JP2021069222A - Power supply device and reporting module - Google Patents

Abstract

To construct a power supply device for an e-call system at a low cost and high accuracy.SOLUTION: A power supply device 1a comprises: a step-down power supply circuit 10 which can execute a step-down operation for stepping-down a voltage from a first voltage source VS1; a step-up power supply circuit 20 which can execute a step-up operation for stepping-up the voltage from a second voltage power source VS2; a main power supply line LN1 to which an output terminal of each voltage circuit is connected in common, and a main power supply voltage VM based on an output of the step-down power supply circuit or an output of the step-up power supply circuit is applied; and a control part 62 that sets a step-down target voltage that becomes a target of the step-down output voltage and a step-up target voltage that becomes a target of the step-up output voltage. The control part can be operated in a normal mode for setting the step-down target voltage to be higher than the step-up target voltage or in a diagnostic mode for setting the step-up target voltage to be higher than the step-down target voltage, and makes a diagnosis of the presence/absence of the step-up power supply circuit in the diagnostic mode.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power supply device and a notification module.

The application of the vehicle emergency call system to vehicles such as automobiles is expanding. The vehicle emergency call system is also called an e-call system. In the vehicle emergency call system, when an emergency situation such as a vehicle accident occurs, an emergency call signal is transmitted from the ECU for the e-call system mounted on the vehicle to an external device (server device or the like). The ECU for the e-call system basically operates by receiving drive power from a battery (lead-acid battery, etc.) mounted on the vehicle, but even if the battery and the ECU are disconnected due to a vehicle accident or the like. It is equipped with a spare battery made of lithium ion or the like so that an emergency call signal can be transmitted.

JP-A-2018-148609

As an ECU for an e-call system equipped with a spare battery, an ECU 901 as shown in FIG. 15 is considered. FIG. 15 shows a schematic configuration of the ECU 901 according to the reference configuration. The ECU 901 uses a step-down power supply circuit 910 capable of generating a step-down output voltage by stepping down the output voltage (for example, 12V) of the voltage source 951 which is the main battery, and an output voltage (for example, 3V) of the voltage source 952 which is a spare battery. It includes a boost power supply circuit 920 capable of generating a boost output voltage by boosting the voltage. The step-down power supply circuit 910 is configured as a step-down switching regulator (step-down DC / DC converter), and the step-up power supply circuit 920 is configured as a step-up switching regulator (step-up DC / DC converter).

The output terminal of the power supply circuit 910 is connected to the main power supply line 971, and the output terminal of the power supply circuit 920 is connected to the main power supply line 971 via the transistor M900. The CAN transceiver 961, MPU 962, communication module 963, and GPS processing unit 964 that form a circuit block for realizing the function of the vehicle emergency notification system are driven based on the main power supply voltage Vm in the main power supply line 971.

When the main battery (voltage source 951) is connected to the step-down power supply circuit 910, the wiring between the main battery and the step-down power supply circuit 910 is broken while preventing the storage energy of the spare battery (voltage source 952) from being consumed. In that case, it is necessary to immediately supply power from the spare battery. Therefore, after the system is started, the step-up power supply circuit 920 is always enabled (the signal EN is set to the assert state), the transistor M900 is turned on, and the output target of the step-up power supply circuit 920 is the step-down power supply circuit 910. It is necessary to set it lower than that of. For example, when the main power supply voltage Vm is required to be "5V ± 5%", the output targets of the power supply circuits 910 and 920 are set to 5.14V and 4.85V, respectively.

It is necessary to always ensure that the boost power supply circuit 920 can operate without any abnormality when the above-mentioned disconnection or the like occurs. However, unless disconnection or the like occurs, the boost power supply circuit 920 does not actually perform the boost operation due to the high / low relationship of the output target. In consideration of these, it is necessary to consider how to detect an abnormality (failure detection) of the boost power supply circuit 920.

In this regard, in the configuration of FIG. 15, at the time of abnormality diagnosis, the step-up power supply circuit 920 is caused to perform a boost-up operation while temporarily disconnecting the output of the step-up power supply circuit 920 from the main power supply line 971 by turning off the transistor M900. By monitoring the output voltage of the boost power supply circuit 920 at this time with the A / D converter of MPU962, it is possible to confirm whether the normal boost voltage is output (that is, it is possible to confirm whether the boost power supply circuit 920 has an abnormality). ..

However, in the configuration of FIG. 15, an expensive transistor M900 with low on-resistance (P-channel MOSFET in FIG. 15) is required. Further, the voltage accuracy when the main power supply voltage Vm is generated at the output of the boost power supply circuit 920 is deteriorated by the voltage drop of the transistor M900 (for example, the requirement "5V ± 5%" for the main power supply voltage Vm is satisfied. On the other hand, it is necessary to set the output target of the step-up power supply circuit 920 lower than that of the step-down power supply circuit 910, but it becomes difficult to satisfy the demand).

An object of the present invention is to provide a power supply device and a notification module capable of diagnosing the presence or absence of an abnormality in a power supply circuit with a low cost and a simple configuration.

The power supply device according to the present invention has a step-down power supply circuit, a step-down power supply circuit capable of outputting a step-down output voltage from the step-down output terminal by stepping down the voltage from the first voltage source, and a step-up output terminal. , The step-up power supply circuit capable of outputting a step-up output voltage from the step-up output terminal by boosting the voltage from the second voltage source, and the step-down output terminal and the step-up output terminal are commonly connected to the step-down power supply circuit. A main power supply line to which a main power supply voltage based on an output or the output of the step-up power supply circuit is applied, a control unit that sets a target step-down target voltage of the step-down output voltage and a target boost-up target voltage of the step-up output voltage, and a control unit. The control unit can operate in a normal mode in which the step-down target voltage is set higher than the step-up target voltage or a diagnostic mode in which the step-up target voltage is set higher than the step-down target voltage. This is a configuration (first configuration) for diagnosing the presence or absence of an abnormality in the boost power supply circuit.

In the power supply device according to the first configuration, the control unit lowers the step-down target voltage and raises the step-up target voltage based on the normal mode to raise the step-up target voltage in the diagnostic mode. The configuration may be set higher than the step-down target voltage (second configuration).

In the power supply device according to the first or second configuration, the step-down power supply circuit is a step-down switching regulator that has a step-down transistor and generates the step-down output voltage by a step-down operation accompanied by switching of the step-down transistor. Therefore, the step-down operation is executed or stopped according to the relationship between the main power supply voltage and the step-down target voltage, and the step-up power supply circuit has a step-up transistor and is driven by a step-up operation accompanied by switching of the step-up transistor. The boost switching regulator that generates the boost output voltage may be configured to execute or stop the boost operation according to the relationship between the main power supply voltage and the boost target voltage (third configuration).

In the power supply device according to the third configuration, a step-down voltage dividing circuit composed of a series circuit of a plurality of voltage dividing resistors and generating a step-down feedback voltage by dividing the main power supply voltage, and a plurality of other components. The step-down power supply circuit further includes a step-up voltage dividing circuit that is composed of a series circuit of pressure resistors and generates a step-up feedback voltage by dividing the main power supply voltage. The step-down operation is executed or stopped so as to match or approach the reference voltage for boosting, and the boost power supply circuit executes or stops the step-up operation so that the feedback voltage for boosting matches or approaches a predetermined reference voltage for boosting. The step-down voltage dividing circuit and the step-up voltage dividing circuit are each configured so that the voltage dividing ratio is variable, and the control unit controls the step-down target voltage through a variable setting of the voltage dividing ratio in the step-down voltage dividing circuit. May be variably set, and the boost target voltage may be variably set through the variable setting of the voltage division ratio in the boosting voltage dividing circuit (fourth configuration).

In the power supply device according to the third configuration, the power supply device is composed of a series circuit of a plurality of voltage dividing resistors, and the main power supply voltage is divided by different voltage dividing ratios to generate a step-down feedback voltage and a step-up feedback voltage. The step-down power supply circuit further includes a circuit, the step-down power supply circuit executes or stops the step-down operation so that the step-down feedback voltage matches or approaches a predetermined step-down reference voltage, and the step-up power supply circuit has a predetermined step-up feedback voltage. The boosting operation is executed or stopped so as to match or approach the boosting reference voltage of the above, and the voltage dividing circuit is used for boosting from the voltage dividing ratio for obtaining the step-down feedback voltage from the main power supply voltage and the boosting voltage from the main power supply voltage. The voltage division ratio for obtaining the feedback voltage is configured to be variable, and the control unit simultaneously changes these voltage division ratios at the time of switching between the normal mode and the diagnostic mode, thereby causing the step-down target voltage and the step-up. The configuration may be such that the target voltage is changed at the same time (fifth configuration).

In the power supply device according to the fifth configuration, the series circuit of the plurality of voltage dividing resistors is inserted between the main power supply line and the ground, and in the voltage dividing circuit, a part of the plurality of voltage dividing resistors. The bypass circuit is connected in parallel to the voltage dividing resistor, the step-down feedback voltage and the step-up feedback voltage are generated in the first node and the second node which are different from each other in the series circuit, and the bypass circuit is connected in parallel. A part of the voltage dividing resistance is interposed between the first node and the second node, and the control unit controls the state of the bypass circuit to control the part of the voltage dividing resistance and the bypass circuit. The voltage dividing ratio for obtaining the step-down feedback voltage from the main power supply voltage and the main voltage by changing the resistance value of the parallel circuit in switching between the normal mode and the diagnostic mode by making the resistance value of the parallel circuit variable. The voltage dividing ratio for obtaining the boost feedback voltage from the power supply voltage may be changed at the same time, whereby the step-down target voltage and the boost-up target voltage may be changed at the same time (sixth configuration).

In the power supply device according to any one of the first to sixth configurations, the control unit diagnoses the presence or absence of an abnormality in the boost power supply circuit based on the main power supply voltage in the diagnostic mode (seventh configuration). ) May be.

In the power supply device according to the seventh configuration, the control unit determines whether or not the main power supply voltage in the diagnostic mode is within a predetermined normal voltage range corresponding to the boost target voltage in the diagnostic mode. The configuration may be such that the presence or absence of an abnormality in the boost power supply circuit is diagnosed by detecting the above (eighth configuration).

In the power supply device according to any one of the third to sixth configurations, when the voltage is connected to the boosting transistor and the boosting operation is executed, the voltage from the second voltage source is boosted. Further, a monitor circuit for generating a voltage different from the voltage at the boost output terminal on a predetermined monitor line is further provided, and the control unit of the boost power supply circuit is based on the voltage of the monitor line in the diagnostic mode. It may be a configuration (9th configuration) for diagnosing the presence or absence of an abnormality.

In the power supply device according to the ninth configuration, the control unit can execute the normal mode diagnostic process in the normal mode, and in the normal mode diagnostic process, the boosting operation is executed based on the voltage of the monitor line. The configuration may be such that, when it is determined that the boosting operation is being executed, it is determined that there is an abnormality in the power supply device (tenth configuration).

In the power supply device according to the ninth or tenth configuration, the boost power supply circuit has an anode at the connection node of the boost transistor, the inductor connected in series with the boost transistor, and the inductor and the boost transistor. With a freewheeling diode to which the freewheeling diode is connected and a smoothing capacitor inserted between the cathode and ground of the freewheeling diode, the cathode of the freewheeling diode is connected to the main power supply line, and the inductor and the boosting are performed. A voltage from the second voltage source is applied to the series circuit with the transistor, and in the monitor circuit, the anode is connected to the connection node between the inductor and the boosting diode, and the cathode is connected to the monitor line. The configuration (fifth configuration) may include a monitoring recirculation diode and a monitor smoothing capacitor inserted between the monitor line and the ground.

In the power supply device according to any one of the first to tenth and fifty configurations, a voltage accuracy specification that requires the main power supply voltage to be within a predetermined voltage range is defined for the main power supply voltage. The step-down target voltage and the step-up target voltage in the normal mode, and the step-down target voltage and the step-up target voltage in the diagnostic mode are all configured to be within the predetermined voltage range (11th configuration). You may.

