Automotive semiconductor circuits and semiconductor circuits

Abstract

A semiconductor circuit connected to a load circuit and controlling the power supply to the load circuit comprises: a power line to which a power supply voltage is applied; an overvoltage protection unit having an output unit for cutting off the power supply from the power line to the load circuit when the power supply voltage of the power line is overvoltage; and a status notification unit for notifying the outside of a status signal indicating whether the output unit has cut off the power supply.

Description

Technical Field

[0001] The present invention relates to a vehicle-mounted semiconductor circuit having an overvoltage protection function and a fault detection function. Background Art

[0002] Semiconductor circuits having an overvoltage protection function that protects the circuit when an overvoltage is applied are known (for example, see Patent Document 1). In addition, semiconductor circuits having a fault detection function that externally notifies the outside of a fault state have also been developed (for example, see Patent Document 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 3899984

[0006] Patent Document 2: Japanese Patent No. 3918614 Summary of the Invention

[0007] Technical issues

[0008] It is desired that an in-vehicle semiconductor circuit be able to notify the outside of the overvoltage application state even when an overvoltage is applied thereto.

[0009] Technical Solution

[0010] In a first embodiment of the present invention, a vehicle-mounted semiconductor circuit is provided. The vehicle-mounted semiconductor circuit can be connected to a load circuit. The vehicle-mounted semiconductor circuit can control the power supply to the load circuit. The vehicle-mounted semiconductor circuit can include a power supply line. A power supply voltage can be applied to the power supply line. The vehicle-mounted semiconductor circuit can include an overvoltage protection unit. The overvoltage protection unit can include an output unit. The output unit can cut off the power supply from the power supply line to the load circuit when the power supply voltage of the power supply line is overvoltage. The vehicle-mounted semiconductor circuit can include a status notification unit. The status notification unit can notify the outside of a status signal indicating whether the output unit has cut off the power supply.

[0011] The state notification unit may generate the state signal based on the voltage of the detection node. The voltage of the detection node may have different potentials when the power supply is cut off and when the power supply is not cut off in the overvoltage protection unit.

[0012] An in-vehicle semiconductor circuit may include a reference potential line. A reference potential may be applied to the reference potential line. A status notification unit may include a status notification line. The status notification line may transmit a status signal to the outside. The status notification unit may include a status notification switch. The status notification switch may switch whether the status notification line is connected to the reference potential line based on the voltage of a detection node. The status notification switch may switch whether the status notification line is connected to a power supply line based on the voltage of a detection node. The status notification switch may switch whether the status notification line is connected to a load circuit based on the voltage of a detection node.

[0013] The in-vehicle semiconductor circuit may include an output line. The output line may be connected to a load circuit. The output unit may be an output transistor. The output transistor may switch whether or not the power line is connected to the output line. The status notification unit may detect a voltage at a gate terminal of the output transistor as the voltage of the detection node.

[0014] The overvoltage protection unit may include a protection transistor. The protection transistor may be disposed between a power supply line and a reference potential line. Depending on the magnitude of the power supply voltage, the protection transistor may select a voltage corresponding to the power supply voltage or a voltage corresponding to the reference potential and apply it to the gate terminal of the output transistor. The status notification unit may detect the voltage outputted from the protection transistor to the gate terminal as the voltage of the detection node.

[0015] The overvoltage protection unit may include a Zener diode. The overvoltage protection unit may include a first resistor element. The first resistor element may be connected in series with the Zener diode. The voltage at the connection point between the Zener diode and the first resistor element may be applied to the gate terminal of the protection transistor. The status notification unit may detect the voltage at the connection point between the Zener diode and the first resistor element as the voltage of the detection node. The status notification unit may detect the voltage of the output line as the voltage of the detection node.

[0016] The in-vehicle semiconductor circuit may include a disconnection detection unit. The disconnection detection unit may be connected to the power supply line, the reference potential line, and the status notification line. The disconnection detection unit may externally notify a disconnection signal indicating whether the in-vehicle semiconductor circuit is disconnected.

[0017] The disconnection detection unit may include a second resistor connected between the power supply line and the state notification line. The disconnection detection unit may include a third resistor connected between the state notification line and the reference potential line. The disconnection detection unit may include a fourth resistor connected between the power supply line and the reference potential line.

[0018] The status notification line can transmit a disconnection signal to the outside. The status notification line can transmit a status signal and a disconnection signal to the outside in different voltage ranges.

[0019] In a second embodiment of the present invention, a semiconductor circuit is provided. The semiconductor circuit can be connected to a load circuit. The semiconductor circuit can control the power supply to the load circuit. The semiconductor circuit can include a power supply line. A power supply voltage can be applied to the power supply line. The semiconductor circuit can include an overvoltage protection unit. The overvoltage protection unit can include an output unit. The output unit can cut off the power supply from the power supply line to the load circuit when the power supply voltage of the power supply line is overvoltage. The semiconductor circuit can include a status notification unit. The status notification unit can notify the outside of a status signal indicating whether the output unit has cut off the power supply. The semiconductor circuit can include a disconnection detection unit. The disconnection detection unit can notify the outside of a disconnection signal indicating whether the semiconductor circuit is disconnected. The semiconductor circuit can include a status notification line. The status notification line can transmit a status signal and a disconnection signal to the outside.

[0020] The load circuit may be a pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is a diagram showing an example of the configuration of a semiconductor circuit 100 according to an embodiment of the present invention.

[0022] Figure 2 To show Figure 1 FIG. 1 is a diagram showing an example of output voltage Vout characteristics of the load circuit 5 of the semiconductor circuit 100 .

[0023] Figure 3 Graph showing the relationship between the power supply voltage Vcc and the output voltage Vout of the semiconductor circuit 100 .

[0024] Figure 4 This is a diagram showing an example of the configuration of a semiconductor circuit 200 according to another embodiment of the present invention.

[0025] Figure 5 This is a diagram showing an example of the configuration of a semiconductor circuit 300 according to another embodiment of the present invention.

[0026] Figure 6 This is a diagram showing an example of the configuration of a semiconductor circuit 400 according to another embodiment of the present invention.

[0027] Figure 7 This is a diagram showing an example of the configuration of a semiconductor circuit 500 according to another embodiment of the present invention.

[0028] Figure 8 This is a diagram showing an example of the configuration of a semiconductor circuit 600 according to another embodiment of the present invention.

[0029] Figure 9 1 is a diagram showing a configuration of a semiconductor circuit 700 for explaining the operation of the disconnection detection unit 2 .

[0030] Figure 10 To show Figure 9 FIG. 7 is a diagram showing a state in which the external power supply line 75 of the semiconductor circuit 700 is disconnected.

[0031] Figure 11 To show Figure 9 FIG. 7 is a diagram showing a state in which the external reference potential line 77 of the semiconductor circuit 700 is disconnected.

[0032] Figure 12 To show Figure 9 FIG. 7 is a diagram of an example of output voltage Vout characteristics of the output stage amplifier 84 of the semiconductor circuit 700 .

[0033] Figure 13 1 is a diagram showing an example of the configuration of a semiconductor circuit 800 according to a comparative example.

