Vehicle control device, overvoltage protection circuit and method for testing overvoltage protection circuit

Abstract

An overvoltage protection circuit (120) for a vehicle control device is provided. The overvoltage protection circuit (120) has a circuit for applying an input voltage (U in ), an input interface (122) for applying a test voltage (TST), and a test interface (126) for providing an output voltage (U out ) to supply an output interface (124) to a control device. The overvoltage protection circuit (120) also has a reference device (221), which is configured to use an input voltage (U in ) provides a reference voltage (U ref The overvoltage protection circuit (120) also has a voltage dividing device (223), which is configured to use the output voltage (U out ). In addition, the overvoltage protection circuit (120) has a control device (225) which is configured to provide a partial voltage when using a reference voltage (U ref ) and the divided voltage. The overvoltage protection circuit (120) also has a regulating device (227) connected between the input interface (122) and the output interface (124). Here, the regulating device (227) is configured to use the input voltage (U in ) and the regulation signal to provide output voltage (U out The overvoltage protection circuit (120) also has a modification device (229) which is designed to modify the value of the partial voltage when using a test voltage (TST).

Description

Technical Field

[0001] The invention relates to an overvoltage protection circuit for a control device for a vehicle, a control device for a vehicle and a method for testing an overvoltage protection circuit for a control device for a vehicle. Background Art

[0002] For control devices and the like, overvoltage protection circuits, for example in the form of Z-diodes, can be used, which generally cannot be checked for correct function during the service life of the control device. Summary of the invention

[0003] Against this background, the object of the present invention is to specify an improved overvoltage protection circuit for a control unit of a vehicle, an improved control unit for a vehicle and an improved method for testing an overvoltage protection circuit for a control unit of a vehicle.

[0004] This object is achieved according to the invention by an improved overvoltage protection circuit for a control device for a vehicle, an improved control device for a vehicle and an improved method for testing an overvoltage protection circuit for a control device for a vehicle.

[0005] According to embodiments, in particular, the monitorability of overvoltage protection for control devices, in particular for safety-related voltage supply components, can be provided. Thus, for example, the overvoltage protection circuit can also be used to increase safety requirements. In order to realize such an overvoltage protection circuit, according to embodiments, in particular, discrete components can be used, so that the overvoltage protection circuit can be matched to the requirements set forth in a wide voltage range. Thus, it is possible to check the overvoltage protection circuit in the control device. In this case, in particular, two different high input levels can be used to periodically control the overvoltage protection circuit for testing the overvoltage protection circuit.

[0006] Advantageously, according to the embodiment, in particular, a low-cost, testable overvoltage protection can be provided for the voltage supply inside the control device. Here, for example, it is also possible to switch on the voltage supply only from a predefined voltage. In other words, the overvoltage protection circuit can therefore be tested in the normal voltage range in particular during the total service life of the circuit. In addition, for example, the overvoltage protection circuit can be constructed without specific components or using only standard components. In addition, in particular, any limit voltage can be set in the normal operation and test operation of the overvoltage protection circuit. Such a test operation or the execution of the test can be carried out using only one additional interface for test control, so that resources can be saved in particular in terms of hardware.

[0007] An overvoltage protection circuit for vehicle control equipment has the following characteristics:

[0008] an input interface for applying an input voltage, a test interface for applying a test voltage, and an output interface for providing an output voltage to supply a control device;

[0009] a reference device configured to provide a reference voltage using an input voltage;

[0010] A voltage divider device configured to provide a divided voltage when using the output voltage;

[0011] a control device configured to provide a control signal using a reference voltage and a partial voltage;

[0012] a regulating device connected between the input interface and the output interface, wherein the regulating device is designed to provide an output voltage using an input voltage and a regulating signal; and

[0013] A modification device is designed to modify the value of the partial voltage when using the test voltage.

[0014] The overvoltage protection circuit can be implemented as part of the control device, or can be integrated into the control device. The control device can be arranged or arranged in the vehicle. The vehicle can be a motor vehicle, in particular a land vehicle, an air vehicle or a water vehicle, such as a passenger car, a truck or other commercial vehicle. In conjunction with the overvoltage protection circuit, "connection" means: an electrical connection is established directly or through at least one component, such as a resistor or the like. The adjustment signal can represent a voltage and, in addition or alternatively, a current. The individual devices can be implemented using discrete components, for example, using resistors and transistors.

[0015] According to one embodiment, the regulating device can have a transistor having a first interface, a second interface and a control interface for receiving a regulating signal. Here, the first interface of the transistor can be connected to the input interface. The second interface of the transistor can be connected to the output interface. The control interface of the transistor can be connected to the control device. The transistor can be a pnp transistor. However, other suitable types of transistors can also be used as transistors. This embodiment provides the following advantages: a reliable output voltage protected against overvoltage can be provided in a simple manner.

[0016] In addition, the control device can have an operational amplifier having an inverting input, a non-inverting input and an output. Here, the inverting input of the operational amplifier can be connected to a reference device for receiving a reference voltage. The non-inverting input of the operational amplifier can be connected to a voltage divider for receiving a divided voltage, and the non-inverting input can be connected to a modification device for modifying the divided voltage. The output of the operational amplifier can be connected to a regulating device for providing a regulating signal. More precisely, the output of the operational amplifier can be connected to a control interface of a transistor of the regulating device. This embodiment provides the following advantages: reliable overvoltage protection can be provided. In particular, a regulating signal suitable for reliably regulating the output voltage can be provided.

