High-side driving circuit

Abstract

The utility model relates to the technical field of power supplies, and discloses a high-side driving circuit, which comprises an over-current detection unit, a driving unit, a diagnosis unit, a control unit and an acquisition unit, and is characterized in that the first end of the over-current detection unit is connected with an external power supply, and the second end of the over-current detection unit is connected with the first end of the driving unit; the output end of the overcurrent detection unit is connected with the first end of the control unit; the first end of the acquisition unit is connected with the second end of the driving unit and the second end of the control unit, the second end of the acquisition unit is connected with the input end of the diagnosis unit, and the third end of the acquisition unit is connected with the power supply output end and outputs power supply voltage; the input end of the control unit is connected with the output end of the diagnosis unit, and the output end of the control unit is connected with the control end of the driving unit. The high-side driving circuit provided by the utility model can carry out self-protection when a fault occurs, and can still realize over-current protection even when the diagnosis unit is dormant, so that the reliability of the high-side driving circuit is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply technical field, concretely relates to a high side drive circuit. BACKGROUND

[0002] The high side drive circuit is a kind of circuit specially designed for controlling high-voltage side switch, and its main function is to convert low-voltage, low-current control signal into high-voltage, high-current output to drive high-voltage side switch element.The existing high side drive circuit cannot work in hibernation state or cannot meet the static current demand of diagnostic unit, and the self-made high side drive circuit cannot realize self-protection when overcurrent occurs, and needs software intervention. SUMMARY

[0003] Therefore, the utility model provides a kind of high side drive circuit to solve the problem that the existing high side drive circuit cannot be self-protected.

[0004] The high side drive circuit provided by the utility model includes: overcurrent detection unit, drive unit, diagnostic unit, control unit and acquisition unit, wherein the first end of overcurrent detection unit is connected with external power supply, the second end of overcurrent detection unit is connected with the first end of drive unit, the output end of overcurrent detection unit is connected with the first end of control unit, and overcurrent detection unit is used to output overcurrent signal when overcurrent is detected;The first end of acquisition unit is connected with the second end of drive unit and the second end of control unit, the second end of acquisition unit is connected with the input end of diagnostic unit, the third end of acquisition unit is connected with power supply output end and outputs power supply voltage, and acquisition unit is used to divide power supply voltage;The input end of control unit is connected with the output end of diagnostic unit, and the output end of control unit is connected with the control end of drive unit;Diagnostic unit is preset with fault voltage interval;When diagnostic unit determines that the divided power supply voltage is in fault voltage interval, diagnostic unit outputs fault signal, and control unit outputs off signal based on fault signal and / or overcurrent signal;Drive unit is used to off based on off signal, so that power supply output end stops outputting power supply voltage.

[0005] The high side drive circuit provided by the utility model, control unit can control power supply output end to stop outputting power supply voltage based on fault signal outputted by diagnostic unit, and can also control power supply output end to stop outputting power supply voltage based on overcurrent signal outputted by overcurrent detection unit, that is, even if diagnostic unit is in hibernation state or stops working due to fault, high side drive circuit can still perform overcurrent protection, and the reliability of high side drive circuit is improved.

[0006] In an alternative embodiment, the overcurrent detection unit comprises a first switch, a first resistor and a second resistor, wherein the first end of the first switch is connected with the external power supply and the first end of the first resistor, the control end of the first switch is connected with the first end of the second resistor, the second end of the first switch is connected with the first end of the control unit, and the first switch is turned on when the power output end overcurrents; the second end of the first resistor is connected with the second end of the second resistor and the first end of the driving unit.

[0007] In an alternative embodiment, the acquisition unit comprises a current limiting unit and a voltage dividing unit, wherein the first end of the current limiting unit is connected with the pull-up power supply, the second end of the current limiting unit is connected with the second end of the control unit, the first end of the voltage dividing unit and the power output end; the second end of the voltage dividing unit is connected with the input end of the diagnosis unit; the diagnosis unit is provided with a fault voltage interval; the degree of voltage division on the power supply voltage is adjusted by adjusting the resistance value of the current limiting unit and the voltage dividing unit.

[0008] The resistance value of the current limiting unit and the voltage dividing unit in the high-side drive circuit can be flexibly adjusted according to the size of the power supply voltage, and the degree of voltage division is adjusted, so that different levels of power supply voltage can be judged by using a unified fault voltage interval standard, and the adaptability of the high-side drive circuit is improved.