The notification module according to the present invention includes a power supply device according to any one of the above 1st to 11th and 50th configurations, and is a notification module mounted on a vehicle to acquire position information indicating the position of the vehicle. A position information acquisition device, an external communication device capable of wirelessly transmitting a predetermined emergency call signal including the position information to an external device when a predetermined report condition is satisfied, and other circuits mounted on the vehicle. The in-vehicle communication device that communicates with the above-mentioned position information acquisition device, the external communication device, the in-vehicle communication device, and the control unit in the power supply device are driven based on the main power supply voltage. It is a configuration (12th configuration).

According to the present invention, it is possible to provide a power supply device and a notification module capable of diagnosing the presence or absence of an abnormality in a power supply circuit with a low cost and a simple configuration.

FIG. 5 is a diagram schematically showing how an ECU is mounted on a vehicle according to an embodiment of the present invention. It is a figure which showed the mode that bidirectional communication between an ECU and a server device becomes possible according to the Embodiment of this invention. It is a block diagram of the ECU which concerns on 1st Embodiment of this invention. It is a circuit diagram of the step-down power supply circuit of FIG. It is a circuit diagram of the boost power supply circuit of FIG. It is a figure which shows the relationship between the step-down target voltage and the step-up target voltage in a normal mode and a diagnostic mode, according to the first embodiment of the present invention. It is a figure which shows the relationship between the step-down target voltage and the step-up target voltage in a normal mode and a diagnostic mode, according to the first embodiment of the present invention. FIG. 5 is a diagram showing a fluctuation range of a step-down target voltage and a step-up target voltage in a normal mode and a diagnostic mode according to the first embodiment of the present invention. It is an operation flowchart of the ECU which concerns on 1st Embodiment of this invention. FIG. 5 is a waveform diagram of a main power supply voltage in a normal case according to the first embodiment of the present invention. FIG. 5 is a waveform diagram of a main power supply voltage in a boosting abnormality case according to the first embodiment of the present invention. It is a block diagram of the ECU which concerns on 2nd Embodiment of this invention. It is a block diagram of the ECU which concerns on 3rd Embodiment of this invention. It is a circuit diagram of the boost power supply circuit and the monitor circuit which concerns on 3rd Embodiment of this invention. It is a block diagram of the ECU which concerns on a reference configuration.

Hereinafter, examples of embodiments of the present invention will be specifically described with reference to the drawings. In each of the referenced figures, the same parts are designated by the same reference numerals, and duplicate explanations regarding the same parts will be omitted in principle. In this specification, for the sake of simplification of description, by describing a symbol or a code that refers to an information, a signal, a physical quantity, an element or a part, etc., the information, a signal, a physical quantity, an element or a part corresponding to the symbol or the code is described. Etc. may be omitted or abbreviated. For example, the step-down power supply circuit referred to by “10” described later (see FIG. 3) may be referred to as a step-down power supply circuit 10 or abbreviated as a power supply circuit 10, but they are all. Refers to the same thing.

First, some terms used in the description of the embodiments of the present invention will be described. Lines and wiring are synonymous in circuits. The ground refers to a conductive portion having a reference potential of 0 V (zero volt) or the potential of 0 V itself. The potential of 0 V may be referred to as the ground potential. In the embodiment of the present invention, the voltage shown without any particular reference represents the potential seen from the ground. Level refers to the level of potential, where a high level has a higher potential than a low level for any signal or voltage. For any signal or voltage, a signal or voltage at a high level means that the signal or voltage level is at a high level, and a signal or voltage at a low level means that the signal or voltage level is at a low level. Means that it is in. A level for a signal is sometimes referred to as a signal level, and a level for a voltage is sometimes referred to as a voltage level.

For any transistor configured as a FET (Field Effect Transistor) including a MOSFET, the on state means that the drain and source of the transistor are in a conductive state, and the off state means the drain of the transistor. And it means that there is a non-conduction state (interruption state) between the sources. The same applies to transistors that are not classified as FETs. Unless otherwise specified, the MOSFET may be understood as an enhancement type MOSFET. MOSFET is an abbreviation for "metal-oxide-semiconductor field-effect transistor".

Any switch can be composed of one or more FETs (Field Effect Transistors), and when a switch is on, both ends of the switch are conducting, while when a switch is off, the switch is connected. There is no conduction between both ends. Hereinafter, the on state and the off state of any transistor or switch may be simply expressed as on and off. For any transistor or switch, switching from the off state to the on state is referred to as turn-on, and switching from the on state to the off state is referred to as turn-off. Further, for any transistor or switch, a section in which the transistor or switch is in the on state may be referred to as an on section, and a section in which the transistor or switch is in the off state may be referred to as an off section.

<< First Embodiment >>
The first embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing how the ECU 1 is mounted on the vehicle CC. The voltage source VS1 is a battery mounted on the vehicle CC, and is composed of an arbitrary secondary battery such as a lead storage battery. The voltage source VS1 is externally connected to the ECU 1. In FIG. 1, a passenger car is shown as a vehicle CC, but the vehicle CC may be any vehicle (particularly, a vehicle capable of traveling on a road). The ECU 1 is an ECU ((Electronic Control Unit)) mounted on the vehicle CC to realize the function of the so-called vehicle emergency call system, and functions as a report module (vehicle emergency call module). The vehicle emergency call system is e-. Also called a call system.

As shown in FIG. 2, the vehicle emergency call system includes an ECU 1 and an external device SV existing outside the vehicle CC. The external device SV is, for example, a server device connected to a communication network such as an Internet network. The ECU 1 is capable of bidirectional communication with the external device SV via a predetermined mobile communication network.

Further, the vehicle CC is equipped with a plurality of ECUs including the ECU 1 as a notification module, and the plurality of ECUs are mutually various via CAN (Controller Area Network) which is a communication network provided in the vehicle CC. Information can be sent and received.

FIG. 3 shows the configuration of the ECU 1a according to the first embodiment. In the first embodiment, the ECU 1a of FIG. 3 is used as the ECU 1 of FIG. The ECU 1a includes a voltage source VS2 different from the voltage source VS1, a step-down power supply circuit 10, a step-up power supply circuit 20, voltage divider circuits DIV1, DIV2 and DIV3, a CAN transceiver 61, and an MPU (Micro-processing unit). A 62, a communication module 63, and a GPS processing unit 64 are provided.

The voltage source VS2 is a DC voltage source composed of a lithium ion battery or the like. The ECU 1 (here, ECU 1a) drives the voltage source VS1 as the main voltage source, and the voltage source VS2 functions as a spare battery that functions effectively when the power supply based on the voltage source VS1 is interrupted. The voltage source VS2 may be a primary battery or a secondary battery. The capacity of the voltage source VS2 is smaller than the capacity of the voltage source VS1. Further, the nominal voltage value of the output voltage of the voltage source VS1 (for example, 12V) is larger than the nominal voltage value of the output voltage of the voltage source VS2 (for example, 3V). In the following, the output voltage of the voltage source VS1 is represented by the voltage VA, and the output voltage of the voltage source VS2 is represented by the voltage VB.

Step-down power supply circuit 10 includes an input terminal _{10 IN} for receiving the output voltage VA of the voltage source VS1, an output terminal _{10 OUT,} the output terminal _{10 OUT} by stepping down the input voltage to the input terminal _{10 IN} (hence voltage VA) It is possible to output its own output voltage (step-down output voltage) from. A feedback voltage VfbA is input to the step-down power supply circuit 10 from the voltage dividing circuit DIV1, and the step-down power supply circuit 10 performs a step-down output voltage generation operation (corresponding to a step-down operation described later) based on the feedback voltage VfbA.

Booster power supply circuit 20 has an input terminal _{20 IN} for receiving the output voltage VB of the voltage source VS2, the output terminal ₂₀ with the _OUT, the output terminal _{20 OUT} by boosting the input voltage to the input terminal _{20 IN} (hence voltage VB) It is possible to output its own output voltage (boosting output voltage) from. A feedback voltage VfbB is input to the boost power supply circuit 20 from the voltage dividing circuit DIV2, and the boost power supply circuit 20 performs a boost output voltage generation operation (corresponding to a boost operation described later) based on the feedback voltage VfbB.

However, the output since the terminal 10 _OUT and the output terminal 20 _OUT boosting power source circuit 20 are connected together by the main power supply line LN1, operation of generating generation operation and the boosted output voltage of the step-down output voltage of the step-down power supply circuit 10 Of these, only one of the generation operations will be executed. The voltage applied to the main power supply line LN1 provided in the ECU 1a is referred to as the main power supply voltage VM.

The voltage dividing circuit DIV1 includes voltage dividing resistors R1, R2 and R3, and a transistor M1 configured as an N-channel MOSFET. A series circuit of the voltage dividing resistors R1 to R3 is arranged between the main power supply line LN1 and the ground, and at this time, the voltage dividing resistors R1, R2, and R3 are arranged in this order from the main power supply line LN1 toward the ground. Will be done. More specifically, one end of the voltage dividing resistor R1 is connected to the main power supply line LN1, the other end of the voltage dividing resistor R1 is connected to one end of the voltage dividing resistor R2, and the other end of the voltage dividing resistor R2 is the voltage dividing resistor. It is connected to one end of R3, and the other end of the voltage dividing resistor R3 is connected to the ground. The drain of the transistor M1 is connected to the connecting node between the voltage dividing resistors R1 and R2, and the source of the transistor M1 is connected to the connecting node between the voltage dividing resistors R2 and R3. A feedback voltage VfbA is generated at the connection node between the voltage dividing resistors R2 and R3.

The voltage dividing circuit DIV1 functions as a step-down voltage dividing circuit that generates a feedback voltage VfbA to the step-down power supply circuit 10 by dividing the main power supply voltage VM, but when generating a feedback voltage VfbA from the main power supply voltage VM. The voltage division ratio is variable. That is, the voltage division ratio is variable depending on whether the transistor M1 is turned on or off.

More specifically, when the resistance values of the voltage dividing resistors R1, R2, and R3 are represented by the symbols "R1", "R2", and "R3", respectively, the feedback voltage VfbA is obtained by dividing the main power supply voltage VM. The voltage dividing ratio at the time of generating is “R3 / (R1 + R2 + R3)” when the transistor M1 is off, while it is “R3 / (R1 + R3)” when the transistor M1 is on. However, here, it is assumed that the on-resistance of the transistor M1 is sufficiently low to be zero.

The voltage dividing circuit DIV2 includes voltage dividing resistors R4, R5 and R6, and a transistor M2 configured as an N-channel MOSFET. A series circuit of the voltage dividing resistors R4 to R6 is arranged between the main power supply line LN1 and the ground, and at this time, the voltage dividing resistors R4, R5, and R6 are arranged in this order from the main power supply line LN1 toward the ground. Will be done. More specifically, one end of the voltage dividing resistor R4 is connected to the main power supply line LN1, the other end of the voltage dividing resistor R4 is connected to one end of the voltage dividing resistor R5, and the other end of the voltage dividing resistor R5 is the voltage dividing resistor. It is connected to one end of R6, and the other end of the voltage dividing resistor R6 is connected to the ground. The drain of the transistor M2 is connected to the connection node between the voltage dividing resistors R5 and R6, and the source of the transistor M2 is connected to the ground. A feedback voltage VfbB is generated at the connection node between the voltage dividing resistors R4 and R5.

The voltage dividing circuit DIV2 functions as a boosting voltage dividing circuit that generates a feedback voltage VfbB to the boosting power supply circuit 20 by dividing the main power supply voltage VM, but when generating a feedback voltage VfbB from the main power supply voltage VM. The voltage division ratio is variable. That is, the voltage division ratio is variable depending on whether the transistor M2 is turned on or off.