[0017] The modification device may also have a switch and a modification resistor. Here, the switch and the modification resistor may be connected in series with each other between the reference potential and the control device. Here, the control interface of the switch may be connected to the test interface. More precisely, the switch and the modification resistor may be connected in series with each other between the reference potential and the non-inverting input of the operational amplifier of the control device. The switch may be implemented as an npn transistor or other suitable type of transistor. Such an embodiment provides the following advantages: the testability of the overvoltage protection circuit can be achieved in a simple and reliable manner.

[0018] In addition, the voltage divider device may have a first voltage divider resistor and a second voltage divider resistor. Here, the first interface of the first voltage divider resistor may be connected to the output interface. The second interface of the first voltage divider resistor may be connected to the first interface of the second voltage divider resistor. The second interface of the second voltage divider resistor may be connected to a reference potential. The second interface of the first voltage divider resistor may be connected to a control device for providing a divided voltage. Here, the resistance value of the voltage divider resistor may be predefined depending on the application scenario. Such an embodiment provides the following advantages: the divided voltage can be provided reliably and accurately.

[0019] The reference device can also have a reference interface for applying a reference voltage. Alternatively, the reference device can have a reference resistor, a first diode and a second diode. Here, the reference resistor, the first diode and the second diode can be connected in series to each other between the control interface for applying a control voltage and the reference potential or between the input interface and the reference potential. The reference node between the first diode and the second diode can be connected to the control device. The first diode can be implemented as a Zener diode or a diode of other suitable types. The second diode can be implemented as a Zener diode or a diode of other suitable types. Such an embodiment provides the following advantages: the reference voltage can be provided without much trouble. With the help of the first diode, the switch-on hysteresis of the overvoltage protection circuit can also be set in particular. If the reference resistor, the first diode and the second diode are connected in series to each other between the input interface and the reference potential, the number of interfaces can be reduced in terms of the control device.

[0020] In particular, in terms of the control device, the operational amplifier can have two npn amplifier transistors, one pnp amplifier transistor, two amplifier capacitors and three amplifier resistors. Here, the inverting input of the operational amplifier can be implemented as a control interface of the first npn amplifier transistor in the npn amplifier transistor. The non-inverting input of the operational amplifier can be implemented as a control interface of the second npn amplifier transistor in the npn amplifier transistor. The first interface of the first npn amplifier transistor in the npn amplifier transistor and the first interface of the second npn amplifier transistor in the npn amplifier transistor can be connected to the reference potential through the first amplifier resistor in the amplifier resistor. The second interface of the first npn amplifier transistor in the npn amplifier transistor can be connected to the second interface of the pnp amplifier transistor and can be connected to the regulating device in order to provide a regulating signal. The second interface of the second npn amplifier transistor in the npn amplifier transistor can be connected to the output interface. The first interface of the pnp amplifier transistor can be connected to the input interface. The control interface of the pnp amplifier transistor can be connected to the regulating device through the second amplifier resistor in the amplifier resistor. The first interface of the first amplifier capacitor in the amplifier capacitor can be connected to the input interface. The second interface of the first amplifier capacitor in the amplifier capacitor can be connected between the control interface of the pnp amplifier transistor and the second amplifier resistor in the amplifier resistor. The first interface of the third amplifier resistor in the amplifier resistor can be connected to the control interface of the first npn amplifier transistor in the npn amplifier transistor. The second interface of the third amplifier resistor in the amplifier resistor can be connected to the output interface. The first interface of the second amplifier capacitor in the amplifier capacitor can be connected to the control interface of the first npn amplifier transistor in the npn amplifier transistor. The second interface of the second amplifier capacitor in the amplifier capacitor can be connected to the reference potential. The amplifier transistor can also be other suitable types of transistors. Such an embodiment provides the following advantages: a regulation signal can be provided in a reliable manner, and the regulation signal can achieve reliable protection against overvoltage.

[0021] According to one embodiment, the overvoltage protection circuit can have a setting device for setting the control signal when using an input voltage. In this case, the setting device can have a series circuit consisting of a switch and a first setting resistor, which can be connected between the control device and a reference potential. In this case, the switch can be switched depending on the input voltage. More precisely, the series circuit can be connected between a first connection of a second npn amplifier transistor of an operational amplifier of the control device and the reference potential. Such an embodiment offers the advantage that the base current of the transistor of the setting device can be controlled depending on the input voltage.

[0022] In the adjustment device, the switch can also be implemented as a first npn adjustment transistor. Here, the adjustment device also has a second npn adjustment transistor, a second adjustment resistor, a third adjustment resistor, a fourth adjustment resistor and a fifth adjustment resistor. The first interface of the first npn adjustment transistor can be connected to the first interface of the first adjustment resistor. The second interface of the first adjustment resistor can be connected to the reference potential. The second interface of the first npn adjustment transistor can be connected to the control device. The control interface of the first npn adjustment transistor can be connected to the second interface of the second npn adjustment transistor. The first interface of the second npn adjustment transistor can be connected to the reference potential. The second adjustment resistor and the third adjustment resistor can be connected in series with each other between the input interface and the reference potential. The control interface of the second npn adjustment transistor can be connected to the adjustment node between the second adjustment resistor and the third adjustment resistor. The first interface of the fourth adjustment resistor can be connected to the adjustment node. The second interface of the fourth adjustment resistor can be connected to the second interface of the second npn adjustment transistor. The first interface of the fifth adjustment resistor can be connected to the second interface of the second npn adjustment transistor. The second interface of the fifth setting resistor can be connected to the input interface. More precisely, the second interface of the first npn setting transistor can be connected to the first interface of the second npn amplifier transistor of the operational amplifier of the control device. Alternatively, the setting transistor can also be another suitable type of transistor. Such an embodiment provides the following advantages: the output voltage can also be supplied to the switching regulator of the control device in a suitable manner.