[0009] In an alternative embodiment, the voltage dividing unit comprises a third resistor, a fourth resistor and a first capacitor, wherein the first end of the third resistor is connected with the second end of the control unit, the second end of the third resistor is connected with the first end of the fourth resistor, the first end of the first capacitor and the input end of the diagnosis unit; the second end of the fourth resistor is connected with the first end of the first capacitor and grounded.

[0010] In an alternative embodiment, the voltage dividing unit further comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a second switch, a third switch and a second capacitor, wherein the first end of the fifth resistor is connected with the input end of the control unit, the second end of the fifth resistor is connected with the first end of the sixth resistor and the control end of the second switch; the second end of the sixth resistor is connected with the first end of the second switch, the first end of the ninth resistor, the first end of the second capacitor and grounded; the second end of the second switch is connected with the first end of the seventh resistor; the second end of the seventh resistor is connected with the control end of the third switch; the first end of the third switch is connected with the second end of the current limiting unit, the second end of the third switch is connected with the first end of the eighth resistor; the second end of the eighth resistor is connected with the second end of the ninth resistor, the second end of the second capacitor and the input end of the diagnosis unit; when the diagnosis unit is in sleep state, the diagnosis unit stops outputting the control signal, so that the second switch and the third switch are turned off, and the input end of the diagnosis unit stops inputting the divided power supply voltage.

[0011] In an alternative embodiment, the control unit comprises: an anti-reverse unit, a first switch unit and a second switch unit, wherein the first end of the anti-reverse unit is connected to the output end of the overcurrent detection unit, the second end of the anti-reverse unit is connected to the second end of the drive unit, the third end of the anti-reverse unit is connected to the output end of the diagnosis unit, the fourth end of the anti-reverse unit is connected to the control end of the first switch unit, the fifth end of the anti-reverse unit is connected to the control end of the second switch unit, the anti-reverse unit is used to prevent the current flowing to the first switch unit and the second switch unit from reversing; the first end of the first switch unit is connected to the first end of the second switch unit, and the second end of the first switch unit is connected to the control end of the drive unit; when the power supply output end overflows or is short-circuited, the second switch unit is turned on, and the first switch unit is turned off.

[0012] In an alternative embodiment, the anti-reverse unit comprises: a first diode, a second diode, a third diode and a fourth diode, wherein the anode of the first diode is connected to the second end of the drive unit, the cathode of the first diode is connected to the cathode of the second diode and the control end of the first switch unit; the anode of the second diode is connected to the anode of the fourth diode and the output end of the diagnosis unit; the anode of the third diode is connected to the output end of the overcurrent detection unit, and the cathode of the third diode is connected to the cathode of the fourth diode and the control end of the second switch unit.

[0013] In an alternative embodiment, the first switch unit comprises: a tenth resistor, a fourth switch and a first zener diode, wherein the first end of the tenth resistor is connected to the fourth end of the anti-reverse unit, the second end of the tenth resistor is connected to the control end of the fourth switch, the first end of the first zener diode and the first end of the second switch unit; the first end of the fourth switch is connected to the control end of the drive unit, and the second end of the fourth switch is connected to the second end of the first zener diode and grounded.

[0014] In an alternative embodiment, the second switch unit comprises: an eleventh resistor, a twelfth resistor and a fifth switch, wherein the first end of the eleventh resistor is connected to the fifth end of the anti-reverse unit, the second end of the eleventh resistor is connected to the first end of the twelfth resistor and the control end of the fifth switch; the second end of the twelfth resistor is connected to the first end of the fifth switch and grounded; and the second end of the fifth switch is connected to the first end of the first switch unit.

[0015] In an alternative embodiment, the driving unit comprises a thirteenth resistor, a fourteenth resistor, a second voltage stabilizing tube and a sixth switch, wherein the first end of the thirteenth resistor is connected with the first end of the second voltage stabilizing tube, the first end of the sixth switch and the second end of the overcurrent detection unit, the second end of the thirteenth resistor is connected with the second end of the second voltage stabilizing tube, the control end of the sixth switch and the first end of the fourteenth resistor; the second end of the fourteenth resistor is connected with the output end of the control unit; the second end of the sixth switch is connected with the first end of the collecting unit, and the sixth switch is used for being turned off based on the turn-off signal. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0017] Figure 1 is a component diagram of the high-side driving circuit according to an embodiment of the present application;

[0018] Figure 2 is a circuit structure diagram of the high-side driving circuit according to an embodiment of the present application;

[0019] Figure 3 is another component diagram of the high-side driving circuit according to an embodiment of the present application;

[0020] Figure 4 is a circuit structure diagram of the voltage dividing unit according to an embodiment of the present application;

[0021] Figure 5 is another component diagram of the high-side driving circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some 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 creative labor are within the scope of protection of the present application.

