Low-side drive circuit and electronic equipment and vehicle having the same

Abstract

The present application relates to the field of electronic and electrical technology, and provides a low-side drive circuit and an electronic device and a vehicle having the same. The low-side drive circuit includes a switch module, a sampling module, a current detection module and a current control module, wherein the sampling module is configured to convert the output current of the load into a first voltage signal and then output it to the current detection module; the current detection module is configured to convert the first voltage signal into a second voltage signal and then output it to the controller to instruct the controller to output a pulse width modulation signal to the current control module according to the second voltage signal; the current control module is configured to control the on-off duration of the switch module according to the pulse width modulation signal output by the controller to adjust the output current of the load. The low-side drive circuit of the present application can replace the functional chip, and while achieving the same function as the functional chip, it can greatly reduce the manufacturing cost.

Description

Technical Field

[0001] The present application relates to the technical field of electronic appliances, and in particular to a low-side drive circuit and electronic equipment and vehicles having the same. Background Art

[0002] Cars are an indispensable means of transportation in life, bringing great convenience to people's daily travel. The various equipment installed in cars can meet different usage needs.

[0003] At present, in the related technology, the low-side driving circuit adopts functional chips to realize the corresponding control, but this method has high manufacturing cost, is not conducive to wide application, and seriously limits the mass production of automobiles. Summary of the invention

[0004] Based on this, it is necessary to provide a low-side driving circuit and an electronic device and vehicle having the same to address the above defects or shortcomings, which can achieve the same function as a functional chip while significantly reducing the manufacturing cost.

[0005] In a first aspect, an embodiment of the present application provides a low-side driving circuit, the circuit comprising a switch module, a sampling module, a current detection module and a current control module;

[0006] The first end of the switch module is connected to the load, the second end of the switch module is respectively connected to the first end of the sampling module and the first end of the current detection module, the second end of the sampling module is grounded, the second end of the current detection module is connected to the first end of the controller, the first end of the current control module is connected to the second end of the controller, and the second end of the current control module is connected to the third end of the switch module;

[0007] The sampling module is configured to convert the output current of the load into a first voltage signal and then output it to the current detection module;

[0008] The current detection module is configured to convert the first voltage signal into a second voltage signal and then output it to the controller, so as to instruct the controller to output a pulse width modulation signal to the current control module according to the second voltage signal;

[0009] The current control module is configured to control the on-off duration of the switch module according to the pulse width modulation signal output by the controller, so as to adjust the output current of the load.

[0010] Optionally, in some embodiments of the present application, the switch module includes a switch tube;

[0011] The first end of the switch tube is connected to the load, the second end of the switch tube is respectively connected to the first end of the sampling module and the first end of the current detection module, and the third end of the switch tube is connected to the second end of the current control module.

[0012] Optionally, in some embodiments of the present application, the circuit further includes a first diode, an anode of the first diode is connected to the first end of the switch tube, and a cathode of the first diode is connected to the output end of the high-side drive circuit.

[0013] Optionally, in some embodiments of the present application, the switch module further includes a first triode, a second triode, a first resistor and a second resistor;

[0014] The second end of the current control module is respectively connected to the base of the first transistor and the base of the second transistor, the collector of the second transistor is grounded, the emitter of the second transistor is connected to the third end of the switch tube, the emitter of the first transistor is connected to the first end of the first resistor, the second end of the first resistor is connected to the third end of the switch tube, the collector of the first transistor is connected to the positive pole of the power supply, the first end of the second resistor is connected to the third end of the switch tube, and the second end of the second resistor is grounded.

[0015] Optionally, in some embodiments of the present application, the current detection module includes an amplification unit;

[0016] The first end of the amplifying unit is connected to the second end of the switch module and the first end of the sampling module respectively, the second end of the amplifying unit is connected to the first end of the controller, and the third end of the amplifying unit is connected to the second end of the sampling module;

[0017] The amplifying unit is configured to convert the first voltage signal to obtain the second voltage signal and then output the second voltage signal to the controller.

[0018] Optionally, in some embodiments of the present application, the amplification unit includes an operational amplifier, a third resistor, a fourth resistor and a fifth resistor;

[0019] The first end of the third resistor is respectively connected to the second end of the switch module and the first end of the sampling module, the second end of the third resistor is connected to the positive input end of the operational amplifier, the first end of the fourth resistor is connected to the second end of the sampling module, the second end of the fourth resistor is respectively connected to the negative input end of the operational amplifier and the output end of the operational amplifier, the output end of the operational amplifier is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the first end of the controller.

[0020] Optionally, in some embodiments of the present application, the amplification unit further includes a sixth resistor, a seventh resistor, a first capacitor, a second capacitor and a third capacitor;

[0021] The first end of the sixth resistor is connected to the second end of the third resistor, and the second end of the sixth resistor is grounded. The first end of the first capacitor is connected to the second end of the third resistor, and the second end of the first capacitor is grounded. The first end of the seventh resistor is connected to the negative input terminal of the operational amplifier, and the second end of the seventh resistor is connected to the output terminal of the operational amplifier. The first end of the second capacitor is connected to the first end of the seventh resistor, and the second end of the second capacitor is connected to the second end of the seventh resistor. The first end of the third capacitor is connected to the second end of the fifth resistor, and the second end of the third capacitor is grounded.

[0022] Optionally, in some embodiments of the present application, the current detection module further includes a diagnosis unit;

[0023] A first end of the diagnostic unit is connected to the output end of the high-side driving circuit, and a second end of the diagnostic unit is connected to the first end of the switch module;

[0024] The diagnosis unit is configured to output a voltage signal so that the controller identifies a circuit operation status according to the voltage signal.

[0025] Optionally, in some embodiments of the present application, the circuit operation state includes any one of a normal connection between the low-side driving circuit and the load, an open circuit between the low-side driving circuit and the load, and a short circuit between the low-side driving circuit and the load;

[0026] Wherein, in the case of the open circuit or the short circuit, the current control module controls the switch module to switch to a disconnected state, and reconnects the switch module.

[0027] Optionally, in some embodiments of the present application, the diagnostic unit includes an eighth resistor, a first end of the eighth resistor is connected to the output end of the high-side driving circuit, and a second end of the eighth resistor is connected to the first end of the switch module.

[0028] Optionally, in some embodiments of the present application, the current control module includes a control unit and a starting unit;

[0029] The first end of the control unit is connected to the second end of the controller, the second end of the control unit is connected to the first end of the start unit, and the second end of the start unit is connected to the third end of the switch module;

[0030] The control unit is configured to receive the pulse width modulation signal output by the controller, and the start unit is configured to perform on-off switching according to the pulse width modulation signal to control the on-off duration of the switch module.