[0023] The overvoltage protection circuit can also have a current limiting resistor. Here, the first interface of the current limiting resistor can be connected to the input interface. The second interface of the current limiting resistor can be connected to the regulating device. The second interface of the current limiting resistor can be connected to the first interface of the transistor of the regulating device. According to the set current limit of the output current, the resistance value of the current limiting resistor can be predefined. Therefore, a predefined current limit can be achieved in a simple manner.

[0024] A control device for a vehicle comprises the above-mentioned overvoltage protection circuit and a voltage supply interface, wherein an output interface of the overvoltage protection circuit is connected to the voltage supply interface of the control device.

[0025] Advantageously, an overvoltage protection circuit can be employed or used in conjunction with a control device in order to provide overvoltage protection with respect to a voltage supply of the control device.

[0026] According to one embodiment, the control device may have a test device for testing the functionality of the overvoltage protection circuit. Here, the test device may be configured to detect a first value of the output voltage or a first value variation curve during the application of a test voltage with a first voltage level to the test interface; and to detect a second value of the output voltage or a second value variation curve during the application of a test voltage with a second voltage level to the test interface. In the case of using the first value or the first value variation curve and the second value or the second value variation curve, the test device may provide a test signal. The test device may be used, for example, to test the functionality of the overvoltage protection circuit when the control device is put into operation or during a functional test of the control device.

[0027] A method for testing an overvoltage protection circuit of a vehicle control device, wherein the overvoltage protection circuit is an embodiment of the overvoltage protection circuit mentioned above, and the method comprises the following steps:

[0028] Applying a test voltage having a first voltage level to a test interface of the overvoltage protection circuit;

[0029] detecting a first output voltage in response to a test voltage having a first voltage level;

[0030] Applying a test voltage having a second voltage level to a test interface of the overvoltage protection circuit, wherein the second voltage level is lower than the first voltage level;

[0031] detecting a second output voltage in response to a test voltage having a second voltage level;

[0032] Whether the detected first output voltage and the detected second output voltage meet at least one test criterion is verified to generate a test result.

[0033] The testing method can be carried out in order to advantageously check the functionality of the aforementioned overvoltage protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In the following description, an exemplary embodiment of the solution proposed here is explained in more detail with reference to the accompanying drawings. The drawings show:

[0035] Figure 1 A schematic illustration of a vehicle having a control device according to an exemplary embodiment;

[0036] Figure 2 Figure 1 The principle circuit diagram of the overvoltage protection circuit;

[0037] Figure 3 Figure 1 or Figure 2 Circuit diagram of overvoltage protection circuit;

[0038] Figure 4 With adjustment device Figure 3 Circuit diagram of overvoltage protection circuit;

[0039] Figure 5 Flow chart of a method for testing according to an embodiment. DETAILED DESCRIPTION

[0040] Figure 1 A schematic diagram of a vehicle 100 having a control device 110 according to an exemplary embodiment is shown. Vehicle 100 is a motor vehicle, for example a passenger car, a truck or another commercial vehicle. Control device 110 is arranged in vehicle 100. Vehicle 100 therefore has control device 110. Control device 110 has a control unit for applying an input voltage U in Input voltage U in For example, it is provided by battery 102 of vehicle 100 .

[0041] Control device 110 has a control device arrangement 112 which is designed to carry out a control function of control device 110. The control function involves, for example, actuating at least one actuator of a vehicle system of the vehicle, such as a brake system.

[0042] In order to supply electrical energy to control unit arrangement 112 , control unit arrangement 112 has a voltage supply interface 114 . Control unit arrangement 112 can be supplied with voltage via voltage supply interface 114 .

[0043] The control device 110 has an overvoltage protection circuit 120, which is connected between the voltage supply interface 114 of the control device device 112 and the input of the control device 110, for applying an input voltage U in Overvoltage protection circuit 120 is designed to implement overvoltage protection for control unit 110 or, in particular, for control unit device 112 of control unit 110 .

[0044] exist Figure 1 In the diagram of FIG. 1 , the overvoltage protection circuit 120 is shown to be used to apply an input voltage U to the overvoltage protection circuit 120. in The input interface 122 is used to provide an output voltage U out An output interface 124 for supplying the control device 110 or the control device device 112 and a test interface 126 for applying a test voltage TST to the overvoltage protection circuit 120. The overvoltage protection circuit 120 and the control device device 112 are connected to each other. Here, the output interface 124 of the overvoltage protection circuit 120 is connected to the voltage supply interface 114. According to the following figures, the structure and function of the overvoltage protection circuit 120 are described according to different embodiments.