[0023] In the description of the present application, it should be noted that the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0024] In the description of the utility model, it is necessary to explain, unless another explicit provision and limitation, term "installation", "link", "connection" should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can be indirectly connected through intermediate medium, also can be two element internal communication, can be wireless connection, also can be wired connection.For ordinary skilled person in the art, the specific meaning of the above terms in the utility model can be understood according to specific circumstances.

[0025] In addition, the technical features involved in the different embodiments of the utility model described below can be combined with each other as long as there is no conflict between them.

[0026] The high-side drive circuit provided by the embodiment comprises an overcurrent detection unit 1, a drive unit 2, a diagnosis unit 3, a control unit 4 and an acquisition unit 5. Figure 1 As shown in the figure, the overcurrent detection unit 1, the drive unit 2, the diagnosis unit 3, the control unit 4 and the acquisition unit 5 are connected in series.

[0027] Figure 1 In the embodiment, the first end of the overcurrent detection unit 1 is connected with an external power supply POWER, the second end of the overcurrent detection unit 1 is connected with the first end of the drive unit 2, the output end of the overcurrent detection unit 1 is connected with the first end of the control unit 4, and the overcurrent detection unit 1 is used for outputting an overcurrent signal when overcurrent is detected.

[0028] Figure 1 In the embodiment, the first end of the overcurrent detection unit 1 is connected with an external power supply POWER, the second end of the overcurrent detection unit 1 is connected with the first end of the drive unit 2, the output end of the overcurrent detection unit 1 is connected with the first end of the control unit 4, and the overcurrent detection unit 1 is used for outputting an overcurrent signal when overcurrent is detected.

[0029] Specifically, Figure 1 In the embodiment, a plurality of voltage intervals are preset in the diagnosis unit 3, which are respectively used for diagnosing different fault types of the high-side drive circuit, and the acquisition unit 5 is used for dividing the supply voltage OUTPUT.When the high-side drive circuit works normally, the output supply voltage OUTPUT is within a normal range, at this time, the voltage range corresponding to the supply voltage after voltage division is used as a normal voltage interval;When the output supply voltage OUTPUT of the high-side drive circuit exceeds the highest limit value of the normal range, at this time, the voltage range corresponding to the supply voltage OUTPUT after voltage division is used as an overvoltage voltage interval;When the output supply voltage OUTPUT of the high-side drive circuit is less than the lowest limit value of the normal range, at this time, the voltage range corresponding to the supply voltage OUTPUT after voltage division is used as an undervoltage voltage interval.

[0030] Figure 1 In the embodiment, the input end of the control unit 4 is connected with the output end of the diagnosis unit 3, and the output end of the control unit 4 is connected with the control end of the drive unit 2.

[0031] Figure 1 In particular, when the diagnostic unit 3 determines that the divided supply voltage is in the fault voltage interval, the diagnostic unit 3 outputs a fault signal.

[0032] In particular, Figure 1 In particular, when the diagnostic unit 3 determines that the divided supply voltage is in the fault voltage interval, the diagnostic unit 3 outputs a fault signal.

[0033] Figure 1 In particular, the control unit 4 outputs a shutdown signal based on the fault signal and / or the overcurrent signal. The driving unit 2 is configured to shut down based on the shutdown signal, so that the supply output end stops outputting the supply voltage OUTPUT.

[0034] In particular, Figure 1 In particular, when the diagnostic unit 3 determines that the divided supply voltage is in the fault voltage interval, the diagnostic unit 3 outputs a fault signal.

[0035] In particular, the control unit 4 outputs a shutdown signal based on the fault signal and / or the overcurrent signal. The driving unit 2 is configured to shut down based on the shutdown signal, so that the supply output end stops outputting the supply voltage OUTPUT.

[0036] In particular, the control unit 4 outputs a shutdown signal based on the fault signal and / or the overcurrent signal. The driving unit 2 is configured to shut down based on the shutdown signal, so that the supply output end stops outputting the supply voltage OUTPUT.

