Integrated circuit device

Abstract

In the present invention, accurate and highly reliable open defect detection is performed on the ground line of the integrated circuit device regardless of the connection state of the load or the operation state of the drive circuit. In the integrated circuit device (10) of the present invention, the drive circuit (30) uses switching elements (40, 45) to switch on and off the load current. The ground line (31) is connected to a common ground line provided outside the integrated circuit device (10) via a GND terminal (32) and is connected to the drive circuit (30). The ground line (21) is connected to the common ground line via a GND terminal (22) and is connected to the control circuit (20). The diagnosis current supply circuit (90) supplies a prescribed diagnosis current to the ground line (31). Rectifying elements (61, 62) are connected between the ground line (21) and the ground line (31). The diagnosis circuit (70) measures the potential difference between the ground line (31) and the ground line (21), compares the potential difference with a prescribed comparison voltage (73) to diagnose the grounding state of the ground line (31).

Description

Technical Field

[0001] This invention relates to an integrated circuit device. Background Technology

[0002] Electronic control devices that control the current supply to loads such as solenoids in automatic transmissions for vehicles are widely used. Such electronic control devices are configured to have a drive circuit and a control circuit. The drive circuit controls a switching element that receives power from a vehicle battery and switches it ON or OFF to supply current to the solenoid. The control circuit generates a reference voltage and / or electrical signal required for the operation control of the drive circuit. As a device used in electronic control devices, integrated circuits (ICs) that integrate the drive circuit and the control circuit are known. In implementing an electronic control device that uses an integrated circuit to control the solenoid, because a large current flows in the ground wire of the drive circuit, it is necessary to prevent malfunctions and / or characteristic degradation of the control circuit caused by this effect. As a method, it is recommended to separate the ground wires of the drive circuit and the control circuit within the integrated circuit device, connecting them to the ground wire of the integrated circuit device via separate GND terminals.

[0003] The ground wire of an integrated circuit device serves as the reference potential for the operating points of the drive and control circuits, connected to the ground wires of these circuits via their respective GND terminals. However, if an open circuit occurs in the ground wire of any circuit due to poor GND terminal connection or a broken ground wire, the potential fluctuation of the ground wire will cause malfunctions and / or a deterioration in circuit characteristics. In particular, because large currents flow in the ground wire of the drive circuit, the potential fluctuations caused by open circuits have a significant impact.

[0004] Therefore, a method for detecting open-circuit defects in the grounding wire of an integrated circuit device that controls the current supplied to the load has been proposed in the past. Patent Document 1 discloses the following technique: voltage drift is set for the potentials of the logic ground wire and the power ground wire respectively, the forward voltage Vf of the ESD diode is set to a larger voltage and a smaller voltage, and a comparator is used to compare the voltage drift and the voltage of the power ground wire to determine whether the logic ground wire and the power ground wire are open-circuited.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-136078 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In the technology described in Patent Document 1, when the power ground line is open-circuited, the current flowing in the power ground line flows through the logic ground line via the ESD diode, so the potential of the power ground line rises to the forward voltage Vf of the ESD diode to detect a faulty open circuit. However, when the drive circuit (high-side gate, low-side gate) is stopped, the potential rise of the power ground line is unstable because the current does not flow in the drive circuit, and an accurate and reliable judgment result cannot be obtained. Furthermore, when the power ground line is open-circuited depending on the load connection state, the current flowing in the power ground line does not flow in the logic ground line but flows through the load via the drive circuit, so a faulty open circuit cannot be detected. Thus, in the technology of Patent Document 1, depending on the load connection state or the operating state of the drive circuit, an accurate and reliable detection result for a faulty open circuit may not always be obtained.

[0010] Technical solutions for solving the problem

[0011] The integrated circuit device of the present invention, connected to a load to control the load current supplied to the load, comprises: a drive circuit having a switching element that uses the switching element to switch the load current on and off; a control circuit that controls the operation of the drive circuit; a first ground wire connected to the drive circuit and connected via a first ground wire connection terminal to a common ground wire disposed outside the integrated circuit device; a second ground wire connected to the control circuit and connected via a second ground wire connection terminal to the common ground wire; a diagnostic current supply circuit that supplies a predetermined diagnostic current to the first ground wire; a bidirectional rectifier element connected between the first ground wire and the second ground wire; and a diagnostic circuit that measures the potential difference between the first ground wire and the second ground wire and compares the potential difference with a predetermined comparison voltage to diagnose the grounding state of the first ground wire.

[0012] Invention Effects

[0013] According to the present invention, regardless of the connection state of the load or the operating state of the drive circuit, it is possible to perform accurate and reliable open circuit fault detection on the ground wire of the integrated circuit device. Attached Figure Description

[0014] Figure 1 This is a structural diagram of an integrated circuit device according to the first embodiment of the present invention.

[0015] Figure 2 This diagram illustrates an example of a protection diode configured on the input side of a control signal.

[0016] Figure 3 This is a diagram illustrating an example of the electrical characteristics of a rectifier element.

[0017] Figure 4 This is a diagram showing an example of the structure of a switching element.

[0018] Figure 5 This is an explanatory diagram of the detection method for open circuit defects when the load terminal is connected to the common ground wire.

[0019] Figure 6 This is an explanatory diagram of a method for detecting open circuit defects when the load terminal is connected to the vehicle's battery.

[0020] Figure 7 This is a structural diagram of an integrated circuit device according to the second embodiment of the present invention. Detailed Implementation

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, since the drawings are simplified, the technical scope of the present invention should not be narrowly interpreted based on the description in the drawings. Additionally, the same reference numerals are used to denote the same elements, and repeated descriptions are omitted.

[0022] (First Implementation)

[0023] The following is for reference Figures 1-6 The first embodiment of the present invention will be described.