[0045] According to one exemplary embodiment, a test device 130 is provided, which is designed to test the functionality of the overvoltage protection circuit 120. According to one exemplary embodiment, the test device 130 is integrated into the control device 110, but can also be a part of the overvoltage protection circuit 120, or can be a circuit arranged outside the control device 110. The test device 130 is designed to detect the output voltage U during the application of a test voltage TST having a first voltage level to the test interface 126. out The test device 130 is further configured to detect the output voltage U during the application of the test voltage TST having the second voltage level to the test interface 126. out The test device 130 is configured to determine a test result using the first value or the first value profile and the second value or the second value profile and to provide a test signal 132 representing the test result. The test signal 132 represents, for example, a correct functionality of the overvoltage protection circuit 120 and, in addition or as an alternative, represents an incorrect functionality of the overvoltage protection circuit 120. According to one embodiment, the test device 130 is configured to receive a test voltage TST. Alternatively, the test device 130 is configured to provide a test voltage TST.

[0046] Figure 2 According to an embodiment Figure 1 The schematic circuit diagram of the overvoltage protection circuit 120 is shown in FIG. Figure 2 In the principle circuit diagram of the overvoltage protection circuit 120, it is shown that the input voltage U in The input interface 122 is used to provide an output voltage U out The output interface 124 for applying the test voltage TST, the test interface 126 for applying the test voltage TST, and the reference device 221, the reference voltage U ref , a voltage dividing device 223 having a first voltage dividing resistor R1 and a second voltage dividing resistor R2 , a control device 225 , a regulating device 227 having a transistor T1 , and a modifying device 229 having a modifying resistor R3 and a switch S1 .

[0047] Reference device 221 is designed to provide a reference voltage U ref According to the exemplary embodiment shown here, the reference device 221 has a circuit for applying a reference voltage U ref According to one embodiment, the reference device 221 is configured to use the input voltage U in Provide reference voltage U ref .

[0048] The voltage divider 223 is configured to use the output voltage U outAccording to the embodiment shown here, the voltage divider device 223 has a series circuit consisting of a first voltage divider resistor R1 and a second voltage divider resistor R2. The first interface of the first voltage divider resistor R1 is connected to the output interface 124. The second interface of the first voltage divider resistor R1 is connected to the first interface of the second voltage divider resistor R2. The second interface of the second voltage divider resistor R2 is connected to the reference potential. The second interface of the first voltage divider resistor R1 is connected to the control device 225 for providing the divided voltage.

[0049] The control device 225 is designed to, using the reference voltage U ref and provide regulation signals in the case of divided voltage.

[0050] According to the embodiment shown here, the control device 225 has an operational amplifier. The operational amplifier has an inverting input terminal (-), a non-inverting input terminal (+) and an output terminal. The inverting input terminal of the operational amplifier is connected to the reference device 221 for receiving the reference voltage U ref The non-inverting input terminal of the operational amplifier is connected to the voltage divider 223 for receiving the divided voltage, and the non-inverting input terminal is connected to the modification device 229 for modifying the divided voltage. The output terminal of the operational amplifier is connected to the adjustment device 227 for providing an adjustment signal.

[0051] The regulating device 227 is connected between the input interface 122 and the output interface 124. The regulating device 227 is configured to use the input voltage U in and regulating signal to provide or regulate the output voltage U out According to the embodiment shown here, the regulating device 227 has a transistor T1. The transistor T1 has a first interface, a second interface and a control interface for receiving a regulating signal. The first interface of the transistor T1 is connected to the input interface 122. The second interface of the transistor T1 is connected to the output interface 124. The control interface of the transistor T1 is connected to the control device 225. According to the embodiment shown here, the transistor T1 is a pnp transistor.

[0052] The modification device 229 is configured to modify the value of the divided voltage provided by the voltage divider 223 when using the test voltage TST. To this end, the modification device 229 is connected to the test input 126, or the modification device 229 has a test input 146. According to the embodiment shown here, the modification device 229 has a switch S1 and a modification resistor R3. The switch S1 and the modification resistor R3 are connected in series with each other between the reference potential and the control device 225 (more precisely, the non-inverting input of the operational amplifier of the control device 225). The control interface of the switch S1 is connected to the test interface 126. According to the embodiment shown here, the switch S1 is connected between the modification resistor R3 and the reference potential. Alternatively, the positions of the switch S1 and the modification resistor R3 can be interchanged.

[0053] The test voltage TST applied to the test input 126 is used to modify the resistance value of the total resistance existing between the non-inverting input (+) and the reference potential of the operational amplifier 225. To this end, the switch S1 is closed and opened according to the voltage level of the test voltage TST.

[0054] The overvoltage protection circuit 120 may be used as a so-called testable PRESTAB in safety-critical systems.

[0055] Figure 3 According to an embodiment Figure 1 or Figure 2 Here, the overvoltage protection circuit 120 corresponds to the overvoltage protection circuit 121, except that the reference device 221 is designed differently and / or shown in more detail, a current limiting resistor R7 is additionally provided, the modification device 229 has a switch 1 in the form of a transistor and an additional series resistor R9, and the operational amplifier of the control device 225 is shown in more detail. Figure 2 Overvoltage protection circuit.

[0056] The current limiting resistor R7 can be predefined in terms of resistance value in order to set the current limitation of the output current of the overvoltage protection circuit 120. A first terminal of the current limiting resistor R7 is connected to the input terminal 122. A second terminal of the current limiting resistor R7 is connected to the regulating device 227 (more precisely, to the first terminal of the transistor T1 of the regulating device 227).

