Power supply device and control method

Abstract

Regarding a power supply device that provides power to connected devices, when providing high-output power based on the power supplied from the power source, the effects of a voltage drop in the power source are suppressed. [Solution] The power supply device 10 includes a power supply unit 26 capable of supplying power in either a first mode, which supplies power of a fixed first power value based on the power supplied from the vehicle battery 29, or a second mode, which supplies power of a second power value that can take a value greater than the first power value based on the power supplied from the vehicle battery 29 and is determined by negotiation with the device 11; a detection unit 27 that detects when the voltage of the power supplied from the vehicle battery 29 has decreased in a predetermined manner; and a control unit 25 that switches from the second mode to the first mode when the detection unit 27 detects a decrease in voltage while in the second mode.

Description

Technical Field

[0001] The present disclosure relates to a power supply device and a control method.

Background Art

[0002] Conventionally, a power supply device configured to be able to connect a device and supply power to the device based on the supplied power from a power supply source is known. In this type of power supply device, in addition to a mode of supplying power at a fixed power value as a power supply mode (hereinafter referred to as the "first mode"), there is a mode of communicating with the device to perform negotiation and supplying power at a determined power value based on this (hereinafter referred to as the "second mode"). In this second mode, it is possible to achieve a higher output power supply compared to the first mode. Hereinafter, this type of power supply device is referred to as a "conventional power supply device". In recent years, USB (Universal Serial Bus)-TypeC's charging standard, USB PD (Power Delivery), has been spreading, but a power supply device compatible with USB PD corresponds to a conventional power supply device. Patent Document 1 describes the following technology regarding a power control device 1 mounted on a vehicle. That is, before starting the engine 60 stopped by the idling stop function, the power control device 1 sets a current limit state in which the current supplied from the storage battery 50 to the electrical equipment 71 is limited to a predetermined upper limit current or less. The above technology is described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In conventional power supply devices, the voltage of the power source can drop significantly while supplying power to a device. For example, if the power source is an on-board battery, the battery voltage can drop significantly when the engine restarts from idle stop, as shown in Patent Document 1. Such a large voltage drop in the power source can affect conventional power supply devices when they are supplying high power in second mode, and there has been a need to suppress this.

[0005] This disclosure is made to solve such problems and aims to suppress the effects of a voltage drop in the power supply source when a power supply device that supplies power to connected devices is supplying high-power power based on the power supplied from the power supply source. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the power supply device according to the present disclosure includes a power supply unit capable of supplying power to a device in either a first mode, which supplies power of a fixed first power value based on power supplied from a power source, or a second mode, which supplies power of a second power value that can take a value greater than the first power value based on power supplied from the power source and is determined by negotiation with the connected device; a detection unit that detects when the voltage of the power supplied from the power source has decreased in a predetermined manner; and a control unit that switches from the second mode to the first mode when the detection unit detects a decrease in voltage in the second mode. [Effects of the Invention]

[0007] According to the configuration of this disclosure, if a voltage drop occurs in the power supply source while in the second mode, the system switches to the first mode. Therefore, even when high-power power supply is being performed in the second mode, the power required for power supply is reduced to the power required in the first mode, thereby suppressing the effects of a voltage drop in the power supply source. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing an example configuration of a power supply device according to the first embodiment. [Figure 2] This block diagram shows an example configuration of a power supply device and equipment according to the second embodiment. [Figure 3] This is a diagram used to explain conventional problems. [Figure 4] This is a diagram used to explain the prerequisites. [Figure 5] This is a diagram showing an example of the configuration of a power supply device. [Figure 6] This flowchart shows the control method for the power supply device. [Figure 7] This is a block diagram showing an example configuration of a power supply device according to the third embodiment. [Modes for carrying out the invention]

[0009] <First Embodiment> The first embodiment of this disclosure will be described below with reference to the drawings. The first embodiment is an embodiment that outlines the disclosure. Figure 1 is a block diagram showing an example configuration of a power supply device 1 according to this embodiment. The power supply device 1 is configured to receive power from an external power supply source 2. The power supply device 1 includes a connector 3, to which a device 4 is connected directly or indirectly via a cable, hub, or other component.

[0010] As shown in Figure 1, the power supply device 1 comprises a power supply unit 5, a detection unit 6, and a control unit 7. The power supply unit 5 supplies power to the device 4 connected to the connector 3 based on the power supplied from the power supply source 2. The power supply unit 5 can supply power to the device 4 in either of the following first and second modes. • First mode: A mode that supplies power of a fixed first power value based on the power supplied from power source 2. • Second mode: Based on the power supplied from power source 2, this mode allows for a power value greater than the first power value, and supplies power of a second power value determined by negotiation with device 4. The detection unit 6 detects that the voltage of the power supplied by the power supply source 2 has decreased in a predetermined manner. When the detection unit 6 detects a decrease in voltage while in the second mode, the control unit 7 switches from the second mode to the first mode.

