Low-side driver circuit

Abstract

The present application provides a low-side driver circuit, comprising a driver control module and a fault diagnosis module; the driver control module is connected to one end of a load, the other end of which is connected to a power supply, for driving and controlling the load; the fault diagnosis module is connected to the load and the driver control module, for determining a fault condition of the load, generating fault information, and sending it to the driver control module, wherein the driver control module adaptively adjusts the operating state of the load based on the fault information. This eliminates the need for tedious on-site troubleshooting, and the circuit has a simple structure and is easy to operate, effectively reducing repair and maintenance costs and improving safety.

Description

Technical Field

[0001] The present application relates to the technical field of circuit design, and in particular to a low-side driver circuit. Background Art

[0002] The new energy vehicle industry is currently experiencing rapid growth. New energy electric vehicles utilize numerous power electronic switching devices, which drive power devices such as warning lights and horns through low-side driver circuits. However, currently available driver chips lack fault diagnosis capabilities and are unable to determine the specific nature of load faults. This can lead to vehicle malfunctions, necessitating tedious on-site troubleshooting and resulting in high repair and maintenance costs. Summary of the Invention

[0003] The purpose of this application is to provide a low-side driver circuit with a fault diagnosis function.

[0004] To achieve the above-mentioned object, the present application provides a low-side driver circuit, which includes a driver control module and a fault diagnosis module;

[0005] The drive control module is connected to one end of the load, and the other end of the load is connected to a power supply, for driving and controlling the load;

[0006] The fault diagnosis module is connected to the load and the drive control module, and is used to determine the fault condition of the load and control the working state of the drive control module.

[0007] Furthermore, the low-side drive circuit also includes a short-circuit protection module, which is connected to the fault diagnosis module and the drive control module. The short-circuit protection module controls the working state of the drive control module according to the electrical signal input by the fault diagnosis module.

[0008] Furthermore, the drive control module includes a first MOS tube and a drive chip, the drive chip is connected to the fault diagnosis module and the gate of the first MOS tube, the drain of the first MOS tube is connected to the load via the fault diagnosis module, and the source of the first MOS tube is grounded.

[0009] Furthermore, the fault diagnosis module includes a main control chip, a current sensor, a first resistor and a second resistor. The current sensor is connected to the load, the main control chip and the drive control module. The current sensor detects the current passing through the load and generates a detection voltage; the main control chip is connected to the first end of the first resistor and the first end of the second resistor, the second end of the second resistor is grounded, and the second end of the first resistor is connected to the load. The main control chip detects the input current and input voltage of the load into the fault diagnosis module.

[0010] Furthermore, the short-circuit protection module includes a first comparator and a first transistor, the negative input end of the first comparator is connected to the short-circuit protection threshold voltage; the positive input end of the first comparator is connected to the current sensor of the fault diagnosis module and obtains the detection voltage, the output end of the first comparator is connected to the base of the first transistor, and the emitter of the first transistor is grounded; the collector of the first transistor is connected to the drive control module.

[0011] Furthermore, the short-circuit protection module also includes a third resistor and a fourth resistor, the first end of the third resistor is connected to the power supply, the second end of the fourth resistor is grounded, and the second end of the third resistor is connected to the first end of the fourth resistor and to the negative input end of the first comparator to provide the short-circuit protection threshold voltage.

[0012] Furthermore, the resistance values ​​of the third resistor and the fourth resistor are adjustable, and the short-circuit protection module sets the short-circuit protection threshold voltage by adjusting the resistance values ​​of the third resistor and the fourth resistor.

[0013] Furthermore, the fault diagnosis module is provided with an overcurrent protection threshold, and the drive control module also includes a seventh resistor, an eighth resistor, a second capacitor, and a first diode; the seventh pin of the driver chip is connected to the first end of the eighth resistor and the first end of the first diode, the second end of the eighth resistor is connected to the second end of the first diode, and is connected to the first end of the second capacitor, the first end of the seventh resistor, the gate of the first MOS tube and the short-circuit protection module; the second end of the second capacitor is connected to the second end of the seventh resistor, the source of the first MOS tube and grounded; the second pin of the driver chip is connected to the fault diagnosis module.