[0057] The switch S1 of the modification device 229, which is implemented as a transistor (more precisely, as an npn transistor), has a first interface, a second interface and a control interface. The first interface of the switch S1 is connected to the reference potential. The second interface of the switch S1 is connected to the modification resistor R3. The control interface of the switch S1 is connected to the test interface TST via the series resistor R9. Therefore, the series resistor R9 is connected between the test interface TST and the control interface of the switch S1.

[0058] According to the exemplary embodiment shown here, the reference device 221 has a reference resistor R8, a first diode D1 and a second diode D2. A reference node REF between the first diode D1 and the second diode D2 is connected to the control device 225. The reference voltage U ref According to the embodiment shown here, the reference resistor R8, the first diode D1 and the second diode D2 are connected in series to each other for applying the control voltage U sbetween the control interface 330 and the reference potential. According to the embodiment shown here, the first diode D1 is in particular connected between the reference resistor R8 and the second diode D2 or the reference node REF. According to an alternative embodiment, the control interface 330 can be omitted, wherein the reference resistor R8, the first diode D1 and the second diode D2 are connected in series with each other between the input interface 122 and the reference potential.

[0059] According to the exemplary embodiment shown here, the operational amplifier of the control device 225 has a first amplifier capacitor C1, a second amplifier capacitor C2, a first amplifier resistor R4, a second amplifier resistor R6, a third amplifier resistor R5, a pnp amplifier transistor T2, a first npn amplifier transistor T3 and a second npn amplifier transistor T4.

[0060] The inverting input of the operational amplifier is implemented as a control interface of the first npn amplifier transistor T3. The non-inverting input of the operational amplifier is implemented as a control interface of the second npn amplifier transistor T4. The first interface of the first npn amplifier transistor T3 and the first interface of the second npn amplifier transistor T4 are connected to the reference potential via the first amplifier resistor R4. The second interface of the first npn amplifier transistor T3 is connected to the second interface of the pnp amplifier transistor T2. In addition, the second interface of the first npn amplifier transistor T3 is connected to the regulating device 227 (more precisely, to the control input of the transistor T1 of the regulating device 227) for providing a regulating signal. The second interface of the second npn amplifier transistor T4 is connected to the output interface 124. The first interface of the pnp amplifier transistor T2 is connected to the input interface 122. The control interface of the pnp amplifier transistor T2 is connected to the regulating device 227 (more precisely, to the first input of the transistor T1 of the regulating device 227) via the second amplifier resistor R6.

[0061] The first interface of the first amplifier capacitor C1 of the operational amplifier is connected to the input interface 122. The second interface of the first amplifier capacitor C1 is connected between the control interface of the pnp amplifier transistor T2 and the second amplifier resistor R6. The first interface of the third amplifier resistor R5 is connected to the control interface of the first npn amplifier transistor T3. The second interface of the third amplifier resistor R5 is connected to the output interface 124. The first interface of the second amplifier capacitor C2 is connected to the control interface of the first npn amplifier transistor T3. The second interface of the second amplifier capacitor C2 is connected to the reference potential.

[0062] The following merely shows exemplary parameters of several components of the overvoltage protection circuit 120. The first amplifier capacitor C1 may have a capacitance value of 1 nanofarad. The second amplifier capacitor C2 may have a capacitance value of 100 nanofarads. The first voltage divider resistor R1 may have a resistance value of 23.7 kiloohms. The second voltage divider resistor R2 may have a resistance value of 10 kiloohms. The modified resistor R3 may have a resistance value of 6.81 kiloohms. The first amplifier resistor R4 may have a resistance value of 750 ohms. The second amplifier resistor R6 may have a resistance value of 100 ohms. The third amplifier resistor R5 may have a resistance value of 26.1 kiloohms. The reference resistor R8 may have a resistance value of 26.1 kiloohms. The series resistor R9 may have a resistance value of 10 kiloohms.

[0063] Figure 4 A diagram showing a configuration device 440 according to an embodiment of the present invention. Figure 3 The schematic circuit diagram of the overvoltage protection circuit 120 is shown in FIG. Figure 4 In addition to the adjustment device 440 additionally provided in the embodiment shown in FIG. , the overvoltage protection circuit 120 corresponds to Figure 3 The adjustment device 440 has an adjustment node 445, a first adjustment resistor R14, a second adjustment resistor R10, a third adjustment resistor R11, a fourth adjustment resistor R12, a fifth adjustment resistor R13, a first npn adjustment transistor T6 and a second npn adjustment transistor T5.

[0064] The setting device 440 is designed to use the input voltage U in The adjustment device 440 has a series circuit consisting of a switch in the form of a first npn adjustment transistor T6 and a first adjustment resistor R14. The series circuit is connected between the control device 225 and the reference potential. The first npn adjustment transistor T6 or the switch can be adjusted according to the input voltage U in to switch.

[0065] The first interface of the first npn setting transistor T6 is connected to the first interface of the first setting resistor R14. The second interface of the first setting resistor R14 is connected to the reference potential. The second interface of the first npn setting transistor T6 is connected to the control device 225 (more precisely, to the first interface of the second npn amplifier transistor T4 of the operational amplifier of the control device 225). The control interface of the first npn setting transistor T6 is connected to the second interface of the second npn setting transistor T5. The first interface of the second npn setting transistor T5 is connected to the reference potential. The second setting resistor R10 and the third setting resistor R11 are connected in series with each other between the input interface 122 and the reference potential. The setting node 445 is arranged between the second setting resistor R10 and the third setting resistor R11. The control interface of the second npn setting transistor T5 is connected to the setting node 445. The first interface of the fourth setting resistor R12 is connected to the setting node 445. The second interface of the fourth setting resistor R12 is connected to the second interface of the second npn setting transistor T5. A first interface of the fifth adjustment resistor R13 is connected to a second interface of the second npn adjustment transistor T5 , and a second interface of the fifth adjustment resistor R13 is connected to the input interface 122 .