[0034] Figure 14 For illustration Figure 13 FIG. 8 is a diagram of a current path of a semiconductor circuit 800 .

[0035] Figure 15 Graph showing the relationship between the power supply voltage Vcc and the output voltage Vout of a semiconductor circuit 800 according to a comparative example.

[0036] Explanation of symbols

[0037] 1: Overvoltage protection unit; 2: Disconnection detection unit; 3: Status notification unit; 4: Reverse connection protection unit; 5: Load circuit; 8: Synthesis circuit; 9: External circuit; 11: First resistor; 12: Zener diode; 13: Protection transistor; 14: Resistor; 15: Output transistor; 16: Resistor; 17: Zener diode; 18: Resistor; 19: Zener diode; 20: Zener diode; 21: Second resistor; 22: Third resistor; 23: Fourth resistor; 24: Zener diode; 31: Status notification switch; 32: Zener diode; 33: Resistor; 34: Boost circuit; 41: Zener diode; 42: Zener diode; 43: Zener diode; 61 : Power supply terminal; 62: Output terminal; 63: Reference potential terminal; 71: Internal power supply line; 72: Internal state notification line; 73: Internal reference potential line; 74: Output line; 75: External power supply line; 76: External state notification line; 77: External reference potential line; 81: Resistor element; 82: Resistor element; 83: Resistor element; 84: Output stage amplifier; 91: Resistor element; 92: Resistor element; 93: Power supply terminal; 94: Output terminal; 95: Reference potential terminal; 100: Semiconductor circuit; 200: Semiconductor circuit; 300: Semiconductor circuit; 400: Semiconductor circuit; 500: Semiconductor circuit; 600: Semiconductor circuit; 700: Semiconductor circuit; 800: Semiconductor circuit DETAILED DESCRIPTION

[0038] The present invention will be described below by way of embodiments of the invention, but the following embodiments do not limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential for the solution provided by the invention.

[0039] Figure 1This figure illustrates an example of the configuration of a semiconductor circuit 100 according to one embodiment of the present invention. The semiconductor circuit 100 of this example can be an in-vehicle semiconductor circuit. The semiconductor circuit 100 of this example includes an overvoltage protection unit 1, a disconnection detection unit 2, a status notification unit 3, a reverse connection protection unit 4, and a load circuit 5. Furthermore, to operate the overvoltage protection unit 1, disconnection detection unit 2, status notification unit 3, reverse connection protection unit 4, and load circuit 5, the semiconductor circuit 100 of this example includes a power supply terminal 61, an output terminal 62, a reference potential terminal 63, an internal power supply line 71, an internal status notification line 72, an internal reference potential line 73, and an output line 74. The overvoltage protection unit 1, disconnection detection unit 2, status notification unit 3, reverse connection protection unit 4, and load circuit 5 can be formed on the same semiconductor substrate. Furthermore, while the semiconductor circuit 100 includes the load circuit 5 in this example, it is not necessary for the semiconductor circuit 100 to include the load circuit 5. In other words, the semiconductor circuit 100 can be connected to an external load circuit 5.

[0040] The power supply terminal 61 is a terminal for supplying a power supply voltage Vcc from an external power source. The output terminal 62 is a terminal for outputting an output voltage Vout to the outside. The reference potential terminal 63 is a terminal for supplying a ground voltage GND to the outside. The power supply terminal 61, the output terminal 62, and the reference potential terminal 63 are connected to an internal power supply line 71, an internal state notification line 72, and an internal reference potential line 73, respectively. The internal power supply line 71 is an example of a power supply line. The internal state notification line 72 is an example of a state notification line. The internal reference potential line 73 is an example of a reference potential line. The external power supply voltage Vcc is supplied to the overvoltage protection unit 1, the disconnection detection unit 2, and the reverse connection protection unit 4 via the internal power supply line 71. In other words, the power supply voltage Vcc can be applied to the internal power supply line 71. The output voltage Vout is output to the outside from the disconnection notification unit 2, the state notification unit 3, and the load circuit 5 via the internal state notification line 72. An external ground voltage GND (reference potential) is supplied to the overvoltage protection unit 1, the disconnection detection unit 2, the status notification unit 3, the reverse connection protection unit 4, and the load circuit 5 via the internal reference potential line 73. In other words, the ground voltage GND (reference potential) can be applied to the internal reference potential line 73. It should be noted that in this specification, the ground voltage GND may sometimes be referred to as the reference potential.

[0041] The overvoltage protection unit 1 is connected to an internal power supply line 71, an internal reference potential line 73, and an output line 74. When the external power supply voltage Vcc is stable, the overvoltage protection unit 1 provides a supply voltage Vdd to the load circuit 5 via the output line 74. The overvoltage protection unit 1 may have a function to cut off the voltage supplied from the power supply line to the load circuit 5 when the external power supply voltage Vcc is overvoltage. It should be noted that in this specification, the supply voltage may sometimes be expressed as power supply. The semiconductor circuit 100 can control the power supply to the load circuit 5.

[0042] The overvoltage protection unit 1 includes a first resistor 11, a Zener diode 12, a protection transistor 13, a resistor 14, and an output transistor 15. The first resistor 11 can be connected in series with the Zener diode 12. One end of the first resistor 11 can be connected to the Zener diode 12, and the other end can be connected to the internal power supply line 71. The Zener diode 12 can have a cathode connected to the first resistor 11 and an anode connected to the internal reference potential line 73. The connection point between the first resistor 11 and the Zener diode 12 can be connected to the gate terminal of the protection transistor 13. The connection point between the first resistor 11 and the Zener diode 12 is set to a connection point N1. The voltage Va at the connection point N1 can be applied to the gate terminal of the protection transistor 13.

[0043] The protection transistor 13 can be a P-type high-voltage MOS transistor. The source terminal of the protection transistor 13 can be connected to the internal power supply line 71. The drain terminal of the protection transistor 13 can be connected to the resistor element 14 and the gate terminal of the output transistor 15. The connection point between the drain terminal of the protection transistor 13 and the resistor element 14 is set to the connection point N2. The voltage Vb at the connection point N2 can be applied to the gate terminal of the output transistor 15. The resistor element 14 can have one end connected to the drain terminal of the protection transistor 13 and the gate terminal of the output transistor 15, and the other end connected to the internal reference potential line 73. The protection transistor 13 can be arranged between the internal power supply line 71 and the internal reference potential line 73.

[0044] Output transistor 15 may be a P-type high-voltage MOS transistor. The source terminal of output transistor 15 may be connected to internal power supply line 71. The drain terminal of output transistor 15 may be connected to load circuit 5. In other words, output transistor 15 may output supply voltage Vdd to load circuit 5. Output transistor 15 is an example of an output unit.

[0045] The operation of overvoltage protection unit 1 will be described. When external power supply voltage Vcc is lower than the breakdown voltage of Zener diode 12, the absolute value of the difference between power supply voltage Vcc and voltage Va at connection point N1 decreases, and protection transistor 13 is turned off. When protection transistor 13 is turned off, voltage Vb at connection point N2 becomes approximately equal to external ground voltage GND. Consequently, output transistor 15 is turned on, supplying power supply voltage Vcc to load circuit 5.

