WO2014087854A1

WO2014087854A1 - Electronic control apparatus

Info

Publication number: WO2014087854A1
Application number: PCT/JP2013/081515
Authority: WO
Inventors: 遼一稲田; 広津　鉄平; 康史森田; 尚廣秦
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2012-12-04
Filing date: 2013-11-22
Publication date: 2014-06-12
Also published as: JP2014110361A; JP5830458B2

Abstract

This electronic control apparatus (1) has an integrated circuit (20), and a controller (10) for controlling the integrated circuit (20). The integrated circuit (20) has: a monitored circuit (30); a voltage-irregularity detection circuit (40) for comparing the terminal voltage of the monitored circuit (30) and a predetermined threshold voltage, and detecting a failure in the monitored circuit (30); and a test-voltage generation circuit (50) for generating a predetermined test voltage to detect a failure in the voltage-irregularity detection circuit (40). The temperature coefficient of the test voltage and the temperature coefficient of the threshold voltage are made to be substantially equal.

Description

Electronic control unit

The present invention relates to an electronic control device including an abnormality detection circuit.

For example, an electronic control device for an automobile has a large number of abnormality detection circuits inside to prevent malfunction when a failure occurs. One of the abnormality detection circuits is a voltage abnormality detection circuit. The voltage abnormality detection circuit measures the terminal voltage of the circuit to be monitored, and outputs a voltage abnormality detection signal when the voltage value is out of the normal range. When the voltage abnormality detection signal is output, the electronic control unit determines that an abnormality has occurred inside and performs processing such as operation stop to prevent malfunction.

However, if the voltage abnormality detection circuit breaks down, the voltage abnormality of the terminal voltage cannot be determined accurately, and the electronic control device may malfunction. In order to prevent this state, several fault detection methods for the voltage abnormality detection circuit have been proposed.

For example, there are Patent Documents 1 and 2 as background art of this failure detection method. In Patent Document 1, “the voltage abnormality detecting means (voltage sensor and voltage abnormality determining unit) is disconnected from the secondary battery and the voltage abnormality detecting means is a constant voltage generating means (conversion) different from the secondary battery. A constant DC voltage having a constant voltage value out of the normal voltage range is applied to the voltage abnormality detection means (voltage sensor) by the constant voltage generation means, and the voltage abnormality detection means has a voltage abnormality. If it is not determined, it is determined that the voltage abnormality detecting means has failed. "

Further, in Patent Document 2, “a test signal, for example, an overcharge test signal is input to the test signal input terminal, and the abnormal state detection means is differentiated so that an overcharge state occurs, "Activate a protective means that shuts off the circuit that conducts the electrical energy delivered and received by the battery".

Japanese Patent No. 4715875 Japanese Patent Application Laid-Open No. 11-98701

In Patent Document 1, a stable DC constant voltage without voltage fluctuation is generated by a constant voltage generating means, and a failure of the voltage abnormality detecting means is accurately diagnosed by applying this DC constant voltage to the voltage abnormality detecting means. Yes. However, when the constant voltage generating means and the voltage abnormality detecting means are accommodated in one integrated circuit, the constant voltage generating means is affected by manufacturing variations of the integrated circuit and temperature, so that voltage fluctuation of the DC constant voltage should be kept small. If this is the case, the circuit scale will increase, leading to increased costs. On the contrary, if the voltage fluctuation of the DC constant voltage is allowed to be large, there is a problem that the failure diagnosis accuracy of the voltage abnormality detecting means is lowered.

Further, Patent Document 2 has a problem that when the overcharge test signal fluctuates, the abnormal state detection means cannot be diagnosed with high accuracy.

In order to solve the above problems, for example, the configuration described in the claims is adopted.