[0037] The high-side drive circuit provided in this embodiment allows the control unit to stop outputting the power supply voltage based on the fault signal output by the diagnostic unit, and also to stop outputting the power supply voltage based on the overcurrent signal output by the overcurrent detection unit. In other words, even if the diagnostic unit is in a dormant state or stops working due to a fault, the high-side drive circuit can still perform overcurrent protection. This enables the diagnostic unit to perform short-power, short-ground, and open-circuit diagnoses in the dormant state, and overcurrent and short-ground protection and diagnosis in the working state, thereby improving the reliability of the high-side drive circuit.

[0038] In some alternative implementations, such as Figure 2 As shown, the overcurrent detection unit 1 includes: a first switch Q1, a first resistor R1, and a second resistor R2. The first terminal of the first switch Q1 is connected to the external power supply POWER and the first terminal of the first resistor R1. The control terminal of the first switch Q1 is connected to the first terminal of the second resistor R2. The second terminal of the first switch Q1 is connected to the first terminal of the control unit 4. When there is an overcurrent at the power supply output terminal, the first switch Q1 is turned on. The second terminal of the first resistor R1 is connected to the second terminal of the second resistor R2 and the first terminal of the drive unit 2.

[0039] Specifically, Figure 2 In the middle, when the power supply output terminal of the high-side drive circuit normally outputs the power supply voltage OUTPUT, when an overcurrent or short-to-ground fault occurs at the power supply output terminal, the voltage across the first resistor R1 will be greater than the opening voltage of the first switch Q1, so that after the first switch Q1 is turned on, its collector outputs an overcurrent signal to the control unit 4.

[0040] Specifically, Figure 2 In this circuit, diagnostic unit 3 is an MCU chip with multiple preset voltage ranges and integrates mature voltage comparison methods from existing technologies. When diagnostic unit 3 is in sleep mode, it no longer outputs MCUEN1 and MCUEN2. At this time, even if there is an overcurrent or short-to-ground fault at the power supply output terminal, the overcurrent detection unit 1 will output an overcurrent signal to the control unit 4. The control unit 4 can still control the drive unit 2 to shut down based on the overcurrent signal. The overcurrent or short-to-ground protection process of the high-side drive circuit does not require software intervention and can effectively reduce the static current.

[0041] In some alternative implementations, such as Figure 3 As shown, the acquisition unit 5 includes a current limiting unit 51 and a voltage divider unit 52. The first end of the current limiting unit 51 is connected to the pull-up power supply POWER_UP, and the second end of the current limiting unit 51 is connected to the second end of the control unit 4, the first end of the voltage divider unit 52, and the power supply output terminal. The second end of the voltage divider unit 52 is connected to the input terminal of the diagnostic unit 3. The diagnostic unit 3 has a fault voltage range. The degree of voltage division of the power supply voltage OUTPUT is adjusted by adjusting the resistance values ​​of the resistors in the current limiting unit 51 and the voltage divider unit 52.

[0042] Specifically, Figure 2 In the specific embodiment, the voltage dividing unit 52 comprises a third resistor R9, a fourth resistor R10 and a first capacitor C2, wherein the first end of the third resistor R9 is connected with the second end of the control unit 4, the second end of the third resistor R9 is connected with the first end of the fourth resistor R10, the first end of the first capacitor C2 and the input end of the diagnosis unit 3; the second end of the fourth resistor R10 is connected with the first end of the first capacitor C2 and grounded.

[0043] Specifically, Figure 2 In the specific embodiment, the diagnosis unit 3 is preset with a normal voltage interval, an overvoltage voltage interval and an undervoltage voltage interval. Since the three voltage intervals are fixed, when the power supply output end of the high-side drive circuit is connected with different power loads, the normal range interval of the output power supply voltage OUTPUT can be different. In order to improve the application range of the high-side drive circuit, the user can adjust the resistance value of the resistor in the current limiting unit 51 and the resistance value of the third resistor R9 and the fourth resistor R10 to adjust the voltage dividing degree of the power supply voltage OUTPUT, and unify the judgment standard of the power supply voltage fault after voltage division, so that when different power loads are connected with the power supply output end, the diagnosis unit 3 can judge whether the power supply output end is faulty with the same set of voltage intervals.