[0014] Further, when the input voltage is the same as the power supply voltage, the short-circuit protection module also includes a fifth resistor, a sixth resistor and a first capacitor, the first end of the fifth resistor is connected to the fault diagnosis module, the second end of the fifth resistor is connected to the first end of the first capacitor and the positive input end of the first comparator, the second end of the first capacitor is grounded, the first end of the sixth resistor is connected to the power supply and the third pin of the first comparator, the second end of the sixth resistor is connected to the output end of the first comparator, i.e., the first pin, and the base of the first transistor, and the twelfth pin of the first comparator is grounded.

[0015] Furthermore, the fault diagnosis module is provided with an overcurrent protection threshold. When the input current is greater than the overcurrent protection threshold, the fault diagnosis module generates overcurrent fault information and sends it to the drive control module. The drive control module adjusts the working state of the load to non-working according to the overcurrent fault information.

[0016] When the input voltage is the same as the power supply voltage, the fault diagnosis module generates short-circuit fault information and sends it to the drive control module, and the drive control module adjusts the working state of the load to non-working according to the short-circuit fault information;

[0017] When the input voltage is zero, the fault diagnosis module generates circuit-breaking fault information and sends it to the drive control module. The drive control module adjusts the working state of the load to non-working according to the circuit-breaking fault information.

[0018] Beneficial Effects: The present application provides a low-side drive circuit, comprising a drive control module and a fault diagnosis module; the drive control module is connected to one end of a load, the other end of which is connected to a power supply, for driving and controlling the load; the fault diagnosis module is connected to the load and the drive control module, for determining a fault condition of the load, generating fault information, and sending it to the drive control module, wherein the drive control module adaptively adjusts the operating state of the load based on the fault information. This eliminates the need for tedious on-site troubleshooting, and the circuit has a simple structure and is easy to operate, effectively reducing repair and maintenance costs and improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 1 is a schematic structural diagram of a low-side driver circuit provided in one embodiment of the present application;

[0021] Figure 2 This is a circuit schematic diagram of a portion of a low-side driver circuit provided in one embodiment of the present application;

[0022] Figure 3 This is a circuit schematic diagram of a driver chip provided in one embodiment of the present application;

[0023] Figure 4 This is a circuit schematic diagram of a main control chip provided in one embodiment of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise specified, the directional words used, such as "up", "down", "left", and "right", generally refer to the up, down, left, and right of the device in actual use or working state, specifically the drawing direction in the accompanying drawings.

[0025] The present application provides a low-side driver circuit, which is described in detail below. It should be noted that the order in which the following embodiments are described does not limit the preferred order of the embodiments of the present application. In the following embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in one embodiment, please refer to the relevant description of other embodiments.

[0026] In the embodiments and patent claims, unless otherwise specified herein, "a," "an," "the," and "the" may include plural forms. If there are descriptions involving "first," "second," etc. in the embodiments of this application, the descriptions of "first," "second," etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features specified as "first" or "second" may explicitly or implicitly include at least one of such features.

[0027] It should be further understood that the term "comprising" as used in the specification of the present application refers to the presence of the stated features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intermediate elements. In addition, "connected" or "coupled" as used herein can include wireless connections or wireless couplings. The term "and / or" as used herein includes all or any units and all combinations of one or more associated listed items.

[0028] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0029] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0030] like Figure 1 As shown, the present application provides a low-side drive circuit, including a drive control module 100, a fault diagnosis module 200 and a short-circuit protection module 300. The drive control module 100 is connected to one end of the load L1, and the other end of the load L1 is connected to the power supply, for driving and controlling the load L1; the fault diagnosis module 200 is connected to the load L1 and the drive control module 100, for judging the fault condition of the load L1 and generating fault information to be sent to the drive control module 100, and the drive control module 100 adapts to adjust the working state of the load L1 according to the fault information. The short-circuit protection module 300 is connected to the fault diagnosis module 200 and the drive control module 100, and the short-circuit protection module 300 generates short-circuit information according to the electrical signal input by the fault diagnosis module 200 and sends it to the drive control module 100, and the drive control module 100 adapts to adjust the working state of the load L1 according to the short-circuit information. The fault diagnosis module 200 shown can determine the fault condition of the load L1 and control the working state of the load L1, without the need for tedious on-site troubleshooting. The operation is convenient, effectively reducing the cost of repair and maintenance and improving safety.