[0024] (Structure of an integrated circuit device)

[0025] Figure 1 This is a structural diagram of an integrated circuit device according to a first embodiment of the present invention. The integrated circuit device 10 of this embodiment is installed within an electronic control unit 1 of a vehicle system such as an automobile, and is connected to a load 50 such as a solenoid, controlling the load current supplied to the load 50. The load 50 is, for example, a solenoid used to operate the vehicle's automatic transmission. The integrated circuit device 10 controls the automatic transmission by controlling the load current flowing in the load 50. The integrated circuit device 10 is configured to include a control circuit 20, a drive circuit 30, a rectifier circuit 60, a diagnostic circuit 70, and a diagnostic current supply circuit 90.

[0026] Furthermore, in general, multiple loads can be controlled in electronic control devices used in vehicles. However, in this embodiment, in order to explain the operation of the integrated circuit device 10 in a way that is easy to understand, an example is given in which a load 50 is connected to the integrated circuit device 10 and the load current flowing in the load 50 is controlled by a drive circuit 30.

[0027] The control circuit 20 generates the operating power 25 and control signals 26 required for the operation of the drive circuit 30, and outputs them to the drive circuit 30. The control circuit 20 receives power from a vehicle battery (not shown) mounted in the vehicle system via power terminal 15, and uses this power to operate. The control circuit 20 is connected to a ground wire 21, which is connected via a GND terminal 22 to the common ground wire of the electronic control device 1 located outside the integrated circuit device 10. Through this connection, the control circuit 20 is grounded via the ground wire 21 and the GND terminal 22.

[0028] The drive circuit 30 uses the operating power supply 25 supplied from the control circuit 20 and operates according to the control signal 26 from the control circuit 20. The drive circuit 30 has a high-side switching element 40 and a low-side switching element 45 connected in series between the power supply terminal 16 and the GND terminal 32. Using these switching elements, the conduction and cutoff of the load current supplied from the vehicle battery (not shown) to the load 50, as well as the conduction path, are switched. By setting the high-side switching element 40 to the ON state and the low-side switching element 45 to the OFF state, the power supply terminal 16 and the LOAD output 47 connected to the load 50 are connected with low loss. By setting the low-side switching element 45 to the ON state and the high-side switching element 40 to the OFF state, the GND terminal 32 and the LOAD output 47 are connected with low loss. Thus, the conduction and cutoff of the load current flowing in the load 50, as well as the conduction path of the load current, can be switched.

[0029] The drive circuit 30 includes a switching element control circuit 35. Based on the control signal 26 from the control circuit 20, the switching element control circuit 35 outputs switching control signals 36 and 37 to the high-side switching element 40 and the low-side switching element 45, respectively. This allows the high-side switching element 40 and the low-side switching element 45 to be switched to an ON or OFF state, respectively, to control the load current as described above.

[0030] The drive circuit 30 is connected to the ground wire 31, which is connected to the common ground wire of the electronic control device 1 located outside the integrated circuit device 10 via the GND terminal 32. Through this connection, the drive circuit 30 is grounded via the ground wire 31 and the GND terminal 32.

[0031] Generally, loads such as load 50, which are controlled by electronic control devices for vehicles, require an ampere-level current supply. In this embodiment, in order to prevent performance degradation or malfunction of the control circuit 20 caused by ground noise generated by this current, the ground wire 21 of the control circuit 20 and the ground wire 31 of the drive circuit 30 are separated within the integrated circuit device 10.

[0032] These grounding wires are connected to the common ground wire of the electronic control device 1 via different GND terminals 22 and 32, as described above.

[0033] A rectifier circuit 60 is connected between ground wire 21 and ground wire 31. In the integrated circuit device 10 of this embodiment, from the viewpoint of electrostatic discharge protection between ground wires 21 and 31, which are independently connected to a common ground wire, a rectifier circuit 60 is inserted between these ground wires. The rectifier circuit 60 is constructed using rectifier elements 61 and 62, such as diodes, connected in reverse order, and has a bidirectional rectification function. As a result, if a ground wire and a common ground wire become open-circuited (non-conductive) due to poor connection of GND terminals 22 and 32, and a constant potential difference is generated between the ground wires, current flows from the ground wire on the high potential side through the rectifier circuit 60 to the ground wire on the low potential side, releasing charge.

[0034] Furthermore, in the event that the potential of grounding wire 21 and / or grounding wire 31 rises due to poor connection of GND terminals 22 and 32, a protection diode may be configured on the input side of the control signal 26, which serves as the interface between them, in order to protect the control circuit 20 and the drive circuit 30. Figure 2 This diagram illustrates an example where a protection diode is configured on the input side of control signal 26. Figure 2 In the example, in the control circuit 20 and the drive circuit 30, protection diodes 65 and 66 are respectively configured between the control signal 26 and the ground lines 21 and 31.

[0035] Here, in the normal state where grounding wires 21 and 31 and the common ground of electronic control device 1 are in a conducting state via GND terminals 22 and 32, almost no current flows in the rectifier circuit 60 and the protection diodes 65 and 66. In this case, the current consumed by the control circuit 20 flows from grounding wire 21 to the common ground via GND terminal 22. Additionally, the current consumed by the drive circuit 30 flows from grounding wire 31 to the common ground via GND terminal 32.

[0036] The load terminal 51, opposite to the one connected to the LOAD output 47, is connected to either the vehicle battery or the common ground. When the load terminal 51 is connected to the vehicle battery, the current consumed by the switching element control circuit 35, or the load current supplied to the load 50 by switching the low-side switching element 45 to the ON state, flows into the ground wire 31 while the drive circuit 30 is operating. Conversely, when the load terminal 51 is connected to the common ground, the current consumed by the switching element control circuit 35 flows into the ground wire 31 while the drive circuit 30 is operating by switching the high-side switching element 40 to the OFF state. In these states, if the connection between the ground wire 31 and the common ground is broken due to a poor connection at the GND terminal 32, and the ground wire 31 becomes an open circuit, the current flowing into the ground wire 31 will not flow out to the common ground via the GND terminal 32, and the potential of the ground wire 31 will rise. As a result, a forward bias voltage is applied to the rectifier element 62 in the direction from the ground wire 31 towards the ground wire 21. The rectifier element 62 causes the current corresponding to the positive voltage to flow from the ground wire 31 to the ground wire 21, and releases it to the common ground wire of the electronic control device 1 via the GND terminal 22. In other words, the rectifier element 62 generates voltage by causing current to flow from the ground wire 31 to the ground wire 21, and operates in a way that creates a potential difference between the ground wire 31 and the ground wire 21.