[0046] On the other hand, when the external power supply voltage Vcc is greater than the breakdown voltage of the Zener diode 12, the voltage Va at the connection point N1 is clamped to the breakdown voltage of the Zener diode 12. While clamped to the breakdown voltage, if the external power supply voltage Vcc further exceeds the sum of the breakdown voltage of the Zener diode 12 and the threshold voltage of the protection transistor 13, the absolute value of the difference between the power supply voltage Vcc and the voltage Va at the connection point N1 increases, and the protection transistor 13 turns on. The case where the external power supply voltage Vcc exceeds the sum of the breakdown voltage of the Zener diode 12 and the threshold voltage of the protection transistor 13 can be considered as a case where the power supply voltage Vcc is an overvoltage. Furthermore, the case where the external power supply voltage Vcc is less than the sum of the breakdown voltage of the Zener diode 12 and the threshold voltage of the protection transistor 13 can be considered as a case where the power supply voltage Vcc is stable.

[0047] When protection transistor 13 turns on, voltage Vb at connection point N2 reaches approximately power supply voltage Vcc. Consequently, output transistor 15 turns off, shutting off the power supply to load circuit 5. Specifically, output transistor 15 can shut off the power supply from internal power supply line 71 to load circuit 5 when power supply voltage Vcc on internal power supply line 71 exceeds the voltage limit. Output transistor 15 can switch whether to connect internal power supply line 71 to output line 74. Depending on the magnitude of power supply voltage Vcc, protection transistor 13 can select either a voltage corresponding to power supply voltage Vcc or a voltage corresponding to a reference potential and apply it to the gate terminal of output transistor 15.

[0048] Through the above operation, the overvoltage protection unit 1 supplies the supply voltage Vdd to the load circuit 5 when the power supply voltage Vcc is stable. Furthermore, the overvoltage protection unit 1 cuts off the power supply to the load circuit 5 when the power supply voltage Vcc is overvoltage. The overvoltage protection unit 1 has the function of cutting off the voltage supply in the event of an overvoltage. Therefore, the risk of failure of the load circuit 5 when an overvoltage is applied to the internal power line 71, such as when the wiring of the power supply voltage Vcc is incorrectly connected, can be reduced.

[0049] The disconnection detection unit 2 is connected to the internal power supply line 71, the internal state notification line 72, and the internal reference potential line 73. The disconnection detection unit 2 can detect whether the semiconductor circuit 100 is disconnected and notify the outside of the disconnection via the internal state notification line 72 with a disconnection signal indicating whether the disconnection is occurring. The internal state notification line 72 can transmit the disconnection signal to the outside.

[0050] The disconnection detection unit 2 includes a second resistor element 21, a third resistor element 22, and a fourth resistor element 23. The second resistor element 21 can be connected to the internal power supply line 71 at one end and to the internal state notification line 72 at the other end. The third resistor element 22 can be connected to the internal state notification line 72 at one end and to the internal reference potential line 73 at the other end. The fourth resistor element 23 can be connected to the internal power supply line 71 at one end and to the internal reference potential line 73 at the other end. The detailed operation of disconnection detection by the disconnection detection unit 2 will be described later.

[0051] The status notification unit 3 is connected to an internal status notification line 72 and an internal reference potential line 73. The status notification unit 3 can detect a status signal indicating whether the power supply to the output transistor 15 is cut off, and notify the external device of this status signal via the internal status notification line 72. Furthermore, the status notification unit 3 can share the internal status notification line 72 with the disconnection detection unit 2. In other words, the internal status notification line 72 can transmit both the status signal and the disconnection signal to the external device.

[0052] The status notification unit 3 can generate a status signal based on the voltage of the detection node. The detection node is a node that can detect the on / off state of the overvoltage protection unit 1. That is, the voltage of the detection node is a different potential when the power supply is cut off in the overvoltage protection unit 1 and when the power supply is not cut off. In this example, the status notification unit 3 is connected to the connection point N2, so the voltage of the detection node is the voltage Vb at the connection point N2. In addition, the voltage of the detection node can be the voltage Va at the connection point N1. The voltage of the detection node can be the supply voltage Vdd. By setting the voltage of the detection node to the voltage Vb at the connection point N2, the status notification unit 3 can be implemented with a simple circuit configuration. In other words, the status notification unit 3 can detect the voltage of the gate terminal of the output transistor 15 as the voltage of the detection node. In other words, the status notification unit 3 can detect the voltage output to the gate terminal of the protection transistor 13 as the voltage of the detection node.

[0053] The circuit configuration of the status notification unit 3 will be described. The status notification unit 3 may include a status notification switch 31. The status notification switch 31 may be an N-type high-voltage MOS transistor. The source terminal of the status notification switch 31 may be connected to the internal reference potential line 73. The drain terminal of the status notification switch 31 may be connected to the internal status notification line 72. The gate terminal of the status notification switch 31 may be connected to the connection point N2. Furthermore, the status notification unit 3 may include an internal status notification line 72. The internal status notification line 72 transmits the status signal generated by the status notification unit 3 to the outside.

[0054] Since the status notification unit 3 is connected to the connection point N2, it switches based on the voltage Vb at the connection point N2. When the power supply voltage Vcc is stable (when the external power supply voltage Vcc is below the sum of the breakdown voltage of the Zener diode 12 and the threshold voltage of the protection transistor 13), the voltage Vb at the connection point N2 is approximately equal to the external ground voltage GND. If the voltage Vb at the connection point N2 reaches the ground voltage GND, the status notification switch 31, which is an N-type high-voltage MOS transistor, is turned off. Therefore, the status notification switch 31 enters a high-impedance state and does not affect the output voltage Vout. On the other hand, when the power supply voltage Vcc is overvoltage (when the external power supply voltage Vcc exceeds the sum of the breakdown voltage of the Zener diode 12 and the threshold voltage of the protection transistor 13), the voltage Vb at the connection point N2 is approximately equal to the power supply voltage Vcc. Therefore, the status notification switch 31 enters a conductive state, the impedance from the output terminal 62 to the reference potential terminal 63 becomes low, and the output voltage Vout is forced to reach the ground voltage GND. The state notification switch 31 switches whether to connect the internal state notification line 72 to the internal reference potential line 73 based on the voltage of the detection node (voltage Vb at the connection point N2). When the voltage of the detection node (voltage Vb at the connection point N2) reaches approximately the power supply voltage Vcc, the state notification switch 31 connects the internal state notification line 72 to the internal reference potential line 73. This allows notification of an overvoltage condition to the outside.

[0055] Furthermore, since the source terminal of the state notification switch 31 is connected to the internal reference potential line 73 , there is no risk of an overvoltage being output to the output terminal 62 , and the external circuit can be operated safely.

