Electronic devices

Abstract

To provide an electronic control device that can prevent reverse current flow while suppressing heat generation. [Solution] The electronic control device 100 includes a positive terminal 91 connected to the positive terminal of an external power supply, a negative terminal 92 connected to the negative terminal of an external power supply, a load circuit 40, an internal power supply circuit 50 that supplies power to the load circuit when the power supply from the external power supply is stopped, a PMOS 10, and an NMOS 70. The PMOS includes a body diode 12 provided between the positive terminal and the load circuit and the internal power supply circuit, with the anode connected to the positive terminal side and the cathode connected to the circuit element side. The NMOS prevents current from flowing from the internal power supply circuit to the external power supply side to the PMOS by the body diode when the positive terminal is ground faulted.

Description

Technical Field

[0001] This disclosure relates to an electronic device.

Background Art

[0002] As disclosed in Patent Document 1, there is an electronic device provided with a reverse current prevention diode for preventing reverse current.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when current is flowing normally in the electronic device (during normal operation), current flows through the reverse current prevention diode. Therefore, the electronic device has a problem that the heat generation of the reverse current prevention diode increases.

[0005] One object of the disclosure is to provide an electronic device that can prevent reverse current while suppressing heat generation.

Means for Solving the Problems

[0006] The electronic device disclosed herein is an electronic device connected to an external power supply device (200), a positive terminal (91) connected to the positive terminal of the external power supply device, a negative terminal (92) connected to the negative terminal of the external power supply device, a circuit element (40), an internal power supply circuit (50) that supplies power to the circuit element when power supply from the external power supply device is stopped, A reverse polarity protection switch (10) is provided between the positive terminal and the circuit element and internal power supply circuit, and includes a body diode with the anode connected to the positive terminal side and the cathode connected to the circuit element side. In the event of a ground fault at the positive terminal, the device is equipped with additional functional elements (70-73) that prevent current from flowing from the internal power supply circuit to the external power supply unit via a body diode to the reverse connection protection switch.

[0007] According to the electronic device disclosed herein, the body diode prevents current from flowing from the internal power supply circuit to the external power supply, i.e., prevents reverse current flow. Furthermore, when the external power supply is properly connected (during normal operation), the electronic device supplies power from the external power supply to the circuit elements via the body diode of the reverse-connection protection switch. Typically, a body diode has a lower resistance than a resistive element. Therefore, the electronic device can suppress heat generation more effectively than a configuration equipped with a diode element as a reverse-current prevention diode.

[0008] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The claims and the reference numerals in parentheses in this section are intended to illustrate an example of correspondence with parts of the embodiments described later, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings. [Brief explanation of the drawing]

[0009] [Figure 1] This is a circuit diagram showing the schematic configuration of the electronic control device in the first embodiment. [Figure 2] This is a circuit diagram showing the operation of an electronic control unit when the connection is reversed. [Figure 3] This is a circuit diagram showing the operation of the electronic control unit during a ground fault. [Figure 4] This is a circuit diagram showing the schematic configuration of the electronic control device in the second embodiment. [Figure 5]This is a circuit diagram showing the schematic configuration of the electronic control device in the third embodiment. [Modes for carrying out the invention]

[0010] In the following, several embodiments for implementing this disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in a prior embodiment may be denoted by the same reference numerals, and redundant descriptions may be omitted. If only a part of the configuration is described in each embodiment, other parts of the configuration can be referred to and applied to other embodiments described in advance.

[0011] (First Embodiment) The electronic control device 100 of this embodiment will be described with reference to Figures 1 to 3. In this embodiment, the electronic control device 100 is used as an example of an electronic device. The electronic control device 100 is configured to be mounted on a mobile device, for example. Examples of mobile devices include vehicles such as electric vehicles, hybrid vehicles, and fuel cell vehicles; aircraft such as electric vertical take-off and landing aircraft and drones; ships; construction machinery; agricultural machinery; and so on.

[0012] The electronic control unit 100 is configured to be electrically connectable to the external power supply unit 200 and the high-voltage power supply unit 300. Furthermore, the electronic control unit 100 is configured to be electrically connectable to external devices. In the drawings, the external power supply unit 200 is denoted as OP and the high-voltage power supply unit as HP.

[0013] The external power supply unit 200 is a power source that supplies operating power to the electronic control unit 100. The external power supply unit 200 has a positive terminal 201 and a negative terminal 202. The high-voltage power supply unit 300 is connected to the internal power supply circuit 50, which will be described later. The high-voltage power supply unit 300 supplies power to the internal power supply circuit 50.