[0037] Therefore, the diagnostic circuit 70 diagnoses the grounding state of grounding wire 31 by measuring the potential difference between grounding wire 31 and grounding wire 21 and determining whether this potential difference corresponds to the positive voltage generated in the rectifier element 62. The diagnostic circuit 70 is constructed using a monitoring circuit 71 and a comparison judgment circuit 74. The monitoring circuit 71 measures the potential difference between grounding wire 31 and grounding wire 21 and outputs the measurement result as a monitoring circuit output 72. The comparison judgment circuit 74 compares the monitoring circuit output 72 from the monitoring circuit 71 with a predetermined comparison voltage 73 and outputs the comparison result as a diagnostic result 75 for the grounding state of grounding wire 31. Specifically, if the monitoring circuit output 72 is below the comparison voltage 73, the grounding state of grounding wire 31 is determined to be normal, and this determination result is output as a diagnostic result 75. On the other hand, if the monitoring circuit output 72 is greater than the comparison voltage 73, the grounding state of grounding wire 31 is determined to be abnormal, with an open circuit caused by a poor connection of the GND terminal 32 in grounding wire 31, and this determination result is output as a diagnostic result 75.

[0038] The diagnostic result 75 output from the comparison and judgment circuit 74 of the diagnostic circuit 70 is input to the control circuit 20. The control circuit 20 records the diagnostic result 75 and outputs it to other devices (not shown) located separately from the integrated circuit device 1 within the electronic control device 1, or implements safety measures prescribed based on the diagnostic result 75. For example, if a diagnostic result 75 indicating an abnormal grounding state of the grounding wire 31 is input, the drive circuit 30 is stopped, and the supply of load current to the load 50 is cut off.

[0039] Here, in the comparison voltage 73 of the diagnostic circuit 70, it is preferable to set a value larger than the potential difference generated between ground wire 31 and ground wire 21 when the grounding state of ground wire 31 is normal. As mentioned above, the load current supplied from the integrated circuit device 10 to the load 50 sometimes reaches the ampere level. Therefore, even when the grounding state of ground wire 31 is normal, a potential rise in ground wire 31 occurs due to parasitic impedance between ground wire 31 and GND terminal 32, and from GND terminal 32 to the common ground wire. For example, if there is a parasitic impedance of 0.1Ω, a potential rise of 200mV is generated in ground wire 31 for a load current of 2A. It is necessary to sufficiently increase the comparison voltage 73 so as not to falsely detect it as an open circuit failure. Furthermore, although not specifically in Figure 1 The diagram is shown in the figure. However, in order to remove spike noise generated in the grounding wire 31 due to instantaneous current fluctuations, or noise generated during control switching, a filter circuit can be added after the comparison and judgment circuit 74.

[0040] The diagnostic current supply circuit 90 is connected to the ground wire 31 and supplies a predetermined diagnostic current to the ground wire 31. When the integrated circuit device 10 is not controlling the load 50 and the drive circuit 30 is stopped, no current is consumed in the switching element control circuit 35. Therefore, the current flowing from the switching element control circuit 35 into the ground wire 31 is zero or minimal. Therefore, even when the ground wire 31 is open, sometimes a sufficient potential difference is not generated between the ground wire 31 and the ground wire 21, and open-circuit defects cannot be reliably detected in the diagnostic circuit 70. Therefore, in this embodiment, by providing a diagnostic current supply circuit 90 within the integrated circuit device 10 and supplying a predetermined diagnostic current to the ground wire 31 from this diagnostic current supply circuit 90, a sufficient potential difference is generated between the ground wire 31 and the ground wire 21 regardless of the operating state of the drive circuit 30 when the ground wire 31 is open, enabling reliable detection of open-circuit defects in the diagnostic circuit 70.

[0041] Considering the potential damage to other devices within the integrated circuit device 10 or electronic control device 1, it is preferable to detect open circuit defects in the grounding wire 31 before the integrated circuit device 10 begins controlling the load current supplied to the load 50. In this embodiment, by providing a diagnostic current supply circuit 90 within the integrated circuit device 10, open circuit defects can be accurately detected in the diagnostic circuit 70 regardless of the operating state of the drive circuit 30, as described above. Therefore, there is the advantage of ensuring a normal grounding state for the grounding wire 31 before the load current flows to the load 50.

[0042] (Compare voltages)

[0043] Next, the comparison voltage 73 in the diagnostic circuit 70 will be explained. As described above, if the grounding wire 31 becomes open-circuited due to a poor connection of the GND terminal 32, a potential difference corresponding to the forward voltage of the rectifier element 62 will be generated between the grounding wire 31 and the grounding wire 21. On the other hand, even when the grounding state of the grounding wire 31 is normal, a potential rise corresponding to the parasitic impedance between the grounding wire 31 and the GND terminal 32, and from the GND terminal 32 to the common ground wire, will occur in the grounding wire 31. Therefore, in order for the diagnostic circuit 70 to accurately detect the poor open circuit of the grounding wire 31, the comparison voltage 73 needs to be set to a value that is smaller than the forward voltage of the rectifier element 62 and sufficiently larger than the potential rise caused by the parasitic impedance.

[0044] Figure 3 This is a diagram illustrating an example of the electrical characteristics of rectifier element 62. Figure 3 In the figures, the solid line graph indicated by reference numeral 101 shows the relationship between the forward voltage and forward current of the rectifier element 62 at standard temperature. Conversely, the dashed line graph indicated by reference numeral 102 shows the relationship between the forward voltage and forward current of the rectifier element 62 at low temperature, and the dashed line graph indicated by reference numeral 103 shows the relationship between the forward voltage and forward current of the rectifier element 62 at high temperature. In these graphs, the horizontal axis represents the forward current value, and the vertical axis represents the forward voltage value.