The present application includes a plurality of means for solving the above-mentioned problems. To give an example, “a monitoring target circuit provided in an integrated circuit composed of one chip, a terminal voltage of the monitoring target circuit, and A voltage abnormality detection circuit that detects an abnormality of the monitoring target circuit by comparing the set threshold voltage, and is set in advance to detect a failure of the voltage abnormality detection circuit, and is compared with the threshold voltage of the voltage abnormality detection circuit. A test voltage generation circuit for generating a test voltage to be set, and the temperature coefficient of the test voltage and the temperature coefficient of the threshold voltage are set to be equal.

According to the present invention, fault diagnosis of the voltage abnormality detection circuit can be performed with high accuracy even under conditions where the voltage fluctuation of the test voltage is large.

Issues, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a block diagram of the electronic controller in Example 1 of this invention. It is a circuit diagram which shows a structure of an example of the voltage abnormality detection circuit in Example 1 of this invention. It is a circuit diagram which shows the structure of another example of the voltage abnormality detection circuit in Example 1 of this invention. It is a circuit diagram which shows the structure of the test voltage generation circuit in Example 1 of this invention. It is a flowchart showing the failure diagnosis process of the voltage abnormality detection circuit of this invention. It is a characteristic view showing an example of the relationship between the temperature coefficient of a test voltage and the temperature coefficient of a threshold voltage. It is a characteristic view showing another example of the relationship between the temperature coefficient of a test voltage and the temperature coefficient of a threshold voltage. It is a characteristic view showing still another example of the relationship between the temperature coefficient of the test voltage and the temperature coefficient of the threshold voltage. It is a common centroid arrangement | positioning figure in the example of this embodiment. It is a block diagram of the electronic controller in Example 2 of this invention. It is a circuit diagram which shows the structure of the test voltage generation circuit in Example 2 of this invention. It is a block diagram of the electronic controller in Example 3 of this invention. It is a circuit diagram which shows a structure of an example of the voltage abnormality detection circuit in Example 3 of this invention. It is a circuit diagram which shows the structure of another example of the voltage abnormality detection circuit in Example 3 of this invention. It is a block diagram of the electronic controller in Example 4 of this invention. It is a figure showing the example of the failure information of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, an example in which the present invention is applied to an automobile electronic control device will be described, but the present invention is not limited to the following embodiments.

In this embodiment, an example of an electronic control device that can accurately perform failure diagnosis of the voltage abnormality detection circuit even when the amount of variation in the test voltage is large will be described.

FIG. 1 is a configuration diagram of an electronic control device according to this embodiment. *

The electronic control device 1 includes a control controller 10 and an integrated circuit 20. Among these, the controller 10 includes a CPU (not shown), a RAM (not shown), and a communication function (not shown) inside, and in addition to instructing the integrated circuit 20 to perform processing, Outputs failure detection signals and communicates with other electronic control devices. In FIG. 1, the controller 10 is shown outside the integrated circuit 20, but may be inside the integrated circuit 20.

The integrated circuit 20 includes a monitoring target circuit 30, a voltage abnormality detection circuit 40, a test voltage generation circuit 50, a switch 21, and a switch 22 in one chip. The

switches

21 and 22 are controlled to open and close by a signal from the controller 10.

The monitoring target circuit 30 is a circuit for which the voltage abnormality detection circuit 40 is to measure a voltage abnormality. The monitoring target circuit 30 is an arbitrary analog circuit, and examples thereof include a voltage boosting circuit, a voltage stepping down circuit, and a circuit for acquiring a sensor voltage outside the electronic control device 1.

The voltage abnormality detection circuit 40 is connected to the test voltage generation circuit 50 via the input side wiring 41 and the switch 21, and is connected to the monitoring target circuit 30 via the wiring 41 and the switch 22. Therefore, either the test voltage 55 output from the test voltage generation circuit 50 or the terminal voltage 31 of the monitoring target circuit 30 is input to the voltage abnormality detection circuit 40.