[0056] The reverse connection protection unit 4 is connected to the internal power supply line 71 and the internal reference potential line 73. The reverse connection protection unit 4 protects the semiconductor circuit 100 in the case of reverse connection. Reverse connection is a case where, for example, the battery of a car is reversely connected, and an external ground voltage GND is supplied to the power supply terminal 61, and an external power supply voltage Vcc is supplied to the reference potential terminal 63. The reverse connection protection unit 4 has a plurality of Zener diodes (in this example, a Zener diode 41, a Zener diode 42, and a Zener diode 43) connected in series between the internal power supply line 71 and the internal reference potential line 73. The Zener diode 41 can have its cathode connected to the internal power supply line 71 and its anode connected to the Zener diode 42. The Zener diode 42 can have its cathode connected to the Zener diode 41 and its anode connected to the Zener diode 43. The Zener diode 43 can have its cathode connected to the Zener diode 42 and its anode connected to the internal reference potential line 73. Since there are multiple Zener diodes, the semiconductor circuit 100 can be protected in the case of reverse connection. As an example, the semiconductor circuit 100 can be protected when a voltage of 2V or more is supplied. In addition, the reverse connection protection unit 4 may not be provided.

[0057] The load circuit 5 is connected to an internal state notification line 72, an internal reference potential line 73, and an output line 74. The output transistor 15 outputs a supply voltage Vdd to the load circuit 5 via the output line 74. When the power supply voltage Vcc is overvoltage, the output transistor 15 cuts off the power supply to the load circuit 5, thereby preventing overvoltage from being applied to the output transistor 15. Furthermore, the load circuit 5 outputs a voltage to the output terminal 62 via the internal state notification line 72. For example, the load circuit 5 is a pressure sensor. The load circuit 5 can be a semiconductor pressure sensor for use in vehicles. For example, a semiconductor pressure sensor can measure the pressure within the intake manifold.

[0058] As described above, semiconductor circuit 100 includes an overvoltage protection unit 1 and a status notification unit 3. Overvoltage protection unit 1 includes an output unit (output transistor 15) that interrupts the power supply from internal power line 71 to load circuit 5 when power supply voltage Vcc on internal power line 71 exceeds an overvoltage. Status notification unit 3 externally notifies the output unit (output transistor 15) of a status signal indicating whether the power supply has been interrupted. The inclusion of overvoltage protection unit 1 and status notification unit 3 allows external notification of an overvoltage condition and detection of a fault condition on the host system side.

[0059] Figure 2 To show Figure 1 FIG. 1 is a diagram showing an example of the output voltage Vout characteristic of the load circuit 5 of the semiconductor circuit 100. Figure 2 In the example, the load circuit 5 is a pressure sensor. Figure 2As shown, when neither an overvoltage nor a disconnection fault occurs, the output voltage Vout of the load circuit 5 varies within the stable output range according to the applied pressure, as shown by output line a. The stable output range is from V12 to V13. As an example, the range from V12 to V13 is from 0.2V to 4.8V. The saturation voltage (clamping voltage) of the load circuit 5 is set so that the output of the load circuit 5 does not enter the upper fault detection range or the lower fault detection range. If a disconnection fault occurs, the output voltage Vout will enter the upper fault detection range or the lower fault detection range. The upper fault detection range is from V13 to V14. As an example, the range from V13 to V14 is from 4.8V to 5.0V. The lower fault detection range is from V11 to V12. As an example, the range from V11 to V12 is from 0.0V to 0.2V.

[0060] When the power supply voltage Vcc reaches an overvoltage, the status notification switch 31 turns on, forcing the output voltage Vout to ground voltage GND. Consequently, the output voltage Vout enters the lower fault detection range, which extends from V11 to V12. As described above, since the output voltage Vout can be externally detected when it enters the lower fault detection range, the host system can detect a fault condition.

[0061] Figure 3 The graph shows the relationship between the power supply voltage Vcc and the output voltage Vout of the semiconductor circuit 100. When the power supply voltage Vcc is stable (the power supply voltage Vcc is V21 or less), the output voltage Vout is Figure 2 V21 is the sum of the breakdown voltage of the Zener diode 12 and the threshold voltage of the protection transistor 13.

[0062] On the other hand, if the power supply voltage Vcc is overvoltage (when the power supply voltage Vcc exceeds V21), the output voltage Vout becomes approximately 0V. The output voltage Vout becomes approximately 0V because the status notification switch 31 is turned on, forcibly reaching the ground voltage GND. When the power supply voltage Vcc is overvoltage, the output voltage Vout remains constant at approximately 0V.

[0063] Figure 4 This is a diagram showing an example of the configuration of a semiconductor circuit 200 according to another embodiment of the present invention. The semiconductor circuit 200 of this example includes an overvoltage protection unit 1, a disconnection detection unit 2, a state notification unit 3, a reverse connection protection unit 4, and a load circuit 5. The semiconductor circuit 200 of this example is similar to Figure 1The semiconductor circuit 100 is different in that the overvoltage protection unit 1, the disconnection detection unit 2, and the state notification unit 3 further include a protection circuit. The other configurations of the semiconductor circuit 200 may be the same as those of the semiconductor circuit 100.

[0064] Overvoltage protection unit 1 except Figure 1 In addition to the configuration of the power supply terminal 61, the power supply terminal 61 further includes a resistor element 16, a Zener diode 17, a resistor element 18, a Zener diode 19, and a Zener diode 20. The resistor element 16 can be connected to the connection point N1 at one end and to the gate terminal of the protection transistor 13 at the other end. In other words, the resistor element 16 can be provided between the connection point N1 and the gate terminal of the protection transistor 13. By providing the resistor element 16, the current flowing from the power supply terminal 61 to the reference potential terminal 63 can be reduced, thereby protecting the gate terminal of the protection transistor 13. It should be noted that if the gate film thickness of the protection transistor 13 is sufficiently thick, the resistor element 16 can be omitted.

[0065] The cathode of the Zener diode 17 may be connected to the internal power supply line 71, and the anode may be connected to the gate terminal of the protection transistor 13. The Zener diode 17 can prevent an overvoltage from being applied between the source and gate of the protection transistor 13.

[0066] Resistor element 18 can have one end connected to connection point N2 and the other end connected to the gate terminal of output transistor 15. In other words, resistor element 18 can be provided between connection point N2 and the gate terminal of output transistor 15. The provision of resistor element 18 reduces the current flowing from power supply terminal 61 to reference potential terminal 63, thereby protecting the gate terminal of output transistor 15. Note that resistor element 18 may not be provided if the gate film thickness of output transistor 15 is sufficiently thick.

[0067] The cathode of the Zener diode 19 may be connected to the internal power supply line 71, and the anode may be connected to the gate terminal of the output transistor 15. By providing the Zener diode 19, an overvoltage may be prevented from being applied between the source and gate of the output transistor 15.

[0068] The Zener diode 20 may have an anode connected to the internal reference potential line 73 and a cathode connected to the output line 74. By providing the Zener diode 20, the load circuit 5 can be protected.

[0069] The disconnection detection unit 2 is Figure 1 In addition to the configuration, the Zener diode 24 is further provided. The cathode of the Zener diode 24 can be connected to the internal state notification line 72, and the anode can be connected to the internal reference potential line 73. By providing the Zener diode 24, the external circuit connected to the output terminal 62 can be protected.

[0070] Status notification unit 3 except Figure 1 In addition to the configuration of the state notification switch 31, the state notification switch 31 further includes a Zener diode 32 and a resistor 33. The cathode of the Zener diode 32 can be connected to the gate terminal of the state notification switch 31, and the anode can be connected to the internal reference potential line 73. The provision of the Zener diode 32 can prevent an overvoltage from being applied between the source and gate of the state notification switch 31.