[0031] Furthermore, the drive control module 100 includes a first MOS transistor Q1 and a driver chip U4, the driver chip U4 is connected to the short circuit protection module 300 and the gate of the first MOS transistor Q1, the drain of the first MOS transistor Q1 is connected to the load via the fault diagnosis module, and the source of the first MOS transistor Q1 is grounded. Figure 2 and Figure 3As shown, the drive control module 100 also includes a seventh resistor R7, an eighth resistor R8, a second capacitor C2, and a first diode D1. The sixth pin VDD of the driver chip U4 is connected to a power supply. The seventh pin OUTA of the driver chip U4 is connected to the first end of the eighth resistor R8 and the first end of the first diode D1. The second end of the eighth resistor R8 is connected to the second end of the first diode D1 and is also connected to the first end of the second capacitor C2, the first end of the seventh resistor R7, the gate of the first MOS transistor Q1, and the short-circuit protection module 300. That is, the seventh pin OUTA of the driver chip U4 is coupled to the gate of the first MOS transistor Q1; the second end of the second capacitor C2 is connected to the second end of the seventh resistor R7, the source of the first MOS transistor Q1, and ground. The second pin INA and the fourth pin INB of the driver chip U4 receive PWM signals, and the second pin INA of the driver chip U4 is connected to the fault diagnosis module 200. The eighth pin GND and the third pin GND of the driver chip U4 are grounded. The driving control module 100 drives and controls the load L1 through the driving chip U4 and the first MOS transistor Q1.

[0032] Further, if Figure 1 As shown, the fault diagnosis module 200 includes a main control chip U2, a current sensor U1, a first resistor R1 and a second resistor R2. The current sensor U1 is connected to the load L1, the main control chip U2 and the drive control module 100. The current sensor U1 detects the current passing through the load L1 and generates a detection voltage. The main control chip U2 is connected to the first end of the first resistor R1 and the first end of the second resistor R2. The second end of the second resistor R2 is grounded. The second end of the first resistor R1 is connected to the load L1. The main control chip U2 detects the input current and input voltage of the load L1 into the fault diagnosis module 200. In one embodiment of the present application, Figure 2 and Figure 4As shown, the third and fourth pins IP- of the current sensor U1 are connected to the drive control module 100, the eighth pin of the current sensor U1 is connected to the power supply Vcc, the seventh pin Vout of the current sensor U1 is connected to the 42nd pin of the main control chip U2 and the short-circuit protection module 300, the fifth pin GND of the current sensor U1 is grounded, and the fifth pin of the main control chip U2 is connected to the second pin INA of the driver chip U4 of the drive control module 100. The main control chip U2 can generate a control signal and output it to the driver chip U4 to control the drive control module 100. The fault diagnosis module 200 can determine the fault condition of the load L1 and control the working state of the drive control module 100. Specifically, the fault diagnosis module can determine whether the load L1 is in a fault condition such as overcurrent, short circuit, or open circuit, and control the drive control module 100 through the main control chip U2.

[0033] First, an overcurrent protection threshold is set inside the main control chip U2 of the fault diagnosis module 200, and the main control chip U2 detects the input current of the load L1 input to the fault diagnosis module 200. When the input current is greater than the overcurrent protection threshold, the fault diagnosis module 200 determines that the fault condition is overcurrent, and the fault diagnosis module generates overcurrent fault information and sends it to the drive chip U4 of the drive control module 100. The drive control module 100 adjusts the working state of the load L1 to non-working according to the overcurrent fault information. In a specific embodiment, the overcurrent protection threshold can be set according to the specific parameters of the different loads L1. By setting the main control chip U2, the fault diagnosis module 200 can diagnose the overcurrent fault condition without the need for tedious on-site troubleshooting, and promptly control the drive control module 100 to stop the load L1 from working. It is easy to operate, effectively reduces the cost of repair and maintenance, and improves safety.