[0045] like Figure 3 As shown in Figures 101-103, the larger the forward current and the lower the temperature, the larger the forward voltage generated in the rectifier element 62. That is, the forward voltage of the rectifier element 62 has both current-dependent and temperature-dependent characteristics. Therefore, taking these relationships into account, the value of the comparison voltage 73 is set such that the minimum forward current flowing in the rectifier element 62 when the ground wire 31 is open is greater than the minimum value of the forward voltage generated in the rectifier element 62.

[0046] For example, if the minimum forward current flowing in rectifier element 62 is 100 μA, according to Figure 3The intersection of the dotted line 103 and the dashed line 104 is used to set the comparison voltage 73 to below 0.4V. If the potential difference between the ground wire 31 and the ground wire 21 measured by the monitoring circuit 71 is greater than the set value of the comparison voltage 73, it can be determined that the ground wire 31 is open-circuited.

[0047] Therefore, it can be seen that the presence or absence of an open circuit in the grounding wire 31 can be accurately detected based on the positive current and temperature within the specified range.

[0048] However, even when the same forward current is applied to the rectifier element 62 at the same temperature, variations in the manufacturing process can cause individual differences in the forward voltage generated in the rectifier element 62. Therefore, it is preferable to take these individual differences into account when determining the set value of the comparison voltage 73. For example, a semiconductor element manufactured using the same process as the rectifier element 62 is placed in the diagnostic circuit 70, and the comparison voltage 73 is generated by the voltage when the same forward current as the rectifier element 62 flows through that semiconductor element. By using the comparison voltage 73 thus generated, the comparison voltage 73 can be changed according to the temperature of the rectifier element 62 based on the temperature dependence of the forward voltage of the rectifier element 62. As a result, a diagnostic circuit 70 with high tolerance to individual differences or temperature dependence of the rectifier element 62 can be realized.

[0049] (Diagnostic current)

[0050] Next, the diagnostic current supplied by the diagnostic current supply circuit 90 to the grounding wire 31 will be explained.

[0051] In the integrated circuit device 10, when the grounding state of the grounding wire 31 is normal, the diagnostic current supplied from the diagnostic current supply circuit 90 to the grounding wire 31 becomes a useless draining current flowing from the grounding wire 31 through the GND terminal 32 to the common ground wire of the electronic control device 1. Therefore, it is preferable that when the grounding wire 31 is open, the diagnostic current supply circuit 90 supplies the minimum current required to generate a potential difference of at least a comparison voltage 73 between the grounding wire 31 and the grounding wire 21 as the diagnostic current.

[0052] Here, the value of the diagnostic current supplied by the diagnostic current supply circuit 90 can be changed according to the operating state of the drive circuit 30 or the implementation status of the open-circuit diagnosis performed by the diagnostic circuit 70. For example, when the drive circuit 30 is operating, if a potential difference of comparison voltage 73 or more is obtained between the ground wire 31 and the ground wire 21 through the forward voltage of the rectifier element 62 corresponding to its consumed current, the diagnostic current supply circuit 90 is stopped, and the diagnostic current is set to 0. On the other hand, if the drive circuit 30 stops operating or if a potential difference of comparison voltage 73 or more cannot be obtained between the ground wire 31 and the ground wire 21 with the consumed current of the drive circuit 30, a diagnostic current corresponding to the amount of insufficient current is supplied from the diagnostic current supply circuit 90. Moreover, by stopping the diagnostic current supply circuit 90 when the diagnostic circuit 70 is not performing open-circuit diagnosis, the diagnostic current is supplied only when diagnosis is performed. Accordingly, further efficiency improvements can be achieved.

[0053] (Switching element)

[0054] Next, the structures of the high-side switching element 40 and the low-side switching element 45 will be described. Generally, the high-side switching element 40 and the low-side switching element 45, which are mounted in the integrated circuit device 10 and used for load current control, are constructed using MOS transistors.

[0055] Figure 4 This is a diagram illustrating an example structure of a switching element based on a MOS transistor. For example... Figure 4 As shown, parasitic diodes 41 and 46 are formed from the low side to the high side in the high-side switching element 40 and low-side switching element 45, which are composed of MOS transistors. Furthermore, in Figure 4 In the middle, the portion other than the high-side switching element 40 and the low-side switching element 45 is... Figure 1 The structural diagram of the integrated circuit device 10 shown is the same.

[0056] Because the low-side switching element 45 has a parasitic diode 46, even when the low-side switching element 45 is in the OFF state, a current path sometimes forms from the ground wire 31 through the parasitic diode 46, and then through the LOAD output 47 and the load 50 to the common ground wire when the connection destination of the load terminal 51 is a common ground wire. At this time, the positive voltage generated by the current flowing in the parasitic diode 46, which does not flow in the rectifier element 62, dominates the potential difference between the ground wire 31 and the ground wire 21.

[0057] Therefore, when the load 50 is an inductive load solenoid and the load terminal 51 is connected to a common ground wire, and the diagnostic circuit 70 performs open-circuit diagnosis while the drive circuit 30 is in a stopped state, a diagnostic current set according to the forward voltage and current characteristics of the parasitic diode 46 is supplied from the diagnostic current supply circuit 90. Thus, when the grounding state of the grounding wire 31 is open, the potential difference generated between the grounding wire 31 and the grounding wire 21 due to the current flowing in the parasitic diode 46 is set to a comparison voltage 73 or higher, allowing the diagnostic circuit 70 to accurately detect open-circuit defects in the grounding wire 31.