[0071] Resistor element 33 can have one end connected to connection point N2 and the other end connected to the gate terminal of status notification switch 31. In other words, resistor element 33 can be provided between connection point N2 and the gate terminal of status notification switch 31. The provision of resistor element 33 reduces the current flowing from power supply terminal 61 to reference potential terminal 63, thereby protecting the gate terminal of status notification switch 31. Note that resistor element 33 may not be provided if the gate film thickness of status notification switch 31 is sufficiently thick.

[0072] Figure 4 The semiconductor circuit 200 is Figure 1 In addition to the structure, a protection circuit is also provided. Therefore, the risk of circuit failure can be further reduced when the power supply voltage Vcc is an overvoltage.

[0073] Figure 5 This is a diagram showing an example of the configuration of a semiconductor circuit 300 according to another embodiment of the present invention. The semiconductor circuit 300 of this example includes an overvoltage protection unit 1, a disconnection detection unit 2, a state notification unit 3, a reverse connection protection unit 4, and a load circuit 5. Figure 4 The semiconductor circuit 200 is different in that the state notification unit 3 has a structure and the source terminal of the state notification switch 31 of the state notification unit 3 is connected to the internal power supply line 71. The other structures of the semiconductor circuit 300 may be the same as those of the semiconductor circuit 200.

[0074] The status notification unit 3 may include a status notification switch 31, a Zener diode 32, a resistor element 33, and a boost circuit 34. The status notification switch 31 may be an N-type high-voltage MOS transistor. Alternatively, the status notification switch 31 may be a P-type high-voltage MOS transistor. The source terminal of the status notification switch 31 may be connected to the internal power supply line 71. The drain terminal of the status notification switch 31 may be connected to the internal status notification line 72. The gate terminal of the status notification switch 31 may be connected to the connection point N2. The Zener diode 32 may have its anode connected to the gate terminal of the status notification switch 31 and its cathode connected to the internal power supply line 71. The resistor element 33 may have one end connected to the connection point N2 and the other end connected to the gate terminal of the status notification switch 31. The Zener diode 32 and the resistor element 33 are a protection circuit that protects the internal circuit when an overvoltage is applied.

[0075] Boosting circuit 34 is a circuit that boosts the voltage at connection point N2. As a method of boosting the voltage, voltage Vb at connection point N2 can be boosted such that when output transistor 15 is in the on state, status notification switch 31 is in the off state, and when output transistor 15 is in the off state, status notification switch 31 is in the on state. Boosting circuit 34 can be implemented using any known configuration.

[0076] By providing the boost circuit 34, when the power supply voltage Vcc is stable, the state notification switch 31 is in a high impedance state and does not affect the output voltage Vout. On the other hand, when the power supply voltage Vcc is overvoltage, the impedance from the output terminal 62 to the power supply terminal 61 becomes low, and the output voltage Vout is forced to reach the power supply voltage Vcc. If the output voltage Vout reaches the power supply voltage Vcc, the state notification switch 31 enters the high impedance state. Figure 2 Therefore, since it is possible to externally detect that the output voltage Vout has entered the upper fault detection zone, it is possible to detect that the upper system is in a fault state.

[0077] Figure 6 This is a diagram showing an example of the configuration of a semiconductor circuit 400 according to another embodiment of the present invention. The semiconductor circuit 400 of this example includes an overvoltage protection unit 1, a disconnection detection unit 2, a state notification unit 3, a reverse connection protection unit 4, and a load circuit 5. The semiconductor circuit 400 of this example is similar to Figure 5 The semiconductor circuit 300 is different from the semiconductor circuit 400 in that the state notification unit 3 is configured and connected to the connection point N1. The other configurations of the semiconductor circuit 400 may be the same as those of the semiconductor circuit 300.

[0078] The status notification unit 3 may include a status notification switch 31, a Zener diode 32, and a resistor element 33. The status notification switch 31 may be a P-type high-voltage MOS transistor. The source terminal of the status notification switch 31 may be connected to the internal power supply line 71. The drain terminal of the status notification switch 31 may be connected to the internal status notification line 72. The gate terminal of the status notification switch 31 may be connected to the connection point N1. The Zener diode 32 may have its anode connected to the gate terminal of the status notification switch 31 and its cathode connected to the internal power supply line 71. The resistor element 33 may have one end connected to the connection point N1 and the other end connected to the gate terminal of the status notification switch 31. The Zener diode 32 and the resistor element 33 are a protection circuit that protects the internal circuit when an overvoltage is applied.

[0079] The status notification switch 31 is a P-type high-voltage MOS transistor, and the gate terminal is connected to the connection point N1. That is, the voltage Va at the connection point N1 can be set to the voltage of the detection node. When the output transistor 15 is in the on state (the power supply voltage Vcc is stable), the status notification switch 31 becomes the off state, and when the output transistor 15 is in the off state (the power supply voltage Vcc is overvoltage), the status notification switch 31 becomes the on state. When the power supply voltage Vcc is stable, the status notification switch 31 becomes a high impedance state and does not affect the output voltage Vout. On the other hand, when the power supply voltage Vcc is overvoltage, the impedance from the output terminal 62 to the power supply terminal 61 becomes low, and the output voltage Vout is forcibly changed to the power supply voltage Vcc. The status notification switch 31 can switch whether to connect the internal status notification line 72 to the internal power supply line 71 according to the voltage of the detection node (the voltage Va at the connection point N1). If the output voltage Vout becomes the power supply voltage Vcc, it enters Figure 2 Therefore, since it is possible to externally detect when the output voltage Vout enters the upper fault detection zone, a fault condition can be detected on the upper system side using a simple circuit configuration. The voltage Va at the connection point N1 can be detected as the voltage of the detection node.

[0080] Furthermore, the status notification switch 31 may be an N-type high-voltage MOS transistor. If the status notification switch 31 is an N-type high-voltage MOS transistor, a boost circuit may be provided on the gate terminal side of the status notification switch 31. The boost circuit can boost the voltage Va at the connection point N1 so that when the output transistor 15 is in the on state, the status notification switch 31 is in the off state, and when the output transistor 15 is in the off state, the status notification switch 31 is in the on state. The boost circuit can be implemented using any known configuration.

[0081] Figure 7 This is a diagram showing an example of the configuration of a semiconductor circuit 500 according to another embodiment of the present invention. The semiconductor circuit 500 of this example includes an overvoltage protection unit 1, a disconnection detection unit 2, a state notification unit 3, a reverse connection protection unit 4, and a load circuit 5. The semiconductor circuit 500 of this example is similar to Figure 6 The semiconductor circuit 400 is different in that the state notification unit 3 is connected to the output line 74. The other configurations of the semiconductor circuit 500 may be the same as those of the semiconductor circuit 400.

[0082] The state notification unit 3 may include a state notification switch 31 , a Zener diode 32 , and a resistor 33 . The state notification switch 31 may be a P-type high-voltage MOS transistor. The gate terminal of the state notification switch 31 may be connected to the output line 74 .

