Vehicle-mounted domain controller and T-BOX power supply circuit
By designing a power supply circuit consisting of a main power supply branch, a backup power supply branch, and a switching control circuit, the high-cost switching problem of the integrated T-BOX cockpit domain controller in the event of an external power supply failure was solved, achieving low-cost backup battery switching and ensuring the normal operation and functionality of the controller.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-18
- Publication Date
- 2026-03-13
AI Technical Summary
In the cockpit domain controller that integrates T-BOX, the instantaneous switch to backup battery power in the event of an external power failure requires a large amount of energy, resulting in high hardware costs.
A power supply circuit is designed, which includes a main power supply branch, a first backup power supply branch, and a switching control circuit. The switching of the backup power supply branch is realized through a switching unit and a switching control circuit, and the power supply switching is completed using a low-cost backup battery capacity.
It enables low-cost backup battery switching, ensuring the normal operation of the integrated T-BOX cockpit domain controller in the event of power failure, and meeting the functions of information uploading and emergency call.
Smart Images
Figure CN121663776A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power supply technology, and in particular to a power supply circuit for an in-vehicle domain controller and a T-BOX. Background Technology
[0002] The T-BOX (Telematics box, in-vehicle wireless communication box) is a core terminal component in the "cloud-pipe-terminal" architecture of the vehicle-to-everything (V2X) system, used to realize information interaction and control between the inside and outside of the vehicle, and has become a standard feature of new energy vehicles. The in-vehicle terminal needs to maintain independent operation even after an external power supply failure, requiring the T-BOX to be equipped with a backup battery. A standalone T-BOX control system only has communication functions and consumes very little power during operation. When the external power supply fails, the energy stored in the primary power supply's filter capacitor can be used to switch to backup battery power, successfully switching the entire T-BOX system to power by a small backup battery. However, when this design is used in a cockpit domain controller integrating the T-BOX, the cockpit domain controller with the integrated T-box consumes a lot of power during operation, needing to drive the central control screen, instrument panel, passenger screen, multiple cameras, and many other peripherals. When an external power supply failure occurs, the instantaneous switch to backup battery power requires a large amount of energy. Simply increasing the number and capacity of backup batteries to achieve this switch would result in high hardware costs. Summary of the Invention
[0003] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a power supply circuit for an in-vehicle domain controller and a T-BOX.
[0004] In a first aspect, embodiments of the present invention provide a power supply circuit for a T-BOX, comprising: a main power supply branch, a first backup power supply branch, and a switching control circuit. One end of the main power supply branch is connected to a main power supply, one end of the first backup power supply branch is connected to a backup power supply, and the other ends of both the main power supply branch and the first backup power supply branch are connected to the power input terminal of the T-BOX control unit. A switching unit is connected in series on the first backup power supply branch, and the control terminal of the switching unit is connected to the output terminal of the switching control circuit.
[0005] The main power supply branch is configured to output the main power supply voltage to power the T-BOX control unit when the main power supply input is normal.
[0006] The switching control circuit is configured to generate a level signal for controlling the closing or opening of the switching unit based on the main power supply input state.
[0007] The switching unit is configured to perform an on or off action according to the level signal, so as to realize the switching of the first backup power supply branch.
[0008] In some embodiments, the switching unit includes a first transistor, the control electrode of the first transistor is connected to the output terminal of the switching control circuit, the first electrode of the first transistor is the input terminal of the switching unit for connection to a backup power supply, and the second electrode of the first transistor is the output terminal of the switching unit for connection to the power supply input terminal of the T-BOX control unit.
[0009] The switching unit further includes a fourth diode, the positive terminal of which is connected to the second terminal of the first transistor, and the negative terminal of which is connected to the first terminal of the first transistor.
[0010] In some embodiments, the first transistor is a P-MOSFET. The first electrode of the P-MOSFET is the source, the second electrode is the drain, and the control electrode of the first transistor is the gate.