[0058] (Method for detecting open circuit defects when the load terminal is connected to the common ground wire)

[0059] Next, refer to Figure 5 A method for detecting open-circuit defects when the load terminal 51 is connected to the common ground wire is described. Furthermore, in the following description, the integrated circuit device 10 has… Figure 4 In the drive circuit 30, the switching element control circuit 35, based on the control signal 26 from the control circuit 20, repeatedly and complementaryly switches the high-side switching element 40 and the low-side switching element 45 to the ON or OFF state at a certain period. Additionally, the load 50 is a solenoid for sensing loads, and the load terminal 51 is connected to a common ground wire.

[0060] exist Figure 5 In the accompanying drawing, reference numeral 111 indicates a state where the integrated circuit device 10 has not yet started controlling the load 50 and the drive circuit 30 has stopped operating. In this state, the current consumption of the switching element control circuit 35 is 0, and both the high-side switching element 40 and the low-side switching element 45 are in the OFF state. At this time, the diagnostic current from the diagnostic current supply circuit 90 flows into the ground wire 31.

[0061] In state 111 described above, a connection abnormality occurs between GND terminal 32 and the common ground, causing grounding wire 31 to be open-circuited. In this case, as shown by the dashed lines in the figure, the diagnostic current flowing into grounding wire 31 flows separately to the current path via rectifier element 62, grounding wire 21, and GND terminal 22 to the common ground; and to the current path via parasitic diode 46 of low-side switching element 45, LOAD output 47, and load 50 to the common ground.

[0062] The low-side switching element 45 requires a large current in the ampere range to serve as the return current for the load 50, and therefore is larger in size compared to the rectifier element 62. Consequently, when comparing the magnitude of the current flowing relative to the same forward voltage in the parasitic diode 46 within the low-side switching element 45 and the rectifier element 62, the parasitic diode 46 is larger than the rectifier element 62. Therefore, most of the diagnostic current flowing into the ground wire 31 flows through the parasitic diode 46, the LOAD output 47, and the load 50 to the common ground wire. At this time, the potential difference generated between the ground wire 31 and the ground wire 21 is approximately equal to the forward voltage of the parasitic diode 46 relative to the diagnostic current.

[0063] As explained above, if load terminal 51 is connected to a common ground wire, and ground wire 31 becomes open-circuited when drive circuit 30 is in a stopped state, a potential difference approximately equal to the forward voltage of parasitic diode 46 corresponding to the diagnostic current is generated between ground wire 31 and ground wire 21. In the diagnostic current supply circuit 90, the value of the diagnostic current needs to be set so that the diagnostic circuit 70 can detect this potential difference as an abnormal grounding condition of ground wire 31. For example, based on the characteristics of the forward voltage and current of parasitic diode 46, a current value at which the forward voltage of parasitic diode 46 becomes a comparison voltage 73 or higher is pre-calculated and stored in the diagnostic current supply circuit 90. When drive circuit 30 is stopped, this value is set as the diagnostic current setting, and diagnostic current is supplied from the diagnostic current supply circuit 90 to ground wire 31. Therefore, when ground wire 31 becomes open-circuited, because a potential difference at a comparison voltage 73 or higher is generated between ground wire 31 and ground wire 21, the diagnostic circuit 70 can accurately detect the open-circuit fault of ground wire 31.

[0064] exist Figure 5 In the figure, reference numeral 112 indicates the following state: the integrated circuit device 10 activates the drive circuit 30, controlling the load 50 and supplying load current to the load 50 from a vehicle battery (not shown). In this state, the high-side switch element 40 is switched from OFF to ON by the switch element control circuit 35, thereby supplying load current to the load 50 from the vehicle battery (not shown) via power terminal 16, high-side switch element 40, and LOAD output 47, as shown by the dashed line in the figure. At this time, a diagnostic current from the diagnostic current supply circuit 90 is applied to the ground wire 31, and the current consumption of the switch element control circuit 35 flows in.

[0065] In state 112 described above, a connection abnormality occurs between GND terminal 32 and the common ground wire, causing ground wire 31 to be open-circuited. In this case, as shown by the dashed line in the figure, the current flowing into ground wire 31 flows through the rectifier element 62, ground wire 21, and GND terminal 22 to the common ground wire. Therefore, a potential difference is generated between ground wire 31 and ground wire 21, corresponding to the forward voltage of rectifier element 62 relative to the sum of the diagnostic current and the current consumed by the switching element control circuit 35.

[0066] Furthermore, in the aforementioned state, because the high-side switching element 40 is ON, the potential of the LOAD output 47 reaches the same level as the power supply terminal 16. Therefore, the parasitic diode 46 is not forward biased by the current flowing into the ground wire 31, and no current path is formed from the ground wire 31 to the load 50.

[0067] As explained above, if the load terminal 51 is connected to the common ground wire, and the ground wire 31 becomes an open circuit when the high-side switching element 40 switches to the ON state and the low-side switching element 45 switches to the OFF state during the operation of the drive circuit 30, a potential difference equivalent to the forward voltage of the rectifier element 62 is generated between the ground wire 31 and the ground wire 21. The forward voltage of the rectifier element 62 corresponds to the sum of the diagnostic current and the current consumed by the switching element control circuit 35. Therefore, in the diagnostic current supply circuit 90, the value of the diagnostic current is set so that the diagnostic circuit 70 can detect this potential difference as an abnormal grounding state of the ground wire 31. Furthermore, if a sufficient potential difference is obtained through the current consumed by the switching element control circuit 35, the diagnostic current supply circuit 90 can be stopped, and the diagnostic current can be set to 0.

[0068] exist Figure 5 In the figure, reference numeral 113 indicates the following state: the integrated circuit device 10 activates the drive circuit 30 to control the load 50, cutting off the load current supply from the vehicle battery (not shown) to the load 50. In this state, the switching element control circuit 35 switches the high-side switching element 40 from the ON state to the OFF state and the low-side switching element 45 from the OFF state to the ON state, cutting off the load current supplied from the vehicle battery to the load 50. At this time, since the load 50 is an inductive load, the energy stored in the load 50 is released. As shown by the dashed line in the figure, the return current flows from the ground wire 31 through the low-side switching element 45 and the LOAD output 47 to the load 50. As a result, the potential of the LOAD output 47 decreases.