More specifically, when the resistance values of the voltage dividing resistors R4, R5, and R6 are represented by the symbols "R4", "R5", and "R6", respectively, the feedback voltage VfbB is obtained by dividing the main power supply voltage VM. The voltage dividing ratio at the time of generating is “(R5 + R6) / (R4 + R5 + R6)” when the transistor M2 is off, while it is “R5 / (R4 + R5)” when the transistor M2 is on. However, here, it is assumed that the on-resistance of the transistor M2 is sufficiently low to be zero.

The voltage dividing circuit DIV3 is composed of a series circuit of voltage dividing resistors R7 and R8. Specifically, one end of the voltage dividing resistor R7 is connected to the main power supply line LN1, the other end of the voltage dividing resistor R7 is connected to one end of the voltage dividing resistor R8, and the other end of the voltage dividing resistor R8 is connected to the ground. To. At the connection node between the voltage dividing resistors R7 and R8, a voltage Vdet, which is a voltage divider of the main power supply voltage VM, is generated.

A plurality of load devices operating with the main power supply voltage VM as a drive source are connected to the main power supply line LN1. Here, the CAN transceiver 61, the MPU 62, the communication module 63, and the GPS processing unit 64 are mentioned as a plurality of load devices, but load devices other than these can also be connected to the main power supply line LN1.

The CAN transceiver 61 is an ECU different from the ECU 1a and realizes bidirectional communication of arbitrary information with each ECU mounted on the vehicle CC via the CAN.

The MPU 62 has a function of outputting signals FET_EN and Boost_EN and a function of evaluating voltage Vdet, and comprehensively controls the operation of each part in the ECU 1a. Each of the signals FET_EN and Boost_EN is a binary signal having a low level or a high level signal level. In the ECU 1a, the signal FET_EN is supplied to each gate of the transistors M1 and M2. Transistors M1 and M2 are turned on when the signal FET_EN is at a high level, and transistors M1 and M2 are turned off when the signal FET_EN is at a low level. The signal Boost_EN is an enable signal of the boost power supply circuit 20, and here, it is assumed that the boost power supply circuit 20 is activated only when the signal Boost_EN is at a high level.

The communication module 63 realizes bidirectional communication of arbitrary information with the external device SV (see FIG. 2).

The GPS processing unit 64 detects the current position of the vehicle CC by receiving signals from a plurality of GPS satellites forming a GPS (Global Positioning System), and generates vehicle position information indicating the current position of the vehicle CC. In the vehicle position information, the current position of the vehicle CC is represented by the longitude and latitude on the earth.

In the vehicle emergency call function realized by the ECU 1a, when a predetermined emergency call condition is satisfied, a predetermined emergency call signal is transmitted to the external device SV using the communication module 63 under the control of the MPU 62. The emergency call signal includes the latest vehicle position information generated by the GPS processing unit 64, and may also include various registration information (vehicle type of vehicle CC, owner information of vehicle CC, etc.). For example, the vehicle CC is provided with an airbag ECU that controls the deployment of the airbag and the airbag, and when the airbag is deployed, the airbag ECU notifies the CAN transceiver 61 of the predetermined airbag deployment. The signal is transmitted. The emergency call condition is satisfied by receiving the airbag deployment notification signal on the CAN transceiver 61. In addition, the emergency call condition can be satisfied even when the impact sensor mounted on the vehicle CC detects an impact of a certain value or more.

FIG. 4 shows a specific configuration example of the step-down power supply circuit 10. The step-down power supply circuit 10 is a step-down switching regulator (step-down DC / DC converter) having a step-down transistor (step-down switching transistor), and obtains a step-down output voltage based on voltage VA by a step-down operation accompanied by switching of the step-down transistor. It is generated at the output terminal 10 _OUT.

The step-down power supply circuit 10 of FIG. 4 includes a transistor 11 configured as an N-channel MOSFET, a diode 12 functioning as a freewheeling diode (rectifier diode), an inductor 13, a smoothing capacitor 14, a reference voltage source 15, and a reference voltage source 15. A control circuit 16 and a control circuit 16 are provided.

In the transistor 11, the drain is _{connected to the input terminal 10 IN} , and the source is commonly connected to the cathode of the diode 12 and one end of the inductor 13. The other end of the inductor 13 is connected to the _{output terminal 10 OUT.} One end of the smoothing capacitor 14 is _{connected to the output terminal 10 OUT,} and the other end of the smoothing capacitor 14 is connected to the ground. The anode of the diode 12 is connected to ground. The reference voltage source 15 generates a reference voltage VrefA having a predetermined positive DC voltage value based on the voltage VA.

The control circuit 16 switches the transistor 11 or keeps the transistor 11 off based on the feedback voltage VfbA and the reference voltage VrefA so that the feedback voltage VfbA matches or approaches the reference voltage VrefA. Specifically, for example, the control circuit 16 includes an error amplifier 16a that generates an error signal according to the difference between the feedback voltage VfbA and the reference voltage VrefA, and a PWM comparator that compares the error signal with a triangular wave signal having a predetermined PWM frequency. 16b and a driver 16c that turns on or on the transistor 11 by controlling the gate potential of the transistor 11 according to the output signal of the PWM comparator.

Depending on the states of the transistors M1 and M2 in FIG. 3, the switching of the transistor 11 may be stopped (details will be described later), but the description of the step-down operation in which the switching of the transistor 11 is performed will be supplemented. In the step-down operation, the transistors 11 are alternately turned on and off in a predetermined PWM cycle, and the on-duty of the transistor 11 is controlled so that the feedback voltage VfbA matches the reference voltage VrefA, so that the step-down output _{is output to the output terminal 10 OUT.} A voltage is generated. In the step-down operation, the on-duty of the transistor 11 refers to the ratio of the on-section of the transistor 11 to the sum of the on-section and the off-section of the transistor 11.

When the step-down operation is performed, the step-down output voltage generated at the _{output terminal 10 OUT becomes the main power supply voltage VM.} In the step-down operation, when the feedback voltage VfbA matches the reference voltage VrefA, the _{step-down output voltage (main power supply voltage VM) generated at the output terminal 10 OUT} coincides with the step-down target voltage which is the target of the step-down output voltage. Therefore, in the step-down operation, the on-duty of the transistor 11 is controlled so that the step-down output voltage matches the step-down target voltage. The step-down target voltage is determined by the reference voltage VrefA and the voltage dividing ratio of the voltage dividing circuit DIV1 (the voltage dividing ratio when the feedback voltage VfbA is obtained by dividing the main power supply voltage VM), and therefore depends on the state of the transistor M1. Change.

The control circuit 16 is activated when the value of the voltage VA becomes equal to or higher than a certain value, and is in a state in which the above-mentioned step-down operation can be executed. _{The wiring between the voltage source VS1 and the input terminal 10 IN} may be broken due to the occurrence of a vehicle CC accident, etc., and the voltage VA value may be less than a certain value. However, in the following, unless otherwise specified, the voltage VA value. Is equal to or higher than a certain value, and the control circuit 16 is in a state where the step-down operation can be executed.

FIG. 5 shows a specific configuration example of the boost power supply circuit 20. The step-up power supply circuit 20 is a step-up switching regulator (boost DC / DC converter) having a step-up transistor (step-up switching transistor), and obtains a step-up output voltage based on voltage VB by a step-up operation accompanied by switching of the step-up transistor. It is generated at the output terminal 20 _OUT.

The boost power supply circuit 20 of FIG. 5 includes a transistor 21 configured as an N-channel MOSFET, a diode 22 functioning as a freewheeling diode (rectifier diode), an inductor 23, a smoothing capacitor 24, a reference voltage source 25, and the like. It includes a control circuit 26.

The inductor 23 is inserted between the drain of the transistor 21 and the input terminal 20 _IN. That is, one end of the inductor 23 is _{connected to the input terminal 20 IN,} and the other end of the inductor 23 is connected to the drain of the transistor 21. The source of transistor 21 is connected to ground. Therefore, the voltage VB from the voltage source VS2 is applied to the series circuit of the inductor 23 and the transistor 21. The anode of the diode 22 is connected to the drain of the transistor 21, and the cathode of the diode 22 is connected to the _{output terminal 20 OUT.} One end of the smoothing capacitor 24 is _{connected to the output terminal 20 OUT,} and the other end of the smoothing capacitor 24 is connected to the ground. The reference voltage source 25 generates a reference voltage VrefB having a predetermined positive DC voltage value based on the voltage VB.

The control circuit 26 switches the transistor 21 or keeps the transistor 21 off based on the feedback voltage VfbB and the reference voltage VrefB so that the feedback voltage VfbB matches or approaches the reference voltage VrefB. Specifically, for example, the control circuit 26 includes an error amplifier 26a that generates an error signal according to the difference between the feedback voltage VfbB and the reference voltage VrefB, and a PWM comparator that compares the error signal with a triangular wave signal having a predetermined PWM frequency. It includes 26b and a driver 26c that turns on or on the transistor 21 by controlling the gate potential of the transistor 21 according to the output signal of the PWM comparator. However, the control circuit 26 operates only when the signal Boost_EN is at a high level, and when the signal Boost_EN is at a low level, the control circuit 26 does not operate and the transistor 21 is maintained in the off state.

The switching of the transistor 21 may be stopped depending on the state of the transistors M1 and M2 in FIG. 3 or the level of the signal Boost_EN, but the description of the boosting operation in which the switching of the transistor 21 is performed is supplemented. In the boosting operation, the transistors 21 are alternately turned on and off in a predetermined PWM cycle, and the on-duty of the transistors 21 is controlled so that the feedback voltage VfbB matches the reference voltage VrefB, so that the boost output _{is performed to the output terminal 20 OUT.} A voltage is generated. In the boosting operation, the on-duty of the transistor 21 refers to the ratio of the on-section of the transistor 21 to the sum of the on-section and the off-section of the transistor 21.

When the boosting operation is performed, the _{boosted output voltage generated at the output terminal 20 OUT} becomes the main power supply voltage VM. In the boosting operation, when the feedback voltage VfbB matches the reference voltage VrefB, the _{boosted output voltage (main power supply voltage VM) generated at the output terminal 20 OUT} coincides with the boosted target voltage which is the target of the boosted output voltage. Therefore, in the boost operation, the on-duty of the transistor 21 is controlled so that the boost output voltage matches the boost target voltage. The boost target voltage is determined by the reference voltage VrefB and the voltage dividing ratio of the voltage dividing circuit DIV2 (the voltage dividing ratio when the feedback voltage VfbB is obtained by dividing the main power supply voltage VM), and therefore depends on the state of the transistor M2. Change.

The configurations of the power supply circuits 10 and 20 shown in FIGS. 4 and 5 are merely examples, and various modifications are possible. For example, the step-down power supply circuit 10 or the step-up power supply circuit 20 may employ a synchronous rectification method. Further, a single capacitor may also be used as the smoothing capacitors 14 and 24.

[Normal mode and diagnostic mode]
The MPU 62 can operate in normal mode or diagnostic mode. The MPU 62 may operate in an operation mode different from that of the normal mode and the diagnostic mode, but here, attention is paid only to the normal mode and the diagnostic mode. It is also possible to adopt the idea that the ECU 1a operates in the normal mode and the diagnostic mode, and the MPU 62 switches and controls the operation mode of the ECU 1a.

The MPU 62 turns the transistors M1 and M2 off by setting the signal FET_EN to a low level in the normal mode, and turns the transistors M1 and M2 on by setting the signal FET_EN to a high level in the diagnostic mode.

6 and 7 show the relationship between the step-down target voltage and the step-up target voltage in the normal mode and the diagnostic mode. In the following, the step-down target voltage and the step-up target voltage will be referred to by the symbols “VtgA” and “VtgB”, respectively. In FIG. 7, for convenience of illustration, the solid line waveform representing the step-down target voltage VtgA and the broken line waveform representing the step-up target voltage VtgB are shown slightly shifted in the left-right direction. Further, the step-down target voltage and the step-up target voltage in the normal mode are represented by the symbols “VtgA_N” and “VtgB_N”, respectively, and the step-down target voltage and the step-up target voltage in the diagnostic mode are represented by the symbols “VtgA_S” and “”, respectively. It is represented by "VtgB_S".