[0011] The configuration of this embodiment provides the following effects. Specifically, if a voltage drop occurs in the power supply source 2 while in the second mode, the system switches to the first mode. Therefore, even when high-output power supply is being performed in the second mode, the power required for power supply is reduced to the power required in the first mode, thereby suppressing the effects of a voltage drop in the power supply source.

[0012] <Second Embodiment> Next, a second embodiment of the present disclosure will be described with reference to the drawings. Figure 2 is a block diagram showing an example configuration of a power supply device 10 and a device 11 according to this embodiment. The power supply system 12 is composed of the power supply device 10 and a device 11 that can be connected thereto. The power supply device 10 and the device 11 are compliant with USB (Universal Serial Bus) Type-C, and the power supply device 10 and the device 11 are connected via a cable 13, which is a USB Type-C cable. Hereinafter, the USB Type-C cable will be referred to as a "Type-C cable". A Type-C cable is a cable that has a chip called an eMarker built into the plug.

[0013] The power supply device 10 according to this embodiment is a device mounted in a vehicle. The power supply device 10 is implemented in, for example, a car navigation system, car audio system, or other in-vehicle equipment. However, the power supply device 10 may be implemented in an adapter or may be a standalone device. The power supply device 10 is a USB PD (Power Delivery) compliant device and has the function of supplying power according to USB PD. In principle, the power supply device 10 provides power according to USB PD when a USB Type-C compliant device is connected via a Type-C cable. The power supply device 10 has a source-side connector 14 and can supply power to a device 11 connected to the source-side connector 14. The device 11 that receives the power supply charges its own battery or supplies power to a load. Hereinafter, the connection of the device 11 to the source-side connector 14 of the power supply device 10 via a cable 13 may simply be expressed as "the device 11 is connected to the power supply device 10".

[0014] In this embodiment, the source-side connector 14 is a USB Type-C compliant receptacle and is equipped with a CC1 terminal 15 (CC: Configuration Channel), a CC2 terminal 16, and a VBUS terminal 17 for supplying bus voltage (see Figure 5). The source-side connector 14 also naturally includes a GND terminal for ground voltage and other terminals. When the device 11 is connected to the power supply device 10, power is supplied from the power supply device 10 to the device 11 using a power supply line 18 via cable 13. In this state, communication between the power supply device 10 and the device 11 is performed using a CC line 19 via cable 13.

[0015] As shown in Figure 2, the power supply device 10 includes a control unit 25, a power supply unit 26, a detection unit 27, and a specific function unit 28.

[0016] The control unit 25 is a controller compatible with USB PD and USB Type-C, and includes an IC in which various circuits including a processor are integrated. The control unit 25 executes processing through cooperation between hardware and software, such as reading and executing a program stored in a predetermined memory by the processor. The control unit 25 has a function of controlling a transceiver (not shown) for communication via the CC line 19 and communicating with the connected device 11. The control unit 25 has a function of controlling the power supply unit 26 to control power supply. The control of power supply will be described later.

[0017] The power supply unit 26 includes a power supply circuit including a DC / DC converter, a switch element that opens and closes the power supply line 18, and other elements (for example, necessary switches and necessary capacitors). The power supply unit 26 receives power supply from an in-vehicle battery 29 (power supply source) which is an external power source. The in-vehicle battery 29 is a battery mounted on the vehicle. The power supply unit 26 converts the voltage value of the voltage of the in-vehicle battery 29 into an appropriate voltage value under the control of the control unit 25, and then supplies power to the device 11 connected to the power supply device 10 via the power supply line 18. The control unit 25 has a function of controlling the output voltage of the power supply unit 26. In particular, the control unit 25 can control the power supply unit 26 to supply power to the device 11 at a specific voltage value and a specific maximum current value (upper limit value of current). Regarding the supplied power, although the current value basically varies depending on the circumstances on the device 11 side, it cannot exceed the maximum current value set on the power supply device 10 side.

[0018] The power supply unit 26 according to the present embodiment can supply power to the device 11 in any of the following Type-C modes (first mode) and power delivery modes (second mode) according to the protocol related to USB Type-C or USB PD (hereinafter sometimes simply referred to as "protocol"). That is, the Type-C mode is a mode of supplying power with a fixed power value of 15W (5V, 3A). The power delivery mode is a mode of supplying power with a power value determined by negotiation with the device 11 performed according to the protocol. In the power delivery mode, with 240W as the common maximum value, it is possible to set the power value of the supplied power within the range below the maximum value determined for each device (for example, 100W or 60W). That is, in the power delivery mode, the power value of the supplied power can be made much larger compared to the Type-C mode. In the power delivery mode, being able to supply power with a high output such as 60W, 100W, or 240W is one of the features of USB Type-C and USB PD. The control unit 25 can control the power supply unit 26 to switch the power supply mode between the Type-C mode and the power delivery mode.