[0031] Optionally, in some embodiments of the present application, the control unit includes a band-stop transistor and a ninth resistor, and the start-up unit includes a tenth resistor, a third transistor, an eleventh resistor and a twelfth resistor;

[0032] The base of the band-stop transistor is connected to the second end of the controller, the emitter of the band-stop transistor is grounded, the collector of the band-stop transistor is connected to the first end of the ninth resistor, the second end of the ninth resistor is respectively connected to the first end of the tenth resistor and the base of the third transistor, the emitter of the third transistor and the second end of the tenth resistor are both connected to the positive electrode of the power supply, the collector of the third transistor is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is respectively connected to the third end of the switch module and the first end of the twelfth resistor, and the second end of the twelfth resistor is grounded.

[0033] Optionally, in some embodiments of the present application, the control unit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor and a fourth transistor, and the start-up unit includes a tenth resistor, a third transistor, an eleventh resistor and a twelfth resistor;

[0034] The first end of the thirteenth resistor is connected to the second end of the controller, the second end of the thirteenth resistor is respectively connected to the first end of the fourteenth resistor and the base of the fourth transistor, the second end of the fourteenth resistor is grounded, the emitter of the fourth transistor is connected to the first end of the fifteenth resistor, the second end of the fifteenth resistor is grounded, the collector of the fourth transistor is respectively connected to the first end of the tenth resistor and the base of the third transistor, the emitter of the third transistor and the second end of the tenth resistor are both connected to the positive electrode of the power supply, the collector of the third transistor is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is respectively connected to the third end of the switch module and the first end of the twelfth resistor, and the second end of the twelfth resistor is grounded.

[0035] Optionally, in some embodiments of the present application, the control unit further includes a second diode and a third diode, and the start-up unit further includes a fourth diode;

[0036] The anode of the second diode is connected to the second end of the controller, the cathode of the second diode is connected to the output end of the power management chip, the anode of the third diode is grounded, the cathode of the third diode is connected to the anode of the second diode, the anode of the fourth diode is connected to the second end of the twelfth resistor, and the cathode of the fourth diode is connected to the first end of the twelfth resistor.

[0037] Optionally, in some embodiments of the present application, the circuit further includes an overcurrent protection module;

[0038] The first end of the overcurrent protection module is connected to the first end of the sampling module, the second end of the overcurrent protection module is connected to the second end of the sampling module, and the third end of the overcurrent protection module is connected to the third end of the switch module;

[0039] The overcurrent protection module is configured to convert the first voltage signal into a third voltage signal when the first voltage signal output by the sampling module is greater than a preset voltage threshold, so as to keep the switch module in a disconnected state.

[0040] Optionally, in some embodiments of the present application, the overcurrent protection module includes a first level conversion unit, a second level conversion unit and a third level conversion unit;

[0041] The first end of the sampling module is connected to the first level conversion unit, the first level conversion unit is connected to the second level conversion unit, the second level conversion unit is connected to the third level conversion unit, and the third level conversion unit is connected to the third end of the switch module;

[0042] The first level conversion unit is configured to convert the first voltage signal into a fourth voltage signal, the second level conversion unit is configured to convert the fourth voltage signal into a fifth voltage signal and output it to the first level conversion unit and the third level conversion unit, the third level conversion unit is configured to convert the fifth voltage signal into the third voltage signal, and the first level conversion unit is further configured to convert the fifth voltage signal into the fourth voltage signal when the first voltage signal is not received.

[0043] Optionally, in some embodiments of the present application, the first level conversion unit includes a sixteenth resistor, a seventeenth resistor, an eighteenth resistor and a fifth triode, the second level conversion unit includes a sixth triode and a nineteenth resistor, and the third level conversion unit includes a twentieth resistor and a seventh triode;

[0044] The first end of the sixteenth resistor is connected to the first end of the sampling module, the second end of the sixteenth resistor is respectively connected to the base of the fifth transistor and the first end of the eighteenth resistor, the emitter of the fifth transistor is connected to the second end of the sampling module, the collector of the fifth transistor is respectively connected to the first end of the seventeenth resistor and the first end of the nineteenth resistor, the second end of the seventeenth resistor is connected to the positive electrode of the power supply, the second end of the nineteenth resistor is connected to the base of the sixth transistor, the emitter of the sixth transistor is connected to the third end of the current control module, the collector of the sixth transistor is respectively connected to the second end of the eighteenth resistor and the first end of the twentieth resistor, the second end of the twentieth resistor is connected to the base of the seventh transistor, the emitter of the seventh transistor is connected to the second end of the sampling module, and the collector of the seventh transistor is connected to the third end of the switch module.

[0045] Optionally, in some embodiments of the present application, the second level conversion unit further includes a fifth diode, an anode of the fifth diode is connected to the third end of the current control module, and a cathode of the fifth diode is connected to the emitter of the sixth transistor.

[0046] Optionally, in some embodiments of the present application, the overcurrent protection module further includes a voltage limiting unit;

[0047] The first end of the voltage limiting unit is connected to the second end of the second level conversion unit, the second end of the voltage limiting unit is connected to the third end of the controller, the third end of the voltage limiting unit is grounded, the fourth end of the voltage limiting unit is connected to the output end of the power management chip, and the fifth end of the voltage limiting unit is grounded;

[0048] The voltage limiting unit is configured to detect a change in the first voltage signal and perform voltage division to protect the port of the controller.

[0049] Optionally, in some embodiments of the present application, the voltage limiting unit includes a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a sixth diode and a seventh diode;

[0050] The first end of the twenty-first resistor is connected to the second end of the second level conversion unit, the second end of the twenty-first resistor is respectively connected to the first end of the twenty-second resistor and the anode of the sixth diode, the cathode of the sixth diode is connected to the output end of the power management chip, the cathode of the seventh diode is connected to the anode of the sixth diode, the anode of the seventh diode is grounded, the second end of the twenty-second resistor is respectively connected to the third end of the controller and the first end of the twenty-third resistor, and the second end of the twenty-third resistor is grounded.

[0051] In a second aspect, an embodiment of the present application provides an electronic device, wherein the electronic device comprises the low-side driving circuit described in any one of the first aspects.

[0052] Optionally, in some embodiments of the present application, the electronic device further includes a high-side drive circuit and a controller;

[0053] The first end, the second end and the third end of the controller are respectively connected to the low-side driving circuit, and the fourth end, the fifth end and the sixth end of the controller are respectively connected to the high-side driving circuit.

[0054] In a third aspect, an embodiment of the present application provides a vehicle, comprising the electronic device described in any one of the second aspects.