Through the state control of the transistors M1 and M2, each voltage dividing ratio of the voltage dividing circuits DIV1 and DIV2 changes between the normal mode and the diagnostic mode. At this time, first
The first inequality "VtgA_N>VtgA_S" and
The second inequality "VtgB_N <VtgB_S" holds. Also,
The third inequality "VtgA_N>VtgB_N" and
The resistance values of the voltage dividing resistors R1 to R6 and the values of the reference voltages VrefA and VrefB are determined so that the fourth inequality “VtgA_S <VtgB_S” holds. That is, the step-up target voltage is set higher than the step-down target voltage in the diagnostic mode by lowering the step-down target voltage and increasing the step-up target voltage based on the normal mode.

Further, the resistance values of the voltage dividing resistors R1 to R6 and the values of the reference voltages VrefA and VrefB are determined so that the four target voltages VtgA_N, VtgA_S, VtgB_N and VtgB_S are all within the predetermined specified voltage range RNG. There is. A voltage accuracy specification that requires the mains voltage VM to be within a predetermined voltage range is defined for the mains voltage VM (in other words, for the ECU 1a), and the predetermined voltage range is the specified voltage range RNG. is there. The specification voltage range RNG is a voltage range _{from a predetermined lower limit voltage V LL} to a predetermined upper limit voltage V _HL (0 <V _LL <V _HL ). The value of the upper limit voltage _{V HL} is the nominal voltage value of the output voltage VA of the voltage source VS1 (e.g. 12V) lower than, the value of the lower limit voltage _{V LL} is the nominal voltage value of the output voltage VB of the voltage source VS2 (e.g. 3V) Higher than.

_{The voltage that is expected to appear in the output terminal 10 OUT} and the main power supply line LN1 when the step-down power supply circuit 10 performs the step-down operation in the normal mode is referred to as a normal step-down voltage. Normally, the assumed step-down voltage has a constant voltage range. The design upper limit voltage and lower limit voltage that can be taken by the normal step-down assumed voltage are represented by the symbols “VtgA_N_H” and “VtgA_N_L”, respectively (see FIG. 8A). “VtgA_N_H> VtgA_N_L” is established. Each value of the voltage VtgA_N_H and VtgA_N_L can be estimated at the design stage of the ECU 1a based on the accuracy of each value of the voltage dividing resistors R1 to R3 and the reference voltage VrefA. It can be said that the voltage range from the upper limit voltage VtgA_N_H to the lower limit voltage VtgA_N_L represents the fluctuation range of the step-down target voltage VtgA_N in the normal mode.

_{The voltage that is expected to appear in the output terminal 20 OUT} and the main power supply line LN1 when the boost power supply circuit 20 performs the boost operation in the normal mode is referred to as a normal boost power supply voltage. Normally, the assumed boost voltage has a constant voltage range. The design upper limit voltage and lower limit voltage that can be taken by the normal step-up assumed voltage are represented by the symbols “VtgB_N_H” and “VtgB_N_L”, respectively (see FIG. 8A). “VtgB_N_H> VtgB_N_L” is established. Each value of the voltage VtgB_N_H and VtgB_N_L can be estimated at the design stage of the ECU 1a based on the accuracy of each value of the voltage dividing resistors R4 to R6 and the reference voltage VrefB. It can be said that the voltage range from the upper limit voltage VtgB_N_H to the lower limit voltage VtgB_N_L represents the fluctuation range of the boost target voltage VtgB_N in the normal mode.

_{The voltage that is assumed to appear in the output terminal 10 OUT} and the main power supply line LN1 when the step-down power supply circuit 10 performs the step-down operation in the diagnostic mode is referred to as a diagnostic step-down assumed voltage. The diagnostic step-down assumed voltage has a constant voltage range. The design upper limit voltage and lower limit voltage that can be taken by the diagnostic step-down assumed voltage are represented by the symbols “VtgA_S_H” and “VtgA_S_L”, respectively (see FIG. 8 (b)). “VtgA_S_H> VtgA_S_L” is established. Each value of the voltage VtgA_S_H and VtgA_S_L can be estimated at the design stage of the ECU 1a based on the accuracy of each value of the voltage dividing resistors R1 to R3 and the reference voltage VrefA. It can be said that the voltage range from the upper limit voltage VtgA_S_H to the lower limit voltage VtgA_S_L represents the fluctuation range of the step-down target voltage VtgA_S in the diagnostic mode.

_{The voltage that is expected to appear in the output terminal 20 OUT} and the main power supply line LN1 when the boost power supply circuit 20 performs the boost operation in the diagnostic mode is referred to as a diagnostic boosted voltage. The diagnostic boosted voltage has a constant voltage range. The design upper limit voltage and lower limit voltage that can be taken by the diagnostic boosting voltage are represented by the symbols “VtgB_S_H” and “VtgB_S_L”, respectively (see FIG. 8B). “VtgB_S_H> VtgB_S_L” is established. Each value of the voltage VtgB_S_H and VtgB_S_L can be estimated at the design stage of the ECU 1a based on the accuracy of each value of the voltage dividing resistors R4 to R6 and the reference voltage VrefB. It can be said that the voltage range from the upper limit voltage VtgB_S_H to the lower limit voltage VtgB_S_L represents the fluctuation range of the boost target voltage VtgB_S in the diagnostic mode.

FIG 8 (a) and (b), the normal buck assumed voltage, usually boosted assumed voltage, diagnostic buck assumed voltages and the upper limit voltage and lower limit voltage in each of the diagnostic boosted assumed voltage, the upper limit voltage V _HL in the specified voltage range RNG And the relationship with the lower limit voltage _{VLL is shown.}

Regarding normal mode
_"V HL>VtgA_N_H",
"VtgA_N_L>VtgB_N_H" and
As _{"VtgB_N_L> V LL"} is satisfied, and,
Regarding diagnostic mode
_"V HL>VtgB_S_H",
"VtgB_S_L>VtgA_S_H" and
As _{"VtgA_S_L> V LL"} is satisfied, ECU 1a are formed.

That is, even if the resistance values of the voltage dividing resistors R1 to R6 and the errors of the reference voltages VrefA and VrefB are included, as shown in FIGS. Is always higher than the normal step-up voltage, and for the diagnostic mode, the diagnostic step-up voltage is always higher than the diagnostic step-down voltage. Furthermore, specifications for normal mode, even including the error, as shown in FIG. 8 (a), higher in the upper limit voltage V _HL specifications voltage range RNG than normal buck assumed voltage than normal boost assumed voltage low towards the lower limit voltage _{V LL} voltage range RNG. Similarly, with respect to the diagnostic mode, even including the error, as shown in FIG. 8 (b), higher in the upper limit voltage V _HL specifications voltage range RNG than diagnostic boosted assumed voltage, than diagnostic buck assumed voltage the lower the lower limit voltage _{V LL} of specification voltage range RNG.

A concrete numerical example is given. Here, it is assumed that the main power supply voltage VM (for example, the power supply voltage of the CAN transceiver 61) is required to be kept within the range of “5V ± 5%”. Then, the lower limit voltage V _LL and the upper limit voltage V _HL are set to 4.75 V and 5.25 V, respectively. In this case, for example, the step-down target voltage VtgA_N in the normal mode is set to 5.14V, the step-up target voltage VtgB_N in the normal mode is set to 4.85V, and the step-down target voltage VtgA_S in the diagnostic mode is set to 4.85V for diagnosis. The boost target voltage VtgB_S in the mode is set to 5.14V. In addition
Fluctuation range of normal step-down assumed voltage centered on step-down target voltage VtgA_N (here, 5.14V) in normal mode,
Fluctuation range of normal boost voltage assumed voltage centered on boost target voltage VtgB_N (4.85V here) in normal mode,
Fluctuation range of diagnostic step-down assumed voltage centering on step-down target voltage VtgA_S (here 4.85V) in diagnostic mode, and
The fluctuation range of the assumed voltage for boosting the diagnostic boost centered on the target voltage for boosting VtgB_S (5.14V in this case) in the diagnostic mode is ± 2% with respect to the voltage at the center.

As a result, the high-low relationship between each voltage as shown in FIGS. 8A and 8B is guaranteed. In this numerical example, "VtgA_N = VtgB_S" and "VtgB_N = VtgA_S" are set, but the match or mismatch between the voltages VtgA_N and VtgB_S does not matter, and the match or mismatch between the voltages VtgB_N and VtgA_S does not matter.

The configurations of the voltage dividing circuits DIV1 and DIV2 are arbitrary as long as the above-mentioned relationship between the step-down target voltage and the step-up target voltage in each of the normal mode and the diagnostic mode is satisfied.

For example, the transistor M1 constitutes a bypass circuit connected in parallel to the voltage dividing resistor R2, and in the voltage dividing circuit DIV1 of FIG. 3, a parallel circuit of the voltage dividing resistor R2 and the bypass circuit when the transistor M1 is turned on. However, if the resistance value of the parallel circuit of the voltage dividing resistor R2 and the bypass circuit becomes smaller when the transistor M1 is on than when the transistor M1 is off. , The configuration of the bypass circuit of the voltage dividing circuit DIV1 is arbitrary. For example, the bypass circuit of the voltage dividing circuit DIV1 may be a series circuit of the transistor M1 and the resistor.

Similarly, for example, the transistor M2 constitutes a bypass circuit connected in parallel to the voltage dividing resistor R6, and in the voltage dividing circuit DIV2 of FIG. 3, when the transistor M2 is turned on, the voltage dividing resistor R6 and the bypass circuit are connected. The resistance value of the parallel circuit becomes substantially zero, but the resistance value of the parallel circuit of the voltage dividing resistor R6 and the bypass circuit becomes smaller when the transistor M2 is on than when the transistor M2 is off. If there is, the configuration of the bypass circuit of the voltage dividing circuit DIV2 is arbitrary. For example, the bypass circuit of the voltage dividing circuit DIV2 may be a series circuit of the transistor M2 and the resistor.

[Operation flowchart]
FIG. 9 is an operation flowchart of the ECU 1a. The operation flow of the ECU 1a will be described with reference to the operation flowchart of FIG. First, in step S11, the battery as the voltage source VS1 is mounted on the vehicle CC. Then, the step-down power supply circuit 10 is activated in step S12 to perform a step-down operation, the step-down output voltage obtained by the step-down operation is applied to the main power supply line LN1 as the main power supply voltage VM, and the MPU 62 is started in step S13.

By the way, each line (wiring) to which the signals FET_EN and Boost_EN are added is pulled down to the ground by a pull-down resistor provided inside the MPU 62 or outside the MPU 62. Therefore, before the MPU 62 is started, the signals FET_EN and Boost_EN are at a low level, and after the start of the MPU 62, the step-down power supply circuit 10 has a step-down output voltage (main power supply voltage VM) of the step-down target voltage VtgA_N (for example, in the normal mode). The step-down operation is performed so as to match 5.14V), while the step-up power supply circuit 20 stops the step-up operation.

After its own activation, the MPU 62 operates in the normal mode in principle, and operates in the diagnostic mode only when the boost diagnosis process in step S16 described later is executed. In the normal mode, the signal FET_EN is set to a low level as described above.

The vehicle CC is provided with an ignition key (not shown). The ignition key is turned off or on by being operated by an operator (for example, the driver of the vehicle CC). The engine of the vehicle CC starts when the ignition key is on, and the engine of the vehicle CC does not start when the ignition key is off.