[0019] Here, the control unit 25 can detect that the power supply device 10 is in the following state based on the voltage values of the CC1 terminal 15 and the CC2 terminal 16. · Corresponding state S1: A state in which the device 11 functioning as a sink is connected and the USB Type-C cable 13 (that is, a cable with an eMarker implemented in the plug) is connected as the cable · Non-corresponding state S2: A state that is not the corresponding state S1 And the control unit 25 allows power supply in the power delivery mode when in the corresponding state S1 under the protocol. On the other hand, the control unit 25 does not allow power supply in the power delivery mode when in the non-corresponding state S2 and only permits power supply in the Type-C mode. That is, the control unit 25 does not perform power supply in the power delivery mode when the power supply device 10 is in the non-corresponding state S2.

[0020] Referring to Figure 2, the detection unit 27 detects when the voltage value of the power supplied by the onboard battery 29 falls below a predetermined threshold (when the power supplied by the power source decreases in a predetermined manner). Hereinafter, the voltage of the onboard battery 29, or the voltage value of said voltage, will be referred to as the "battery voltage". In this embodiment, the detection unit 27 is equipped with a detection circuit 30 (Figure 5). The detection circuit 30 detects when the battery voltage falls below a threshold. Hereinafter, the threshold value compared with the battery voltage in the detection circuit 30 will be referred to as the "voltage threshold". The voltage threshold is predetermined with the aim of detecting an irregular large drop in battery voltage that would affect the power supply to the device 11. As an example, the voltage threshold is set to "10V" when the normal battery voltage is 12 to 14V. The functions and roles of the detection unit 27 will be described in detail later.

[0021] The special function unit 28, when the detection unit 27 detects a drop in battery voltage during power delivery mode, causes the voltage state of the CC1 terminal 15 and CC2 terminal 16 to deviate from a predetermined range. The specific hardware configuration, functions, and roles of the special function unit 28 will be described later.

[0022] Device 11 is an electronic device. The type of electronic device 11 is not limited. Examples of devices 11 include laptop computers, tablet devices (including so-called smartphones), portable game consoles, or wearable devices.

[0023] As shown in Figure 2, device 11 is equipped with a sink-side connector 35 that supports USB Type-C. The sink-side connector 35 is configured as a receptacle to which a USB Type-C compatible plug can be connected. The sink-side connector 35 and the source-side connector 14 of the power supply device 10 are connected via a cable 13. Device 11 also incorporates a device battery 36, which is a secondary battery.

[0024] As shown in Figure 1, the device 11 has a functional configuration that includes a device control unit 37 and a device charging unit 38.

[0025] The device control unit 37 is a controller compatible with USB PD and USB Type-C, and includes an integrated circuit (IC) that integrates various circuits, including a processor. The device control unit 37 performs processing through the cooperation of hardware and software, such as when the processor reads and executes a program stored in a predetermined memory. The device control unit 37 also has the function of controlling a transceiver for communication via the CC line 19 and communicating with the control unit 25.

[0026] The device charging unit 38 comprises a charging circuit including a DC / DC converter, a switching element for opening and closing the power supply line 18, and other elements (e.g., necessary switches and necessary capacitors). The device charging unit 38 receives power from the power supply unit 26 of the power supply device 10 via the power supply line 18. Under the control of the device control unit 37, the device charging unit 38 charges the device battery 36 by adjusting the voltage / current, adjusting the power supply timing, and performing other necessary charging processes.

[0027] Although not shown in the diagram, device 11 is equipped with various loads that receive power from the device battery 36.

[0028] As mentioned above, the power supply device 10 according to this embodiment supplies power to the connected device 11 based on power supplied from an external on-board battery 29. The on-board battery 29 has the following characteristics. In many cases, vehicles with internal combustion engines are equipped with an idle stop function to improve fuel efficiency. In this function, the on-board battery 29 is used to operate the starter motor when starting the engine, so a phenomenon occurs in which the battery voltage drops considerably at the time of starting. For example, it may drop to 10V or less. In addition, due to the characteristics of the on-board battery 29 being mounted on the vehicle and serving as a power source that supplies power to various loads related to the vehicle, a large drop in battery voltage can occur. As described above, the on-board battery 29 has the characteristic that a phenomenon in which the battery voltage drops significantly can occur.

[0029] Due to these characteristics, power supply devices that utilize the vehicle's battery for power supply had the following problems. Figure 3 is used to explain these problems. That is, let's assume that, as shown in Figure 3(A), power supply device 1X is supplying power to device 2X with an output of 60W in power delivery mode. As mentioned above, in power delivery mode, high-output power supply of 60W or more (other than 60W, for example 100W or 240W) is possible. The power supplied by the vehicle's battery 3X is boosted by a boost circuit before use, but in the case of Figure 3(A), if the battery voltage of the vehicle's battery 3X is 14V, the current value of the current consumed by the vehicle's battery 3X will be approximately 4.51A (theoretically 4.29A, but this value takes into account the battery's efficiency). Note that "battery efficiency" means "DCD power supply efficiency" or "efficiency when converting battery voltage to USB VBUS voltage" (the same applies below). Hereinafter, the current consumption of the vehicle battery 3X and other vehicle batteries, or the current value of said current consumption, will simply be referred to as "current consumption."