[0011] In some embodiments, the first backup power supply branch includes a second unidirectional conducting device. The second unidirectional conducting device has a third connection terminal and a fourth connection terminal. The third connection terminal of the second unidirectional conducting device is connected to the output terminal of the switching unit, the input terminal of the switching unit is connected to the backup power supply, and the fourth connection terminal of the second unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The second unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the third connection terminal to the fourth connection terminal and to block the voltage from being transmitted from the fourth connection terminal to the third connection terminal.
[0012] In some embodiments, the second unidirectional conducting device is a second diode, wherein the positive terminal of the second diode is the third connection terminal and the negative terminal of the second diode is the fourth connection terminal.
[0013] In some embodiments, the main power supply branch includes a DC-DC step-down circuit, which is configured to step down the main power supply voltage and output the main power supply voltage to power the T-BOX control unit.
[0014] The main power supply branch includes a first unidirectional conducting device. The first unidirectional conducting device has a first connection terminal and a second connection terminal. The first connection terminal of the first unidirectional conducting device is connected to the output terminal of the DC-DC step-down circuit, and the second connection terminal of the first unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The first unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the first connection terminal to the second connection terminal, and to block the voltage from being transmitted from the second connection terminal to the first connection terminal.
[0015] In some embodiments, the main power supply branch further includes an LC filter circuit, which is located at the input terminal of the DC-DC step-down circuit.
[0016] In some embodiments, the first unidirectional conducting device employs a first diode, wherein the anode of the first diode is a first connection terminal and the cathode of the first diode is a second connection terminal.
[0017] In some embodiments, the switching control circuit includes a main power supply detection circuit and a switching logic circuit. The switching logic circuit has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the switching logic circuit is connected to the output terminal of the main power supply detection circuit. The second input terminal of the switching logic circuit is used to receive an externally input valid level signal. The output terminal of the switching logic circuit is the output terminal of the switching control circuit.
[0018] The main power supply detection circuit is configured to detect the input status of the main power supply and output a valid level signal when the main power supply input is abnormal.
[0019] The switching logic circuit is configured to output a valid level signal through its output terminal when both its first and second input terminals are input with valid level signals, so as to close the switching unit.
[0020] In some embodiments, the main power supply detection circuit includes a second transistor, the control electrode of the second transistor is connected to the main power supply via a first resistor, the control electrode of the second transistor is grounded via a second resistor, the first electrode of the second transistor is grounded, the second electrode of the second transistor is connected to the backup power supply voltage via a third resistor, and the second electrode of the second transistor is the output terminal of the main power supply detection circuit.
[0021] In some embodiments, the second transistor is a triode.
[0022] In some embodiments, the switching logic circuit is a NAND gate circuit.
[0023] In some embodiments, the power supply circuit of the T-BOX of the present invention further includes a second backup power supply branch. One end of the second backup power supply branch is connected to a backup power source, and the other end of the second backup power supply branch is connected to the power input terminal of the T-BOX control unit. The second backup power supply branch includes a DC-DC boost circuit, and the control terminal of the DC-DC boost circuit is connected to the control terminal of the switching unit.
[0024] In some embodiments, the second backup power supply branch includes a third unidirectional conducting device. The third unidirectional conducting device has a fifth connection terminal and a sixth connection terminal. The fifth connection terminal of the third unidirectional conducting device is connected to the output terminal of the DC-DC boost circuit, and the input terminal of the DC-DC boost circuit is connected to the backup power supply. The sixth connection terminal of the third unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The third unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the fifth connection terminal to the sixth connection terminal and to block the voltage from being transmitted from the sixth connection terminal to the fifth connection terminal.
[0025] In some embodiments, the third unidirectional conducting device is a third diode, wherein the positive terminal of the third diode is the fifth connection terminal and the negative terminal of the third diode is the sixth connection terminal.
[0026] Secondly, this disclosure also provides an on-board domain controller, including: a power supply circuit for the T-BOX as provided in the first aspect.
[0027] The power supply circuit of the T-BOX is configured to provide power to the minimum system of the T-BOX control unit.