After the MPU 62 is activated in step S13, it is checked in step S14 whether or not the ignition key is in the ON state, and when the ignition key is in the ON state, an engine start signal indicating that effect is transmitted to the ECU 1a. .. When the engine start signal is received by the ECU 1a, the process proceeds to step S15. The engine start signal is transmitted to the ECU 1a from the ECU that detects the state of the ignition key, which is different from the ECU 1a (the same applies to the engine stop signal described later).

In step S15, the MPU 62 switches the signal Boost_EN from low level to high level. After that, the signal Boost_EN is maintained at a high level until the ignition key is turned off. After step S15, the process proceeds to step S16.

In step S16, the MPU 62 switches the operation mode from the normal mode to the diagnostic mode and performs a predetermined boost diagnosis process. In the diagnostic mode, the signal FET_EN is set to a high level as described above. In the boost diagnosis process, the presence or absence of an abnormality in the boost power supply circuit 20 is diagnosed (diagnosis method will be described later). For example, a failure in which the transistor 21 is fixed in the off state regardless of the gate potential of the transistor 21 (see FIG. 5) is one aspect of the abnormality of the boost power supply circuit 20. After the step-up diagnosis process in step S16 is completed, the process proceeds to step S17.

In step S17, the MPU 62 returns the operating mode from the diagnostic mode to the normal mode. Therefore, the signal FET_EN is returned from the high level to the low level in step S17, and the signal FET_EN is maintained at the low level unless the transition to the diagnostic mode is performed again thereafter. After step S17, the process proceeds to step S18.

In step S18, the diagnosis result of the boost diagnosis process in step S16 is confirmed, and if it is determined that there is no abnormality in the boost power supply circuit 20 (in other words, when it is not determined that there is an abnormality), the process proceeds to step S19. If it is determined that the boost power supply circuit 20 has an abnormality, the process proceeds to step S30.

In step S19, it is checked whether or not the ignition key is in the off state, and when the ignition key is in the off state, an engine stop signal indicating that effect is transmitted to the ECU 1a. When the engine stop signal is received by the ECU 1a, the process proceeds to step S20.

In step S20, the MPU 62 switches the signal Boost_EN from high level to low level. After that, the process returns to step S14, and the above-mentioned processes after step S14 are repeated.

In step S30, the MPU 62 performs a predetermined error processing. In the error processing, the MPU 62 transmits a predetermined error signal to an ECU different from the ECU 1a. The ECU that has received the error signal displays a predetermined warning on, for example, a display device provided in the vehicle CC. After the error processing, the MPU 62 switches the signal Boost_EN from the high level to the low level and proceeds to step S19.

A switch composed of MOSFET or the like is inserted between the negative output terminal of the voltage source VS2 and the ground, or between the positive output terminal of the voltage source VS2 and the input terminal 20 _IN. You can stay. In this case, the MPU 62 may turn on the switch in synchronization with the switching of the signal Boost_EN to the high level, and turn off the switch in synchronization with the switching of the signal Boost_EN to the low level. In the following, unless otherwise specified, the signal Boost_EN is assumed to be at a high level.

[Normal case]
FIG. 10 shows the waveform 610 of the main power supply voltage VM in the normal case. The normal case is a case in which both the power supply circuits 10 and 20 operate as designed without any abnormality.

In the normal case of FIG. 10, a transition from the normal mode to the diagnostic mode occurs at the timing Ta1 through the operation of the ignition key, and then the boost diagnostic process is performed between the timings Ta1 and Ta2, and the diagnostic mode is performed at the timing Ta2. A transition from to normal mode occurs.

After its own activation, the boost power supply circuit 20 stops the boosting operation when the feedback voltage VfbB is higher than the reference voltage VrefB. That is, the boost power supply circuit 20 stops the boost operation when the main power supply voltage VM is higher than the boost target voltage VtgB after its own activation. In the boost power supply circuit 20, the control circuit 26 controls the state of the transistor 21 so that the feedback voltage VfbB matches or approaches the reference voltage VrefB, but the boost operation is performed when the feedback voltage VfbB is higher than the reference voltage VrefB. This is because the error between the voltages VfbB and VrefB increases. Stopping the boosting operation means keeping the transistor 21 in the off state without switching the transistor 21.

In the normal mode before the timing Ta1, the step-down target voltage VtgA (VtgA_N) is higher than the step-up target voltage VtgB (VtgB_N) (see FIGS. 6 and 7). This holds even if these fluctuation ranges are taken into consideration (see FIG. 8 (a)). Therefore, in the normal mode before the timing Ta1, the step-down power supply circuit 10 performs the step-down operation so that the main power supply voltage VM matches the step-down target voltage VtgA (VtgA_N), while the step-up power supply circuit 20 performs the step-up operation. It will be stopped.

After its own activation, the step-down power supply circuit 10 stops the step-down operation when the feedback voltage VfbA is higher than the reference voltage VrefA. That is, the step-down power supply circuit 10 stops the step-down operation when the main power supply voltage VM is higher than the step-down target voltage VtgA after its own activation. In the step-down power supply circuit 10, the control circuit 16 controls the state of the transistor 11 so that the feedback voltage VfbA matches or approaches the reference voltage VrefA, but the step-down operation is performed when the feedback voltage VfbA is higher than the reference voltage VrefA. This is because the error between the voltages VfbA and VrefA increases. Stopping the step-down operation means keeping the transistor 11 in the off state without switching the transistor 11.

In the diagnostic mode between timings Ta1 and Ta2, the step-up target voltage VtgB (VtgB_S) is higher than the step-down target voltage VtgA (VtgA_S) (see FIGS. 6 and 7). This holds even if these fluctuation ranges are taken into consideration (see FIG. 8 (b)). Therefore, in the diagnostic mode between the timings Ta1 and Ta2, the step-up power supply circuit 20 performs the step-up operation so that the main power supply voltage VM matches the step-up target voltage VtgB (VtgB_S), while the step-down power supply circuit 10 performs the step-down operation. Is stopped.

The normal mode is returned at the timing Ta2, but the operation of the normal mode after the timing Ta2 is the same as the operation of the normal mode before the timing Ta1. That is, in the normal mode after the timing Ta2, the step-down operation is performed in the step-down power supply circuit 10 so that the main power supply voltage VM matches the step-down target voltage VtgA (VtgA_N), while the step-up operation is stopped in the step-up power supply circuit 20. Will be done.

Immediately after the operation mode is switched, the step-down operation and the step-up operation may coexist for a short time, and the main power supply voltage VM may be slightly disturbed.

The boost diagnostic process of step S16 (see FIG. 9) is executed between the timings Ta1 and Ta2. In the diagnostic mode, the voltage based on the boost operation, which is expected to match the boost target voltage VtgB_S, should appear as the mains voltage VM. Therefore, the MPU 62 acquires the voltage Vdet (see FIG. 3) in the diagnostic mode as the evaluation voltage Vdet. At this time, in order to exclude the influence of the fluctuation of the main power supply voltage VM due to the mode transition, the voltage Vdet after the transition from the normal mode to the diagnostic mode and the elapse of a predetermined stable time is acquired as the evaluation voltage Vdet. For example, the voltage Vdet immediately before the timing Ta2 may be acquired as the evaluation voltage Vdet.

Then, the MPU 62 determines whether or not the main power supply voltage VM in the diagnostic mode has a voltage within the fluctuation range of the boost target voltage VtgB_S in the diagnostic mode based on the evaluation voltage Vdet, thereby determining whether or not the boost power supply circuit has a voltage within the fluctuation range of the boost target voltage VtgB_S in the diagnostic mode. Diagnose the presence or absence of 20 abnormalities. That is, in the boost diagnosis process, based on the evaluation voltage Vdet, it is determined whether or not the normal boost condition that the main power supply voltage VM in the diagnosis mode is equal to or lower than the voltage VtgB_S_H and equal to or higher than the voltage VtgB_S_L is satisfied ( See FIG. 8 (b)). It is possible to judge the success or failure of the normal boosting condition from the resistance value ratio between the voltage dividing resistors R7 and R8, which is known information, and the evaluation voltage Vdet. Then, when the normal boosting condition is satisfied, it is determined that there is no abnormality in the boosting power supply circuit 20, and when the normal boosting condition is not satisfied, it is determined that there is an abnormality in the boosting power supply circuit 20. In the normal case of FIG. 10, the normal boosting condition is satisfied.

The MPU 62 includes an A / D converter. The MPU 62 converts the analog evaluation voltage Vdet into a digital voltage value by the A / D converter, and determines whether the boost normal condition is satisfied / unsatisfied based on the obtained voltage value. Alternatively, instead of the A / D converter, the ECU 1a may be provided with a window comparator composed of a plurality of comparators, and the window comparator may be used to determine the satisfaction / non-satisfaction of the normal boosting condition.

_{If, at any timing after timing Ta2, a disconnection occurs between the voltage source VS1 and the input terminal 10 OUT} due to an accident in the vehicle CC, etc., the main power supply voltage VM will change as the step-down operation stops. The step-down target voltage VtgA_N (for example, 5.14V) decreases, but when the main power supply voltage VM drops to the vicinity of the step-up target voltage VtgB_N (for example, 4.85V), the step-up operation accompanied by switching of the transistor 21 starts. Then, the main power supply voltage VM is maintained in the vicinity of the boost target voltage VtgB_N. That is, the continuation of operation of the CAN transceiver 61, the communication module 63, and the like is guaranteed based on the output power of the voltage source VS2 as a spare battery, and the functions of the vehicle emergency notification system can be effectively used.

[Boost abnormal case]
FIG. 11 shows a waveform 620 of the main power supply voltage VM in the case of abnormal boosting. In the step-up abnormal case illustrated in FIG. 11, the step-down power supply circuit 10 operates as designed without any abnormality, but the step-up power supply circuit 20 cannot be boosted due to a failure.

In the case of abnormal boosting in FIG. 11, a transition from the normal mode to the diagnostic mode occurs at the timing Tb1 via the operation of the ignition key, and then the boosting diagnostic processing is performed between the timings Tb1 and Tb2, and the diagnosis is performed at the timing Tb2. A transition from mode to normal mode occurs.

In the normal mode before the timing Tb1, the step-down target voltage VtgA (VtgA_N) is higher than the step-up target voltage VtgB (VtgB_N) (see FIGS. 6 and 7). This holds even if these fluctuation ranges are taken into consideration (see FIG. 8 (a)). Therefore, in the normal mode before the timing Tb1, the step-down power supply circuit 10 performs the step-down operation so that the main power supply voltage VM matches the step-down target voltage VtgA (VtgA_N), while the step-up power supply circuit 20 performs the step-up operation. It will be stopped.

In the diagnostic mode between timings Tb1 and Tb2, the step-up target voltage VtgB (VtgB_S) is higher than the step-down target voltage VtgA (VtgA_S) (see FIGS. 6 and 7). However, in the case of abnormal boosting in FIG. 11, the boosting operation of the boosting power supply circuit 20 is disabled due to a failure, so that the boosting operation is stopped in the diagnostic mode between the timings Tb1 and Tb2. Then, in the diagnostic mode between the timings Tb1 and Tb2, the step-down power supply circuit 10 performs the step-down operation so that the main power supply voltage VM and the step-down target voltage VtgA (VtgA_S) match. Even in the normal mode after the timing Tb2, the step-down power supply circuit 10 performs the step-down operation so that the main power supply voltage VM and the step-down target voltage VtgA (VtgA_N) match.

Since the step-down target voltage VtgA changes as the mode is switched, in the step-up abnormality case of FIG. 11, the main power supply voltage VM is moved from the relatively high step-down target voltage VtgA_N to the relatively low step-down target voltage VtgA_S starting from the timing Tb1. After decreasing, it stabilizes at the step-down target voltage VtgA_S, and then the main power supply voltage VM rises from the relatively low step-down target voltage VtgA_S to the relatively high step-down target voltage VtgA_N starting from the timing Tb2, and then the step-down target voltage. Stabilize with VtgA_N.