[0034] Secondly, the fault diagnosis module 200 can also diagnose the short circuit and open circuit conditions of the load L1. The main control chip U2 can calculate the voltage value of the input voltage V1 by measuring the voltage V2 across the resistor R2, which is V1=V2*(R3+R4) / R4. When the input voltage V1 is the same as the power supply voltage Vcc, the fault diagnosis module 200 determines that the fault condition of the load L1 is a short circuit. The fault diagnosis module 200 generates short circuit fault information and sends it to the driver chip U4 of the drive control module 100. The drive control module 100 adjusts the working state of the load L1 to non-working according to the short circuit fault information. When the input voltage V1 is zero, the fault diagnosis module 200 generates open circuit fault information and sends it to the driver chip U4 of the drive control module 100. The drive control module 100 adjusts the working state of the load L1 to non-working according to the open circuit fault information. By setting up the main control chip U2, the fault diagnosis module 200 can diagnose whether the fault condition of the load L1 is a short circuit or an open circuit without the need for tedious on-site troubleshooting, and can promptly control the drive control module 100 to stop working. It is easy to operate, effectively reduces the cost of repair and maintenance, saves time, and improves safety.

[0035] Further, if Figure 1 and Figure 2As shown, the short-circuit protection module 300 is used to quickly shut down the first MOS transistor Q1 in the event of a short circuit. The short-circuit protection module 300 includes a first comparator U3 and a first transistor Q2. The negative input terminal of the first comparator U3 is connected to the short-circuit protection threshold voltage. The positive input terminal of the first comparator U3 is connected to the seventh pin VOUT of the current sensor U1 of the fault diagnosis module 200 to obtain the detection voltage. The output terminal of the first comparator U3 is connected to the base of the first transistor Q2, and the emitter of the first transistor Q2 is grounded. The collector of the first transistor Q2 is connected to the gate of the first MOS transistor of the drive control module 100. The short-circuit protection module 300 also includes a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected to the power supply Vcc, the second end of the fourth resistor R4 is grounded, and the second end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the negative input terminal of the first comparator U3 to provide the short-circuit protection threshold voltage. In actual application, the resistance values ​​of the third resistor R3 and the fourth resistor R4 can be adjusted according to actual needs, and the short-circuit protection module 300 sets the short-circuit protection threshold voltage by adjusting the resistance values ​​of the third resistor R3 and the fourth resistor R4. In a specific embodiment, the short-circuit protection module further includes a fifth resistor R5, a sixth resistor R6 and a first capacitor C1, the first end of the fifth resistor R5 is connected to the seventh pin VOUT of the current sensor U1 of the fault diagnosis module 200, the second end of the fifth resistor R5 is connected to the first end of the first capacitor C1 and the positive input terminal of the first comparator U3, the second end of the first capacitor C1 is grounded, the first end of the sixth resistor R6 is connected to the power supply Vcc and the third pin of the first comparator U3, the second end of the sixth resistor R6 is connected to the output terminal of the first comparator U3, i.e., the first pin, and the base of the first transistor Q2, and the twelfth pin of the first comparator U3 is grounded. In a specific embodiment, the short-circuit protection module 300 sets the short-circuit protection threshold voltage to V4 by adjusting the resistance values ​​of the third resistor R3 and the fourth resistor R4. The current sensor U1 of the fault diagnosis module 200 converts the measured current value into the detection voltage V3. When a short circuit occurs, the current of the hardware circuit increases, that is, when the detection voltage V3 is greater than the short-circuit protection threshold voltage V4, the first transistor Q2 is turned on, pulling down the PWM signal output by the driver chip U4, thereby turning off the first MOS tube Q1 to perform a rapid short-circuit protection function.Since the short-circuit protection module 300 uses a hardware circuit for short-circuit protection, when the load L1 is short-circuited, the short-circuit protection module 300 will respond more quickly than the fault diagnosis module 200 and can cut off the drive control module very quickly, thereby making the low-side drive circuit safer.

[0036] In summary, the present application provides a low-side drive circuit, which includes a drive control module and a fault diagnosis module; the drive control module is connected to one end of a load, the other end of which is connected to a power supply, and is used to drive and control the load; the fault diagnosis module is connected to the load and the drive control module, and is used to determine the fault condition of the load and generate fault information to send to the drive control module, and the drive control module adapts to adjust the working state of the load according to the fault information. This eliminates the need for tedious on-site troubleshooting, and the circuit has a simple structure and is easy to operate, effectively reducing the cost of repair and maintenance and improving safety.