[0044] Specifically, Figure 4 In the specific embodiment, the voltage dividing unit can further comprise a fifth resistor R11, a sixth resistor R12, a seventh resistor R13, an eighth resistor R21, a ninth resistor R22, a second switch Q5, a third switch Q6 and a second capacitor C3, wherein the first end of the fifth resistor R11 (i.e. one end of the MCUEN3 signal output end) is connected with the input end of the control unit, the second end of the fifth resistor R11 is connected with the first end of the sixth resistor R12 and the control end of the second switch Q5; the second end of the sixth resistor R12 is connected with the first end of the second switch Q5, the first end of the ninth resistor R22, the first end of the second capacitor C3 and grounded; the second end of the second switch Q5 is connected with the first end of the seventh resistor R13; the second end of the seventh resistor R13 is connected with the control end of the third switch Q6; the first end (i.e. the emitter) of the third switch Q6 is connected with the second end of the current limiting unit, the second end of the third switch Q6 is connected with the first end of the eighth resistor R21; the second end of the eighth resistor R21 is connected with the second end of the ninth resistor R22, the second end of the second capacitor C3 and the input end of the diagnosis unit; when the diagnosis unit is in sleep state, the diagnosis unit stops outputting the control signal, so that the second switch Q5 and the third switch Q6 are turned off, and the input end of the diagnosis unit (i.e. one end of the MCUIN input end) stops inputting the power supply voltage after voltage division.

[0045] Specifically, referring to Figure 2 Since the input end of the control unit 4 is connected with the output end of the diagnosis unit 3, i.e. Figure 4The first end of the fifth resistor R11 in the middle is also connected with the output end of the diagnosis unit 3. When Figure 2 The structure of the voltage dividing unit shown in the figure cannot meet the requirement of the static current of the diagnosis unit. The structure of the voltage dividing unit can be replaced by the circuit structure shown in the figure. Figure 4 The structure of the voltage dividing unit shown in the figure cannot meet the requirement of the static current of the diagnosis unit. The structure of the voltage dividing unit can be replaced by the circuit structure shown in the figure. Figure 4 In the middle, when the diagnosis unit 3 is in sleep, the output of the MCUEN3 signal is stopped, and after the second switch Q5 is turned off based on the low level of the base, the collector of the second switch Q5 raises the base of the third switch Q6 so that the third switch Q6 is turned off. The diagnosis unit 3 no longer collects the voltage after voltage division through the eighth resistor R21 and the ninth resistor R22, so that the diagnosis unit 3 sleeps, the voltage dividing unit closes the collection function, reduces the power consumption of the circuit, and reduces the static current.

[0046] In some optional embodiments, as shown in the figure, Figure 5 The control unit includes an anti-reverse unit 41, a first switch unit 42 and a second switch unit 43. The first end of the anti-reverse unit 41 is connected with the output end of the overcurrent detection unit 1, the second end of the anti-reverse unit 41 is connected with the second end of the drive unit 2, the third end of the anti-reverse unit 41 is connected with the output end of the diagnosis unit 3, the fourth end of the anti-reverse unit 41 is connected with the control end of the first switch unit 42, the fifth end of the anti-reverse unit 41 is connected with the control end of the second switch unit 43, and the anti-reverse unit 41 is used to prevent the reverse of the current flowing to the first switch unit 42 and the second switch unit 43. The first end of the first switch unit 42 is connected with the first end of the second switch unit 43, and the second end of the first switch unit 42 is connected with the control end of the drive unit 2. When the power supply output end is overcurrent or short, the second switch unit 43 is turned on, and the first switch unit 42 is turned off.

[0047] Specifically, Figure 5In the case that the diagnosis unit 3 is working normally, if the overcurrent or short ground fault occurs in the power supply output end, the overcurrent detection unit 1 is turned on, the second switch unit 43 is turned on, the first switch unit 42 is turned off and the output off signal is output, then the driving unit 2 is turned off based on the off signal, the power supply output end stops outputting the power supply voltage OUTPUT, that is, the high-side driving circuit is closed, at this time, the diagnosis unit 3 determines that the collected divided power supply voltage is in the under-voltage voltage interval. After the high-side driving circuit is closed, the overcurrent fault disappears, the overcurrent detection unit 1 and the second switch unit 43 are turned off, the first switch unit 42 is turned on, the control end of the driving unit 2 no longer receives the off signal and is turned on, so that the power supply output end resumes outputting the power supply voltage OUTPUT, at this time, if the diagnosis unit 3 determines that the collected divided power supply voltage is in the over-voltage voltage interval, it indicates that the high-side driving circuit has open circuit or short power supply fault, if the diagnosis unit 3 determines that the collected divided power supply voltage is in the normal voltage interval, the power supply output end is in normal output state and the high-side driving circuit is in normal working state. If the diagnosis unit 3 determines that the collected divided power supply voltage is still in the under-voltage voltage interval at this time, it indicates that the power supply output end still has overcurrent, the above steps are repeated until the diagnosis unit 3 determines that there are three overcurrent events, then it is confirmed that there is overcurrent and the overcurrent fault is reported, and the working of the high-side driving circuit is terminated.