The boost diagnostic process of step S16 (see FIG. 9) is executed between the timings Tb1 and Tb2. In the diagnostic mode, the voltage based on the boost operation, which is expected to match the boost target voltage VtgB_S, should appear as the mains voltage VM. Therefore, the MPU 62 acquires the voltage Vdet (see FIG. 3) in the diagnostic mode as the evaluation voltage Vdet. At this time, in order to exclude the influence of the fluctuation of the main power supply voltage VM due to the mode transition, the voltage Vdet after the transition from the normal mode to the diagnostic mode and the elapse of a predetermined stable time is acquired as the evaluation voltage Vdet. For example, the voltage Vdet immediately before the timing Tb2 may be acquired as the evaluation voltage Vdet.

Then, the MPU 62 determines whether or not the main power supply voltage VM in the diagnostic mode has a voltage within the fluctuation range of the boost target voltage VtgB_S in the diagnostic mode based on the evaluation voltage Vdet, thereby determining whether or not the boost power supply circuit 20 has a voltage within the fluctuation range of the boost target voltage VtgB_S. Diagnose the presence or absence of abnormalities. The method of this determination and diagnosis is as described above in relation to the normal case of FIG. In the case of abnormal step-up in FIG. 11, a relatively low voltage corresponding to the target voltage-down voltage VtgA_S is acquired as the evaluation voltage Vdet, so that the normal step-up condition is not satisfied. Therefore, it is determined that the boost power supply circuit 20 has an abnormality.

Even if the step-up power supply circuit 20 does not perform the step-up operation in the diagnostic mode, the step-down target voltage VtgA_S in the diagnostic mode satisfies the voltage accuracy required for the main power supply voltage VM, so that no problem occurs.

The power supply device W according to the present invention embodied in the present embodiment will be considered. The power supply device W in the ECU 1a has a step-down output terminal (10 _OUT ), and a step-down power supply circuit (10) capable of outputting a step-down output voltage from the step-down output terminal by stepping down the voltage from the first voltage source (VS1). A boost power supply circuit (20) having a boost output terminal (20 _OUT ) and capable of outputting a boost output voltage from the boost output terminal by boosting the voltage from the second voltage source (VS2), and a step-down output terminal. The main power supply line (LN1) to which the step-up output terminal is connected in common and the main power supply voltage (VM) based on the output of the step-down power supply circuit or the output of the step-up power supply circuit is applied, and the step-down target voltage (LN1) which is the target of the step-down output voltage ( It includes a control unit (62) that sets a VtgA) and a boost target voltage (VtgB) that is a target of the boost output voltage, and the control unit sets the step-down target voltage (VtgA) higher than the boost target voltage (VtgB). It can operate in the normal mode or the diagnostic mode in which the step-up target voltage (VtgB) is set higher than the step-down target voltage (VtgA), and is characterized in that the presence or absence of an abnormality in the boost power supply circuit is diagnosed in the diagnostic mode.

When the main first voltage source is connected to the step-down power supply circuit, the wiring between the first voltage source and the step-down power supply circuit is broken while preventing the stored energy of the second voltage source as a spare battery from being consumed. Is required to immediately supply power from the spare battery. The power supply device W can basically respond to this request by operating in the normal mode. On top of that, by enabling the operation in the diagnostic mode, it is possible to easily diagnose the presence or absence of an abnormality in the boost power supply circuit. At this time, the expensive transistor (corresponding to M900 in FIG. 15) required in the configuration of FIG. 15 is unnecessary. Further, deterioration of voltage accuracy due to the installation of such a transistor is avoided.

In the power supply device W (see FIG. 6), the control unit lowers the step-down target voltage and raises the step-up target voltage based on the normal mode, thereby lowering the step-up target voltage in the diagnostic mode. It is better to set it higher than the target voltage.

This makes it possible to relatively easily meet the voltage accuracy required for the mains supply voltage in both the normal mode and the diagnostic mode.

More specifically, in the power supply device W, the step-down power supply circuit (10) is a step-down switching regulator that has a step-down transistor (11) and generates a step-down output voltage by a step-down operation accompanied by switching of the step-down transistor. Therefore, the step-down operation is executed or stopped according to the relationship between the main power supply voltage (VM) and the step-down target voltage (VtgA), and the step-up power supply circuit (20) has a step-up transistor (21) and is a step-up transistor. It is a boost switching regulator that generates a boost output voltage by a boost operation accompanied by switching of the above, and executes or stops the boost operation according to the relationship between the main power supply voltage (VM) and the boost target voltage (VtgB).

As a result, for example, in the normal mode, the step-down power supply circuit performs a step-down operation so that the main power supply voltage matches the step-down target voltage (VtgA_N; for example, 5.14V), while the step-up power supply circuit “main power supply voltage ≈ step-down target voltage”. > Stop the boosting operation because it is the "boosting target voltage". In the diagnostic mode, the step-up power supply circuit performs a step-up operation so that the main power supply voltage matches the step-up target voltage (VtgB_S; for example, 5.14V), while the step-down power supply circuit "main power supply voltage ≒ boost target voltage> step-down target voltage". Therefore, the step-down operation is stopped.

The power supply device W according to the first embodiment is composed of a series circuit of a plurality of voltage dividing resistors, and is a voltage divider circuit (DIV1) for generating a step-down feedback voltage (VfbA) by dividing the main power supply voltage. And a voltage divider circuit (DIV2) for boosting, which is composed of a series circuit of a plurality of other voltage dividing resistors and generates a boosting feedback voltage (VfbB) by dividing the main power supply voltage. Executes or stops the step-down operation so that the step-down feedback voltage matches or approaches the predetermined step-down reference voltage (VrefA), and the boost power supply circuit matches the step-up feedback voltage with the predetermined boost reference voltage (VrefB). Alternatively, the step-up operation is executed or stopped so as to approach, the step-down voltage divider circuit and the step-up voltage divider circuit are configured so that the voltage divider ratios are variable, and the control unit (62) is a step-down voltage divider circuit. The step-down target voltage (VtgA) can be variably set through the variable setting of the voltage dividing ratio in, and the boosted target voltage (VtgB) can be variably set through the variable setting of the voltage dividing ratio in the voltage dividing circuit for boosting.

In the power supply device W according to the first embodiment, the control unit (62) diagnoses the presence or absence of an abnormality in the boost power supply circuit based on the main power supply voltage (VM) in the diagnosis mode.

In the diagnostic mode, the voltage based on the boosting operation of the boosted power supply circuit should appear as the main power supply voltage, so this configuration can correctly diagnose the presence or absence of an abnormality in the boosted power supply circuit.

More specifically, for example, the control unit (62) determines whether or not the main power supply voltage (VM) in the diagnostic mode is within a predetermined normal voltage range corresponding to the boost target voltage (VtgB_S) in the diagnostic mode. By detecting this, the presence or absence of an abnormality in the boost power supply circuit may be diagnosed. The normal voltage range here may be, for example, a voltage range of voltage VtgB_S_H or less and voltage VtgB_S_L or more (see FIG. 8B).

Further, in the power supply device W, a voltage accuracy specification that requires the main power supply voltage (VM) to be within a predetermined voltage range (RNG) is defined for the main power supply voltage, and the step-down target voltage in the normal mode is defined. And the step-up target voltage, and the step-down target voltage and the step-up target voltage in the diagnostic mode are all preferably within the predetermined voltage range.

This makes it possible to satisfy the voltage accuracy required for the main power supply voltage in both the normal mode and the diagnostic mode.

The notification module according to the present invention provided with the power supply device W is a notification module (1; 1a in the first embodiment) mounted on the vehicle (CC), and acquires position information indicating the position of the vehicle. A position information acquisition device (64) to be mounted on the vehicle, and an external communication device (63) capable of wirelessly transmitting a predetermined emergency call signal including the position information to an external device when a predetermined report condition is satisfied. An in-vehicle communication device (61) that communicates with other circuits is provided, and a position information acquisition device, an external communication device, an in-vehicle communication device, and a control unit (62) in the power supply device are used as main power supply voltages. It is preferable that the configuration is driven based on (VM).

As a result, it is possible to form a notification module that includes the superiority of the power supply device W.

<< Second Embodiment >>
A second embodiment of the present invention will be described. The second embodiment and the third and fourth embodiments described later are embodiments based on the first embodiment, and the matters not particularly described in the second to fourth embodiments are the first unless there is a contradiction. The description of the embodiment also applies to the second to fourth embodiments. In interpreting the description of the second embodiment, the description of the second embodiment may be prioritized for matters that conflict between the first and second embodiments (the same applies to the third and fourth embodiments described later). .. As long as there is no contradiction, any plurality of embodiments may be combined among the first to fourth embodiments. When the matter described in the first embodiment is applied to the second embodiment, the description "ECU 1a" in the first embodiment is read as "ECU 1b" in the second embodiment.

FIG. 12 shows the configuration of the ECU 1b according to the second embodiment. In the second embodiment, the ECU 1b of FIG. 12 is used as the ECU 1 of FIG. The ECU 1b in FIG. 12 is a modification of the ECU 1a in FIG. That is, the ECU 1b is formed by deleting the voltage dividing circuits DIV1 and DIV2 with reference to the ECU 1a of FIG. 3 and providing the voltage dividing circuit DIV4 instead. In other respects, since the ECU 1a and the ECU 1b have the same configuration as each other, duplicate description of the same portion will be omitted.

The voltage dividing circuit DIV4 provided in the ECU 1b includes voltage dividing resistors R11 to R14 and a transistor M3 configured as an N-channel MOSFET. A series circuit of the voltage dividing resistors R11 to R14 is arranged between the main power supply line LN1 and the ground, and at this time, the voltage dividing resistors R11, R12, R13, and R14 are arranged in this order from the main power supply line LN1 toward the ground. Placed in. More specifically, one end of the voltage dividing resistor R11 is connected to the main power supply line LN1, the other end of the voltage dividing resistor R11 is connected to one end of the voltage dividing resistor R12 by the node ND11, and the other end of the voltage dividing resistor R12. Is connected to one end of the voltage dividing resistor R13 at the node ND 12, the other end of the voltage dividing resistor R13 is connected to one end of the voltage dividing resistor R14 at the node ND 13, and the other end of the voltage dividing resistor R14 is connected to the ground. .. The drain of the transistor M3 is connected to the node ND12, and the source of the transistor M3 is connected to the node ND13.

In the ECU 1b, the voltage generated in the node ND 13 is input to the step-down power supply circuit 10 as the feedback voltage VfbA, and the voltage generated in the node ND 11 is input to the step-up power supply circuit 20 as the feedback voltage VfbB. As described above, the voltage dividing circuit DIV4 has a function of generating feedback voltages VfbA and VfbB by dividing the main power supply voltage VMs at different voltage dividing ratios, and is a component for generating the feedback voltage VfbA from the main power supply voltage VM. The pressure ratio and the voltage dividing ratio when the feedback voltage VfbB is generated from the main power supply voltage VM are configured to be changed at the same time by turning on / off the transistor M3.

More specifically, when the resistance values of the voltage dividing resistors R11, R12, R13, and R14 are represented by the symbols "R11", "R12", "R13", and "R14", respectively, the main power supply voltage VM is divided. The voltage dividing ratio when the feedback voltage VfbA is generated by pressing is "R14 / (R11 + R12 + R13 + R14)" when the transistor M3 is off, while it is "R14 / (R11 + R12 + R14)" when the transistor M3 is on. The voltage division ratio when the feedback voltage VfbB is generated by dividing the main power supply voltage VM is "(R12 + R13 + R14) / (R11 + R12 + R13 + R14)" when the transistor M3 is off, while "(R12 + R12 + R13 + R14)" when the transistor M3 is on. R12 + R14) / (R11 + R12 + R14) ”. However, here, it is assumed that the on-resistance of the transistor M3 is sufficiently low to be zero.