[0028] The beneficial effects of this invention are as follows: The power supply circuit for the T-BOX provided by this disclosure includes a main power supply branch, a first backup power supply branch, and a switching control circuit. The main power supply branch is configured to output a main power supply voltage to power the T-BOX control unit when the main power supply input is normal. The switching control circuit is configured to generate a level signal for controlling the closing or opening of the switching unit based on the main power supply input state. The switching unit is configured to perform an on or off action according to the level signal to realize the switching of the first backup power supply branch. Using the above power supply circuit, a low-cost battery can be used to complete the backup battery switching of the high-power controller, enabling vehicle information uploading and emergency call functions. Attached Figure Description
[0029] Figure 1 A schematic diagram of the power supply circuit for a T-BOX with an independent T-BOX controller;
[0030] Figure 2 A schematic block diagram of a power supply circuit for a T-BOX provided in an embodiment of this disclosure;
[0031] Figure 3 A circuit diagram of a power supply circuit for a T-BOX provided in an embodiment of this disclosure;
[0032] Figure 4 A circuit diagram of another power supply circuit for a T-BOX provided in an embodiment of this disclosure;
[0033] Figure 5 This is a waveform diagram of the backup battery dropping instantaneously. Detailed Implementation
[0034] To enable those skilled in the art to better understand the technical solutions of the present invention, exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.
[0035] Where there is no conflict, the various embodiments of the present invention and the features thereof may be combined with each other.
[0036] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.
[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Terms such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.
[0038] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art and the invention, and will not be interpreted as having an idealized or overly formal meaning unless expressly so defined herein.
[0039] In this disclosure, "valid level signal" refers to a signal that can control the corresponding chip to perform the corresponding function, and "invalid level signal" refers to a signal that cannot control the corresponding chip to perform the corresponding function; "valid level signal" and "invalid level signal" are inverse signals of each other; for example, if the valid level signal is a high level signal, then the invalid level signal is a low level signal; if the valid level signal is a low level signal, then the invalid level signal is a high level signal.
[0040] The integrated T-BOX cockpit domain controller integrates the T-BOX controller into the cockpit domain controller. This cockpit domain controller can not only drive the screen display and collect camera data, but also communicate with the cloud to perform vehicle information uploading and emergency call functions.
[0041] Figure 1 This is a circuit diagram of the power supply circuit for an independent T-BOX controller. The circuit switches to the backup power supply (such as a backup battery) by comparing the voltage at the controller's battery power supply port with the controller's internal VREF reference voltage. The controller's internal VREF reference voltage is obtained by using the battery's B+ primary power supply, which is filtered by an inductor and a large capacitor, and then stepped down by a DC-DC step-down circuit. When the battery B+ suddenly disconnects, the voltage drop of the subsequent stage, due to the large capacitor storing energy, will be delayed compared to the B+ voltage drop, approximately by milliseconds. Therefore, when the battery B+ suddenly disconnects, the comparator determines that the battery B+ voltage is less than the VREF reference voltage, and the comparator outputs a high level to open the backup power supply branch powered by the backup battery, which then supplies power to the controller. The key feature of this circuit is its sufficient backup battery capacity. When suddenly switching to backup battery power, the backup battery continuously discharges at a 2C rate. Assuming three 600mAh backup batteries are used, the 2C discharge would be 1200mA, resulting in an input power consumption of 3.6V * 1200mA = 4.32W. A 600mAh battery is sufficient to power the entire T-box controller, so during a full-charge switch, the backup battery voltage will not momentarily drop below the VIN input voltage range of the boost circuit, allowing for a normal switching operation.
[0042] When the power supply circuit of the T-BOX mentioned above is applied to the integrated T-BOX cockpit domain controller, it is necessary to ensure that the backup battery capacity is large enough. For example, when the normal power consumption of the cockpit domain controller is about 12V*2A=24W, at least 4 to 5 backup batteries with a capacity of 1200mAh are needed to complete the switching using existing technology, and the cost of the batteries is too high.