[0066] The following only shows exemplary parameters of several components of the adjustment device 440 of the overvoltage protection circuit 120. The first adjustment resistor R14 may have a resistance value of 60 ohms. The second adjustment resistor R10 may have a resistance value of 100 kiloohms. The third adjustment resistor R11 may have a resistance value of 3.83 kiloohms. The fourth adjustment resistor R12 may have a resistance value of 21.5 kiloohms. The fifth adjustment resistor R13 may have a resistance value of 51.1 kiloohms.

[0067] Figure 5 A flow chart of a method 500 for testing according to an embodiment is shown. The method 500 for testing can be implemented to test an overvoltage protection circuit of a vehicle control device. More specifically, the method 500 for testing can be implemented to test the overvoltage protection circuit of one of the aforementioned figures or a similar overvoltage protection circuit.

[0068] As per Figure 1 As described above, method 500 may be performed, for example, using a testing device.

[0069] Here, in a first applying step 510, a test voltage having a first voltage level is applied to a test interface of the overvoltage protection circuit. Subsequently, in a first detecting step 520, a first output voltage is detected in response to the test voltage having the first voltage level. Subsequently, in a second applying step 530, a test voltage having a second voltage level is applied to the test interface of the overvoltage protection circuit. The second voltage level is lower than the first voltage level. Subsequently, in a second detecting step 540, a second output voltage is detected in response to the test voltage having the second voltage level. In a checking step 550, it is finally checked whether the detected first output voltage and the detected second output voltage meet at least one test criterion so as to generate a test result.

[0070] A brief functional description of an embodiment of the present invention is given below with reference to the aforementioned drawings.

[0071] If a test voltage TST having a first voltage level, for example exceeding 1.5 volts, is connected to the test input 126, the switch S1 of the modification device 229 is closed and the output voltage U out For example, it is limited to (U ref -0.65V)×(R1+R2 / / R3) / R1. The voltage value 0.65V is a typical, but exemplary value resulting from the characteristics of the circuit components used. Below this voltage value or this limiting voltage, the output voltage U out Following input voltage U in , so it applies: U out =U in The voltage drop across the current-limiting resistor R7 and across the transistor T1 of the control device 227 .

[0072] If a test voltage TST having a second voltage level, for example below 0.4 volt, is connected to the test input 126, the switch S1 of the modification device 229 opens and the output voltage U out For example, it is limited to (U ref -0.65V)×(R1+R2) / R1. Below this voltage value or this limit voltage, the output voltage U out Following input voltage U in , so it applies: U out =U in The voltage drop across the current-limiting resistor R7 and across the transistor T1 of the control device 227 .

[0073] Therefore, when switch S1 is closed, the output voltage U out is limited to a first voltage value which depends on the reference voltage U ref , the values ​​of resistors R1, R2, R3 and the specific voltage values ​​of the circuit components used.

[0074] Correspondingly, when the switch S1 is open, the output voltage U out is limited to a second voltage value different from the first voltage value, the second voltage value depending on the reference voltage U ref , the values ​​of resistors R1 and R2 and the specific voltage values ​​of the circuit components used.

[0075] If the output voltage U out , then it can be from an input voltage U in The function of the overvoltage protection circuit 120 is tested when the input voltage is greater than the lower limit voltage of the aforementioned limit voltages plus the voltage drop across the current limiting resistor R7 and the transistor T1 of the adjustment device 227 .

[0076] In the overvoltage protection circuit 120 there is a switch-on hysteresis which can be set by means of the first diode D1 and a current limitation of the output current which can be set by means of the current-limiting resistor R7 .

[0077] Control voltage U s Can be compared with the input voltage U in The control interface 330 may be connected to or used as a separate switch input or control interface 330. The control interface 330 may be connected or connected to a terminal of the vehicle 100, for example.

[0078] The setting device 440 represents a circuit part which has setting resistors R10 to R14 and transistors T5, T6 and is designed to adjust the input voltage U in To control the regulating signal or base current of the transistor T1 of the regulating device 227. Therefore, it can be achieved that at low input voltage U in In the case of a high or higher base current of transistor T1, a control signal is generated, and at a high input voltage U in In the case of , a low or lower base current of transistor T1 is generated as a control signal without overloading the first npn amplifier transistor T3. This is the case when the switching regulator of the control device 110 is supplied with an output voltage U out This is particularly advantageous when the switching regulator has a high input current requirement at a low supply voltage and a low input current requirement at a high supply voltage.