[0055] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0056] The low-side drive circuit provided by the embodiment of the present application and the electronic device and vehicle having the same, the sampling module of the low-side drive circuit can convert the output current of the load into a first voltage signal, and output the first voltage signal to the current detection module, and then the current detection module can convert the first voltage signal, and output the converted second voltage signal to the controller, so that the controller can output a pulse width modulation signal to the current control module according to the second voltage signal, and then the current control module can control the on-off duration of the switch module according to the pulse width modulation signal output by the controller to adjust the output current of the load. Therefore, the embodiment of the present application can replace the functional chip through the four component modules of the switch module, the sampling module, the current detection module and the current control module in the low-side drive circuit, and achieve the same function as the functional chip, thereby greatly reducing the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0058] Figure 1 An application block diagram of a low-side drive circuit provided in an embodiment of the present application;

[0059] Figure 2 A structural block diagram of a low-side drive circuit provided in an embodiment of the present application;

[0060] Figure 3 A structural block diagram of another low-side driver circuit provided in an embodiment of the present application;

[0061] Figure 4 A structural block diagram of another low-side driver circuit provided in an embodiment of the present application;

[0062] Figure 5 A structural block diagram of another low-side drive circuit provided in an embodiment of the present application;

[0063] Figure 6 A structural block diagram of a low-side drive circuit provided by another embodiment of the present application;

[0064] Figure 7 A schematic diagram of a specific structure of a low-side drive circuit provided in an embodiment of the present application;

[0065] Figure 8 A schematic diagram of the specific structure of another low-side drive circuit provided in an embodiment of the present application;

[0066] Fig. 9 A delay schematic diagram of a low-side drive circuit provided in an embodiment of the present application;

[0067] Fig.10 A schematic diagram of current flow of a low-side drive circuit provided in an embodiment of the present application;

[0068] Fig.11 A structural block diagram of an electronic device provided in an embodiment of the present application;

[0069] Fig.12 A structural block diagram of another electronic device provided in an embodiment of the present application;

[0070] Fig.13 A schematic diagram of a specific structure of a high-side drive circuit provided in an embodiment of the present application;

[0071] Fig.14 A structural block diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0072] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0073] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the application described can be implemented in an order other than those illustrated or described herein.

[0074] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or modules is not necessarily limited to those steps or modules explicitly listed, but may include other steps or modules not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0075] For ease of understanding, now combined Figure 1 For example, the low-side drive circuit provided in the embodiment of the present application can be applied in the drive circuit of the vehicle load. For example, the current of the power supply reaches the load through the high-side drive circuit, and then returns to the power supply through the low-side drive circuit of the embodiment of the present application to form a loop. It should be noted that Figure 1 In the figure, "———" indicates the connection line of the power supply end, "—·—" indicates the connection line of the ground end, and "—" indicates the signal interaction line between the controller and the high-side drive circuit or the controller and the low-side drive circuit. In actual use, for example, the controller can be a microcontroller (Microcontroller Unit, MCU), which sends a control signal to the low-side drive circuit, and then the low-side drive circuit converts the output current of the load into a voltage signal and feeds it back to the microcontroller, so that the microcontroller can adjust the pulse width modulation signal output to the low-side drive circuit according to the voltage signal to affect the output current of the load, and perform fault identification according to the voltage signal, such as the output end is open, short-circuited to the ground or short-circuited to the power supply, and perform port protection of the microcontroller according to the protection information, and handle the abnormal state of the circuit in time to ensure safety.

[0076] Please refer to Figure 2 , which is a structural block diagram of a low-side drive circuit provided in an embodiment of the present application, the low-side drive circuit 100 includes a switch module 101, a sampling module 102, a current detection module 103 and a current control module 104. Among them, the first end of the switch module 101 is connected to the load, the second end of the switch module 101 is respectively connected to the first end of the sampling module 102 and the first end of the current detection module 103, the second end of the sampling module 102 is grounded, the second end of the current detection module 103 is connected to the first end of the controller, the first end of the current control module 104 is connected to the second end of the controller, and the second end of the current control module 104 is connected to the third end of the switch module 101. It should be noted that if there is no mark below, it means that the ground end can be the negative pole of the power supply, for example, the second end of the sampling module 102 is connected to the negative pole of the power supply.

[0077] For example, in the embodiment of the present application, the low-side driving circuit 100 first converts the output current of the load into a first voltage signal through the sampling module 102 and then outputs it to the current detection module 103, and then converts the first voltage signal into a second voltage signal through the current detection module 103 and outputs it to the controller, so as to instruct the controller to output a pulse width modulation (PWM) signal to the current control module 104 according to the second voltage signal, and then the current control module 104 controls the on-off duration of the switch module 101 according to the pulse width modulation signal output by the controller to adjust the output current of the load. Therefore, the embodiment of the present application can replace the functional chip through the four components of the switch module 101, the sampling module 102, the current detection module 103 and the current control module 104 in the low-side driving circuit 100, and achieve the same function as the functional chip, thereby greatly reducing the manufacturing cost.

[0078] Optionally, in some embodiments of the present application, the switch module 101 may include a switch tube, wherein the first end of the switch tube is connected to the load, the second end of the switch tube is respectively connected to the first end of the sampling module 102 and the first end of the current detection module 103, and the third end of the switch tube is connected to the second end of the current control module 104. For example, the switch tube may include but is not limited to a triode or a field effect tube. Taking the switch tube as an N-channel field effect tube as an example, the first end of the switch tube refers to the drain d of the N-channel field effect tube, the second end of the switch tube refers to the source s of the N-channel field effect tube, and the third end of the switch tube refers to the gate g of the N-channel field effect tube.

[0079] Alternatively, if Figure 3 As shown, in some embodiments of the present application, the current detection module 103 may include an amplifying unit 1031, which is configured to convert the first voltage signal to obtain a second voltage signal and then output it to the controller. The first end of the amplifying unit 1031 is respectively connected to the second end of the switch module 101 and the first end of the sampling module 102, the second end of the amplifying unit 1031 is connected to the first end of the controller, and the third end of the amplifying unit 1031 is connected to the second end of the sampling module 102.

[0080] Alternatively, if Figure 4As shown, in some embodiments of the present application, the current detection module 103 may also include a diagnostic unit 1032, and the diagnostic unit 1032 is configured to output a voltage signal so that the controller can identify the circuit operation state according to the voltage signal. For example, the circuit operation state may include but is not limited to any one of a normal connection between the low-side drive circuit 100 and the load, an open circuit between the low-side drive circuit 100 and the load, and a short circuit between the low-side drive circuit 100 and the load, wherein in the case of an open circuit or a short circuit, the current control module 104 controls the switch module 101 to switch to a disconnected state and reconnects the switch module 101.