[0069] In addition, Figure 5The diagram is omitted, but during the transition from state 112 to state 113, a dead time is set for both the high-side switching element 40 and the low-side switching element 45 to switch to the OFF state. During this dead time, the return current flows from the ground wire 31 through the parasitic diode 46 of the low-side switching element 45 to the load 50.

[0070] In state 113 described above, a connection anomaly occurs between GND terminal 32 and the common ground wire, and ground wire 31 becomes an open circuit. In this case, the return path from the common ground wire through GND terminal 32 to ground wire 31 is shut off, and the potential of ground wire 31 decreases along with LOAD output 47. As a result, a forward bias voltage is applied to rectifier element 61 from ground wire 21 to ground wire 31, and the current corresponding to this forward voltage flows in rectifier element 61. As a result, as shown by the dashed line in the figure, the return current flows from the common ground wire through GND terminal 22, ground wire 21, ground wire 31, low-side switching element 45, and LOAD output 47 to load 50.

[0071] The diagnostic circuit 70 determines an abnormal grounding condition of the grounding wire 31 by detecting a rise in the potential of the grounding wire 31 relative to the potential of the grounding wire 21. Here, after switching the high-side switching element 40 from state 112 to OFF and the low-side switching element 45 to ON to transition to state 113, as described above, the potential of the LOAD output 47 decreases, thereby also decreasing the potential of the grounding wire 31. Furthermore, in state 113, the grounding wire 31 is connected to the common ground wire via the low-side switching element 45 and the load 50; therefore, the potential of the grounding wire 31 converges to the ground wire level over time. Therefore, even if the grounding wire 31 becomes open in state 113, the diagnostic circuit 70 cannot detect an abnormal grounding condition of the grounding wire 31. However, in the implementation of load current control by the integrated circuit device 10, the high-side switching element 40 and the low-side switching element 45 periodically switch ON and OFF, respectively, thus alternating between states 112 and 113. Therefore, it is possible to detect abnormal grounding status of grounding wire 31 in state 112 without causing any operational problems.

[0072] (Method for detecting open circuit defects when connecting load terminals to vehicle batteries)

[0073] Next, refer to Figure 6 The method for detecting open-circuit defects when the load terminal 51 is connected to a vehicle battery (not shown) is explained. Furthermore, the following description also relates to... Figure 5 Similarly, integrated circuit device 10 has Figure 4In the drive circuit 30, the switching element control circuit 35, based on the control signal 26 from the control circuit 20, repeatedly and complementaryly switches the high-side switching element 40 and the low-side switching element 45 to the ON or OFF state at a certain period. Additionally, the load 50 is a solenoid for inductive loads, connecting the load terminal 51 to a vehicle battery (not shown).

[0074] exist Figure 6 In the accompanying drawing, reference numeral 121 indicates a state where the integrated circuit device 10 has not yet started controlling the load 50 and the drive circuit 30 has stopped operating. In this state, the current consumption of the switching element control circuit 35 is 0, and both the high-side switching element 40 and the low-side switching element 45 are in the OFF state. At this time, the diagnostic current from the diagnostic current supply circuit 90 flows into the ground wire 31.

[0075] In state 121 described above, a connection abnormality occurs between GND terminal 32 and the common ground wire, causing ground wire 31 to be open-circuited. In this case, as shown by the dashed line in the diagram, the diagnostic current flowing into ground wire 31 flows through the rectifier element 62, ground wire 21, and GND terminal 22 to the common ground wire. Therefore, a potential difference equivalent to the forward voltage of the rectifier element 62 relative to the diagnostic current is generated between ground wire 31 and ground wire 21. Therefore, in the diagnostic current supply circuit 90, the value of the diagnostic current is set such that the diagnostic circuit 70 can detect this potential difference as an abnormal grounding state of ground wire 31. Furthermore, the value of the diagnostic current at this time can be set to be higher than... Figure 5 The required diagnostic current is small under state 111.

[0076] exist Figure 6 In the accompanying drawing, reference numeral 122 indicates the following state: the integrated circuit device 10 activates the drive circuit 30, controlling the load 50 and supplying load current to the load 50 from a vehicle battery (not shown). In this state, the low-side switching element 45 is switched from OFF to ON by the switching element control circuit 35, thereby allowing the load current supplied to the load 50 from the vehicle battery (not shown) to flow into the ground wire 31 via the LOAD output 47 and the low-side switching element 45. Furthermore, the diagnostic current from the diagnostic current supply circuit 90 and the current consumed by the switching element control circuit 35 also flow into the ground wire 31.

[0077] In state 122 described above, a connection abnormality occurs between GND terminal 32 and the common ground wire, causing ground wire 31 to be open-circuited. In this case, as shown by the dashed line in the figure, the current flowing into ground wire 31 flows through the rectifier element 62, ground wire 21, and GND terminal 22 to the common ground wire. Therefore, a potential difference is generated between ground wire 31 and ground wire 21, corresponding to the forward voltage of rectifier element 62 relative to the sum of the load current, diagnostic current, and the current consumed by the switching element control circuit 35. Therefore, in the diagnostic current supply circuit 90, the value of the diagnostic current is set such that the diagnostic circuit 70 can detect this potential difference as an abnormal grounding state of ground wire 31. Generally, since the load current is large enough, the value of the diagnostic current can be set to 0.

[0078] exist Figure 6 In the figure, reference numeral 123 indicates the following state: the integrated circuit device 10 activates the drive circuit 30 to control the load 50, cutting off the load current supply from the vehicle battery (not shown) to the load 50. In this state, the high-side switch element 40 is switched from OFF to ON by the switch element control circuit 35, and the low-side switch element 45 is switched from ON to OFF, thereby cutting off the load current supplied from the vehicle battery to the load 50. At this time, since the load 50 is an inductive load, the energy stored in the load 50 is released. As shown by the dashed line in the figure, the return current flows between the vehicle battery and the load 50 via the high-side switch element 40 and the power terminal 16. In addition, besides the diagnostic current from the diagnostic current supply circuit 90, the current consumed by the switch element control circuit 35 also flows into the ground wire 31.