[0079] Reference numerals list

[0080] 100 Vehicles

[0081] 102 Batteries

[0082] 110 Control Equipment

[0083] 112 Control equipment

[0084] 114 Voltage supply interface

[0085] 120 Overvoltage protection circuit

[0086] 122 Input Interface

[0087] 124 Output Interface

[0088] 126 Test interface

[0089] 130 Test Device

[0090] 132 Test signal

[0091] U in Input voltage

[0092] U out Output voltage

[0093] TST test voltage

[0094] 221 Reference Device

[0095] 223 Voltage divider

[0096] 225 Control Device

[0097] 227 Adjustment device

[0098] 229 Modification Device

[0099] R1 The first voltage divider resistor

[0100] R2 Second voltage divider resistor

[0101] R3 Modify the resistor

[0102] S1 switch

[0103] T1 transistor

[0104] U ref Reference voltage

[0105] 330 Control Interface

[0106] C1 First amplifier capacitor

[0107] C2 Second amplifier capacitor

[0108] D1 First diode

[0109] D2 Second diode

[0110] REF Reference Node

[0111] R4 First amplifier resistor

[0112] R5 Third amplifier resistor

[0113] R6 Second amplifier resistor

[0114] R7 Current limiting resistor

[0115] R8 reference resistor

[0116] R9 Series resistor

[0117] T2 pnp amplifier transistor

[0118] T3 First npn amplifier transistor.

[0119] T4 Second npn amplifier transistor

[0120] U s Control voltage

[0121] 440 Adjustment device

[0122] 445 Adjusting Nodes

[0123] R10 Second adjustment resistor

[0124] R11 The third adjustment resistor

[0125] R12 Fourth adjustment resistor

[0126] R13 Fifth adjustment resistor

[0127] R14 The first adjustment resistor

[0128] T5 The second npn setting transistor

[0129] T6 The first npn setting transistor

[0130] 500 methods used for testing

[0131] 510 First application step

[0132] 520 First Detection Step

[0133] 530 Second application step

[0134] 540 Second detection step

[0135] 550 Inspection Steps

Claims

1. An overvoltage protection circuit (120) for a control device (110) of a vehicle (100), wherein: The overvoltage protection circuit (120) has the following characteristics: Used for Apply input voltage U in An input interface (122) for applying a test voltage TST, a test interface (126) for providing an output voltage U out an output interface (124) for supplying the control device (110); A reference device (221) is configured to use the input voltage U in Provide reference voltage U ref ; A voltage dividing device (223) is configured to divide the output voltage U out providing a divided voltage under the condition of: wherein the voltage dividing device (223) comprises a first voltage dividing resistor (R1) and a second voltage dividing resistor (R2), wherein a first interface of the first voltage dividing resistor (R1) is connected to the output interface (124), wherein a second interface of the first voltage dividing resistor (R1) is connected to a first interface of the second voltage dividing resistor (R2), wherein a second interface of the second voltage dividing resistor (R2) is connected to a reference potential, wherein a second interface of the first voltage dividing resistor (R1) is connected to a control device (225) for providing the divided voltage; A control device (225) is configured to use the reference voltage U ref and the divided voltage, wherein the control device (225) has an operational amplifier, the operational amplifier having an inverting input terminal, a non-inverting input terminal and an output terminal, wherein the inverting input terminal of the operational amplifier is connected to the reference device (221) for receiving the reference voltage U ref , wherein the non-inverting input terminal of the operational amplifier of the control device (225) is connected to the second interface of the first voltage-dividing resistor (R1) of the voltage-dividing device (223) for receiving the divided voltage, and the non-inverting input terminal is connected to the modifying device (229) for modifying the divided voltage, wherein the output terminal of the operational amplifier is connected to the regulating device (227) for providing a regulating signal; A regulating device (227) is connected between the input interface (122) and the output interface (124), wherein the regulating device (227) is configured to adjust the input voltage U in and the regulating signal provides the output voltage U out ;and A modification device (229) is configured to modify the value of the partial voltage when using the test voltage TST, wherein the modification device (229) has a switch (S1) and a modification resistor (R3), wherein the switch (S1) and the modification resistor (R3) are connected in series with each other between a reference potential and a non-inverting input of an operational amplifier of the control device (225), wherein a control interface of the switch (S1) is connected to the test interface (126), The operational amplifier comprises two npn amplifier transistors (T3, T4), one pnp amplifier transistor (T2), two amplifier capacitors (C1, C2) and three amplifier resistors (R4, R5, R6), wherein the inverting input of the operational amplifier is implemented as a control interface of a first npn amplifier transistor (T3) of the npn amplifier transistors (T3, T4), wherein the non-inverting input of the operational amplifier is implemented as a control interface of a second npn amplifier transistor (T4) of the npn amplifier transistors (T3, T4), wherein the first interface of the first npn amplifier transistor (T3) of the npn amplifier transistors (T3, T4) and the A first interface of a second npn amplifier transistor (T4) among the npn amplifier transistors (T3, T4) is connected to a reference potential via a first amplifier resistor (R4) among the amplifier resistors (R4, R5, R6), wherein a second interface of a first npn amplifier transistor (T3) among the npn amplifier transistors (T3, T4) is connected to a second interface of the pnp amplifier transistor (T2) and is connected to the regulating device (227) for providing the regulating signal, wherein a second interface of a second npn amplifier transistor (T4) among the npn amplifier transistors (T3, T4) is connected to the output interface (124), wherein the pnp amplifier transistor (T 2) is connected to the input interface (122), wherein the control interface of the pnp amplifier transistor (T2) is connected to the regulating device (227) via the second amplifier resistor (R6) of the amplifier resistors (R4, R5, R6), wherein the first interface of the first amplifier capacitor (C1) of the amplifier capacitors (C1, C2) is connected to the input interface (122), wherein the second interface of the first amplifier capacitor (C1) of the amplifier capacitors (C1, C2) is connected between the control interface of the pnp amplifier transistor (T2) and the second amplifier resistor (R6) of the amplifier resistors (R4, R5, R6), wherein the amplifier resistor ( A first interface of a third amplifier resistor (R5) among the amplifier resistors (R4, R5, R6) is connected to a control interface of a first npn amplifier transistor (T3) among the npn amplifier transistors (T3, T4), wherein a second interface of the third amplifier resistor (R5) among the amplifier resistors (R4, R5, R6) is connected to the output interface (124), wherein a first interface of a second amplifier capacitor (C2) among the amplifier capacitors (C1, C2) is connected to a control interface of the first npn amplifier transistor (T3) among the npn amplifier transistors (T3, T4), wherein a second interface of the second amplifier capacitor (C2) among the amplifier capacitors (C1, C2) is connected to a reference potential.