Then, the voltage abnormality detection circuit 40 compares the input voltage input from the wiring 41 with a preset threshold voltage, and determines whether the input voltage is within the normal range. When the input voltage deviates from the normal range, a voltage abnormality detection signal 46 is output to the controller 10.

The test voltage generation circuit 50 generates a test voltage 55 for performing failure diagnosis of the voltage abnormality detection circuit 40.

The failure notification device 100 receives a failure detection signal from the control controller 10 and notifies, for example, the occurrence of a failure to a vehicle occupant. Examples of the failure notification method include a method of lighting a lamp, generating a warning sound, and notifying by voice.

2A and 2B are diagrams showing a circuit configuration example of the voltage abnormality detection circuit 40. FIG. The voltage abnormality detection circuit 40 has a different circuit configuration depending on whether the voltage abnormality detection signal 46 is output when the input voltage of the wiring 41 is higher than the threshold voltage or the voltage abnormality detection signal 46 is output when the input voltage is lower than the threshold voltage. In the present embodiment, the state in which the voltage abnormality detection signal 46 is output from the voltage abnormality detection circuit 40 indicates a state in which the voltage value of the voltage abnormality detection signal 46 is within the High range at the CMOS level.

FIG. 2A shows a voltage abnormality detection circuit 40 that outputs a voltage abnormality detection signal 46 when the input voltage of the wiring 41 is higher than the threshold voltage. In FIG. 2A, the input voltage of the wiring 41 is divided by the

resistors

42a and 43a, the divided input voltage is input to the non-inverting input terminal (+ side) of the comparator 44a, and the reference voltage 45a is input to the inverting input terminal of the comparator 44a. Input to (-side). Thereby, when the divided input voltage is larger than the reference voltage 45a, the output voltage of the comparator 44a becomes the power supply voltage, and the voltage abnormality detection signal 46 is output. On the other hand, when the divided input voltage is smaller than the reference voltage 45a, the output voltage of the comparator 44a is 0V, and the voltage abnormality detection signal 46 is not output. In the case of this circuit, the threshold voltage is determined by the values of the resistor 42a, the resistor 43a, and the reference voltage 45a.

FIG. 2B shows a voltage abnormality detection circuit 40 that outputs a voltage abnormality detection signal 46 when the input voltage of the wiring 41 is lower than the threshold voltage. In FIG. 2B, the input voltage of the wiring 41 is divided by the

resistors

42b and 43b, the divided input voltage is input to the inverting input terminal (− side) of the comparator 44b, and the reference voltage 45b is input to the non-inverting input terminal of the comparator 44b. Input to (+ side). Thereby, when the divided input voltage is smaller than the reference voltage 45b, the output voltage of the comparator 44b becomes the power supply voltage, and the voltage abnormality detection signal 46 is output. On the contrary, when the divided input voltage is larger than the reference voltage 45b, the output of the comparator 44b is 0V, and the voltage abnormality detection signal 46 is not output. In the case of this circuit, the threshold voltage is determined by the values of the resistor 42b, the resistor 43b, and the reference voltage 45b.

FIG. 3 is a diagram showing a circuit configuration of the test voltage generation circuit 50. The test voltage 55 is generated by dividing the voltage of the power supply line 53 by the MOSFET 54, the resistor 56, and the resistor 57, and is output from the common connection point of the MOSFET 54 and the resistor 56. The operational amplifier 52 has a role of adjusting the resistance value of the MOSFET 54 so that the reference voltage 51 of the non-inverting input terminal (+ side) and the common connection point voltage 58 of the

resistors

56 and 57 of the inverting input terminal (− side) become equal. Thus, the voltage value of the test voltage 55 output from the common connection point of the MOSFET 54 and the resistor 56 is stabilized.

FIG. 4 is a flowchart of the failure diagnosis method in this embodiment.