[0014] External devices can include, for example, power conversion devices such as inverter devices. In this case, the electronic control unit 100 controls the power elements of the power conversion device by switching them on and off.

[0015] Note that the electronic control device 100 may be configured to grasp the state of the battery. In this case, the electronic control device 100 measures the voltage, current, temperature, etc. of the battery and monitors the input / output to the battery. Further, the electronic control device 100 performs cooling control of the battery and the like.

[0016] The electronic control device 100 includes a plurality of terminals 91 to 94. Reference numeral 91 denotes a positive terminal 91 to which the positive terminal 201 of the external power supply device 200 is connected. Reference numeral 92 denotes a negative terminal 92 to which the negative terminal 202 of the external power supply device 200 is connected. Reference numeral 93 denotes an internal power supply terminal 93 to which the high-voltage power supply device 300 is connected. Reference numeral 94 denotes an external load terminal 94 to which an external device is connected.

[0017] When the external power supply device 200 is properly connected (during normal connection), the positive terminal 91 is electrically connected to the positive terminal 201. Similarly, when normally connected, the negative terminal 92 is electrically connected to the negative terminal 202. Normal connection can also be said to be normal operation.

[0018] However, the external power supply device 200 may be connected to the electronic control device 100 with reverse polarity (during reverse connection). In this case, the positive terminal 91 is electrically connected to the negative terminal 202. The negative terminal 92 is electrically connected to the positive terminal 201.

[0019] As a hardware configuration, the electronic control device 100 includes a computer including a processor and a memory. Alternatively, the electronic control device 100 may have a configuration that does not include a processor and includes a hardware circuit other than the processor, or may have a configuration that includes a processor and a hardware circuit other than the processor.

[0020] Furthermore, as shown in Figure 1, the electronic control unit 100 includes, as a hardware configuration, a reverse connection protection element 10, a resistor element 20, a filter circuit 30, a load circuit 40, an internal power supply circuit 50, a diode 60, an additional switching element 70, an additional resistor element 80, and so on. In the drawing, the filter circuit 30 is labeled FC, the load circuit 40 is labeled LC, and the internal power supply circuit 50 is labeled IP.

[0021] The reverse connection protection element 10 is an element for protecting the load circuit 40 and the like when reverse connection occurs. In this embodiment, a P-channel MOSFET is used as the reverse connection protection element 10. However, this disclosure is not limited to this. Hereinafter, the reverse connection protection element 10 will also be referred to as PMOS 10. The reverse connection protection element 10 corresponds to a reverse connection protection switch. MOSFET is an abbreviation for metal-oxide-semiconductor field-effect transistor.

[0022] The PMOS 10 is located between the positive terminal 91 and the load circuit 40 and the internal power supply circuit 50. The PMOS 10 comprises a switching element section 11 and a body diode 12. The drain electrode of the switching element section 11 is connected to the positive terminal 91, and the source electrode is connected to the load circuit 40 and the internal power supply circuit 50 via the filter circuit 30. The gate electrode of the switching element section 11 is also connected to the drain electrode of the additional switching element 70. The gate electrode is connected to the source electrode via the resistive element 20.

[0023] The body diode 12 has an anode on the positive terminal 91 side and a cathode on the load circuit 40 side. The anode of the body diode 12 is connected to the positive terminal 91. The cathode of the body diode 12 is connected to the load circuit 40 via the filter circuit 30. Note that this disclosure does not require the filter circuit 30.

[0024] The load circuit 40 is powered by an external power supply unit 200. The load circuit 40 is, for example, a drive circuit that controls the on / off state of power elements. The load circuit 40 may also be a computer or a sensor. The electronic control unit 100 may have multiple load circuits 40. The load circuit 40 corresponds to a circuit element.

[0025] The internal power supply circuit 50 is connected to the high-voltage power supply unit 300 via the internal power supply terminal 93. The internal power supply circuit 50 is also connected to the load circuit 40 via the diode 60. The internal power supply circuit 50 supplies power to the load circuit 40 when the power supply from the external power supply unit 200 is stopped. The internal power supply circuit 50 transforms the power supplied from the high-voltage power supply unit 300 and supplies it to the load circuit 40.

[0026] Thus, the electronic control unit 100 is equipped with an internal power supply circuit 50. Therefore, the load circuit 40 can operate even if the external power supply unit 200 is unintentionally disconnected. The internal power supply circuit 50 can also be called a backup power supply circuit. Furthermore, the internal power supply circuit 50 can be said to generate a backup power supply.