[0048] Specifically, Figure 5 In the case that the diagnosis unit 3 is in sleep state, the diagnosis unit 3 no longer outputs the fault signal, the driving unit 2 is directly closed after the overcurrent or short ground fault occurs, and repeated test is not performed, so that the protection process of the high-side driving circuit does not need software intervention, and the static current can be effectively reduced.

[0049] Specifically, Figure 2 In the case that the diagnosis unit 3 is in sleep state, the diagnosis unit 3 no longer outputs the fault signal, the driving unit 2 is directly closed after the overcurrent or short ground fault occurs, and repeated test is not performed, so that the protection process of the high-side driving circuit does not need software intervention, and the static current can be effectively reduced.

[0050] Specifically, Figure 2In the embodiment, the first switch unit 42 comprises a tenth resistor R3, a fourth switch Q4 and a first voltage stabilizing tube Z2, wherein the first end of the tenth resistor R3 is connected with the fourth end of the anti-reverse unit 41, the second end of the tenth resistor R3 is connected with the control end of the fourth switch Q4, the first end of the first voltage stabilizing tube Z2 and the first end of the second switch unit 43, the first end of the fourth switch Q4 is connected with the control end of the driving unit 2, and the second end of the fourth switch Q4 is connected with the second end of the first voltage stabilizing tube Z2 and grounded.

[0051] Specifically, Figure 2 In the embodiment, the second switch unit 43 comprises an eleventh resistor R4, a twelfth resistor R6 and a fifth switch Q2, wherein the first end of the eleventh resistor R4 is connected with the fifth end of the anti-reverse unit 41, the second end of the eleventh resistor R4 is connected with the first end of the twelfth resistor R6 and the control end of the fifth switch Q2, the second end of the twelfth resistor R6 is connected with the first end of the fifth switch Q2 and grounded, and the second end of the fifth switch Q2 is connected with the first end of the first switch unit 42.

[0052] Specifically, Figure 2 In the embodiment, the driving unit 2 comprises a thirteenth resistor R5, a fourteenth resistor R7, a second voltage stabilizing tube Z1 and a sixth switch Q3, wherein the first end of the thirteenth resistor R5 is connected with the first end of the second voltage stabilizing tube Z1, the first end of the sixth switch Q3 and the second end of the over-current detection unit 1, the second end of the thirteenth resistor R5 is connected with the second end of the second voltage stabilizing tube Z1, the control end of the sixth switch Q3 and the first end of the fourteenth resistor R7, the second end of the fourteenth resistor R7 is connected with the output end of the control unit 4, and the second end of the sixth switch Q3 is connected with the first end of the collection unit 5, and the sixth switch Q3 is used for being turned off based on the turn-off signal.

[0053] Specifically, Figure 2 In the embodiment, before the high-side driving circuit is operated, the input end of the diagnosis unit 3 (i.e. one end of MCUIN) collects the supply voltage OUTPUT after the voltage division of the level judgment, and judges whether the supply voltage OUTPUT is in the under-voltage voltage interval, if yes, there is no short power supply fault, and the upper pull power supply POWER_UP is enabled; the diagnosis unit 3 collects the supply voltage OUTPUT after the voltage division of the level judgment through MCUIN, and judges whether the supply voltage OUTPUT is in the over-voltage voltage interval, if yes, it is open circuit, if in the under-voltage voltage interval, it is short circuit, whether it is open circuit or short circuit, if H, it is open circuit, if L, it is short circuit, if M, it is normal; at this time, the high-side driving circuit can be normally driven.

[0054] Specifically, Figure 2 In the embodiment, the diagnosis unit 3 outputs the enable MCU_EN, controls the fourth switch Q4 to be opened, at this time, there is a voltage difference between the gate and the source of the sixth switch Q3, and the sixth switch Q3 is turned on. After the controller is in sleep, the fourth switch Q4 can keep the conduction state through the first diode D2, and the static current can be effectively reduced.