[0081] Alternatively, if Figure 5 As shown, in some embodiments of the present application, the current control module 104 may include a control unit 1041 and a start unit 1042, wherein the control unit 1041 is configured to receive a pulse width modulation signal output by the controller, and the start unit 1042 is configured to perform on-off switching according to the pulse width modulation signal to control the on-off duration of the switch module 101. The first end of the control unit 1041 is connected to the second end of the controller, the second end of the control unit 1041 is connected to the first end of the start unit 1042, and the second end of the start unit 1042 is connected to the third end of the switch module 101.

[0082] Alternatively, if Figure 6 As shown, in some embodiments of the present application, the low-side driver circuit 100 may also include an overcurrent protection module 105, which is configured to indicate that the circuit has an abnormal condition when the first voltage signal output by the sampling module 102 is greater than a preset voltage threshold. At this time, the first voltage signal needs to be converted into a third voltage signal to keep the switch module 101 in a disconnected state to ensure the safety of the device. The first end of the overcurrent protection module 105 is connected to the first end of the sampling module 102, the second end of the overcurrent protection module 105 is connected to the second end of the sampling module 102, and the third end of the overcurrent protection module 105 is connected to the third end of the switch module 101.

[0083] Exemplarily, in some embodiments of the present application, the overcurrent protection module 105 may include a first level conversion unit, a second level conversion unit, and a third level conversion unit, wherein the first level conversion unit is configured to convert the first voltage signal into a fourth voltage signal, the second level conversion unit is configured to convert the fourth voltage signal into a fifth voltage signal and then output it to the first level conversion unit and the third level conversion unit, the third level conversion unit is configured to convert the fifth voltage signal into a third voltage signal, and the first level conversion unit is further configured to convert the fifth voltage signal into the fourth voltage signal when the first voltage signal is not received. Wherein, the first end of the sampling module 102 is connected to the first level conversion unit, the first level conversion unit is connected to the second level conversion unit, the second level conversion unit is connected to the third level conversion unit, and the third level conversion unit is connected to the third end of the switch module 101.

[0084] Optionally, in some embodiments of the present application, the overcurrent protection module 105 may further include a voltage limiting unit, which is configured to detect changes in the first voltage signal and perform voltage division to protect the port of the controller. The first end of the voltage limiting unit is connected to the second end of the second level conversion unit, the second end of the voltage limiting unit is connected to the third end of the controller, the third end of the voltage limiting unit is grounded, the fourth end of the voltage limiting unit is connected to the output end of the power management chip, and the fifth end of the voltage limiting unit is grounded.

[0085] For example, please refer to Figure 7 , the specific circuit structure of each component module or unit in the low-side driving circuit 100 is described in detail below.

[0086] For example, the switch tube in the switch module 101 is a field effect tube Q00, and the field effect tube Q00 may include but is not limited to an N-channel MOS tube, which selects a current level according to actual load requirements. Specifically, the drain d of the field effect tube Q00 (corresponding to the first end of the switch module 101) is connected to the load, the source s of the field effect tube Q00 (corresponding to the second end of the switch module 101) is respectively connected to the first end of the sampling module 102 and the first end of the current detection module 103, and the gate g of the field effect tube Q00 (corresponding to the third end of the switch module 101) is connected to the second end of the current control module 104.

[0087] Optionally, in some embodiments of the present application, the low-side drive circuit 100 may further include a first diode D1, which may be used to provide a freewheeling circuit for the load when the field effect tube Q00 is in a disconnected state. The anode of the first diode D1 is connected to the drain d of the field effect tube Q00 (corresponding to the first end of the switch tube), and the cathode of the first diode D1 is connected to the output end of the high-side drive circuit.

[0088] Alternatively, if Figure 8As shown, in some embodiments of the present application, the switch module 101 may include a first transistor Q1, a second transistor Q2, a first resistor R1, and a second resistor R2 in addition to the field effect transistor Q00. The first transistor Q1 may include but is not limited to an NPN transistor, and the second transistor Q2 may include but is not limited to a PNP transistor. Among them, the second end of the current control module 104 is respectively connected to the base b of the first transistor Q1 and the base b of the second transistor Q2, the collector c of the second transistor Q2 is grounded, the emitter e of the second transistor Q2 is connected to the gate g of the field effect transistor Q00 (corresponding to the third end of the switch tube), the emitter e of the first transistor Q1 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the gate g of the field effect transistor Q00 (corresponding to the third end of the switch tube), the collector c of the first transistor Q1 is connected to the positive electrode of the power supply, the first end of the second resistor R2 is connected to the gate g of the field effect transistor Q00 (corresponding to the third end of the switch tube), and the second end of the second resistor R2 is grounded.

[0089] For another example, the sampling module 102 may include a resistor R0 , a first end of the resistor R0 is connected to the second end of the switch module 101 (corresponding to the source s of the field effect transistor Q00 ), and a second end of the resistor R0 is grounded.

[0090] For another example, the amplification unit 1031 in the current detection module 103 may include an operational amplifier U1, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first end of the third resistor R3 (corresponding to the first end of the current detection module 103) is respectively connected to the second end of the switch module 101 (corresponding to the source s of the field effect tube Q00) and the first end of the sampling module 102, the second end of the third resistor R3 is connected to the positive input end of the operational amplifier U1, the first end of the fourth resistor R4 is connected to the second end of the sampling module 102, the second end of the fourth resistor R4 is respectively connected to the negative input end of the operational amplifier U1 and the output end of the operational amplifier U1, the output end of the operational amplifier U1 is connected to the first end of the fifth resistor R5, and the second end of the fifth resistor R5 (corresponding to the second end of the current detection module 103) is connected to the first end of the controller. For example, the first end of the controller is an analog input / output interface.

[0091] Optionally, in some embodiments of the present application, the amplification unit 1031 may further include a sixth resistor R6, a seventh resistor R7, a first capacitor C1, a second capacitor C2, and a third capacitor C3. Among them, the first end of the sixth resistor R6 is connected to the second end of the third resistor R3, the second end of the sixth resistor R6 is grounded, the first end of the first capacitor C1 is connected to the second end of the third resistor R3, the second end of the first capacitor C1 is grounded, the first end of the seventh resistor R7 is connected to the negative input end of the operational amplifier U1, the second end of the seventh resistor R7 is connected to the output end of the operational amplifier U1, the first end of the second capacitor C2 is connected to the first end of the seventh resistor R7, the second end of the second capacitor C2 is connected to the second end of the seventh resistor R7, the first end of the third capacitor C3 is connected to the second end of the fifth resistor R5, and the second end of the third capacitor C3 is grounded.