In step S1, the controller 10 outputs an OFF control signal so that the switch 22 is opened (OFF). As a result, the connection between the voltage abnormality detection circuit 40 and the monitoring target circuit 30 is disconnected. Next, in step S2, the controller 10 outputs an ON control signal so that the switch 21 is closed (ON). As a result, the test voltage 55 output from the test voltage generation circuit 50 is input to the voltage abnormality detection circuit 40.

In the next step S3, the controller 10 confirms whether the voltage abnormality detection signal 46 is output from the voltage abnormality detection circuit 40. When the controller 10 receives the voltage abnormality detection signal 46 (Yes), it is determined that the voltage abnormality detection circuit 40 is normal, and the process proceeds to step S4. If the voltage abnormality detection signal 46 has not been received (No), it is determined that the voltage abnormality detection circuit 40 has failed, and the process proceeds to step S6.

In step S4, the controller 10 outputs an OFF control signal so that the switch 21 is opened (OFF). As a result, the connection between the test voltage generation circuit 50 and the voltage abnormality detection circuit 40 is disconnected. In the next step S5, the controller 10 outputs an ON control signal so that the switch 22 is closed (ON). As a result, the terminal voltage 31 of the monitoring target circuit 30 is input to the voltage abnormality detection circuit 40 as before the failure diagnosis. When the process of step S5 is completed, the fault diagnosis process of the voltage abnormality detection circuit 40 ends.

In step S6, the controller 10 outputs a failure detection signal to the failure notification device 100. In response to this, the failure notification device 100 operates and notifies the passenger of the failure.

Thereby, the failure of the voltage abnormality detection circuit 40 can be notified outside the electronic control unit.

When the process of step S6 is completed, the fault diagnosis process of the voltage abnormality detection circuit 40 is completed.

The timing for starting the failure diagnosis of the voltage abnormality detection circuit 40 is arbitrary. For example, the diagnosis may be performed when power is supplied to the electronic control device 1, or the electronic control device 1 operates for a certain period of time. Diagnosis may be performed every time.

5A, 5B, and 5C are diagrams showing the relationship between the temperature coefficient of the test voltage 55 and the temperature coefficient of the threshold voltage of the voltage abnormality detection circuit 40, respectively. 5A, 5B, and 5C are diagrams when the circuit of FIG. 2A is used as the voltage abnormality detection circuit 40. FIG.

When the circuit of FIG. 2A is used as the voltage abnormality detection circuit 40, the test voltage 55 needs to be larger than the threshold voltage in the entire temperature region. This is because if the test voltage 55 falls below the threshold voltage, the voltage abnormality detection signal 46 is not output from the voltage abnormality detection circuit 40 at the time of failure diagnosis, and it is erroneously detected that the voltage abnormality detection circuit 40 has failed. is there.

This problem of false detection can be reliably avoided by preventing the fluctuation range of the test voltage 55 and the fluctuation range of the threshold voltage from overlapping as shown in FIG. 5A. However, when the variation ranges do not overlap, if the variation amount of the test voltage 55 is large, the potential difference between the test voltage 55 and the threshold voltage is large as shown in FIG. 5B. The greater the potential difference between the test voltage 55 and the threshold voltage, the more difficult it is to detect a failure in which the threshold voltage of the voltage abnormality detection circuit 40 increases.

On the other hand, the above problem can be solved by making the temperature coefficient of the test voltage 55 and the temperature coefficient of the threshold voltage as equal as possible as shown in FIG. 5C. When the temperature coefficient of the test voltage 55 is equal to the temperature coefficient of the threshold voltage, the potential difference between the test voltage 55 and the threshold voltage does not change even if the temperature changes. Therefore, even if the test voltage 55 is set in the vicinity of the threshold voltage, erroneous detection of a failure does not occur, and the accuracy of failure detection can be improved while preventing erroneous detection. This effect increases as the difference between the temperature coefficient of the test voltage 55 and the temperature coefficient of the threshold voltage decreases.