[0037] The above is a detailed introduction to the low-side drive circuit provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A low-side driver circuit, characterized in that: The low-side drive circuit includes a drive control module and a fault diagnosis module; The drive control module is connected to one end of the load, and the other end of the load is connected to a power supply, for driving and controlling the load; The fault diagnosis module is connected to the load and the drive control module, and is used to determine the fault condition of the load and generate fault information to send to the drive control module, and the drive control module adapts to adjust the working state of the load according to the fault information; The drive control module includes a first MOS transistor and a drive chip, the drive chip is connected to the fault diagnosis module and the gate of the first MOS transistor, the drain of the first MOS transistor is connected to the load via the fault diagnosis module, and the source of the first MOS transistor is grounded.

2. The low-side driver circuit according to claim 1, wherein: The low-side drive circuit also includes a short-circuit protection module, which is connected to the fault diagnosis module and the drive control module. The short-circuit protection module generates short-circuit information based on the electrical signal input by the fault diagnosis module and sends it to the drive control module. The drive control module adapts to the working state of the load according to the short-circuit information.

3. The low-side driver circuit according to claim 2, wherein: The fault diagnosis module includes a main control chip, a current sensor, a first resistor and a second resistor. The current sensor is connected to the load, the main control chip and the drive control module. The current sensor detects the current passing through the load and generates a detection voltage. The main control chip is connected to the first end of the first resistor and the first end of the second resistor, the second end of the second resistor is grounded, and the second end of the first resistor is connected to the load. The main control chip detects the input current and input voltage of the load into the fault diagnosis module.

4. The low-side driver circuit according to claim 3, wherein: The short-circuit protection module includes a first comparator and a first transistor. The negative input end of the first comparator is connected to the short-circuit protection threshold voltage; the positive input end of the first comparator is connected to the current sensor of the fault diagnosis module and obtains the detection voltage. The output end of the first comparator is connected to the base of the first transistor, and the emitter of the first transistor is grounded; the collector of the first transistor is connected to the drive control module.

5. The low-side driver circuit according to claim 4, wherein: The short-circuit protection module also includes a third resistor and a fourth resistor, the first end of the third resistor is connected to the power supply, the second end of the fourth resistor is grounded, and the second end of the third resistor is connected to the first end of the fourth resistor and to the negative input end of the first comparator to provide the short-circuit protection threshold voltage.

6. The low-side driver circuit according to claim 5, wherein: The resistance values ​​of the third resistor and the fourth resistor are adjustable, and the short-circuit protection module sets the short-circuit protection threshold voltage by adjusting the resistance values ​​of the third resistor and the fourth resistor.

7. The low-side driver circuit according to claim 2, wherein: The drive control module also includes a seventh resistor, an eighth resistor, a second capacitor, and a first diode; the seventh pin of the driver chip is connected to the first end of the eighth resistor and the first end of the first diode, the second end of the eighth resistor is connected to the second end of the first diode, and is connected to the first end of the second capacitor, the first end of the seventh resistor, the gate of the first MOS tube, and the short-circuit protection module; the second end of the second capacitor is connected to the second end of the seventh resistor, the source of the first MOS tube, and grounded; the second pin of the driver chip is connected to the fault diagnosis module.

8. The low-side driver circuit according to claim 5, wherein: The short-circuit protection module also includes a fifth resistor, a sixth resistor and a first capacitor, the first end of the fifth resistor is connected to the fault diagnosis module, the second end of the fifth resistor is connected to the first end of the first capacitor and the positive input end of the first comparator, the second end of the first capacitor is grounded, the first end of the sixth resistor is connected to the power supply and the third pin of the first comparator, the second end of the sixth resistor is connected to the output end of the first comparator, i.e., the first pin, and the base of the first transistor, and the twelfth pin of the first comparator is grounded.

9. The low-side driver circuit according to claim 3, wherein: The fault diagnosis module is provided with an overcurrent protection threshold. When the input current is greater than the overcurrent protection threshold, the fault diagnosis module generates overcurrent fault information and sends it to the drive control module. The drive control module adjusts the working state of the load to non-working according to the overcurrent fault information. When the input voltage is the same as the power supply voltage, the fault diagnosis module generates short-circuit fault information and sends it to the drive control module, and the drive control module adjusts the working state of the load to non-working according to the short-circuit fault information; When the input voltage is zero, the fault diagnosis module generates circuit-breaking fault information and sends it to the drive control module. The drive control module adjusts the working state of the load to non-working according to the circuit-breaking fault information.

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