The signal FET_EN from the MPU 62 is input to the gate of the transistor M3. The transistor M3 is off when the signal FET_EN is low level, and the transistor M3 is on when the signal FET_EN is high level. The method of controlling the level of the signal FET_EN is as shown in the first embodiment. Therefore, the signal FET_EN is set to a low level in the normal mode, and the signal FET_EN is set to a high level in the diagnostic mode.

Therefore, in the ECU 1b, the feedback voltage VfbA is higher in the diagnostic mode than in the normal mode, and the feedback voltage VfbB is lower in the diagnostic mode than in the normal mode. As a result, in the ECU 1b, the step-down target voltage VtgA is lower in the diagnostic mode than in the normal mode, and the step-up target voltage VtgB is higher in the diagnostic mode than in the normal mode.

Characteristics of step-down target voltage VtgA and step-up target voltage VtgB, including satisfying the above-mentioned first to fourth inequality and keeping all four target voltages VtgA_N, VtgA_S, VtgB_N and VtgB_S within a predetermined specified voltage range RNG. Is as described in the first embodiment (each resistance value of the voltage dividing resistors R11 to R14 and the values of the reference voltages VrefA and VrefB are defined so as as described in the first embodiment).

Since the ECU 1b shares the voltage dividing resistance ladder for setting the step-down target voltage and the boosting target voltage, the potential difference between the step-down target voltage and the boosting target voltage is larger than that in the case where the voltage dividing resistance ladder is provided for each power supply circuit. The accuracy can be improved (the voltage dividing resistance variation of the voltage dividing circuit DIV1 and the voltage dividing resistance variation of the voltage dividing circuit DIV2, which occur in the configuration of FIG. 3, are canceled out in the configuration of FIG. 12). .. As a result, the requirements for the step-down target voltage and the step-up target voltage as shown in FIGS. 6, 7 and 8 (a) and 8 (b) can be easily satisfied. Further, the number of transistors used for switching the voltage division ratio can be reduced (two transistors M1 and M2 are required in the configuration of FIG. 3, while one transistor M3 is sufficient in the configuration of FIG. 12).

The voltage dividing circuit DIV4 has an arbitrary configuration as long as the above-mentioned relationship between the step-down target voltage and the step-up target voltage in each of the normal mode and the diagnostic mode is satisfied.

For example, the transistor M3 constitutes a bypass circuit connected in parallel to the voltage dividing resistor R13, and in the voltage dividing circuit DIV4 of FIG. 12, a parallel circuit of the voltage dividing resistor R13 and the bypass circuit is performed when the transistor M3 is turned on. However, if the resistance value of the parallel circuit of the voltage dividing resistor R13 and the bypass circuit becomes smaller when the transistor M3 is on than when the transistor M3 is off. , The configuration of the bypass circuit of the voltage dividing circuit DIV4 is arbitrary. For example, the bypass circuit of the voltage dividing circuit DIV4 may be a series circuit of the transistor M3 and the resistor.

That is, it can be said that the power supply device W according to the second embodiment has the following configuration. The power supply device W is composed of a series circuit of a plurality of voltage dividing resistors, and is a voltage dividing circuit that generates a step-down feedback voltage (VfbA) and a boosting feedback voltage (VfbB) by dividing the main power supply voltage by different voltage dividing ratios. (DIV4) is further provided, and in this voltage dividing circuit (DIV4), a bypass circuit (M3 in the example of FIG. 12) is parallel to a partial voltage dividing resistance (R13 in the example of FIG. 12) of a plurality of voltage dividing resistors. The control unit (62) is connected, and by controlling the state of the bypass circuit, the resistance value of the parallel circuit between the partial voltage dividing resistance and the bypass circuit is made variable, and the parallel circuit is switched between the normal mode and the diagnostic mode. By changing the resistance value, the voltage dividing ratio for obtaining the step-down feedback voltage from the main power supply voltage and the voltage dividing ratio for obtaining the boosting feedback voltage from the main power supply voltage are changed at the same time, thereby changing the step-down target voltage and the boost target voltage. Is changed at the same time.

<< Third Embodiment >>
A third embodiment of the present invention will be described. When the description of the first or second embodiment is applicable to the third embodiment and the matters described in the first or second embodiment are applied to the third embodiment, the description in the first embodiment " The description "ECU1a" or the description "ECU1b" in the second embodiment is read as "ECU1c" in the third embodiment.

FIG. 13 shows the configuration of the ECU 1c according to the third embodiment. In the third embodiment, the ECU 1c of FIG. 13 is used as the ECU 1 of FIG. The ECU 1c of FIG. 13 is a modified version of the ECU 1b of FIG. That is, the ECU 1c is formed by deleting the voltage dividing circuit DIV3 with reference to the ECU 1b of FIG. 12 and providing a monitor circuit 30 instead. In other respects, the ECU 1b and the ECU 1c have the same configuration as each other, so that duplicate description of the same portion will be omitted. In the ECU 1c of FIG. 13, instead of the method of generating the reference voltages VrefA and VrefB in the second embodiment, it is also possible to adopt the method of generating the reference voltages VrefA and VrefB in the first embodiment (that is, FIG. The voltage dividing circuit DIV3 may be deleted with reference to the ECU 1a of 3, and the monitor circuit 30 may be provided instead to form the ECU 1c).

The monitor circuit 30 is connected to the boost power supply circuit 20 and derives a voltage Vdet2 that depends on whether or not the boost power supply circuit 20 is performing the boost operation.

FIG. 14 shows a configuration example of the boost power supply circuit 20 and the monitor circuit 30. The boost power supply circuit 20 of FIG. 14 is the same as the boost power supply circuit 20 of FIG. The monitor circuit 30 includes a diode 31 that functions as a freewheeling diode (rectifier diode), a smoothing capacitor 32, and voltage dividing resistors 33 and 34. Each anode of the diode 22 and the diode 31 is commonly connected to the drain of the transistor 21. The cathode of the diode 31 is connected to the monitor line LN1'. One end of the smoothing capacitor 32 is connected to the monitor line LN1', and the other end of the smoothing capacitor 32 is connected to the ground. One end of the voltage dividing resistor 33 is connected to the monitor line LN1', and the other end of the voltage dividing resistor 33 is connected to the ground via the voltage dividing resistor 34. The voltage applied to the monitor line LN1'is referred to as voltage VMdmy. A voltage Vdet2, which is a voltage divider of the voltage VMdmy, is generated at the connection node between the voltage dividing resistors 33 and 34.

With the above configuration, when the boosting operation is not performed, the voltage VMdmy becomes a voltage (VB-Vf) lower than the output voltage VB of the voltage source VS2 by the forward voltage Vf of the diode 31. When the boosting operation is performed, a voltage obtained by boosting the voltage VB and different from the voltage at the output terminal 20 _OUT (that is, the main power supply voltage VM) appears as the voltage VMdmy. The voltage VMdmy corresponds to a voltage imitating the mains voltage VM, and when the boosting operation is performed, the voltage VMdmy has substantially the _{same voltage value as the voltage at the output terminal 20 OUT} (that is, the mains voltage VM). Is expected. Therefore, by observing the voltage VMdmy, it is possible to diagnose whether the boosting operation is normally executed. In the configurations of FIGS. 13 and 14, the voltage VMdmy is evaluated using the voltage Vdet2, which is a voltage divider of the voltage VMdmy.

[Use of monitor circuit in diagnostic mode]
The boost diagnostic process in the diagnostic mode using the monitor circuit 30 will be described. In order to embody the description, FIG. 10 or FIG. 11 will be referred to again to explain the boost diagnosis process in the above-mentioned normal case or boost abnormal case. In the normal case of FIG. 10, in the diagnostic mode between the timings Ta1 and Ta2, as described in the first embodiment, the boost power supply circuit 20 so that the main power supply voltage VM matches the boost target voltage VtgB (VtgB_S). While the step-up operation is performed, the step-down operation is stopped in the step-down power supply circuit 10. In the step-up abnormality case of FIG. 11, in the diagnostic mode between timings Tb1 and Tb2, as described in the first embodiment, the step-up operation is stopped due to a failure, and the main power supply voltage VM and the step-down target voltage VtgA (VtgA_S). The step-down power supply circuit 10 performs a step-down operation so as to match with.

The boost diagnostic process of step S16 (see FIG. 9) is executed between timings Ta1 and Ta2 in the normal case and between timings Tb1 and Tb2 in the abnormal boosting case. In the diagnostic mode, the voltage based on the boosting operation and expected to match the boosting target voltage VtgB_S should appear as the main power supply voltage VM, and in conjunction with this, the boosting target voltage VtgB_S and The voltage expected to match should appear as the voltage VMdmy. Therefore, the MPU 62 acquires the voltage Vdet2 in the diagnostic mode as the evaluation voltage Vdet2. At this time, in order to exclude the influence of the fluctuation of the voltage VM and VMdmy due to the mode transition, the voltage Vdet2 after the transition from the normal mode to the diagnostic mode and the elapse of a predetermined stable time is acquired as the evaluation voltage Vdet2. For example, the voltage Vdet2 immediately before the timing Ta2 or Tb2 may be acquired as the evaluation voltage Vdet2.

The MPU 62 diagnoses the presence or absence of an abnormality in the boost power supply circuit 20 by determining whether or not the predetermined boost normal condition is satisfied / unsatisfied based on the evaluation voltage Vdet2. Then, when the normal boosting condition is satisfied, it is determined that there is no abnormality in the boosting power supply circuit 20, and when the normal boosting condition is not satisfied, it is determined that there is an abnormality in the boosting power supply circuit 20.

The success / failure judgment (satisfaction / unsatisfaction judgment) of the normal boosting condition is performed under the assumption that the voltages VM and VMdmy have the same voltage value. The boost normal condition is a condition that the voltage VMdmy in the diagnostic mode is within a predetermined normal voltage range. The normal voltage range here is a voltage range corresponding to the boost target voltage (VtgB_S) in the diagnostic mode, and therefore may be a voltage range from the voltage VtgB_S_L to the voltage VtgB_S_H (see FIG. 8B). However, the lower limit of the normal voltage range can be set lower than the voltage VtgB_S_L (however, at least the lower limit voltage _LL of the specified voltage range RNG or more), and the upper limit of the normal voltage range is set higher than the voltage VtgB_S_H. (However, at least the upper limit voltage _HL of the specified voltage range RNG or less).

From the resistance value ratio between the voltage dividing resistors R7 and R8, which is known information, and the evaluation voltage Vdet2, it is possible to determine the success or failure of the normal boosting condition. The value of the lower limit voltage V _LL specifications voltage range RNG is higher than the nominal voltage value of the output voltage VB of the voltage source VS2 (e.g. 3V), if if the boosting operation in the diagnostic mode has stopped boost Normal conditions are never met.

In the normal case of FIG. 10, the normal boosting condition is satisfied. In the case of abnormal boosting in FIG. 11, the normal boosting condition is not satisfied because the boosting operation is stopped due to the failure of the boosting power supply circuit 20.

When monitoring the main power supply voltage VM as in the configuration of the first or second embodiment, the output of each power supply circuit is used to distinguish whether the main power supply voltage VM is based on a step-down operation or a step-up operation. It is required to improve the voltage accuracy and the reading accuracy of the voltage Vdet. In the third embodiment, such a request is relaxed because the voltage VMdmy of the monitor line LN1'which is directly separated from the main power supply line LN1 is monitored.

The MPU 62 includes an A / D converter. The MPU 62 converts the analog evaluation voltage Vdet2 into a digital voltage value by the A / D converter, and determines whether the boost normal condition is satisfied / unsatisfied based on the obtained voltage value. Alternatively, instead of the A / D converter, the ECU 1c may be provided with a window comparator composed of a plurality of comparators, and the window comparator may be used to determine the satisfaction / non-satisfaction of the normal boosting condition.

[Use of monitor circuit in normal mode (normal mode diagnostic processing)]
The monitor circuit 30 can function effectively even in the normal mode. The normal mode diagnostic process that the MPU 62 can perform using the monitor circuit 30 in the normal mode will be described.