2B is the same as the circuit in FIG. 2A except that the magnitude relationship between the test voltage 55 and the threshold voltage is reversed, the temperature coefficient of the test voltage 55 and the threshold voltage Similarly, the smaller the difference in temperature coefficient, the better the failure detection accuracy.

As a method of matching the temperature coefficient of the test voltage 55 and the threshold voltage, the voltage abnormality detection circuit 40 and the test voltage generation circuit 50 are designed so that the temperature coefficients match, and the voltage abnormality detection circuit 40 and the test voltage generation circuit 50 are combined. Applying a common centroid arrangement.

The method of matching the temperature coefficient according to the design includes, for example, the temperature coefficient of the resistor and the comparator in FIG. 2A or 2B constituting the voltage abnormality detection circuit, and the temperature coefficient of the resistor, comparator and MOSFET constituting the test voltage generation circuit in FIG. Are designed so that both are equal.

FIG. 6 shows an example of a common centroid layout. The common centroid arrangement is a method of arranging elements so that the center of gravity comes to the center. In the case of FIG. 6, the resistor 1 is divided into two, a resistor 1a and a resistor 1b, and the divided resistors 1a and 1b are arranged diagonally. Similarly, the resistor 2 is also arranged diagonally after being divided into a resistor 2a and a resistor 2b. Accordingly, when the resistance values of the resistor 1a, the resistor 1b, the resistor 2a, and the resistor 2b are the same, the center of gravity comes to the center. When the common centroid arrangement is used, it is possible to prevent the center of gravity from being scattered and biased to a specific element when the integrated circuit 20 is manufactured, compared to the case where the elements are simply arranged, and the temperature coefficient of the test voltage 55 and the temperature of the threshold voltage Deviation from the coefficient can be reduced.

For example, in the case of the voltage abnormality detection circuit 40, each of the

resistors

42a and 43a in FIG. 2A is divided into two and then diagonally arranged as shown in FIG. Not only the resistor but also the comparator 44a may be diagonally arranged after being divided into two. The same applies to the circuit of FIG. 2B.

In the case of the test voltage generation circuit 50, the

resistors

56 and 57 shown in FIG. 3 are divided into two parts and then diagonally arranged as shown in FIG. Not only the resistor but also the operational amplifier 52 and the MOSFET 54 may be diagonally arranged after being divided into two.

The first embodiment described above has the following effects.

By bringing the temperature coefficient of the test voltage 55 closer to the temperature coefficient of the threshold voltage of the voltage abnormality detection circuit 40, the test voltage 55 can be set near the threshold voltage, and even if the voltage fluctuation of the test voltage 55 is large, the voltage A failure of the abnormality detection circuit 40 can be diagnosed with high accuracy.

In this embodiment, an example of an electronic control device that enables adjustment of the temperature coefficient of the test voltage from the outside of the integrated circuit is shown. *

FIG. 7 is a configuration diagram of the electronic control unit 1A according to the second embodiment. Here, the same symbols are given to the same elements as those in the configuration diagram of the electronic control device 1 in the first embodiment, and the description for these same elements is omitted.

The electronic control device 1A in the second embodiment has an integrated circuit 20A different from the integrated circuit 20 in the first embodiment. Other than that, the configuration is the same as that of the electronic control unit 1 of the first embodiment.

The integrated circuit 20A according to the second embodiment is different from the first embodiment except that the integrated circuit 20A includes the

terminals

23 and 24 and the test voltage generation circuit 50A different from the test voltage generation circuit 50 according to the first embodiment. 1 has the same configuration as the integrated circuit 20 in FIG. Here, the terminal 23 is connected so that the test voltage 55 output from the test voltage generation circuit 50A is applied, so that the temperature coefficient of the test voltage 55 is increased from the outside of the integrated circuit 20A using the terminal 23. Can be measured. The terminal 24 is connected to the inside of the test voltage generation circuit 50A for adjusting the temperature coefficient of the test voltage 55.