[0092] It should be noted that, assuming the voltage of resistor R0 is U R0 , if the resistance value is R R3 =R R4 , R R6 =R R7 , then the gain β of operational amplifier U1 is R R7 With R R4 The ratio of β = R R7 / R R4 Among them, U R0 is the current through resistor R0 and the resistance value R R0 The product of , and the current through the resistor R0 is approximately equal to the current flowing through the field effect transistor Q00, and is approximately equal to the output current of the load.

[0093] For another example, the diagnostic unit 1032 in the current detection module 103 may include an eighth resistor R8, a first end of the eighth resistor R8 is connected to the output end of the high-side drive circuit, and a second end of the eighth resistor R8 is connected to the first end of the switch module 101 (corresponding to the drain d of the field effect transistor Q00).

[0094] Optionally, in some embodiments of the present application, the amplifying unit 1031 may further include a fourth capacitor C4, which is used to protect the circuit port, wherein a first end of the fourth capacitor C4 is connected to a second end of the eighth resistor R8, and a second end of the fourth capacitor C4 is grounded.

[0095] For another example, the control unit 1041 in the current control module 104 may include a band-stop transistor Q01 and a ninth resistor R9, and the starting unit 1042 may include a tenth resistor R10, a third transistor Q3, an eleventh resistor R11 and a twelfth resistor R12, and the third transistor Q3 may include but is not limited to a PNP tube. Among them, the base b of the band-resistance transistor Q01 (corresponding to the first end of the current control module 104) is connected to the second end of the controller, the emitter e of the band-resistance transistor Q01 is grounded, the collector c of the band-resistance transistor Q01 is connected to the first end of the ninth resistor R9, the second end of the ninth resistor R9 is respectively connected to the first end of the tenth resistor R10 and the base b of the third transistor Q3, the emitter e of the third transistor Q3 and the second end of the tenth resistor R10 are both connected to the positive electrode of the power supply, for example, the voltage of the power supply is 12V, the collector c of the third transistor Q3 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11 (corresponding to the second end of the current control module 104) is respectively connected to the third end of the switch module 101 (corresponding to the gate g of the field effect transistor Q00) and the first end of the twelfth resistor R12, and the second end of the twelfth resistor R12 is grounded.

[0096] Alternatively, if Figure 8 As shown, in some embodiments of the present application, the control unit 1041 may include a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15 and a fourth transistor Q4, and the fourth transistor Q4 may include but is not limited to an NPN tube, and the starting unit 1042 may include a tenth resistor R10, a third transistor Q3, an eleventh resistor R11 and a twelfth resistor R12, and the third transistor Q3 may include but is not limited to a PNP tube. Among them, the first end of the thirteenth resistor R13 (corresponding to the first end of the current control module 104) is connected to the second end of the controller, the second end of the thirteenth resistor R13 is respectively connected to the first end of the fourteenth resistor R14 and the base b of the fourth triode Q4, the second end of the fourteenth resistor R14 is grounded, the emitter e of the fourth triode Q4 is connected to the first end of the fifteenth resistor R15, the second end of the fifteenth resistor R15 is grounded, the collector c of the fourth triode Q4 is respectively connected to the first end of the tenth resistor R10 and the base b of the third triode Q3, the emitter e of the third triode Q3 and the second end of the tenth resistor R10 are both connected to the positive electrode of the power supply, the collector c of the third triode Q3 is connected to the first end of the eleventh resistor R11, the second end of the eleventh resistor R11 (corresponding to the second end of the current control module 104) is respectively connected to the third end of the switch module 101 (corresponding to the gate g of the field effect transistor Q00) and the first end of the twelfth resistor R12, and the second end of the twelfth resistor R12 is grounded.

[0097] It should be noted that the current control module 104 can receive not only the pulse width modulation signal output by the controller, but also the level signal output by the controller. Further, when the pulse width modulation signal rate increases or there is a requirement for the response time of the switch module 101, the current control module 104 can be used. Figure 8 The low-side driver circuit in Figure 7 The low-side driving circuit in the embodiment reduces the turn-off delay time of the switch module 101, for example Fig. 9 The result shown is that the pulse width modulation signal output by the controller changes from high level to low level. Figure 8 The switch module 101 in the circuit has a turn-off response faster than Figure 7 The reason is that when the band-stop transistor Q01 works in the saturation region, its turn-off speed is slow, and it is replaced by the fourth transistor Q4, and the thirteenth resistor R13, the fourteenth resistor R14 and the fifteenth resistor R15 are added accordingly to obtain a common-emitter amplifier circuit, so that the fourth transistor Q4 can work in the amplification region, so that it can be turned off more quickly, and at the same time, the first transistor Q1, the second transistor Q2 and the first resistor R1 are added at the gate g of the field effect transistor Q00 to obtain a push-pull buffer stage, which can increase the charging and discharging speed of the gate capacitance of the field effect transistor Q00, thereby accelerating the switching speed of the field effect transistor Q00.

[0098] Optionally, in some embodiments of the present application, the control unit 1041 may also include a second diode D2 and a third diode D3 to protect the protection circuit port. The startup unit 1042 may also include a fourth diode D4, which may include but is not limited to a clamping diode. The advantage of such a setting is that it can protect the safety of the field effect tube Q00 and avoid damage. Among them, the positive electrode of the second diode D2 is connected to the second end of the controller, the negative electrode of the second diode D2 is connected to the output end of the power management chip, the positive electrode of the third diode D3 is grounded, the negative electrode of the third diode D3 is connected to the positive electrode of the second diode D2, the positive electrode of the fourth diode D4 is connected to the second end of the twelfth resistor R12, and the negative electrode of the fourth diode D4 is connected to the first end of the twelfth resistor R12.