The MPU 62 monitors whether or not the boosting operation is executed based on the voltage VMdmy (actually based on the voltage Vdet2) in the normal mode diagnostic processing, and when it is determined that the boosting operation is being executed, the MPU 62 is included in the ECU 1c. It is determined that there is an abnormality in the power supply device (hereinafter referred to as a specific abnormality for convenience). The power supply device included in the ECU 1c includes power supply circuits 10 and 20, and also includes a circuit for generating feedback voltages VfbA and VfbB (voltage dividing circuit DIV4 in FIG. 13). The specific abnormality is mainly an abnormality in any of the power supply circuits 10 and 20, but an abnormality in a circuit or the like that generates the feedback voltages VfbA and VfbB can also belong to the specific abnormality.

Basically, the boosting operation is not executed in the normal mode, and the voltage VMdmy should be a voltage lower than the output voltage VB of the voltage source VS2. However, if the boosting operation is executed in the normal mode due to some abnormality, the voltage VMdmy becomes higher than when the boosting operation is stopped. Therefore, in the normal mode diagnosis process, the MPU 62 may compare the voltage Vdet2 with the predetermined determination voltage Vth, and if the voltage Vdet2 is equal to or higher than the determination voltage Vth, determine that there is a specific abnormality (the voltage Vdet2 is less than the determination voltage Vth). If so, it is not judged that there is a specific abnormality). For example, the determination voltage Vth may be set so that “Vdet2 ≧ Vth” when “VMdmy ≧ V _LL”.

As the cases where the specific abnormality occurs, the following first specific abnormality case and second specific abnormality case are mainly assumed.
The first specific abnormality case is a case in which the step-down operation is stopped due to a failure of the step-down power supply circuit 10 in the normal mode, and the step-up power supply circuit 20 performs the step-up operation instead.
The second specific abnormality case is a case in which the step-down power supply circuit 10 does not have a failure in the normal mode, but the step-up power supply circuit 20 performs the step-up operation. For example, a case in which the boost target voltage VtgB exceeds the design value and is excessively increased corresponds to the second specific abnormality case. If an abnormality occurs in which the node to which the feedback voltage VfbB should be applied is short-circuited to the ground, the boost power supply circuit 20 performs the boost operation regardless of the main power supply voltage VM.

When it is determined that there is a specific abnormality, the MPU 62 performs a predetermined error processing. The error processing here may be the same as or similar to the error processing in step S30 (see FIG. 9).

The normal mode diagnostic process makes it possible to monitor the presence or absence of an abnormality in the power supply device (mainly an abnormality in the power supply circuit 10 or 20) even in the normal mode.

However, even in the normal mode, the MPU 62 may not execute the normal mode diagnostic process when the voltage VA drops. This is because the boosting operation is performed when the main power supply voltage VM drops as the voltage VA drops because of the correct behavior. Specifically, the ECU 1c is provided with a voltage detection circuit (not shown) for detecting the voltage VA, and when the voltage VA detected by the voltage detection circuit is equal to or lower than the predetermined drop determination voltage Vth2, the normal mode diagnosis is performed. It is good to make the process non-executive. While considering the characteristics of the step-down power supply circuit 10, for example, a voltage equal to or higher than the voltage VtgB_N_H is set to the drop determination voltage Vth2. If the voltage VA recovers (rises) and exceeds the drop judgment voltage Vth2 from the state in which the normal mode diagnostic process is not executed when the voltage VA becomes the predetermined drop judgment voltage Vth2 or less, the normal mode is used. The diagnostic process may be resumed.

<< Fourth Embodiment >>
A fourth embodiment of the present invention will be described. In the fourth embodiment, supplementary items, deformation techniques, and the like for the first to third embodiments will be described.

For any signal or voltage, the high-level and low-level relationships may be reversed in a manner that does not compromise the above-mentioned gist.

The channel types of FETs (Field Effect Transistors) shown in each embodiment are examples, so that the N-channel type FET is changed to the P-channel type FET, or the P-channel type FET is N-channel. The configuration of the circuit containing the FET can be modified so that it is changed to a type FET.

The above-mentioned arbitrary transistor may be any kind of transistor. For example, any transistor described above as a MOSFET (particularly, switching transistor M1) can be replaced with a junction FET, an IGBT (Insulated Gate Bipolar Transistor), or a bipolar transistor. Any transistor has a first electrode, a second electrode and a control electrode. In the FET, one of the first and second electrodes is a drain, the other is a source, and the control electrode is a gate. In the IGBT, one of the first and second electrodes is a collector, the other is an emitter, and the control electrode is a gate. In a bipolar transistor that does not belong to an IGBT, one of the first and second electrodes is a collector, the other is an emitter, and the control electrode is the base.

The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims. The above embodiments are merely examples of the embodiments of the present invention, and the meanings of the terms of the present invention and the constituent requirements are not limited to those described in the above embodiments. The specific numerical values shown in the above description are merely examples, and as a matter of course, they can be changed to various numerical values.

1,1a, 1b, 1c ECU
10 Step-down power supply circuit 20 Step-up power supply circuit 30 Monitor circuit 61 CAN transceiver 62 MPU
63 Communication module 64 GPS processing unit VS1 voltage source (first voltage source)
VS2 voltage source (second voltage source)
LN1 Main power supply line LN1'Monitor line DIV1 to DIV4 Voltage divider circuit

Claims (12)

A step-down power supply circuit having a step-down output terminal and capable of outputting a step-down output voltage from the step-down output terminal by stepping down the voltage from the first voltage source.
A boost power supply circuit that has a boost output terminal and can output a boost output voltage from the boost output terminal by boosting the voltage from the second voltage source.
A main power supply line in which the step-down output terminal and the step-up output terminal are commonly connected and a main power supply voltage based on the output of the step-down power supply circuit or the output of the step-up power supply circuit is applied.
A control unit for setting a step-down target voltage that is a target of the step-down output voltage and a step-up target voltage that is a target of the step-up output voltage is provided.
The control unit can operate in a normal mode in which the step-down target voltage is set higher than the step-up target voltage or a diagnostic mode in which the step-up target voltage is set higher than the step-down target voltage. A power supply device characterized by diagnosing the presence or absence of abnormalities in a circuit. The control unit is characterized in that the step-up target voltage is set higher than the step-down target voltage in the diagnostic mode by lowering the step-down target voltage and increasing the step-up target voltage based on the normal mode. The power supply device according to claim 1. The step-down power supply circuit is a step-down switching regulator that has a step-down transistor and generates the step-down output voltage by a step-down operation accompanied by switching of the step-down transistor, and is a relationship between the main power supply voltage and the step-down target voltage. The step-down operation is executed or stopped according to
The boost power supply circuit is a boost switching regulator that has a boost transistor and generates the boost output voltage by a boost operation accompanied by switching of the boost transistor, and is a relationship between the main power supply voltage and the boost target voltage. The power supply device according to claim 1 or 2, wherein the boosting operation is executed or stopped according to the above. A step-down voltage divider circuit that consists of a series circuit of a plurality of voltage divider resistors and generates a step-down feedback voltage by dividing the main power supply voltage.
It is further provided with a boosting voltage dividing circuit, which is composed of a series circuit of a plurality of other voltage dividing resistors and generates a boosting feedback voltage by dividing the main power supply voltage.
The step-down power supply circuit executes or stops the step-down operation so that the step-down feedback voltage matches or approaches a predetermined step-down reference voltage.
The boost power supply circuit executes or stops the boost operation so that the boost feedback voltage matches or approaches a predetermined boost reference voltage.
The step-down voltage divider circuit and the step-up voltage divider circuit are each configured so that the voltage division ratio is variable.
The control unit variably sets the step-down target voltage through the variable setting of the voltage dividing ratio in the step-down voltage dividing circuit, and variably sets the step-up target voltage through the variable setting of the voltage dividing ratio in the step-up voltage dividing circuit. The power supply device according to claim 3. It is composed of a series circuit of a plurality of voltage dividing resistors, and further includes a voltage dividing circuit that generates a step-down feedback voltage and a step-up feedback voltage by dividing the main power supply voltage at different voltage dividing ratios.
The step-down power supply circuit executes or stops the step-down operation so that the step-down feedback voltage matches or approaches a predetermined step-down reference voltage.
The boost power supply circuit executes or stops the boost operation so that the boost feedback voltage matches or approaches a predetermined boost reference voltage.
The voltage dividing circuit is configured so that the voltage dividing ratio for obtaining the step-down feedback voltage from the main power supply voltage and the voltage dividing ratio for obtaining the step-up feedback voltage from the main power supply voltage are variable.
The third aspect of claim 3, wherein the control unit simultaneously changes the step-down target voltage and the step-up target voltage by changing these voltage division ratios at the same time when switching between the normal mode and the diagnostic mode. Power supply. The series circuit of the plurality of voltage dividing resistors is inserted between the main power supply line and the ground.
In the voltage dividing circuit, a bypass circuit is connected in parallel to some of the voltage dividing resistors of the plurality of voltage dividing resistors.
The step-down feedback voltage and the step-up feedback voltage are generated in the first node and the second node which are different from each other in the series circuit, and the partial voltage dividing resistor to which the bypass circuit is connected in parallel is the same as the first node. Intervening between the second node and
The control unit changes the resistance value of the parallel circuit between the partial voltage dividing resistance and the bypass circuit by controlling the state of the bypass circuit, and the parallel circuit is switched between the normal mode and the diagnostic mode. By changing the resistance value of, the voltage dividing ratio for obtaining the step-down feedback voltage from the main power supply voltage and the voltage dividing ratio for obtaining the boosting feedback voltage from the main power supply voltage are simultaneously changed, thereby causing the step-down. The power supply device according to claim 5, wherein the target voltage and the boost target voltage are changed at the same time. The power supply device according to any one of claims 1 to 6, wherein the control unit diagnoses the presence or absence of an abnormality in the boost power supply circuit based on the main power supply voltage in the diagnosis mode. The control unit detects whether or not the main power supply voltage in the diagnostic mode is within a predetermined normal voltage range corresponding to the boosted target voltage in the diagnostic mode, thereby detecting the boosted power supply circuit. The power supply device according to claim 7, wherein the presence or absence of an abnormality is diagnosed. When connected to the boosting transistor and the boosting operation is being executed, a voltage that boosts the voltage from the second voltage source and is different from the voltage at the boosting output terminal is applied to a predetermined monitoring line. Further equipped with a monitor circuit to generate voltage
The power supply device according to any one of claims 3 to 6, wherein the control unit diagnoses the presence or absence of an abnormality in the boost power supply circuit based on the voltage of the monitor line in the diagnosis mode. The control unit can execute the normal mode diagnostic process in the normal mode, and in the normal mode diagnostic process, monitors whether or not the boosting operation is executed based on the voltage of the monitor line, and the boosting is performed. The power supply device according to claim 9, wherein when it is determined that the operation is being executed, it is determined that the power supply device has an abnormality. A voltage accuracy specification that requires the main power supply voltage to be within a predetermined voltage range is defined for the main power supply voltage.
Claims 1 to 10 are characterized in that the step-down target voltage and the step-up target voltage in the normal mode, and the step-down target voltage and the step-up target voltage in the diagnostic mode are all within the predetermined voltage range. The power supply according to any one of. A notification module including the power supply device according to any one of claims 1 to 11 and mounted on a vehicle.
A position information acquisition device that acquires position information representing the position of the vehicle, and
An external communication device that can wirelessly transmit a predetermined emergency call signal including the location information to an external device when a predetermined report condition is satisfied.
It is provided with an in-vehicle communication device that communicates with other circuits mounted on the vehicle.
A notification module characterized in that the position information acquisition device, the external communication device, the in-vehicle communication device, and the control unit in the power supply device are driven based on the main power supply voltage.

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