[0083] The status notification switch 31 is a P-type high-voltage MOS transistor, and the gate terminal is connected to the output line 74. That is, the supply voltage Vdd supplied by the output transistor 15 to the load circuit 5 can be set to the voltage of the detection node. When the output transistor 15 is in the on state (the power supply voltage Vcc is stable), the status notification switch 31 becomes the off state, and when the output transistor 15 is in the off state (the power supply voltage Vcc is overvoltage), the status notification switch 31 becomes the on state. When the power supply voltage Vcc is stable, the status notification switch 31 becomes a high impedance state and does not affect the output voltage Vout. On the other hand, when the power supply voltage Vcc is overvoltage, the impedance from the output terminal 62 to the power supply terminal 61 becomes low, and the output voltage Vout is forcibly changed to the power supply voltage Vcc. The status notification switch 31 can switch whether to connect the internal status notification line 72 to the internal power supply line 71 according to the supply voltage Vdd of the detection node. If the output voltage Vout becomes the power supply voltage Vcc, it enters Figure 2 The upper fault detection zone. Therefore, since the output voltage Vout can be externally detected when it enters the upper fault detection zone, a fault condition can be detected on the upper system side using a simple circuit configuration. The status notification unit 3 can detect the supply voltage Vdd of the output line 74 as the voltage of the detection node.

[0084] Furthermore, the status notification switch 31 may be an N-type high-voltage MOS transistor. If the status notification switch 31 is an N-type high-voltage MOS transistor, a boost circuit may be provided on the gate terminal side of the status notification switch 31. The boost circuit can boost the supply voltage Vdd so that when the output transistor 15 is in the on state, the status notification switch 31 is in the off state, and when the output transistor 15 is in the off state, the status notification switch 31 is in the on state. The boost circuit can be implemented using any known configuration.

[0085] Figure 8 This is a diagram showing an example of the configuration of a semiconductor circuit 600 according to another embodiment of the present invention. The semiconductor circuit 600 of this example includes an overvoltage protection unit 1, a disconnection detection unit 2, a state notification unit 3, a reverse connection protection unit 4, and a load circuit 5. Figure 4 The semiconductor circuit 200 is different in that the state notification unit 3 is configured and the source terminal of the state notification switch 31 is connected to the load circuit 5. The other configurations of the semiconductor circuit 600 may be the same as those of the semiconductor circuit 200.

[0086] The status notification unit 3 may include a status notification switch 31, a Zener diode 32, and a resistor element 33. The status notification switch 31 may be an N-type high-voltage MOS transistor. The source terminal of the status notification switch 31 may be connected to the load circuit 5. The drain terminal of the status notification switch 31 may be connected to the internal status notification line 72. The gate terminal of the status notification switch 31 may be connected to the connection point N2. The cathode of the Zener diode 32 may be connected to the gate terminal of the status notification switch 31, and the anode may be connected to the internal reference potential line 73. The resistor element 33 may be connected to the connection point N2 at one end and to the gate terminal of the status notification switch 31 at the other end. The Zener diode 32 and the resistor element 33 are a protection circuit that protects the internal circuit when an overvoltage is applied.

[0087] The status notification switch 31 is an N-type high-voltage MOS transistor, and the gate terminal is connected to the connection point N2. That is, the voltage Vb at the connection point N2 can be set to the voltage of the detection node. When the output transistor 15 is in the on state (the power supply voltage Vcc is stable), the status notification switch 31 becomes the off state, and when the output transistor 15 is in the off state (the power supply voltage Vcc is overvoltage), the status notification switch 31 becomes the on state. When the power supply voltage Vcc is stable, the status notification switch 31 becomes a high impedance state and does not affect the output voltage Vout. On the other hand, when the power supply voltage Vcc is overvoltage, the impedance from the output terminal 62 to the load circuit 5 becomes low, and the output voltage Vout is forced to become the output voltage of the load circuit 5. The output voltage of the load circuit 5 is approximately the ground voltage GND when it is overvoltage, so the output voltage Vout is forced to become the ground voltage GND. The status notification switch 31 can switch whether to connect the internal status notification line 72 to the load circuit 5 according to the voltage of the detection node (the voltage Vb at the connection point N2). If the output voltage Vout becomes the ground voltage GND, it enters Figure 2 Therefore, since it is possible to externally detect that the output voltage Vout has entered the lower fault detection zone, it is possible to detect a fault state on the upper system side with a simple circuit configuration.

[0088] Figure 9 The semiconductor circuit 700 is a diagram showing the structure of the semiconductor circuit 700 for explaining the operation of the disconnection detection unit 2. The semiconductor circuit 700 is a circuit that connects the external circuit 9 to the Figure 1The semiconductor circuit 700 of this embodiment includes: a disconnection detection unit 2, a synthesizing circuit 8, and an external circuit 9. In addition, the semiconductor circuit 700 of this embodiment includes a power supply terminal 61, an output terminal 62, a reference potential terminal 63, an internal power supply line 71, an internal state notification line 72, an internal reference potential line 73, an external power supply line 75, an external state notification line 76, and an external reference potential line 77 in order to operate the disconnection detection unit 2, the synthesizing circuit 8, and the external circuit 9. Figure 1 The disconnection detection unit 2 of the semiconductor circuit 100 shown is the same. The synthesis circuit 8 is Figure 1 The semiconductor circuit 100 is shown as a composite circuit of the overvoltage protection unit 1, state notification unit 3, reverse connection protection unit 4, and load circuit 5, and some parts are omitted. The external circuit 9 is an external circuit connected to the power supply terminal 61, output terminal 62, and reference potential terminal 63.

[0089] The structure of the disconnection detection unit 2 Figure 1 The semiconductor circuit 100 shown is the same as the one shown in FIG.

[0090] Synthesizing circuit 8 includes a resistor element 81, a resistor element 82, a resistor element 83, and an output-stage amplifier 84. Resistor element 81 can be connected to internal power supply line 71 at one end and to internal state notification line 72 at the other end. Resistor element 82 can be connected to internal state notification line 72 at one end and to internal reference potential line 73 at the other end. Resistor element 83 can be connected to internal power supply line 71 at one end and to internal reference potential line 73 at the other end. Output-stage amplifier 84 is connected to internal state notification line 72 and outputs a signal to internal state notification line 72.

[0091] The external circuit 9 has a resistor element 91, a resistor element 92, a power supply terminal 93, an output terminal 94, and a reference potential terminal 95. The resistor element 91 can be connected to the external power supply line 75 at one end and to the external state notification line 76 at the other end. The resistor element 92 can be connected to the external state notification line 76 at one end and to the external reference potential line 77 at the other end. The power supply terminal 93 is a terminal to which the power supply voltage Vcc is supplied. The output terminal 94 is a terminal to which the output voltage Vout is output to the outside. The reference potential terminal 95 is a terminal to which the ground voltage GND is supplied. The power supply terminal 93, the output terminal 94, and the reference potential terminal 95 are connected to the power supply terminal 61, the output terminal 62, and the reference potential terminal 63 via the external power supply line 75, the external state notification line 76, and the external reference potential line 77, respectively. As Figure 2 As described above, when neither overvoltage nor disconnection fault occurs, the output voltage Vout changes within the stable output region according to the applied pressure.