[0027] The additional switching element 70 is an element that adds functionality to the PMOS 10 in the event of a ground fault at the positive terminal 91. In this embodiment, an N-channel MOSFET is used as the additional switching element 70. However, this disclosure is not limited to this. Hereinafter, the additional switching element 70 will also be referred to as NMOS 70. The additional switching element 70 corresponds to a functional addition element. Note that the functional addition element may also include an additional resistor element 80.

[0028] The additional function added to PMOS10 is to prevent reverse current. Reverse current refers to the flow of current from the internal power supply circuit 50 to the external power supply unit 200. In other words, NMOS70 is a component that prevents current from flowing from the internal power supply circuit 50 to the external power supply unit 200 to PMOS10 via the body diode 12.

[0029] In the NMOS 70, the drain electrode is connected to the gate electrode of the switching element section 11, and the source electrode is connected to the negative terminal 92. In addition, the gate electrode of the NMOS 70 is connected to the positive terminal 91 and the drain electrode of the switching element section 11 via an additional resistor element 80.

[0030] The NMOS 70 is switched on and off depending on the connection status of the external power supply 200 to the electronic control unit 100. In other words, the NMOS 70 is not controlled on or off by a computer or the like. Furthermore, the NMOS 70 controls the on and off of the PMOS 10 depending on the connection status of the external power supply 200 to the electronic control unit 100. Therefore, the NMOS 70 can also be said to be a control element that controls the on and off of the PMOS 10.

[0031] Here, using Figures 1 to 3, the operation of the electronic control device 100 during normal operation, reverse connection, and ground fault of the positive terminal 91 will be explained.

[0032] First, let's explain the normal operation using Figure 1. As shown in Figure 1, the electronic control unit 100 is properly connected to the external power supply unit 200. That is, the positive terminal 91 is connected to the positive terminal 201, and the negative terminal 92 is connected to the negative terminal 202.

[0033] In this case, as shown by the dotted line a1, the voltage from the external power supply 200 is supplied to the load circuit 40 via the body diode 12. In other words, current flows from the positive terminal 91 through the body diode 12 to the load circuit 40. The current can be said to be flowing in the forward direction.

[0034] Typically, the body diode 12 has a lower resistance than the diode element. Also, the resistance of the reverse-connection protection element 10 is approximately equal to the on-resistance of the PMOS 10. Therefore, the resistance of the reverse-connection protection element 10 can be considered to be sufficiently smaller than the resistance of the diode element used in the reverse-current prevention diode. Consequently, when current is flowing in the forward direction, the reverse-connection protection element 10 generates less heat than the reverse-current prevention diode.

[0035] The voltage from the external power supply 200 is applied to the gate electrode of the NMOS70. The gate-source voltage (a2) of the NMOS70 becomes the voltage from the external power supply 200. Therefore, as shown by the dotted line a3, the NMOS70 turns on and current flows.

[0036] Furthermore, the gate potential of PMOS10 becomes 0V. The source potential (a4) of PMOS10 becomes the voltage of the external power supply 200. Therefore, PMOS10 turns on and current flows.

[0037] Next, we will explain the operation when the connections are reversed using Figure 2. As shown in Figure 2, the electronic control unit 100 has the external power supply unit 200 connected in reverse. That is, the positive terminal 91 is connected to the negative terminal 202, and the negative terminal 92 is connected to the positive terminal 201.

[0038] In this case, the source potential of NMOS70 becomes the voltage of the external power supply 200 (a1). The gate potential of NMOS70 becomes 0V (a1). Then, a negative voltage, such as less than -5V, is applied to the gate-source voltage of NMOS70 (a2) by a Zener diode or the like (not shown in the diagram). Therefore, NMOS70 turns off.

[0039] Furthermore, the source potential of PMOS10 becomes 0V (a3). The gate potential of PMOS10 becomes 0V (a3). Therefore, PMOS10 turns off.

[0040] Thus, when the electronic control unit 100 is reverse-connected, the PMOS 10 and NMOS 70 are turned off. Therefore, as shown by the dotted line a4, the power supply from the external power supply unit 200 is cut off. Thus, the electronic control unit 100 can prevent failures of the load circuit 40 and other components caused by reverse connection of the external power supply unit 200.

[0041] Furthermore, the electronic control unit 100 receives power from the high-voltage power supply unit 300 to its internal power supply circuit 50, provided that power is supplied normally from the external power supply unit 200. Therefore, when the electronic control unit 100 is reverse-connected, power is not supplied from the high-voltage power supply unit 300 to its internal power supply circuit 50. Consequently, the internal power supply circuit 50 cannot generate a backup power supply.