[0079] In state 123 described above, a connection abnormality occurs between GND terminal 32 and the common ground wire, causing ground wire 31 to be set as an open circuit. In this case, as shown by the dashed line in the figure, the current flowing into ground wire 31 flows through the rectifier element 62, ground wire 21, and GND terminal 22 to the common ground wire. Therefore, a potential difference is generated between ground wire 31 and ground wire 21, corresponding to the forward voltage of rectifier element 62 relative to the sum of the diagnostic current and the current consumed by the switching element control circuit 35. Therefore, in the diagnostic current supply circuit 90, the value of the diagnostic current is set such that the diagnostic circuit 70 can detect this potential difference as an abnormal grounding state of ground wire 31. If a sufficient potential difference is obtained through the current consumed by the switching element control circuit 35, the diagnostic current supply circuit 90 can also be stopped, and the diagnostic current can be set to 0.

[0080] Furthermore, in the aforementioned state, because the high-side switching element 40 is ON, the potential of the LOAD output 47 reaches the same level as that of the power supply terminal 16. Therefore, no forward bias is applied to the parasitic diode 46 due to the current flowing into the ground wire 31, and no current path is formed from the ground wire 31 to the load 50.

[0081] As explained above, when the load terminal 51 is connected to the vehicle's battery, even if the drive circuit 30 is stopped or in operation, the potential of the LOAD output 47 is not lower than that of the ground wire 31, and no forward bias is applied to the parasitic diode 46. Therefore, if the ground wire 31 becomes open due to an abnormal connection of the GND terminal 32, the current flowing into the ground wire 31 flows out through the rectifier element 62 to the ground wire 21 and is released from the GND terminal 22 to the common ground wire. Therefore, if the diagnostic current supplied by the diagnostic current supply circuit 90 ensures the current flowing into the ground wire 31, open circuit detection can be performed in the diagnostic circuit 70 regardless of the operating state of the drive circuit 30.

[0082] According to the first embodiment of the present invention described above, regardless of the connection destination of the load terminal 51 and the operating state of the drive circuit 30, the grounding state diagnosis of the grounding wire 31 can be performed more easily and reliably, and open circuit failure detection can be performed. Therefore, because abnormalities can be detected early, it is possible to suppress the operation of the integrated circuit device 10 under abnormal conditions with high losses, and to prevent damage to the integrated circuit device 10 or other devices mounted on the electronic control device 1.

[0083] According to the first embodiment of the present invention described above, the following effects are achieved.

[0084] (1) The integrated circuit device 10 is connected to the load 50 to control the load current supplied to the load 50. The integrated circuit device 10 includes a drive circuit 30, a control circuit 20 that controls the operation of the drive circuit 30, ground wires 21 and 31, a diagnostic current supply circuit 90, bidirectional rectifier elements 61 and 62, and a diagnostic circuit 70. The drive circuit 30 has switching elements 40 and 45, which are used to switch the load current on and off. The ground wire 31 is grounded to a common ground wire located outside the integrated circuit device 10 via a GND terminal 32 and is connected to the drive circuit 30. The ground wire 21 is grounded to the common ground wire via a GND terminal 22 and is connected to the control circuit 20. The diagnostic current supply circuit 90 supplies a specified diagnostic current to the ground wire 31. The rectifier elements 61 and 62 are connected between the ground wire 21 and the ground wire 31. The diagnostic circuit 70 measures the potential difference between the ground wire 31 and the ground wire 21 and compares this potential difference with a specified comparison voltage 73 to diagnose the grounding state of the ground wire 31. Therefore, regardless of the connection status of the load 50 or the operating status of the drive circuit 30, it is possible to perform accurate and reliable open-circuit fault detection on the ground wire 31 of the integrated circuit device 10.

[0085] (2) The switching elements of the drive circuit 30 include a high-side switching element 40 and a low-side switching element 45, which can be switched to ON or OFF states respectively. The drive circuit 30 uses the high-side switching element 40 to turn on or off the load current between the vehicle battery supplying the load current and the load 50, and uses the low-side switching element 45 to turn on or off the load current between the ground wire 31 and the load 50. The control circuit 20 repeatedly controls the drive circuit 30 to alternately and complementaryly switch the high-side switching element 40 and the low-side switching element 45 to ON or OFF states. Therefore, the load current flowing in the load 50 can be appropriately controlled by the integrated circuit device 10.

[0086] (3) The high-side switching element 40 and the low-side switching element 45 are, for example, constructed using MOS transistors. Therefore, the high-side switching element 40 and the low-side switching element 45 for controlling the load current flowing in the load 50 can be easily implemented at a reasonable cost.

[0087] (4) The diagnostic current supply circuit 90 can change the diagnostic current according to the operating state of the drive circuit 30. Accordingly, unnecessary current consumption can be reduced, thereby improving efficiency.

[0088] (5) The diagnostic circuit 70 can change the comparison voltage according to the temperature of the rectifier element 62 based on the temperature dependence of the forward voltage of the rectifier element 62. Accordingly, the grounding status of the grounding wire 31 can also be accurately diagnosed in response to temperature changes.

[0089] (6) If the diagnostic circuit 70 diagnoses an abnormal grounding condition of the grounding wire 31, the control circuit 20 can also stop the operation of the drive circuit 30. Accordingly, safety can be ensured in the event that the grounding wire 31 becomes an open circuit due to poor connection of the GND terminal 32, etc.

[0090] (Second Implementation)

[0091] The following is for reference Figure 7 The second embodiment of the present invention will be described.

[0092] Figure 7 This is a structural diagram of an integrated circuit device according to a second embodiment of the present invention. The integrated circuit device 10A of this embodiment is similarly provided in the electronic control device 1 of a vehicle system such as an automobile, as described in the first embodiment, and is connected to a load 50 such as a solenoid to control the load current supplied to the load 50.