2. The overvoltage protection circuit (120) according to claim 1, wherein: The regulating device (227) has a transistor (T1), which has a first interface, a second interface and a control interface for receiving the regulating signal, wherein the first interface of the transistor (T1) is connected to the input interface (122), wherein the second interface of the transistor is connected to the output interface (124), and wherein the control interface of the transistor (T1) is connected to the control device (225).

3. The overvoltage protection circuit (120) according to claim 1 or 2, wherein: The reference device (221) comprises a reference resistor (R8), a first diode (D1) and a second diode (D2), wherein the reference resistor (R8), the first diode (D1) and the second diode (D2) are connected in series to a control circuit for applying a control voltage U s between the control interface (330) and a reference potential or between the input interface (122) and a reference potential, wherein a reference node (REF) between the first diode (D1) and the second diode (D2) is connected to the control device (225).

4. The overvoltage protection circuit (120) according to claim 1 or 2, comprising a setting device (440) for adjusting the input voltage U in The adjustment signal is set in the case of The setting device (440) has a series circuit consisting of a switch and a first setting resistor (R14), the series circuit being connected between the control device (225) and a reference potential, wherein the switch can be switched according to the input voltage U in Switch.

5. The overvoltage protection circuit (120) according to claim 4, wherein: The switch is implemented as a first npn adjustment transistor (T6), wherein the adjustment device (440) also has a second npn adjustment transistor (T5), a second adjustment resistor (R10), a third adjustment resistor (R11), a fourth adjustment resistor (R12) and a fifth adjustment resistor (R13), wherein a first interface of the first npn adjustment transistor (T6) is connected to a first interface of the first adjustment resistor (R14), wherein a second interface of the first adjustment resistor (R14) is connected to a reference potential, wherein a second interface of the first npn adjustment transistor (T6) is connected to the control device (225), wherein a control interface of the first npn adjustment transistor (T6) is connected to a second interface of the second npn adjustment transistor (T5), wherein the first interface of the second npn adjustment transistor (T5) is connected to a reference potential. The invention relates to a device for controlling a first adjustment resistor (R10) and a second adjustment resistor (R11) connected to a reference potential, wherein the second adjustment resistor (R10) and the third adjustment resistor (R11) are connected in series between the input interface (122) and the reference potential, wherein the control interface of the second npn adjustment transistor (T5) is connected to an adjustment node (445) between the second adjustment resistor (R10) and the third adjustment resistor (R11), wherein a first interface of the fourth adjustment resistor (R12) is connected to the adjustment node (445), wherein a second interface of the fourth adjustment resistor (R12) is connected to a second interface of the second npn adjustment transistor (T5), wherein a first interface of the fifth adjustment resistor (R13) is connected to a second interface of the second npn adjustment transistor (T5), and wherein a second interface of the fifth adjustment resistor (R13) is connected to the input interface (122).

6. The overvoltage protection circuit (120) according to claim 1 or 2, comprising a current limiting resistor (R7), wherein: A first interface of the current-limiting resistor (R7) is connected to the input interface (122), wherein a second interface of the current-limiting resistor (R7) is connected to the regulating device (227).

7. A control device (110) for a vehicle (100), wherein: The control device (110) comprises an overvoltage protection circuit (120) as claimed in any one of the preceding claims and a voltage supply interface (114), wherein an output interface (124) of the overvoltage protection circuit (120) is connected to the voltage supply interface (114) of the control device (110).

8. The control device (110) according to claim 7, comprising a test device (130) for testing the functionality of the overvoltage protection circuit (120), wherein: The test device (130) is configured to detect an output voltage U during a period in which a test voltage having a first voltage level is applied to a test interface (126). out The output voltage U is detected during the period when a test voltage having a second voltage level is applied to the test interface (126). out and providing a test signal (132) using the first value or the first value curve and the second value or the second value curve.

9. A method (500) for testing an overvoltage protection circuit (120) of a control device (110) of a vehicle (100), wherein: The overvoltage protection circuit (120) is an overvoltage protection circuit (120) according to any one of claims 1 to 6, wherein the method (500) comprises the following steps: Applying (510) a test voltage having a first voltage level to a test interface (126) of the overvoltage protection circuit (120); detecting (520) a first output voltage in response to the test voltage having a first voltage level; Applying (530) a test voltage having a second voltage level to a test interface (126) of the overvoltage protection circuit (120), wherein the second voltage level is lower than the first voltage level; detecting (540) a second output voltage in response to the test voltage having a second voltage level; It is checked (550) whether the detected first output voltage and the detected second output voltage meet at least one test criterion to generate a test result.

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