[0042] Next, we will explain the operation during a ground fault using Figure 3. As shown in Figure 3, the positive terminal 91 of the electronic control device 100 is grounded.

[0043] In this case, 0V is applied to the gate electrode of the NMOS70 (a1). The gate-source voltage of the NMOS70 becomes 0V (a2). Therefore, the NMOS70 turns off.

[0044] Furthermore, the source potential of PMOS 10 becomes the voltage of the internal power supply circuit 50 (a3). The gate potential of PMOS 10 also becomes the voltage of the internal power supply circuit 50 (a3). Therefore, PMOS 10 is turned off.

[0045] Therefore, as shown by the dotted line a4, the electronic control unit 100 can prevent reverse current from the internal power supply circuit 50 by the body diode 12. In other words, the electronic control unit 100 can prevent current from flowing from the internal power supply circuit 50 to the positive terminal 91.

[0046] <Effects> As described above, the electronic control unit 100 is equipped with an NMOS 70, which prevents reverse current flow by the body diode 12 during a ground fault. The electronic control unit 100 may also experience a ground fault due to an accident or other reason if the mobile unit on which it is mounted is damaged. In such a case, the electronic control unit 100 can prevent current from flowing from the internal power supply circuit 50 to the positive terminal 91.

[0047] Furthermore, when the external power supply 200 is properly connected, the electronic control unit 100 supplies power from the external power supply 200 to the load circuit 40 via the body diode 12 of the reverse current protection element 10. As described above, when current flows in the forward direction, the reverse current protection element 10 generates less heat than a reverse current prevention diode. Therefore, the electronic control unit 100 can suppress heat generation more effectively than a configuration equipped with a diode element as a reverse current prevention diode.

[0048] Furthermore, the NMOS 70 can prevent reverse current flow depending on the connection status of the external power supply 200 to the electronic control unit 100. In other words, the electronic control unit 100 can prevent reverse current flow without the need for a computer or other device to control the NMOS 70 on or off.

[0049] Furthermore, the PMOS 10 exhibits less voltage drop than a diode element used as a reverse current prevention diode. Therefore, the electronic control unit 100 can suppress a narrowing of the operating voltage of the load circuit 40.

[0050] In this disclosure, the processor is a single or multiple hardware processor configured to read computer program code (i.e., one or more instructions of the computer program) contained in a computer program each time and execute the processing defined by said computer program code.

[0051] In other words, a processor is a hardware device that performs one or more programmed processes. Therefore, computer program code can also be considered software that can define the processor's processing depending on its content. A processor can be a general-purpose or specialized processor, and may include, but is not limited to, a CPU, microprocessor, GPU, and DFP (Data Flow Processor).

[0052] Furthermore, memory refers to one or more hardware memories that are non-transitional tangible recording media configured to record computer program code and / or data in a manner accessible by the processor. Memory can be implemented by memory technologies such as SRAM, SDRAM, non-volatile / flash type memory, or other types of memory. The computer program code that constitutes the program is recorded in memory and executed by the processor, thereby enabling the processor to perform the various functions described above.

[0053] (Second Embodiment) As shown in Figure 4, the electronic control device 100 of the second embodiment includes a low-voltage detection circuit 1 that detects a ground fault (low-voltage failure) at the positive terminal 91, and a power switching element 2 that is controlled on / off by the low-voltage detection circuit 1.

[0054] The low-voltage detection circuit 1 is located between the source electrode of the PMOS 10 and the power switching element 2. When a ground fault occurs at the positive terminal 91, the low-voltage detection circuit 1 turns on the power switching element 2 after the PMOS 10 has turned off. In other words, the low-voltage detection circuit 1 turns on the power switching element 2 to start supplying power from the internal power supply circuit 50 to the load circuit 40. Furthermore, when the low-voltage detection circuit 1 detects a ground fault, it delays supplying power from the internal power supply circuit 50 to the load circuit 40 until the PMOS 10 has reliably turned off. The low-voltage detection circuit 1 corresponds to the detection circuit.

[0055] The power switching element 2 employs a P-channel MOSFET as an example. The gate electrode of the power switching element 2 is connected to the low-voltage detection circuit 1. The source electrode of the power switching element 2 is connected to the internal power supply circuit 50 via a diode 60. The drain electrode of the power switching element 2 is connected between the filter circuit 30 and the load circuit 40.

[0056] The power switching element 2 is located between the internal power supply circuit 50 and the load circuit 40. The power switching element 2 is a switch that interrupts and re-enables (conducts) the power supply line between the internal power supply circuit 50 and the load circuit 40. The power supply line is interrupted when the power switching element 2 is in the off position. The power supply line is re-enabled when the power switching element 2 is in the on position. In other words, the internal power supply circuit 50 and the load circuit 40 become conductive. The power switching element 2 corresponds to a power supply control switch.