[0055] Specifically, Figure 2 When the diagnostic unit 3 is working normally, if the power output end has an overcurrent or short circuit fault, the first switch Q1 is turned on, the base of the fifth switch Q2 is pulled to the bus to turn on, the fourth switch Q4 is turned off and outputs a turn-off signal, and the sixth switch Q3 is turned off based on the turn-off signal, so that the power output end stops outputting the power voltage OUTPUT, that is, the high-side drive circuit is closed, and at this time, the diagnostic unit 3 determines that the collected divided power voltage is in the undervoltage voltage interval.

[0056] Specifically, Figure 2 After the high-side drive circuit is closed, the overcurrent fault disappears, the first switch Q1 and the fifth switch Q2 are turned off, the fourth switch Q4 is turned on, and the control end of the sixth switch Q3 is no longer turned on by the turn-off signal, so that the power output end resumes outputting the power voltage OUTPUT, and at this time, if the diagnostic unit 3 determines that the collected divided power voltage is in the overvoltage voltage interval, it indicates that the high-side drive circuit has an open circuit or a short power supply fault, if the diagnostic unit 3 determines that the collected divided power voltage is in the normal voltage interval, the power output end is in a normal output state, and the high-side drive circuit is in a normal working state, and if the diagnostic unit 3 determines that the collected divided power voltage is still in the undervoltage voltage interval at this time, it indicates that the power output end still has an overcurrent, and the above steps are repeated until the diagnostic unit 3 determines that there are three overcurrent events, and then it is confirmed that there is an overcurrent and an overcurrent fault is reported, and the high-side drive circuit stops working.

[0057] Specifically, Figure 2 After the diagnostic unit 3 is in sleep mode, the diagnostic unit 3 no longer outputs a fault signal, the sixth switch Q3 is directly closed after an overcurrent or short circuit fault occurs, and repeated testing is not performed, so that the protection process of the high-side drive circuit does not require software intervention, and the static current can be effectively reduced.

[0058] Figure 2 When there is an impulse voltage on the power supply POWER bus, the second voltage stabilizing tube Z1 protects the sixth switch Q3 from being damaged. In addition, because the load of the power output end is connected in parallel with R9 and R10, when the load changes, the voltage collected at the input end of the diagnostic unit 3 also changes.

[0059] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A high-side driving circuit, characterized in that, include: The system includes an overcurrent detection unit, a drive unit, a diagnostic unit, a control unit, and a data acquisition unit. The first end of the overcurrent detection unit is connected to an external power supply, the second end of the overcurrent detection unit is connected to the first end of the drive unit, and the output end of the overcurrent detection unit is connected to the first end of the control unit. The overcurrent detection unit is used to output an overcurrent signal when an overcurrent is detected. The first end of the acquisition unit is connected to the second end of the drive unit and the second end of the control unit. The second end of the acquisition unit is connected to the input end of the diagnostic unit. The third end of the acquisition unit is connected to the power supply output end and outputs the power supply voltage. The acquisition unit is used to divide the power supply voltage. The input terminal of the control unit is connected to the output terminal of the diagnostic unit, and the output terminal of the control unit is connected to the control terminal of the drive unit. The diagnostic unit contains a preset fault voltage range; When the diagnostic unit determines that the power supply voltage after voltage division is within the fault voltage range, the diagnostic unit outputs a fault signal, and based on the fault signal and / or the overcurrent signal, the control unit outputs a shutdown signal; The driving unit is used to turn off based on the shutdown signal, so that the power supply output terminal stops outputting the power supply voltage.

2. The high-side driving circuit according to claim 1, characterized in that, The overcurrent detection unit includes: a first switch, a first resistor, and a second resistor, wherein, The first terminal of the first switch is connected to the external power supply and the first terminal of the first resistor. The control terminal of the first switch is connected to the first terminal of the second resistor. The second terminal of the first switch is connected to the first terminal of the control unit. When there is an overcurrent at the power supply output terminal, the first switch is turned on. The second end of the first resistor is connected to the second end of the second resistor and the first end of the driving unit.

3. The high-side driving circuit according to claim 1, characterized in that, The acquisition unit includes: a current limiting unit and a voltage divider unit, wherein... The first end of the current limiting unit is connected to the pull-up power supply, and the second end of the current limiting unit is connected to the second end of the control unit, the first end of the voltage divider unit, and the power supply output terminal. The second end of the voltage divider unit is connected to the input end of the diagnostic unit; The diagnostic unit includes a fault voltage range. The degree of voltage division of the supply voltage can be adjusted by adjusting the resistance values ​​of the current limiting unit and the voltage dividing unit.