[0099] For example, the first level conversion unit in the overcurrent protection module 105 may include a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18 and a fifth transistor Q5, the fifth transistor Q5 may include but is not limited to an NPN tube, the second level conversion unit may include a sixth transistor Q6 and a nineteenth resistor R19, the sixth transistor Q6 may include but is not limited to a PNP tube, the third level conversion unit may include a twentieth resistor R20 and a seventh transistor Q7, the seventh transistor Q7 may include but is not limited to an NPN tube. In actual use, the preset voltage threshold may be the be-pole voltage V be_Q7. Among them, the first end of the sixteenth resistor R16 (corresponding to the first end of the overcurrent protection module 105) is connected to the first end of the sampling module 102, the second end of the sixteenth resistor R16 is respectively connected to the base b of the fifth transistor Q5 and the first end of the eighteenth resistor R18, the emitter e of the fifth transistor Q5 (corresponding to the second end of the overcurrent protection module 105) is connected to the second end of the sampling module 102, the collector c of the fifth transistor Q5 is respectively connected to the first end of the seventeenth resistor R17 and the first end of the nineteenth resistor R19, the second end of the seventeenth resistor R17 is connected to the positive electrode of the power supply, and the nineteenth resistor R18 is connected to the positive electrode of the power supply. The second end of 9 is connected to the base b of the sixth triode Q6, the emitter e of the sixth triode Q6 is connected to the third end of the current control module 104, the collector c of the sixth triode Q6 is connected to the second end of the eighteenth resistor R18 and the first end of the twentieth resistor R20 respectively, the second end of the twentieth resistor R20 is connected to the base b of the seventh triode Q7, the emitter e of the seventh triode Q7 is connected to the second end of the sampling module 102, and the collector c of the seventh triode Q7 (corresponding to the third end of the overcurrent protection module 105) is connected to the third end of the switch module 101 (corresponding to the gate g of the field effect transistor Q00).

[0100] Optionally, in some embodiments of the present application, the second level conversion unit may further include a fifth diode D5, the benefit of which is that the sixth triode Q6 can be protected from reverse breakdown. The anode of the fifth diode D5 is connected to the third terminal of the current control module 104, and the cathode of the fifth diode D5 is connected to the emitter e of the sixth triode Q6.

[0101] For another example, the voltage limiting unit in the overcurrent protection module 105 may include a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, a sixth diode D6, and a seventh diode D7. Among them, the first end of the twenty-first resistor R21 is connected to the second end of the second level conversion unit, the second end of the twenty-first resistor R21 is respectively connected to the first end of the twenty-second resistor R22 and the positive electrode of the sixth diode D6, the negative electrode of the sixth diode D6 is connected to the output end of the power management chip, for example, the voltage of the output end of the power management chip is 5V, the negative electrode of the seventh diode D7 is connected to the positive electrode of the sixth diode D6, the positive electrode of the seventh diode D7 is grounded, the second end of the twenty-second resistor R22 is respectively connected to the third end of the controller and the first end of the twenty-third resistor R23, and the second end of the twenty-third resistor R23 is grounded. For example, the third end of the controller is a digital input / output interface, and the high and low states of the first end of the twenty-third resistor R23 are related to the state of the control signal, that is, the high and low states of the first end of the twenty-third resistor R23 are read when the control signal is at a high level.

[0102] Combine the following Figure 7 and Fig.10, the working principle of the low-side driving circuit 100 provided in the embodiment of the present application is explained. In the first working stage, the field effect transistor Q00, the band-stop transistor Q01, the third transistor Q3, the fifth transistor Q5, the sixth transistor Q6 and the seventh transistor Q7 are all in the off state, that is, the control signal output by the second end of the controller is at a low level. At this time, the low-side driving circuit 100 does not work, and the current flows to Fig.10 The flow direction is ①, that is, load → first diode D1 → eighth resistor R8 → load.

[0103] In the second working stage, when the control signal output from the second end of the controller is at a high level, the band-blocking transistor Q01 is in the on state, so that the third transistor Q3 is turned on, the eleventh resistor R11 and the twelfth resistor R12 divide the voltage, and then the field effect transistor Q00 is turned on to provide a current loop to the load. At this time, the current flows as follows Fig.10 The flow direction is ②, that is, load → field effect transistor Q00 → resistor R0.

[0104] In the third working stage, when the current at the resistor R0 is too large, the overcurrent protection is implemented. At this time, since the voltage between the base b and the emitter e of the fifth transistor Q5 and the seventh transistor Q7 increases, the fifth transistor Q5 and the seventh transistor Q7 are turned on, and the current flows as follows: Fig.10 The flow direction ③, that is, load → field effect tube Q00 → sixteenth resistor R16 → fifth transistor Q5, and Fig.10 Direction ④, that is, load → field effect transistor Q00 → sixteenth resistor R16 → seventh transistor Q7. At this time, due to the influence of the collector c of the seventh transistor Q7 pulling down the voltage, the field effect transistor Q00 can be turned off in time. Afterwards, since there is no current at the resistor R0, the base voltage of the fifth transistor Q5 becomes the voltage of the node between the eighteenth resistor R18 and the twentieth resistor R20, thereby maintaining the fifth transistor Q5 in the on state, further maintaining the sixth transistor Q6 and the seventh transistor Q7 in the on state, so that the field effect transistor Q00 is continuously in the off state, protecting the circuit safety.

[0105] In addition, it should be noted that if the voltage at the first terminal of the controller is β*V be _Q7, it indicates that the second end of the eighth resistor R8 has an abnormal fault of short-circuiting to the power supply; if the voltage of the first end of the controller is 0, it indicates that the second end of the eighth resistor R8 has an abnormal fault of short-circuiting to the ground; if the voltage of the first end of the controller is the voltage of the output end of the high-side drive circuit at the voltage divided by the eighth resistor R8 and the resistor R0 corresponding to the resistor R0, it indicates that the second end of the eighth resistor R8 is suspended; if the voltage of the first end of the controller is the voltage of the output end of the high-side drive circuit at the voltage divided by the eighth resistor R8 and the load resistor R LThe divided voltage corresponding to the resistor R0 after being connected in parallel and then in series with the resistor R0 indicates that the second end of the eighth resistor R8 is normally connected to the load.

[0106] As another aspect, the present application embodiment further provides an electronic device. Fig.11 As shown, the electronic device 200 may include but is not limited to Figure 2 to Figure 10 The low-side driving circuit 100 in the corresponding embodiment.

[0107] Alternatively, if Fig.12 As shown, in some embodiments of the present application, the electronic device 200 may further include a high-side driving circuit 300 and a controller 400. The first end, the second end and the third end of the controller 400 are respectively connected to the low-side driving circuit 100, and the fourth end, the fifth end and the sixth end of the controller 400 are respectively connected to the high-side driving circuit 300.

[0108] For example, Fig.13 As shown, it is a specific structural schematic diagram of a high-side drive circuit provided in an embodiment of the present application. The high-side drive circuit 300 may include a first module 3001, a second module 3002 and a third module 3003, wherein the first module 3001 includes a transistor q1, a transistor q2, a transistor q3, a resistor r1, a resistor r2, a resistor r3, a resistor r4, a resistor r5, a resistor r6, a resistor r7, a resistor r8, a diode d1, a diode d2 and a diode d3; the second module 3002 includes a resistor r0, a resistor r9, a resistor r10, a resistor r11, a resistor r12, a diode d4, a capacitor c1 and a capacitor c2; and the third module 3003 includes a transistor q4, a switch tube q5, a resistor r13, a resistor r14 and a diode d5.