[0030] Then, in the state shown in Figure 3(A), a drop in battery voltage occurs due to the idle stop function, resulting in a voltage of 8V (see Figure 3(B)). In this case, if 60W power supply by power delivery mode continues, the current consumption will be a large value of 8.15A (theoretically 7.5A, but this value takes into account the battery efficiency). Thus, if the battery voltage of the onboard battery 29 drops significantly while high-power supply by power delivery mode is being performed, and no countermeasures are taken, a situation will arise where the current consumption becomes very large as a result.

[0031] Furthermore, if such a large increase in power consumption is to be tolerated, the challenge arises that appropriate measures, such as increasing the fuse capacity, must be taken. To solve this problem, it is possible to configure the system so that if the battery voltage drops while power is being supplied in power delivery mode, the USB connection is disconnected and power supply is stopped. In this embodiment, a USB connection means that the devices are connected in a state where power can be supplied by the power supply device regardless of the mode, and data communication related to USB can be performed. Disconnecting the USB connection means that the devices are disconnected in a state where power supply and data communication are not possible.

[0032] According to the above configuration, high-power power supply stops in response to a drop in battery voltage, thus preventing current consumption when the battery voltage drops and eliminating the need for increased fuse capacity. However, in this configuration, the USB connection must be disconnected every time a significant drop in battery voltage occurs. To reconnect after disconnecting the USB connection, a reconnection operation must be performed again between the power supply unit and the device. Such reconnection operations can cause delays and interruptions in communication between the power supply unit and the device, which may result in delays or interruptions in the processing of device 11. Delays or interruptions in the processing of device 11 can reduce usability. In particular, in environments where the vehicle equipped with the power supply unit experiences repeated stop-and-go driving, the reconnection operation will occur frequently, potentially leading to a significant decrease in usability. As described above, in the above configuration, a reconnection operation occurs every time a significant drop in battery voltage occurs, resulting in the problem of reduced usability.

[0033] In view of the above, the power supply device 10 according to this embodiment has the following characteristic configuration. Before describing the configuration of the power supply device 10, the prerequisites for the configuration will be explained first, and then the configuration of the power supply device 10 will be described.

[0034] Figure 4 is a diagram used to explain the prerequisites. Figure 4(A) shows the connection between the power supply device 10 and the device 11 via the cable 13, with the essential parts extracted. In the explanation of the prerequisites using Figure 4, for the sake of clarity, it is assumed that the specific function unit 28, which is one of the characteristic parts of this embodiment, is not implemented.

[0035] As shown in Figure 4(A), the control unit 25 of the power supply device 10 is connected to a first line 40 connected to the CC1 terminal 15 and a second line 41 connected to the CC2 terminal 16. In the example in Figure 4(A), the line between the CC1 terminal 15 of the power supply device 10 and the CC1 terminal 42 of the device 11 is the CC line 19 for communication. The line connected to the CC2 terminal 16 of the power supply device 10 and the line connected to the CC2 terminal 43 of the device 11 are lines for Vconn.

[0036] As shown in Figure 4(A), the power supply device 10 is equipped with a pull-up resistor Rp1 that pulls up the CC1 terminal 15 to an internal voltage, and a pull-up resistor Rp2 that pulls up the CC2 terminal 16 to an internal voltage. The CC1 terminal 42 of device 11 is pulled down to ground via a 5.1kΩ (this value is according to the protocol) pull-down resistor Rd1. The CC2 terminal 43 of device 11 is also pulled down to ground via a 5.1kΩ pull-down resistor Rd2. In cable 13, the CC2 terminal 16 of power supply device 10 is pulled down to ground via a pull-down resistor Ra1. In cable 13, the CC2 terminal 43 of device 11 is also pulled down to ground via a pull-down resistor Ra2. The pull-down resistors Ra1 and Ra2 are set to 0.8 to 1.2kΩ, respectively, according to the protocol.

[0037] Here, the control unit 25 determines that the state of the power supply device 10 is in "corresponding state S1" if the voltage values ​​of both the CC1 terminal 15 and the CC2 terminal 16 are within a certain range (for example, 0.85 to 2.45V) according to the protocol. In other words, the control unit 25 determines that the state of the power supply device 10 is in corresponding state S1 if the voltage states of the CC1 terminal 15 and the CC2 terminal 16 are within a predetermined range. Hereinafter, this certain range will be referred to as the "corresponding range". The corresponding range is defined by the resistance values ​​of the pull-up resistors Rp1 and Rp2 of the power supply device 10, the pull-down resistors Rd1 and Rd2 of the device 11, and the pull-down resistors Ra1 and Ra2 of the cable 13. On the other hand, the control unit 25 determines that the state of the power supply device 10 is in "non-compatible state S2" if the voltage value of the CC1 terminal 15 is outside the compatible range (for example, less than 0.85V or greater than 2.45V) or if the voltage value of the CC2 terminal 16 is outside the compatible range. In the configuration of Figure 4 (A), the voltage values ​​of both the CC1 terminal 15 and the CC2 terminal 16 will be within the compatible range. In this case, the control unit 25 determines that the state of the power supply device 10 is in "compatible state S1". As described above, in compatible state S1, the control unit 25 allows power supply by power delivery mode and basically performs power supply by power delivery mode.