[0092] Figure 10 To show Figure 9 FIG2 shows a state where the external power supply line 75 of the semiconductor circuit 700 is disconnected. The output voltage Vout when the external power supply line 75 is disconnected is expressed as the following equation 1. In equation 1, the resistance value of the second resistor 21 is R1, the resistance value of the third resistor 22 is R2, the resistance value of the fourth resistor 23 is R3, the resistance value of the resistor 81 is R01, the resistance value of the resistor 82 is R02, the resistance value of the resistor 83 is R03, the resistance value of the resistor 91 is R4, and the resistance value of the resistor 92 is R5. In addition, when expressed as R1 / / R2, it represents the combined resistance value when a resistor element with a resistance value of R1 and a resistor element with a resistance value of R2 are connected in parallel. In addition, when expressed as R1 / / R2 / / R3, it represents the combined resistance value when a resistor element with a resistance value of R1, a resistor element with a resistance value of R2, and a resistor element with a resistance value of R3 are connected in parallel.

[0093] [Formula 1]

[0094]

[0095] The fourth resistor element 23 has nothing to do with the output of the output stage amplifier 84, and therefore does not affect the voltage value of the output signal when the line is not broken. In addition, by changing the resistance value of the fourth resistor element 23, the output voltage Vout when the line is broken can be changed. In other words, by adjusting the resistance value of the fourth resistor element 23, the output voltage Vout when the line is broken can be adjusted. In the case of a break in the external power line 75, the Figure 2 The fourth resistor element 23 is set so as to fit within the range of the lower fault detection zone. The resistance value can be adjusted by a known method such as using a variable resistor.

[0096] Figure 11 To show Figure 9 FIG. 7 is a diagram showing a state where the external reference potential line 77 of the semiconductor circuit 700 is disconnected. The output voltage Vout when the external reference potential line 77 is disconnected is expressed as the following equation 2. By changing the resistance value of the fourth resistor 23, the output voltage Vout when disconnected can be changed. In other words, by adjusting the resistance value of the fourth resistor 23, the output voltage Vout when disconnected can be adjusted. When the external reference potential line 77 is disconnected, the output voltage Vout can be adjusted by entering Figure 2 The fourth resistance element 23 is set in such a manner as to correspond to the range of the upper fault detection zone.

[0097] [Formula 2]

[0098]

[0099] Figure 12 To show Figure 9 FIG. 7 is a diagram showing an example of the output voltage Vout characteristic of the output stage amplifier 84 of the semiconductor circuit 700. Figure 2 Similarly, when neither an overvoltage nor a disconnection fault occurs, the output voltage Vout of the output stage amplifier 84 varies within the stable output range according to the applied pressure, as shown by output line b. The stable output range is from V12 to V13. As an example, the range from V12 to V13 is from 0.2V to 4.8V. The saturation voltage (clamping voltage) of the output stage amplifier 84 is set so that the output of the output stage amplifier 84 does not enter the upper limit fault detection range or the lower limit fault detection range.

[0100] If the external reference potential line 77 is disconnected, the resistance value of the fourth resistor 23 can be adjusted so that the output voltage Vout falls within the upper fault detection range. The upper fault detection range is from V13 to V14. For example, the range from V13 to V14 is from 4.8 V to 5.0 V.

[0101] If the external power supply line 75 is disconnected, the resistance value of the fourth resistor 23 can be adjusted so that the output voltage Vout falls within the lower fault detection range. The lower fault detection range is the range from V11 to V12. For example, the range from V11 to V12 is from 0.0V to 0.2V. Furthermore, by adjusting the resistance value of the fourth resistor 23 so that the output voltage Vout falls within the upper fault detection range when the external reference potential line 77 is disconnected, and falls within the lower fault detection range when the external power supply line 75 is disconnected, the location of the disconnection can be easily determined.

[0102] As described above, when the power supply voltage Vcc is overvoltage, the output voltage Vout reaches a value close to 0.0V. To distinguish between an overvoltage in the power supply voltage Vcc and a disconnection in the external power supply line 75, the resistance value of the fourth resistor 23 can be adjusted so that the output voltage Vout enters the first lower fault detection zone when the power supply voltage Vcc is overvoltage, and enters the second lower fault detection zone when the external power supply line 75 is disconnected. The first lower fault detection zone ranges from V11 to V15. As an example, the range from V11 to V15 is from 0.0V to 0.1V. The second lower fault detection zone ranges from V15 to V12. As an example, the range from V15 to V12 is from 0.1V to 0.2V. In other words, the internal status notification line 72 can transmit the status signal and the disconnection signal to the external device within different voltage ranges. By providing the first lower fault detection area and the second lower fault detection area, it is possible to distinguish between a case where the power supply voltage Vcc is an overvoltage and a case where the power supply voltage Vcc is disconnected.

[0103] Figure 13 This is a diagram showing an example of the configuration of a semiconductor circuit 800 of a comparative example. The semiconductor circuit 800 of this example includes an overvoltage protection unit 1, a disconnection detection unit 2, a reverse connection protection unit 4, and a load circuit 5. Figure 4 The semiconductor circuit 200 is different in that it does not include the state notification unit 3 . Figure 13 The other components can be Figure 4 same.

[0104] The semiconductor circuit 800 of this example is Figure 4 The semiconductor circuit 200 of this embodiment also has an overvoltage protection unit 1. Therefore, it is possible to cut off the voltage supply when the power supply voltage Vcc is an overvoltage. Figure 4 Unlike the semiconductor circuit 200 of this example, the semiconductor circuit 800 does not include the state notification unit 3. Therefore, the semiconductor circuit 800 of this example cannot notify the outside that it is in the overvoltage state.

[0105] Figure 14 For illustration Figure 13 8 is a diagram showing a current path in the semiconductor circuit 800. If the power supply voltage Vcc becomes an overvoltage, a current path is generated that flows from the disconnection detection unit 2 to the load circuit 5 and a current path that flows from the third resistance element 22 to the fourth resistance element 23 in a looped manner. Figure 14 The bold line indicates a current path that flows in a loop from the disconnection detection unit 2 to the load circuit 5 . Figure 14The thick dashed line indicates the current path from the third resistor 22 to the fourth resistor 23. The voltage divided by the voltage at the connection point AA between the third resistor 22 and the fourth resistor 23 and the combined resistance of the current path from the connection point AA to the fourth resistor 23, and the third resistor 22, is output as the output voltage Vout.

[0106] Figure 15 The graph shows the relationship between the power supply voltage Vcc and the output voltage Vout of the semiconductor circuit 800 of the comparative example. When the power supply voltage Vcc is stable (the power supply voltage Vcc is V21 or less), the output voltage Vout is Figure 2 V21 is the sum of the breakdown voltage of the Zener diode 12 and the threshold voltage of the protection transistor 13.