[0109] It should be noted that the fourth terminal of the controller 400 is connected to the first terminal of the resistor r8 in the high-side drive circuit 300, that is, Fig.13 As shown in “(1)”, the fifth terminal of the controller 400 is connected to the second terminal of the resistor r12 in the high-side drive circuit 300, that is, Fig.13 As shown in “(2)”, the sixth terminal of the controller 400 is connected to the input terminal of the transistor q4 in the high-side driving circuit 300, that is, Fig.13 "(3)" shown. In addition, Fig.13 The port "(4)" shown is connected to the load, and "(5) represents the power supply.

[0110] As another aspect, the present application also provides a vehicle. Fig.14 As shown, the vehicle 500 may include but is not limited to Figure 11 to Figure 13 The electronic device 200 in the corresponding embodiment.

[0111] The embodiment of the present application provides a low-side drive circuit and an electronic device and a vehicle having the same. The sampling module of the low-side drive circuit can convert the output current of the load into a first voltage signal and output the first voltage signal to the current detection module. Then the current detection module can convert the first voltage signal and output the converted second voltage signal to the controller, so that the controller can output a pulse width modulation signal to the current control module according to the second voltage signal, and then the current control module can control the on-off duration of the switch module according to the pulse width modulation signal output by the controller to adjust the output current of the load. Therefore, the embodiment of the present application can replace the functional chip through the four component modules of the switch module, the sampling module, the current detection module and the current control module in the low-side drive circuit, and achieve the same function as the functional chip, thereby greatly reducing the manufacturing cost.

[0112] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A low-side driving circuit, characterized in that: The circuit includes a switch module, a sampling module, a current detection module and a current control module; The first end of the switch module is connected to the load, the second end of the switch module is respectively connected to the first end of the sampling module and the first end of the current detection module, the second end of the sampling module is grounded, the second end of the current detection module is connected to the first end of the controller, the first end of the current control module is connected to the second end of the controller, and the second end of the current control module is connected to the third end of the switch module; The sampling module is configured to convert the output current of the load into a first voltage signal and then output it to the current detection module; The current detection module is configured to convert the first voltage signal into a second voltage signal and then output it to the controller, so as to instruct the controller to output a pulse width modulation signal to the current control module according to the second voltage signal; The current control module is configured to control the on-off duration of the switch module according to the pulse width modulation signal output by the controller, so as to adjust the output current of the load; Wherein, the current detection module includes an amplification unit; The first end of the amplifying unit is connected to the second end of the switch module and the first end of the sampling module respectively, the second end of the amplifying unit is connected to the first end of the controller, and the third end of the amplifying unit is connected to the second end of the sampling module; The amplifying unit is configured to convert the first voltage signal to obtain the second voltage signal and then output the second voltage signal to the controller.

2. The low-side driving circuit according to claim 1, characterized in that: The switch module includes a switch tube; The first end of the switch tube is connected to the load, the second end of the switch tube is respectively connected to the first end of the sampling module and the first end of the current detection module, and the third end of the switch tube is connected to the second end of the current control module.

3. The low-side driving circuit according to claim 2, characterized in that: The circuit further includes a first diode, wherein an anode of the first diode is connected to a first end of the switch tube, and a cathode of the first diode is connected to an output end of the high-side drive circuit.

4. The low-side driving circuit according to claim 2, characterized in that: The switch module also includes a first transistor, a second transistor, a first resistor and a second resistor; The second end of the current control module is respectively connected to the base of the first transistor and the base of the second transistor, the collector of the second transistor is grounded, the emitter of the second transistor is connected to the third end of the switch tube, the emitter of the first transistor is connected to the first end of the first resistor, the second end of the first resistor is connected to the third end of the switch tube, the collector of the first transistor is connected to the positive pole of the power supply, the first end of the second resistor is connected to the third end of the switch tube, and the second end of the second resistor is grounded.

5. The low-side driving circuit according to claim 1, characterized in that: The amplifying unit includes an operational amplifier, a third resistor, a fourth resistor and a fifth resistor; The first end of the third resistor is respectively connected to the second end of the switch module and the first end of the sampling module, the second end of the third resistor is connected to the positive input end of the operational amplifier, the first end of the fourth resistor is connected to the second end of the sampling module, the second end of the fourth resistor is respectively connected to the negative input end of the operational amplifier and the output end of the operational amplifier, the output end of the operational amplifier is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the first end of the controller.

6. The low-side driving circuit according to claim 5, characterized in that: The amplifying unit further includes a sixth resistor, a seventh resistor, a first capacitor, a second capacitor and a third capacitor; The first end of the sixth resistor is connected to the second end of the third resistor, and the second end of the sixth resistor is grounded. The first end of the first capacitor is connected to the second end of the third resistor, and the second end of the first capacitor is grounded. The first end of the seventh resistor is connected to the negative input terminal of the operational amplifier, and the second end of the seventh resistor is connected to the output terminal of the operational amplifier. The first end of the second capacitor is connected to the first end of the seventh resistor, and the second end of the second capacitor is connected to the second end of the seventh resistor. The first end of the third capacitor is connected to the second end of the fifth resistor, and the second end of the third capacitor is grounded.

7. The low-side driving circuit according to claim 1, characterized in that: The current detection module also includes a diagnostic unit; A first end of the diagnostic unit is connected to the output end of the high-side driving circuit, and a second end of the diagnostic unit is connected to the first end of the switch module; The diagnosis unit is configured to output a voltage signal so that the controller can identify a circuit operation status according to the voltage signal.

8. The low-side driving circuit according to claim 7, characterized in that: The circuit operation state includes any one of a normal connection between the low-side driving circuit and the load, an open circuit between the low-side driving circuit and the load, and a short circuit between the low-side driving circuit and the load; Wherein, in the case of the open circuit or the short circuit, the current control module controls the switch module to switch to a disconnected state, and reconnects the switch module.

9. The low-side driving circuit according to claim 7, characterized in that: The diagnosis unit includes an eighth resistor, a first end of the eighth resistor is connected to the output end of the high-side driving circuit, and a second end of the eighth resistor is connected to the first end of the switch module.

10. The low-side driving circuit according to claim 1, characterized in that: The current control module includes a control unit and a starting unit; The first end of the control unit is connected to the second end of the controller, the second end of the control unit is connected to the first end of the start unit, and the second end of the start unit is connected to the third end of the switch module; The control unit is configured to receive the pulse width modulation signal output by the controller, and the start unit is configured to perform on-off switching according to the pulse width modulation signal to control the on-off duration of the switch module.