FIG. 8 is a configuration diagram of the test voltage generation circuit 50A in the second embodiment. In addition to the test voltage generation circuit 50 in the first embodiment, the test voltage generation circuit 50A in the second embodiment includes a series circuit of an adjustment resistor 59 and a Zener diode 60 that are connected in parallel to the resistor 57. Another difference is that the common connection point of the adjustment resistor 59 and the Zener diode 60 is connected to the terminal 24.

This terminal 24 is used when adjusting the temperature coefficient of the test voltage 55. When a high voltage is applied to the terminal 24, the anode and cathode of the Zener diode 60 are short-circuited. Thereby, the resistor 57 and the adjustment resistor 59 are connected in parallel, and the temperature coefficient of the test voltage 55 can be changed.

At this time, if the test voltage is not changed, the resistance value of the adjustment resistor 59 connected in parallel to the resistor 57 is assumed to be sufficiently smaller than the resistance value of the resistor 57.

In the second embodiment, the terminal 24 for adjusting the temperature coefficient, the adjusting resistor 59, and the Zener diode 60 (unit for adjusting the temperature coefficient of the test voltage of the present invention) are used only one by one. May use a plurality of terminals and adjusting resistors. Alternatively, the temperature coefficient of the test voltage 55 may be adjusted by changing the resistance value by cutting the resistance in the test voltage generation circuit 50A with a laser.

The second embodiment described above has the following effects.

The integrated circuit 20A in the electronic control apparatus 1A has the terminal 23 that can output the test voltage 55, so that the voltage value of the test voltage 55 can be detected from the outside of the integrated circuit 20A and its temperature coefficient can be measured. As a result of measuring the test voltage 55, if the temperature coefficient is shifted, the temperature coefficient of the test voltage 55 can be adjusted using the terminal 24.

In another embodiment, either the terminal 23 for measuring the temperature coefficient of the test voltage or the unit for adjusting the temperature coefficient of the test voltage (terminal 24, adjustment resistor 59, Zener diode 60) is provided. It is also possible to provide only the above.

In the present embodiment, an example of an electronic control device capable of performing failure diagnosis of the voltage abnormality detection circuit without the voltage booster circuit even when the threshold voltage of the voltage abnormality detection circuit is higher than the power supply voltage of the integrated circuit is shown.

FIG. 9 is a configuration diagram of the electronic control device according to the third embodiment. Here, the same symbols are assigned to the same elements as those in the configuration diagram of the electronic control device according to the first embodiment, and the description for these same elements is omitted.

The electronic control device 1B according to the third embodiment includes an integrated circuit 20B that is different from the integrated circuit 20 according to the first embodiment. Other than that, the configuration is the same as that of the electronic control unit 1 of the first embodiment.

The integrated circuit 20B according to the third embodiment is different from the voltage abnormality detection circuit 40 according to the first embodiment in that the integrated circuit 20B includes a voltage abnormality detection circuit 40B. Also, in the third embodiment, unlike the first embodiment, the terminal voltage 31 of the monitoring target circuit 30 is input to the voltage abnormality detection circuit 40B via the switch 22 and the wiring 41, and the test output from the test voltage generation circuit 50 is performed. The voltage 55 is input to the voltage abnormality detection circuit 40 </ b> B via the switch 21 and a wiring 47 different from the wiring 41.

10A and 10B are diagrams illustrating a configuration example of the voltage abnormality detection circuit 40B according to the third embodiment. In the voltage abnormality detection circuit 40B, the test voltage 55 from the test voltage generation circuit 50 is input between the resistor 42a and the resistor 43a through the wiring 47 as shown in FIG. 10A, or the resistance through the wiring 47 as shown in FIG. 10B. The voltage abnormality detection circuit 40 is the same as that of the first embodiment except that the voltage is input between 42b and the resistor 43b.