[0107] On the other hand, when the power supply voltage Vcc is overvoltage (when the power supply voltage Vcc exceeds V21), the output voltage Vout becomes the voltage of the voltage divider point between the combined resistance of the current path from connection point AA to load circuit 5 and the current path from connection point AA to fourth resistor 23, which are in a loop, and the third resistor 22. In this case, the output voltage Vout does not fall below the voltage at which the active components used within load circuit 5 operate. For example, when semiconductor circuit 800 is formed on a silicon substrate, the output voltage Vout is above 0.6V. Therefore, the output voltage Vout is fixed in the stable output range. Therefore, the semiconductor circuit 800 of this example cannot notify the outside world of the overvoltage condition when the power supply voltage Vcc is overvoltage.

[0108] While the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. In addition, not all combinations of the features described in the embodiments are necessarily required for the solution of the invention.

[0109] It should be noted that the order of execution of actions, sequences, steps, and stages, etc., in the apparatus, system, program, and method described in the claims, specifications, and drawings may be implemented in any order unless otherwise expressly stated, for example, "before," "prior to," or the like, and unless the results of a previous process are used in a subsequent process. Even if, for convenience, the process flow in the claims, specifications, and drawings is described using phrases such as "first" or "next," it does not necessarily mean that the process must be performed in that order.

Claims

1. A semiconductor circuit for use in a vehicle, characterized in that: The vehicle-mounted semiconductor circuit is connected to a load circuit and controls the power supply to the load circuit. The vehicle-mounted semiconductor circuit includes: a power supply line to which a power supply voltage is applied; an overvoltage protection unit having an output unit for cutting off the power supply from the power line to the load circuit when the power voltage of the power line is an overvoltage; a state notification unit configured to notify an external circuit different from the load circuit of a state signal indicating whether the output unit has cut off the power supply; as well as a state notification line connected to the load circuit and outputting the voltage from the load circuit and the state signal to the external circuit; The state notification unit outputs the state signal to the external circuit via the state notification line.

2. The in-vehicle semiconductor circuit according to claim 1, wherein: The status notification line outputs the voltage from the load circuit and the status signal to the external circuit in different voltage ranges.

3. The in-vehicle semiconductor circuit according to claim 2, wherein: The state notification unit generates the state signal based on a voltage of a detection node, the voltage of the detection node having different potentials when the power supply is cut off and when the power supply is not cut off in the overvoltage protection unit.

4. The in-vehicle semiconductor circuit according to claim 3, wherein: The in-vehicle semiconductor circuit further includes a reference potential line to which a reference potential is applied. The state notification unit includes a state notification switch that switches whether to connect the state notification line to the reference potential line according to the voltage of the detection node.

5. The in-vehicle semiconductor circuit according to claim 3, wherein: The state notification section includes a state notification switch configured to switch whether to connect the state notification line to the power supply line according to a voltage of the detection node.

6. The in-vehicle semiconductor circuit according to claim 3, wherein: The state notification section includes a state notification switch configured to switch whether to connect the state notification line to the load circuit based on a voltage at the detection node.

7. The in-vehicle semiconductor circuit according to any one of claims 4 to 6, wherein: The in-vehicle semiconductor circuit further includes an output line connected to the load circuit. The output unit is an output transistor, and the output transistor switches whether to connect the power line to the output line. The state notification section detects a voltage of a gate terminal of the output transistor as a voltage of the detection node.

8. The in-vehicle semiconductor circuit according to claim 7, wherein: The in-vehicle semiconductor circuit further includes a reference potential line to which a reference potential is applied. The overvoltage protection unit further includes a protection transistor, which is provided between the power supply line and the reference potential line and selects, according to the magnitude of the power supply voltage, one of a voltage corresponding to the power supply voltage and a voltage corresponding to the reference potential to be applied to the gate terminal of the output transistor. The state notification section detects a voltage output to the gate terminal by the protection transistor as a voltage of the detection node.

9. The in-vehicle semiconductor circuit according to any one of claims 4 to 6, wherein: The in-vehicle semiconductor circuit further comprises: a reference potential line to which a reference potential is applied; and an output line, which is connected to the load circuit, The output unit is an output transistor, and the output transistor switches whether to connect the power line to the output line. The overvoltage protection unit further comprises: Zener diode; a first resistance element connected in series with the Zener diode; a protection transistor provided between the power supply line and the reference potential line, having a voltage at a connection point between the Zener diode and the first resistor applied to a gate terminal thereof, and selectively applying one of a voltage corresponding to the power supply voltage and a voltage corresponding to the reference potential to the gate terminal of the output transistor; The state notification section detects a voltage at a connection point between the Zener diode and the first resistance element as a voltage of the detection node.

10. The in-vehicle semiconductor circuit according to any one of claims 4 to 6, wherein: The in-vehicle semiconductor circuit further includes an output line connected to the load circuit. The output unit is an output transistor, and the output transistor switches whether to connect the power line to the output line. The state notification section detects a voltage of the output line as a voltage of the detection node.

11. The in-vehicle semiconductor circuit according to claim 4, wherein: The in-vehicle semiconductor circuit further includes a disconnection detection unit connected to the power supply line, the reference potential line, and the state notification line. The disconnection detection unit notifies the external circuit of a disconnection signal indicating whether the in-vehicle semiconductor circuit is disconnected.

12. The in-vehicle semiconductor circuit according to claim 5 or 6, wherein: The in-vehicle semiconductor circuit further comprises: a reference potential line to which a reference potential is applied; and a disconnection detection unit connected to the power supply line, the reference potential line, and the status notification line, The disconnection detection unit notifies the external circuit of a disconnection signal indicating whether the in-vehicle semiconductor circuit is disconnected.

13. The in-vehicle semiconductor circuit according to claim 11, wherein: The disconnection detection unit includes: a second resistance element connected between the power line and the status notification line; a third resistance element connected between the state notification line and the reference potential line; and A fourth resistance element is connected between the power line and the reference potential line.

14. The in-vehicle semiconductor circuit according to claim 11 or 13, wherein: The status notification line outputs the disconnection signal to the external circuit.

15. The in-vehicle semiconductor circuit according to claim 12, wherein: The status notification line outputs the disconnection signal to the external circuit.

16. The in-vehicle semiconductor circuit according to claim 11, wherein The state notification line outputs the voltage from the load circuit, the state signal, and the disconnection signal to the external circuit in different voltage ranges.

17. The in-vehicle semiconductor circuit according to any one of claims 1 to 6, wherein: The load circuit is a pressure sensor.

18. A semiconductor circuit, characterized in that: The semiconductor circuit is connected to a load circuit and controls the power supply to the load circuit, and includes: a power supply line to which a power supply voltage is applied; an overvoltage protection unit having an output unit for cutting off the power supply from the power line to the load circuit when the power voltage of the power line is an overvoltage; a state notification unit configured to notify an external circuit different from the load circuit of a state signal indicating whether the output unit has cut off the power supply; a disconnection detection unit that notifies the external circuit of a disconnection signal indicating whether the semiconductor circuit is disconnected; as well as a state notification line connected to the load circuit and outputting the voltage from the load circuit, the state signal, and the disconnection signal to the external circuit; The state notification unit notifies the external circuit of the state signal via the state notification line. The disconnection detection unit notifies the external circuit of the disconnection signal via the state notification line.

19. The semiconductor circuit according to claim 18, wherein: The load circuit is a pressure sensor.

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