[0038] Now, let's assume that, as shown in Figure 4(B), a pull-down resistor Ry, which is pulled down to ground, is connected between the pull-up resistor Rp1 of the power supply device 10 and the CC1 terminal 15. The resistance value of the pull-down resistor Ry is set to "5.1kΩ", the same as the pull-down resistors Rd1 and Rd2 of the device 11. In this case, the voltage value at the terminal of CC1 terminal 15 will deviate from the corresponding range. As a result, in the configuration of Figure 4(B), the control unit 25 determines that the power supply device 10 is in an unsupported state S2. Also, let's assume that, as shown in Figure 4(C), a pull-down resistor Ry (as described above, 5.1kΩ), which is pulled down to ground, is connected between the pull-up resistor Rp2 of the power supply device 10 and the CC2 terminal 16. In this case, the voltage value at the terminal of CC2 terminal 16 will deviate from the corresponding range. As a result, in the configuration of Figure 4(C), the control unit 25 determines that the power supply device 10 is in an unsupported state S2.

[0039] As described above, by connecting a 5.1kΩ pull-down resistor Ry to either the line of the CC1 terminal 15 or the line of the CC2 terminal 16 of the power supply device 10, a state can be established in which the control unit 25 determines that the state of the power supply device 10 is the incompatible state S2. These are the prerequisites.

[0040] Figure 5 shows the configuration of the main parts of the power supply device 10 according to this embodiment. In Figure 5, the same reference numerals are used for the components shown in Figure 4.

[0041] As shown in Figure 5, the power supply unit 26, under the control of the control unit 25, supplies power to the device 11 via the VBUS terminal 17 based on the power supplied from the vehicle battery 29.

[0042] The detection unit 27 includes a detection circuit 30. The detection circuit 30 outputs a low signal while the battery voltage of the onboard battery 29 is above a voltage threshold (e.g., 10V). On the other hand, the detection circuit 30 outputs a high signal while the battery voltage is below the voltage threshold. The output of the detection circuit 30 is directed to the base of the transistor 44 (described later) of the specific function unit 28.

[0043] The special function unit 28 includes a pull-down resistor Ry connected to the first line 40 and a transistor 44 (special circuit) provided between the pull-down resistor Ry and ground. As described above, the resistance value of the pull-down resistor Ry is 5.1kΩ. In this embodiment, the transistor 44 is an npn type bipolar transistor with switching function, and while a high signal is input to the base from the detection circuit 30, the pull-down resistor Ry is grounded and activated. With the above detection unit 27 (detection circuit 30) and special function unit 28, the CC1 terminal 15 is pulled down to ground via the pull-down resistor Ry while the battery voltage is below the voltage threshold. Conversely, while the battery voltage is above the voltage threshold, the pull-down resistor Ry is inactive.

[0044] The power supply device 10 according to this embodiment has the above-described unique configuration. This configuration enables the following mechanism. • While the battery voltage of the onboard battery 29 exceeds the voltage threshold, power supply is performed in power delivery mode under the control of the control unit 25. When the battery voltage falls below the voltage threshold, the control unit 25 switches from power delivery mode to Type C mode. The details are explained below.

[0045] Referring to Figure 5, let's assume that the battery voltage of the vehicle battery 29 is above the voltage threshold, and the power supply mode is power delivery mode. In this situation, the output of the detection circuit 30 of the detection unit 27 is a low signal, and therefore the pull-down resistor Ry is not functioning. In this situation, the control unit 25 detects that the voltage values ​​of both terminals CC1 15 and CC2 16 are within the corresponding range, permits power supply in power delivery mode, and executes power supply in power delivery mode.

[0046] Subsequently, due to the return from idle stop or other reasons, the battery voltage of the vehicle battery 29 falls below the voltage threshold. In this case, the detection circuit 30 of the detection unit 27 outputs a high signal. In response, the pull-down resistor Ry is activated by the function of the transistor 44, and the voltage value of the CC1 terminal 15 deviates from the corresponding range. The control unit 25 detects that the voltage value of the CC1 terminal 15 has deviated from the corresponding range, detects the non-compatible state S2, and switches the power supply mode from power delivery mode to type C mode. After the power supply mode has been switched, the control unit 25 controls the power supply unit 26 to supply 15W (5V, 3A) of power in type C mode.

[0047] Subsequently, when the battery voltage exceeds the voltage threshold, the detection circuit 30 of the detection unit 27 outputs a low signal. This disables the pull-down resistor Ry due to the function of the transistor 44. As a result, both the CC1 terminal 15 and the CC2 terminal 16 fall within the corresponding range. The control unit 25 detects that both the CC1 terminal 15 and the CC2 terminal 16 are within the corresponding range and determines that the state of the power supply device 10 is corresponding state S1. Accordingly, the control unit 25 switches the power supply mode from type C mode to power delivery mode. Thereafter, the control unit 25 continues to supply power in power delivery mode until the battery voltage falls below the voltage threshold again.