11. The low-side driving circuit according to claim 10, characterized in that: The control unit includes a band-stop transistor and a ninth resistor, and the start-up unit includes a tenth resistor, a third transistor, an eleventh resistor and a twelfth resistor; The base of the band-stop transistor is connected to the second end of the controller, the emitter of the band-stop transistor is grounded, the collector of the band-stop transistor is connected to the first end of the ninth resistor, the second end of the ninth resistor is respectively connected to the first end of the tenth resistor and the base of the third transistor, the emitter of the third transistor and the second end of the tenth resistor are both connected to the positive electrode of the power supply, the collector of the third transistor is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is respectively connected to the third end of the switch module and the first end of the twelfth resistor, and the second end of the twelfth resistor is grounded.

12. The low-side driving circuit according to claim 10, characterized in that: The control unit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor and a fourth transistor, and the start-up unit includes a tenth resistor, a third transistor, an eleventh resistor and a twelfth resistor; The first end of the thirteenth resistor is connected to the second end of the controller, the second end of the thirteenth resistor is respectively connected to the first end of the fourteenth resistor and the base of the fourth transistor, the second end of the fourteenth resistor is grounded, the emitter of the fourth transistor is connected to the first end of the fifteenth resistor, the second end of the fifteenth resistor is grounded, the collector of the fourth transistor is respectively connected to the first end of the tenth resistor and the base of the third transistor, the emitter of the third transistor and the second end of the tenth resistor are both connected to the positive electrode of the power supply, the collector of the third transistor is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is respectively connected to the third end of the switch module and the first end of the twelfth resistor, and the second end of the twelfth resistor is grounded.

13. The low-side driving circuit according to claim 11 or 12, characterized in that: The control unit further includes a second diode and a third diode, and the start-up unit further includes a fourth diode; The anode of the second diode is connected to the second end of the controller, the cathode of the second diode is connected to the output end of the power management chip, the anode of the third diode is grounded, the cathode of the third diode is connected to the anode of the second diode, the anode of the fourth diode is connected to the second end of the twelfth resistor, and the cathode of the fourth diode is connected to the first end of the twelfth resistor.

14. The low-side driving circuit according to claim 1, characterized in that: The circuit also includes an overcurrent protection module; The first end of the overcurrent protection module is connected to the first end of the sampling module, the second end of the overcurrent protection module is connected to the second end of the sampling module, and the third end of the overcurrent protection module is connected to the third end of the switch module; The overcurrent protection module is configured to convert the first voltage signal into a third voltage signal when the first voltage signal output by the sampling module is greater than a preset voltage threshold, so as to keep the switch module in a disconnected state.

15. The low-side driving circuit according to claim 14, characterized in that: The overcurrent protection module includes a first level conversion unit, a second level conversion unit and a third level conversion unit; The first end of the sampling module is connected to the first level conversion unit, the first level conversion unit is connected to the second level conversion unit, the second level conversion unit is connected to the third level conversion unit, and the third level conversion unit is connected to the third end of the switch module; The first level conversion unit is configured to convert the first voltage signal into a fourth voltage signal, the second level conversion unit is configured to convert the fourth voltage signal into a fifth voltage signal and output it to the first level conversion unit and the third level conversion unit, the third level conversion unit is configured to convert the fifth voltage signal into the third voltage signal, and the first level conversion unit is further configured to convert the fifth voltage signal into the fourth voltage signal when the first voltage signal is not received.

16. The low-side driving circuit according to claim 15, characterized in that: The first level conversion unit includes a sixteenth resistor, a seventeenth resistor, an eighteenth resistor and a fifth transistor, the second level conversion unit includes a sixth transistor and a nineteenth resistor, and the third level conversion unit includes a twentieth resistor and a seventh transistor; The first end of the sixteenth resistor is connected to the first end of the sampling module, the second end of the sixteenth resistor is respectively connected to the base of the fifth transistor and the first end of the eighteenth resistor, the emitter of the fifth transistor is connected to the second end of the sampling module, the collector of the fifth transistor is respectively connected to the first end of the seventeenth resistor and the first end of the nineteenth resistor, the second end of the seventeenth resistor is connected to the positive electrode of the power supply, the second end of the nineteenth resistor is connected to the base of the sixth transistor, the emitter of the sixth transistor is connected to the third end of the current control module, the collector of the sixth transistor is respectively connected to the second end of the eighteenth resistor and the first end of the twentieth resistor, the second end of the twentieth resistor is connected to the base of the seventh transistor, the emitter of the seventh transistor is connected to the second end of the sampling module, and the collector of the seventh transistor is connected to the third end of the switch module.

17. The low-side driving circuit according to claim 16, characterized in that: The second level conversion unit further includes a fifth diode, an anode of the fifth diode is connected to the third end of the current control module, and a cathode of the fifth diode is connected to the emitter of the sixth transistor.

18. The low-side driving circuit according to claim 15, characterized in that: The overcurrent protection module also includes a voltage limiting unit; The first end of the voltage limiting unit is connected to the second end of the second level conversion unit, the second end of the voltage limiting unit is connected to the third end of the controller, the third end of the voltage limiting unit is grounded, the fourth end of the voltage limiting unit is connected to the output end of the power management chip, and the fifth end of the voltage limiting unit is grounded; The voltage limiting unit is configured to detect a change in the first voltage signal and perform voltage division to protect the port of the controller.

19. The low-side driving circuit according to claim 18, characterized in that: The voltage limiting unit includes a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a sixth diode and a seventh diode; The first end of the twenty-first resistor is connected to the second end of the second level conversion unit, the second end of the twenty-first resistor is respectively connected to the first end of the twenty-second resistor and the anode of the sixth diode, the cathode of the sixth diode is connected to the output end of the power management chip, the cathode of the seventh diode is connected to the anode of the sixth diode, the anode of the seventh diode is grounded, the second end of the twenty-second resistor is respectively connected to the third end of the controller and the first end of the twenty-third resistor, and the second end of the twenty-third resistor is grounded.

20. An electronic device, characterized in that: The electronic device comprises the low-side driving circuit according to any one of claims 1 to 19.

21. The electronic device according to claim 20, characterized in that: The electronic device also includes a high-side drive circuit and a controller; The first end, the second end and the third end of the controller are respectively connected to the low-side driving circuit, and the fourth end, the fifth end and the sixth end of the controller are respectively connected to the high-side driving circuit.

22. A vehicle, characterized in that: The vehicle comprises the electronic device according to any one of claims 20 to 21.

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