined that the load current exceeds the third preset threshold; wherein the second preset threshold is greater than the third preset threshold. The load short-circuit protection triggering unit is specifically configured to combine the first short-circuit protection triggering signal and the second short-circuit protection triggering signal into the short-circuit protection triggering signal, and send the short-circuit protection triggering signal to the control unit.

11. The circuit of claim 10, wherein, The first load short-circuit protection triggering module comprises a sixth resistor, a seventh resistor and a third comparator, and the second load short-circuit protection triggering module comprises an eighth resistor and a fourth comparator. One end of the sixth resistor is connected with the first power supply, the other end of the sixth resistor is connected with one end of the seventh resistor and the positive input end of the third comparator, the negative input end of the third comparator is connected with the output end of the sampling operational amplifier, the other end of the seventh resistor is connected with one end of the eighth resistor and the positive input end of the fourth comparator, the negative input end of the fourth comparator is connected with the output end of the sampling operational amplifier, the other end of the eighth resistor is grounded, the output end of the third comparator is connected with the output end of the fourth comparator and then connected with the negative electrode of the diode, the power supply pin of the third comparator is connected with the first power supply, the ground pin of the third comparator is grounded, the power supply pin of the fourth comparator is connected with the first power supply, and the ground pin of the fourth comparator is grounded.

12. The circuit of claim 11, wherein, The first load short-circuit protection triggering module further comprises a ninth resistor and a second capacitor, and the second load short-circuit protection triggering module further comprises a tenth resistor and a third capacitor. The negative input end of the third comparator is connected with the output end of the sampling operational amplifier. One end of the ninth resistor is connected with the output end of the sampling operational amplifier, and the other end of the ninth resistor is connected with the negative input end of the third comparator and one end of the second capacitor, and the other end of the second capacitor is grounded. The negative input end of the fourth comparator is connected with the output end of the sampling operational amplifier. One end of the tenth resistor is connected with the output end of the sampling operational amplifier, and the other end of the tenth resistor is connected with the negative input end of the fourth comparator and one end of the third capacitor, and the other end of the third capacitor is grounded.

13. The circuit of claim 6, wherein, The self-locking unit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a fifth comparator. One end of the eleventh resistor is connected with the processing unit, and the other end of the eleventh resistor is connected with the negative input end of the fifth comparator and one end of the twelfth resistor, and the other end of the twelfth resistor is grounded.

14. The circuit of claim 13, wherein, The self-locking unit further comprises a fourteenth resistor, one end of which is connected with the other end of the thirteenth resistor and the positive input end of the fifth comparator, and the other end of the fourteenth resistor is connected with the output end of the third comparator and the output end of the fourth comparator.

15. The circuit of claim 1, wherein, Further comprising: a switching unit, wherein the first end of the switching unit is connected with the first power supply, the second end of the switching unit is connected with the sampling unit, the load short-circuit protection triggering unit, the control unit, and the self-locking unit respectively, and the control end of the switching unit is connected with the processing unit; The processing unit is specifically configured to control the switching unit to be turned on so that the first power supply supplies power to the sampling unit, the load short-circuit protection triggering unit, the control unit, and the self-locking unit when it is determined that the load is powered. The processing unit is specifically configured to control the switching unit to be turned off so that the first power supply stops supplying power to the sampling unit, the load short-circuit protection triggering unit, the control unit, and the self-locking unit when it is determined that the load is powered.

16. An electronic device, comprising: The load short-circuit protection circuit comprises the load short-circuit protection circuit according to any one of claims 1-15.

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