[0093] In the integrated circuit device 10A of this embodiment, a diagnostic circuit 70A is provided instead of the diagnostic circuit 70 of the integrated circuit device 10 described in the first embodiment. The diagnostic circuit 70A has the same structure as the diagnostic circuit 70, except that an input polarity switching unit 76 is provided on the input side of the monitoring circuit 71.

[0094] The input polarity switching unit 76 switches the polarity of the voltage input to the monitoring circuit 71 based on the switching status signal 38 output from the switching element control circuit 35. The switching status signal 38 indicates the switching state of the high-side switching element 40 and the low-side switching element 45. Specifically, when the load terminal 51 is connected to a common ground, the input polarity switching unit 76 switches the polarity of the input voltage to the monitoring circuit 71 when the high-side switching element 40 is switched to OFF and the low-side switching element 45 is switched to ON. Thus, as described in the first embodiment... Figure 5 In state 113, when a connection abnormality occurs between GND terminal 32 and common ground wire and ground wire 31 becomes open circuit, monitoring circuit 71 can detect the potential difference between ground wire 21 and ground wire 31 based on the positive voltage generated in rectifier element 61 and compare it with comparison voltage 73.

[0095] As explained above, according to the second embodiment of the present invention, the load 50 is connected between the drive circuit 30 and the common ground. When the high-side switching element 40 switches from the ON state to the OFF state, the diagnostic circuit 70A reverses the polarity of the potential difference between the ground wire 31 and the ground wire 21 and compares it with the comparison voltage 73. Therefore, even when the load terminal 51 is connected to the common ground and the supply of load current from the vehicle battery to the load 50 is turned off, and the return current flows in the load 50, the grounding status of the ground wire 31 can be diagnosed.

[0096] Furthermore, in the embodiments described above, a representative example of a drive circuit 30 and a load 50 is presented for ease of understanding of the invention, but multiple examples may exist. Regardless of the number of drive circuits 30 and loads 50, the invention can be applied using the same structure. Additionally, in each embodiment, control lines or signal lines are used in the description to indicate lines deemed necessary, but may not necessarily represent all control lines or signal lines in the product.

[0097] The embodiments and variations described above are merely examples, and the invention is not limited to these descriptions as long as they do not impair the characteristics of the invention. Furthermore, while various embodiments and variations have been described above, the invention is not limited to these descriptions. Other methods considered within the scope of the technical concept of the invention are also included within the scope of the invention.

[0098] Explanation of reference numerals in the attached figures

[0099] 1 Electronic control device

[0100] 10. 10A Integrated Circuit Device

[0101] 15 and 16 power terminals

[0102] 20 Control Circuit

[0103] 21 Grounding wire

[0104] 22 GND terminal

[0105] 30. Drive circuit

[0106] 31 Grounding wire

[0107] 32 GND terminal

[0108] 35 Switching element control circuit

[0109] 40 High-side switching element

[0110] 41 Parasitic Diode

[0111] 45 Low-side switching element

[0112] 46 Parasitic Diode

[0113] 47 LOAD output

[0114] 50 load

[0115] 51 Load Terminal

[0116] 60 Rectifier Circuit

[0117] 61, 62 rectifier components

[0118] 65, 66 protection diodes

[0119] 70, 70A Diagnostic Circuit

[0120] 71 Monitoring Circuit

[0121] 72 Monitoring circuit output

[0122] 73 Comparison Voltage

[0123] 74 Comparison and Judgment Circuit

[0124] 75. Diagnostic Results

[0125] 76 Input polarity switching unit

[0126] 90 Diagnostic current supply circuit.

Claims

1. An integrated circuit device connected to a load to control the load current supplied to the load, characterized in that, include: A drive circuit with a switching element, which uses the switching element to switch the load current on and off; A control circuit that controls the operation of the drive circuit; The first grounding wire connected to the drive circuit is connected to a common grounding wire disposed outside the integrated circuit device via a first grounding connection terminal; The second grounding wire, which is connected to the control circuit, is connected to the common grounding wire via a second grounding wire connection terminal. A diagnostic current supply circuit that supplies a specified diagnostic current to the first grounding wire; A bidirectional rectifier element connected between the first grounding wire and the second grounding wire; and The diagnostic circuit measures the potential difference between the first grounding wire and the second grounding wire, and compares the potential difference with a specified comparison voltage to diagnose the grounding status of the first grounding wire. The switching element includes a high-side switching element and a low-side switching element capable of switching to an ON or OFF state, respectively. The drive circuit uses the high-side switching element to turn the load current on or off between the power supply supplying the load current and the load, and uses the low-side switching element to turn the load current on or off between the first ground wire and the load. The control circuit repeatedly controls the drive circuit to alternately and complementaryly switch the high-side switching element and the low-side switching element to the ON or OFF state.

2. The integrated circuit device according to claim 1, characterized in that: The high-side switching element and the low-side switching element are constructed using MOS transistors.

3. The integrated circuit device according to claim 1, characterized in that: The diagnostic current supply circuit changes the diagnostic current in accordance with the operating state of the drive circuit.

4. The integrated circuit device according to claim 1, characterized in that: The diagnostic circuit adjusts the comparison voltage in accordance with the temperature of the rectifier element, based on the temperature dependence of the forward voltage of the rectifier element.

5. The integrated circuit device according to claim 1, characterized in that: The load is an inductive load. The load is connected between the drive circuit and the common ground. When the high-side switching element is switched from the ON state to the OFF state, the diagnostic circuit reverses the polarity of the potential difference to compare it with the comparison voltage.

6. The integrated circuit device according to claim 1, characterized in that: If the diagnostic circuit diagnoses an abnormal grounding state of the first grounding wire, the control circuit stops the operation of the drive circuit.

7. The integrated circuit device according to claim 1, characterized in that: The load is a solenoid used to operate the vehicle's automatic transmission. The automatic transmission is controlled by controlling the load current flowing in the solenoid.

Images