[0057] The electronic control unit 100 can achieve the same effects as the first embodiment. Furthermore, in the first embodiment, when a ground fault occurs, if power from the internal power supply circuit 50 is applied to the source electrode of the PMOS 10, reverse current may occur before the PMOS 10 turns off. However, since the electronic control unit 100 starts supplying power from the internal power supply circuit 50 to the load circuit 40 after the PMOS 10 turns off, it can prevent reverse current by ignoring the power supplied from the internal power supply circuit 50. Therefore, the electronic control unit 100 can reliably prevent reverse current.

[0058] (Third embodiment) As shown in Figure 5, the electronic control device 100 of the third embodiment includes a bipolar transistor as an additional switching element 71. Hereafter, the additional switching element 71 will also be referred to as the bipolar transistor 71.

[0059] The collector electrode of the bipolar transistor 71 is connected to the gate electrode of the PMOS 10. The base electrode of the bipolar transistor 71 is connected to the positive terminal 91 via an additional resistor 80. The emitter electrode of the bipolar transistor 71 is connected to the negative terminal 92. A resistor 72 and a Zener diode 73 are connected between the base and emitter. The Zener diode 73 is provided so as not to exceed its reverse voltage rating.

[0060] The additional switching element 71 corresponds to a functional addition element. The functional addition element may also include a resistor element 72, a Zener diode 73, and an additional resistor element 80.

[0061] The electronic control unit 100 can achieve the same effects as in the first embodiment.

[0062] This disclosure is described in accordance with embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the scope of equivalents. In addition, while various combinations and forms are shown in this disclosure, other combinations and forms that include one, more, or fewer of those elements also fall within the scope and idea of ​​this disclosure. [Explanation of symbols]

[0063] 1...Low-voltage detection circuit, 2...Power switching element, 10...Reverse connection protection element, 11...Switching element section, 12...Body diode, 20...Resistor element, 30...Filter circuit, 40...Load circuit, 50...Internal power supply circuit, 60...Diode, 70, 71...Additional switching elements, 72...Resistor element, 73...Zener diode, 80...Additional resistor element, 91...Positive terminal, 92...Negative terminal, 93...Internal power supply terminal, 94...External load terminal, 100...Electronic device, 200...External power supply device, 201...Positive terminal, 202...Negative terminal, 300...High-voltage power supply device

Claims

1. An electronic device connected to an external power supply unit (200), A positive terminal (91) connected to the positive terminal of the external power supply, A negative terminal (92) connected to the negative terminal of the external power supply, Circuit element (40) and When the power supply from the external power supply device is stopped, an internal power supply circuit (50) supplies power to the circuit element, A reverse polarity protection switch (10) is provided between the positive terminal, the circuit element, and the internal power supply circuit, and includes a body diode with the anode connected to the positive terminal side and the cathode connected to the circuit element side. An electronic device comprising: an additional element (70-73) that, when the positive terminal is grounded, prevents current from flowing from the internal power supply circuit to the external power supply device side to the reverse connection protection switch by the body diode; and a body diode.

2. The reverse-connection protection switch is a P-channel MOSFET equipped with the body diode, The electronic device according to claim 1, wherein the drain electrode of the P-channel MOSFET is connected to the positive electrode terminal, and the source electrode of the P-channel MOSFET is connected to the circuit element and the internal power supply circuit.

3. The aforementioned functional addition element is an N-channel MOSFET. The electronic device according to claim 2, wherein the drain electrode of the N-channel MOSFET is connected to the gate electrode of the P-channel MOSFET, the gate electrode of the N-channel MOSFET is connected to the positive terminal, and the source electrode of the N-channel MOSFET is connected to the negative terminal.

4. The aforementioned functional addition element is a bipolar transistor. The electronic device according to claim 2, wherein the collector electrode of the bipolar transistor is connected to the gate electrode of the P-channel MOSFET, the base electrode of the bipolar transistor is connected to the positive terminal, and the emitter electrode of the bipolar transistor is connected to the negative terminal.

5. A detection circuit (1) for detecting the ground fault of the positive terminal, The system further comprises a supply control switch (2) provided between the internal power supply circuit and the circuit element, which is controlled on / off by the detection circuit, The electronic device according to any one of claims 1 to 4, wherein the detection circuit, when a ground fault occurs, turns on the supply control switch to start supplying power from the internal power supply circuit to the circuit element after the reverse connection protection switch has been turned off.

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