[0048] As described above, in this embodiment, when power is being supplied in power delivery mode, if the battery voltage of the on-board battery 29 falls below the voltage threshold, power is supplied in Type C mode instead of power delivery mode. Then, when the battery voltage exceeds the voltage threshold, power is supplied again in power delivery mode. This configuration provides the following effects.

[0049] In other words, according to this embodiment, if a significant voltage drop occurs in the battery voltage, falling below the voltage threshold, the output voltage of the power supplied to device 11 can be reduced to a relatively small voltage value of 15W. Therefore, even when the battery voltage is low, an excessive increase in current consumption can be effectively suppressed. This effective suppression of current consumption eliminates the need to take appropriate measures such as "increasing the fuse capacity." Furthermore, according to this embodiment, while the battery voltage is below the voltage threshold, the USB connection is not disconnected and power supply to device 11 and data communication are not completely stopped. Instead, the USB connection is maintained and power supply in Type-C mode continues. Therefore, data communication can be continued, and frequent reconnection operations can be prevented, thus suppressing a decrease in usability.

[0050] Next, the control method by the power supply device 10 will be explained using a flowchart. Flowchart FA in Figure 6 is a flowchart of an example of the control method by the power supply device 10. At the start of flowchart FA in Figure 6, it is assumed that the battery voltage of the onboard battery 29 is above the voltage threshold, and power is being supplied by the power supply unit 26 in power delivery mode.

[0051] As shown in Figure 6, the detection unit 27 of the power supply device 10 monitors whether the battery voltage of the onboard battery 29 has fallen below a voltage threshold (step SA1). If it has fallen below the voltage threshold (step SA1: YES), the detection unit 27 detects this and outputs a high signal via the detection circuit 30 (step SA2). In response to the output of the high signal, the specific function unit 28 activates the pull-down resistor Ry (step SA3). Upon activation of the pull-down resistor Ry, the control unit 25 detects that the power supply device 10 has entered an incompatible state S2 (step SA4). Next, the control unit 25 switches the power supply mode from power delivery mode to type C mode (step SA5).

[0052] Subsequently, the detection unit 27 monitors whether the battery voltage of the onboard battery 29 exceeds a voltage threshold (step SA6). If the voltage exceeds the voltage threshold (step SA6: YES), the detection unit 27 detects this and outputs a low signal via the detection circuit 30 (step SA7). In response to the output of the low signal, the specific function unit 28 disables the pull-down resistor Ry (step SA8). Following the disabling of the pull-down resistor Ry, the control unit 25 detects that the power supply device 10 has entered the corresponding state S1 (step SA9). Next, the control unit 25 switches the power supply mode from type C mode to power delivery mode (step SA10). After step SA9, the processing procedure returns to step SA1.

[0053] As described above, the power supply device 10 according to this embodiment includes a power supply unit 26 capable of supplying power to the device 11 in either type C mode (first mode) or power delivery mode (second mode), a detection unit 27 that detects when the voltage of the power supplied by the onboard battery 29 falls below a voltage threshold (decreases in a predetermined manner), and a control unit 25 that switches from power delivery mode to type C mode when the detection unit detects a voltage drop while in power delivery mode.

[0054] With this configuration, if the battery voltage of the onboard battery 29 drops while in power delivery mode, the system switches to Type C mode. Therefore, even when high-output power supply is being performed in power delivery mode, the power required for power supply is reduced to the power required for Type C mode, thereby suppressing the effects of a drop in the battery voltage of the onboard battery 29.

[0055] In this embodiment, the source-side connector 14 is a USB Type-C compatible connector. The control unit 25 determines that the device 11 and the USB Type-C cable 13 are connected in corresponding state S1 when the voltage state of the CC1 terminal 15 and CC2 terminal 16 is within a predetermined range. The control unit 25 allows power supply via power delivery mode when corresponding state S1 is in place, but if the corresponding state S1 is no longer in place while in that mode, it does not allow that mode and switches from that mode to Type-C mode. The power supply device 10 further includes a specific function unit 28 that, when a voltage drop is detected by the detection unit 27 while in power delivery mode, causes the voltage state of the CC1 terminal 15 and CC2 terminal 16 to deviate from a predetermined range. With this configuration, mode switching can be performed accurately in response to a large drop in battery voltage.

[0056] Furthermore, the specific function unit 28 according to this embodiment includes a pull-down resistor Ry connected to the line related to the CC1 terminal 15 or the CC2 terminal 16 and grounded, and a transistor 44 (specific circuit) that activates the pull-down resistor Ry when a voltage drop is detected by the detection unit 27. With this configuration, the function of the specific function unit 28 makes it possible to accurately switch modes in response to a large drop in battery voltage.

[0057] <Third Embodiment> Next, a third embodiment will be described. In the following description of the third embodiment, the same reference numerals are used for elements that are the same as those in the second embodiment, and their descriptions are omitted. Figure 7 is a diagram showing the configuration of the power supply device 50 according to this embodiment. As is clear from comparing Figure 5 and Figure 7, the power supply device 50 according to this embodiment differs from the power supply device 10 according to the second embodiment in that it is equipped with a communication disconnection switch 51.