4. The high-side driving circuit according to claim 3, characterized in that, The voltage divider unit includes: a third resistor, a fourth resistor, and a first capacitor, wherein, The first end of the third resistor is connected to the second end of the control unit, and the second end of the third resistor is connected to the first end of the fourth resistor, the first end of the first capacitor, and the input end of the diagnostic unit. The second end of the fourth resistor is connected to the first end of the first capacitor and grounded.

5. The high-side driving circuit according to claim 3, characterized in that, The voltage divider unit further includes: a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a second switch, a third switch, and a second capacitor, wherein, The first end of the fifth resistor is connected to the input terminal of the control unit, and the second end of the fifth resistor is connected to the first end of the sixth resistor and the control terminal of the second switch. The second end of the sixth resistor is connected to the first end of the second switch, the first end of the ninth resistor, and the first end of the second capacitor and grounded. The second terminal of the second switch is connected to the first terminal of the seventh resistor; The second end of the seventh resistor is connected to the control end of the third switch; The first terminal of the third switch is connected to the second terminal of the current limiting unit, and the second terminal of the third switch is connected to the first terminal of the eighth resistor; The second end of the eighth resistor is connected to the second end of the ninth resistor, the second end of the second capacitor, and the input end of the diagnostic unit; When the diagnostic unit is in sleep mode, it stops outputting control signals, causing the second switch and the third switch to turn off, and the input terminal of the diagnostic unit to stop receiving the divided power supply voltage.

6. The high-side driving circuit according to claim 1, characterized in that, The control unit includes: an anti-reverse unit, a first switch unit, and a second switch unit, wherein... The first end of the anti-reverse unit is connected to the output end of the overcurrent detection unit, the second end of the anti-reverse unit is connected to the second end of the drive unit, the third end of the anti-reverse unit is connected to the output end of the diagnostic unit, the fourth end of the anti-reverse unit is connected to the control end of the first switch unit, and the fifth end of the anti-reverse unit is connected to the control end of the second switch unit. The anti-reverse unit is used to prevent the current flowing to the first switch unit and the second switch unit from flowing in the opposite direction. The first end of the first switching unit is connected to the first end of the second switching unit, and the second end of the first switching unit is connected to the control end of the driving unit. When the power supply output terminal experiences an overcurrent or short-to-ground event, the second switching unit is turned on and the first switching unit is turned off.

7. The high-side driving circuit according to claim 6, characterized in that, The anti-reverse unit includes: a first diode, a second diode, a third diode, and a fourth diode, wherein, The anode of the first diode is connected to the second terminal of the driving unit, and the cathode of the first diode is connected to the cathode of the second diode and the control terminal of the first switching unit. The anode of the second diode is connected to the anode of the fourth diode and the output terminal of the diagnostic unit; The anode of the third diode is connected to the output terminal of the overcurrent detection unit, and the cathode of the third diode is connected to the cathode of the fourth diode and the control terminal of the second switching unit.

8. The high-side driving circuit according to claim 6, characterized in that, The first switching unit includes: a tenth resistor, a fourth switch, and a first Zener diode, wherein, The first end of the tenth resistor is connected to the fourth end of the anti-reverse unit, and the second end of the tenth resistor is connected to the control end of the fourth switch, the first end of the first voltage regulator, and the first end of the second switch unit. The first end of the fourth switch is connected to the control end of the drive unit, and the second end of the fourth switch is connected to the second end of the first voltage regulator and grounded.

9. The high-side driving circuit according to claim 6, characterized in that, The second switching unit includes: an eleventh resistor, a twelfth resistor, and a fifth switch, wherein, The first end of the eleventh resistor is connected to the fifth end of the anti-reverse unit, and the second end of the eleventh resistor is connected to the first end of the twelfth resistor and the control end of the fifth switch. The second terminal of the twelfth resistor is connected to the first terminal of the fifth switch and grounded; The second end of the fifth switch is connected to the first end of the first switch unit.

10. The high-side driving circuit according to claim 1, characterized in that, The driving unit includes: a thirteenth resistor, a fourteenth resistor, a second Zener diode, and a sixth switch, wherein, The first end of the thirteenth resistor is connected to the first end of the second Zener diode, the first end of the sixth switch, and the second end of the overcurrent detection unit; the second end of the thirteenth resistor is connected to the second end of the second Zener diode, the control terminal of the sixth switch, and the first end of the fourteenth resistor. The second end of the fourteenth resistor is connected to the output end of the control unit; The second end of the sixth switch is connected to the first end of the acquisition unit, and the sixth switch is used to turn off based on the turn-off signal.

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