FIG. 10A shows a voltage abnormality detection circuit 40B that outputs a voltage abnormality detection signal 46 when the common connection point voltage of the

resistors

42a and 43a is higher than the threshold voltage. 10A, the input voltage introduced from the monitored circuit 30 through the wiring 41 is divided by the

resistors

42a and 43a, and the common connection point (voltage dividing point) of the

resistors

42a and 43a is divided from the test voltage generation circuit 50 to the wiring 47. The voltage at the voltage dividing point is input to the non-inverting input terminal (+ side) of the comparator 44a, and the reference voltage 45a is input to the inverting input terminal (− side) of the comparator 44a. ing. Thereby, when the test voltage introduced through the wiring 47 or the input voltage introduced through the wiring 41 and divided by the

resistors

42a and 43a is larger than the reference voltage 45a, the output voltage of the comparator 44a becomes the power supply voltage, The voltage abnormality detection signal 46 is being output. On the contrary, when the test voltage introduced through the wiring 47 or the input voltage introduced through the wiring 41 and divided by the

resistors

42a and 43a is smaller than the reference voltage 45a, the output voltage of the comparator 44a becomes 0V. The abnormality detection signal 46 is not output.

FIG. 10B shows a voltage abnormality detection circuit 40B that outputs a voltage abnormality detection signal 46 when the common connection point voltage of the

resistors

42b and 43b is lower than the threshold voltage. In FIG. 10B, the input voltage introduced from the monitored circuit 30 through the wiring 41 is divided by the

resistors

42b and 43b, and the common connection point (voltage dividing point) of the

resistors

42b and 43b is divided from the test voltage generation circuit 50 to the wiring 47. The voltage at the voltage dividing point is input to the inverting input terminal (− side) of the comparator 44b, and the reference voltage 45b is input to the non-inverting input terminal (+ side) of the comparator 44b. ing. Thus, when the test voltage introduced through the wiring 47 or the input voltage introduced through the wiring 41 and divided by the

resistors

42b and 43b is smaller than the reference voltage 45b, the output voltage of the comparator 44b becomes the power supply voltage. The voltage abnormality detection signal 46 is output. On the contrary, when the test voltage introduced through the wiring 47 or the input voltage introduced through the wiring 41 and divided by the

resistors

42b and 43b is larger than the reference voltage 45b, the output of the comparator 44b becomes 0V, and the voltage is abnormal. The detection signal 46 is not output.

In the test voltage generation circuit 50 described in the first embodiment, the test voltage is generated by dividing the power supply voltage. Therefore, when the threshold voltage of the voltage abnormality detection circuit 40 is higher than the power supply voltage, it is necessary to add a voltage booster circuit in the test voltage generation circuit 50 in order to generate a test voltage higher than the power supply voltage. However, when a voltage booster circuit is added, the circuit area of the integrated circuit 20 increases, leading to an increase in cost.

In order to solve this problem, in the voltage abnormality detection circuit 40B according to the third embodiment, a voltage dividing resistor (a common connection point between the

resistors

42a and 43a (FIG. 10A) or a common connection point between the

resistors

42b and 43b (FIG. 10B)). ), A test voltage is input via the wiring 47. In this configuration, since the test voltage introduced at the common connection point of the

resistors

42a and 43a (or the common connection point of the

resistors

42b and 43b) is compared with the threshold voltage, the test is performed more than when input via the wiring 41. The voltage can be lowered, and the voltage booster circuit can be dispensed with. The above is the effect in the third embodiment.

In this embodiment, an example of an electronic control device that can easily identify a faulty part when a fault of a monitoring target circuit or a voltage abnormality detection circuit is detected is shown.

FIG. 11 is a configuration diagram of the electronic control device according to the fourth embodiment. Here, the same symbols are assigned to the same elements as those in the configuration diagram of the electronic control device according to the first embodiment, and descriptions of these same elements are omitted.