[0058] The communication disconnection switch 51 is a switch that can disconnect the first line of the CC1 terminal 15 and the second line of the CC2 terminal 16 while in Type C mode, after the control unit 25 has switched from power delivery mode (second mode) to Type C mode (first mode). In detail, the communication disconnection switch 51 is a switch circuit that changes the conductivity state of the first line 40 and the second line 41. The communication disconnection switch 51 conducts both the first line 40 and the second line 41 while a low signal is input from the detection circuit 30. On the other hand, the communication disconnection switch 51 disconnects both the first line 40 and the second line 41 while a high signal is input from the detection circuit 30.

[0059] The configuration of this embodiment provides the following advantages. Specifically, in Type C mode, communication via the CC line 19 (≠ data communication) is unnecessary. Furthermore, with the above configuration, communication via the CC line can be reliably blocked during Type C mode, and any impact caused by communication occurring during Type C mode can be reliably prevented.

[0060] In this embodiment, the communication disconnection switch 51 was configured to be linked to the output of the detection circuit 30. However, the communication disconnection switch 51 may also be configured to be opened and closed by the control unit 25. Furthermore, the communication disconnection switch 51 may be configured to be in a disconnected state only for a part of the period during which Type C mode charging is performed, rather than for the entire period.

[0061] Although one embodiment of the present disclosure has been described above, this embodiment is merely one example of how the present disclosure may be implemented, and the technical scope of the present disclosure should not be interpreted as being limited by this. In other words, the present disclosure can be implemented in various ways without departing from its gist or its main features. Examples of modifications are given below, and of course, any configuration described using a specific embodiment as an example in the following description may be applied to other embodiments if applicable. Furthermore, any combination of modifications may be implemented if applicable.

[0062] For example, the specific process by which the control unit 25 determines the corresponding state S1 / incompatible state S2 is not limited to the example process. The control unit 25 can determine that the state of the power supply device 10 is the corresponding state S1 when the voltage state of the CC1 terminal 15 and the CC2 terminal is within a predetermined range, and by providing the specific function unit 28 in the manner shown in the second embodiment, the control unit 25 can switch the power supply mode in accordance with a predetermined decrease in the battery voltage.

[0063] Furthermore, the detection unit 27 detected when the battery voltage fell below a voltage threshold. In this regard, the events related to voltage drops detected by the detection unit 27 are not limited to the events exemplified. For example, the detection unit 27 may be configured to detect a battery voltage drop in a predetermined manner when the battery voltage drops below a predetermined threshold and this continues for a certain period of time or longer. This configuration prevents the mode from being switched when the battery voltage drop lasts for only a very short time and the voltage quickly recovers.

[0064] Furthermore, the power supply device 10 was mounted on the vehicle. However, the power supply device 10 does not necessarily have to be mounted on the vehicle. When AC power, such as commercial power, is supplied to the power supply device 10, the power supply unit 26 is configured to include an AC / DC converter and performs AC / DC conversion appropriately.

[0065] Alternatively, the power supply device 10 may be configured to allow multiple devices 11 to be connected, and the power supply device 10 to supply power to multiple devices 11 simultaneously.

[0066] Furthermore, the functional blocks shown in each of the above embodiments can be realized using any hardware, or through the cooperation of any hardware and any software. In other words, these functional blocks are not limited to specific hardware.

[0067] Furthermore, regarding the processing described as being performed by the control unit 25 alone, the control unit 25 may also be configured to perform various processes in cooperation with an external device. For example, the control unit 25 may perform processing in cooperation with the processor of the device on which the power supply device 10 is installed, or it may perform processing in cooperation with an external device that can communicate via a network.

[0068] Furthermore, with respect to the example flowchart, you may change the order of processes, divide the processes into smaller parts, add processes, or delete processes, as long as the objective can be achieved.

[0069] Furthermore, in the above embodiment, the power supply device 10 was a device that performed power supply in accordance with USB PD. However, the standard to which the power supply device 10 conforms is not limited to USB PD.

[0070] Furthermore, the embodiment may include, for example, the provision of a program to be executed by the computer of the power supply device 10. The embodiment may also include the provision of a recording medium on which the program is recorded in a way that is readable by the computer. As the recording medium, magnetic, optical, or semiconductor memory devices can be used. Specifically, examples include portable or fixed recording media such as flexible disks, HDDs (Hard Disc Drives), CD-ROMs (Compact Disc Read Only Memory), DVDs (Digital Versatile Disks), Blu-ray® Discs, magneto-optical disks, flash memory, and card-type recording media.

[0071] As described above, the following has been disclosed in the detailed description of the invention. <Disclosure 1> A power supply unit capable of supplying power to the device in either a first mode, which supplies power of a fixed first power value based on the power supplied from a power source, or a second mode, which supplies power of a second power value that can take a value greater than the first power value based on the power supplied from the power source and is determined by negotiation with the connected device, A detection unit that detects when the voltage of the power supplied by the power supply source decreases in a predetermined manner, The system includes a control unit that switches from the second mode to the first mode when the detection unit detects a voltage drop while in the second mode. A power supply device characterized by the following features. <Disclosure 2> The control unit determines that the device and USB Type-C cable are connected to the connector and are in a compatible state if the voltage state of the CC1 and CC2 terminals of the USB (Universal Serial Bus) Type-C compatible connector is within a predetermined range. If the device and USB Type-C cable are connected to the connector, the control unit allows power supply in the second mode based on USB PD (Power Delivery). However, if the device is no longer in the compatible state while in the second mode, the control unit switches from the second mode to the first mode without allowing the second mode. When the detection unit detects a voltage drop in the second mode, the system further includes a special function unit that causes the voltage state of the CC1 terminal and the CC2 terminal to deviate from the predetermined range. A power supply device according to Disclosure 1, characterized in that it is a power supply device as described in Disclosure 1. <Disclosure 3> The aforementioned specific function unit is, A pull-down resistor connected to the line relating to the CC1 terminal or the CC2 terminal and grounded to ground, The system includes a specific circuit that activates the pull-down resistor when the detection unit detects a voltage drop. The power supply device according to Disclosure 2, characterized by the features described herein. <Disclosure 4> After the control unit switches from the second mode to the first mode, the system further includes a communication disconnection switch that can disconnect the lines of the CC1 terminal and the CC2 terminal while in the first mode. A power supply device according to disclosure 2 or 3, characterized in that it is a power supply device according to disclosure 2 or 3. <Disclosure 5> The power supply source is an on-board battery. A power supply device according to any one of disclosures 1 to 4, characterized in that <Disclosure 6> A power supply device comprising a power supply unit capable of supplying power to a device in either a first mode, which supplies power of a fixed first power value based on power supplied from a power source, or a second mode, which supplies power of a second power value that can take a value greater than the first power value based on power supplied from the power source and is determined by negotiation with the connected device, includes the step of detecting that the voltage of the power supplied from the power source has decreased in a predetermined manner, The control unit of the power supply device includes the step of switching from the second mode to the first mode when the detection unit detects a voltage drop while in the second mode. A control method characterized by the following: [Explanation of Symbols]

[0072] 1...Power supply device 1, 2...Power supply source, 3...Connector, 4...Device, 5...Power supply unit, 6...Detection unit, 7...Control unit, 10...Power supply device, 11...Device, 12...Power supply system, 13...Cable, 14...Source side connector (connector), 15...CC1 terminal, 16...CC2 terminal, 17...VBUS terminal, 18...Power supply line, 19...CC line, 25...Control unit, 26...Power supply unit, 27...Detection unit, 28...Specific function unit, 29...Vehicle battery, 30...Detection circuit, 35...Sink side connector, 36...Device battery, 37...Device control unit, 38...Device charging unit, 40...First line, 41...Second line, 42...CC1 terminal, 43...CC2 terminal, 44...Transistor, 50...Power supply device, 51...Communication disconnection switch.

Claims

1. A power supply unit capable of supplying power to the device in either a first mode, which supplies power of a fixed first power value based on the power supplied from a power source, or a second mode, which supplies power of a second power value that can take a value greater than the first power value based on the power supplied from the power source and is determined by negotiation with the connected device, A detection unit that detects when the voltage of the power supplied by the power source decreases in a predetermined manner, The system includes a control unit that switches from the second mode to the first mode when the detection unit detects a voltage drop while the system is in the second mode. A power supply device characterized by the following features.

2. The control unit determines that the device and USB Type-C cable are connected to the connector and are in a compatible state if the voltage state of the CC1 and CC2 terminals of the USB (Universal Serial Bus) Type-C compatible connector is within a predetermined range. When this compatible state is reached, the control unit allows power supply in the second mode based on USB PD (Power Delivery). However, if the second mode is no longer in a compatible state, the control unit switches from the second mode to the first mode without allowing the second mode. When the detection unit detects a voltage drop in the second mode, the system further includes a special function unit that causes the voltage state of the CC1 terminal and the CC2 terminal to deviate from the predetermined range. The power supply device according to feature 1.

3. The aforementioned specific function unit is, A pull-down resistor connected to the line relating to the CC1 terminal or the CC2 terminal and grounded to ground, The system includes a specific circuit that activates the pull-down resistor when the detection unit detects a voltage drop. The power supply device according to feature 2.

4. After the control unit switches from the second mode to the first mode, the system further includes a communication disconnection switch that can disconnect the lines of the CC1 terminal and the CC2 terminal while in the first mode. The power supply device according to feature 2.

5. The power supply source is an on-board battery. A power supply device according to any one of claims 1 to 4.

6. A power supply device comprising a power supply unit capable of supplying power to a device in either a first mode, which supplies power of a fixed first power value based on power supplied from a power source, or a second mode, which supplies power of a second power value that can take a value greater than the first power value based on power supplied from the power source and is determined by negotiation with the connected device, includes the step of detecting that the voltage of the power supplied from the power source has decreased in a predetermined manner, The control unit of the power supply device includes the step of switching from the second mode to the first mode when the detection unit detects a voltage drop while in the second mode. A control method characterized by the following:

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