The electronic control device 1C according to the fourth embodiment includes a control controller 10C that is different from the control controller 10 according to the first embodiment. Other than that, the configuration is the same as that of the electronic control unit 1 of the first embodiment.

The control controller 10C in the fourth embodiment has failure information 11 in addition to the control controller 10 in the first embodiment.

FIG. 12 is a diagram showing an example of the failure information 11. The failure information 11 includes a failure number 11a, a date 11b, a time 11c, and a failure code 11d. The failure number 11a is a failure registration number. In the case of FIG. 12, a maximum of N pieces of information can be held. Date 11b and time 11c indicate the date and time when the failure occurred. In the part of the fault code 11d, different codes are stored depending on the detected fault contents. For example, the code of C00 is stored when the terminal voltage of the monitoring target circuit 30 becomes abnormal, and the code of C01 is stored when an abnormality is detected during failure diagnosis of the voltage abnormality detection circuit 40.

The failure information 11 can be read out and deleted from the outside of the electronic control unit 1C by the controller 10C.

The fourth embodiment described above has the following effects.

The control controller 10C in the electronic control unit 1C stores the failure content at the time of failure detection as failure information 11, for example, in its internal memory. When a failure occurs, the failure information 11 held in the internal memory is read from the outside of the electronic control unit 1C, so that it is easy to specify the time of failure occurrence and the failure portion.

In addition, this invention is not limited to said Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

In addition, each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. In addition, each of the above-described configurations, functions, and the like may be realized by software obtained by the processor interpreting and executing a program that realizes each function.

Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. In practice, it can be considered that almost all the components are connected to each other.
While the above description has been made with reference to exemplary embodiments, it will be apparent to those skilled in the art that the invention is not limited thereto and that various changes and modifications can be made within the spirit of the invention and the scope of the appended claims.

1, 1A, 1B, 1C

Electronic control device

10,

10C Controller

20, 20A, 20B Integrated circuit 30

Monitored circuit

40, 40B Voltage

abnormality detection circuit

41, 47

Wiring

42a, 42b, 43a, 43b, 56, 57

Resistance

44a 44b Comparator

50, 50A Test voltage generation circuit 52 Operational amplifier 54 MOSFET
59 Adjustment resistor 100 Failure notification device

Claims

A circuit to be monitored;
A voltage abnormality detection circuit that detects an abnormality of the monitoring target circuit by comparing a terminal voltage of the monitoring target circuit with a preset threshold voltage;
A test voltage generation circuit that generates a test voltage that is preset to detect a failure of the voltage abnormality detection circuit and is compared with a threshold voltage of the voltage abnormality detection circuit;
The monitoring target circuit, the voltage abnormality detection circuit, and the test voltage generation circuit are provided in an integrated circuit configured by one chip,
An electronic control device in which a temperature coefficient of the test voltage and a temperature coefficient of the threshold voltage are set to be equal.
The electronic control device according to claim 1, further comprising a control controller that exchanges signals with the integrated circuit, wherein the control controller detects a failure when a failure of the voltage abnormality detection circuit is detected. An electronic control device that outputs a signal to the outside.
The electronic control device according to claim 1.
An electronic control device, wherein the test voltage generation circuit and the voltage abnormality detection circuit are arranged in a common centroid and the temperature coefficient of the test voltage and the temperature coefficient of the threshold voltage are set to be equal.
The electronic control device according to claim 1.
The electronic control device, wherein the integrated circuit has a terminal for outputting the test voltage to the outside of the integrated circuit.
The electronic control device according to claim 1.
The electronic control device, wherein the integrated circuit includes a unit for adjusting a temperature coefficient of the test voltage.
The electronic control device according to claim 1.
The electronic controller according to claim 1, wherein the voltage abnormality detection circuit has an input terminal for the test voltage at a voltage dividing point of a voltage dividing resistor.
The electronic control device according to claim 2,
The electronic controller according to claim 1, wherein the controller has a function of holding failure information from the voltage abnormality detection circuit.