[0043] Table 1 compares the power consumption of the standalone T-BOX controller and the integrated T-box controller. The power consumption of the two is quite different. In the application of the integrated T-box, during instantaneous switching, the backup battery needs to output more power, which requires a very large instantaneous current from the backup battery to switch successfully. When this current exceeds the actual discharge current that the backup battery can withstand, it will instantly pull down the voltage of the backup battery, causing a momentary drop. This drop will be so high that the DC-DC boost circuit cannot be turned on, resulting in switching failure. Figure 5 Current waveform diagram of T-BOX backup battery switching failure ( Figure 5(above) and voltage waveform diagram ( Figure 5 The image below shows the waveform of the backup battery dropping instantaneously during the actual test.
[0044] Table 1 shows:
[0045]
[0046] The purpose of this invention is to solve the problem of switching to the backup branch using a low-cost backup battery when the T-box is integrated into other controller circuits and the other controllers are operating under high load.
[0047] In order to effectively improve or even completely solve the above-mentioned problems in the related technologies, this disclosure provides corresponding solutions.
[0048] Figure 2 This is a schematic diagram of the power supply circuit of a T-BOX provided in an embodiment of the present disclosure. Figure 3 A circuit diagram of a power supply circuit for a T-BOX provided in an embodiment of this disclosure; as shown Figure 2 and Figure 3 As shown, the power supply circuit of the T-BOX includes: a main power supply branch 1, a first backup power supply branch 2, and a switching control circuit 3. One end of the main power supply branch 1 is connected to the main power supply, and the other end of the main power supply branch 1 is connected to the power input terminal of the T-BOX control unit 4. One end of the first backup power supply branch 2 is connected to the backup power supply, and the other end of the first backup power supply branch 2 is connected to the power input terminal of the T-BOX control unit 4. A switching switch unit is connected in series on the first backup power supply branch 2, and the control terminal of the switching switch unit is connected to the output terminal of the switching control circuit 3.
[0049] The main power supply branch 1 is configured to output the main power supply voltage to power the T-BOX control unit when the main power supply input is normal.
[0050] The switching control circuit 3 is configured to generate a level signal for controlling the closing or opening of the switching unit based on the main power supply input state.
[0051] The switching unit is configured to perform an on or off action according to the level signal, so as to realize the on / off switching of the first backup power supply branch 2.
[0052] The power supply circuit of the T-BOX of the present invention uses a circuit that can be switched using only a low-cost backup battery to achieve independent operation of the integrated T-box cockpit domain controller.
[0053] In some embodiments, the backup power source is a backup battery. The main power source is an onboard battery.
[0054] In some embodiments, the switching unit includes a first transistor Q3, the control electrode of the first transistor Q3 is connected to the output terminal of the switching control circuit, the first electrode of the first transistor Q3 is the input terminal of the switching unit for connection to a backup power supply, and the second electrode of the first transistor Q3 is the output terminal of the switching unit for connection to the power supply input terminal of the T-BOX control unit.
[0055] The switching unit further includes a fourth diode, the positive terminal of which is connected to the second terminal of the first transistor, and the negative terminal of which is connected to the first terminal of the first transistor.
[0056] In some embodiments, the first transistor Q3 is a MOSFET, specifically a P-MOSFET. The first electrode of the P-MOSFET is the source, the second electrode is the drain, and the control electrode is the gate. The first transistor is not limited to a P-MOSFET and can be adaptively adjusted as needed.
[0057] In some embodiments, the first backup power supply branch includes a second unidirectional conducting device. The second unidirectional conducting device has a third connection terminal and a fourth connection terminal. The third connection terminal of the second unidirectional conducting device is connected to the output terminal of the switching unit, the input terminal of the switching unit is connected to the backup power supply, and the fourth connection terminal of the second unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The second unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the third connection terminal to the fourth connection terminal and to block the voltage from being transmitted from the fourth connection terminal to the third connection terminal.
[0058] In some embodiments, the second unidirectional conducting device is a diode D2, wherein the positive terminal of diode D2 is the third connection terminal and the negative terminal of diode D2 is the fourth connection terminal.
[0059] In some embodiments, the main power supply branch includes a DC-DC step-down circuit, which is configured to step down the main power supply voltage and output the main power supply voltage to power the T-BOX control unit.
[0060] The main power supply branch includes a first unidirectional conducting device. The first unidirectional conducting device has a first connection terminal and a second connection terminal. The first connection terminal of the first unidirectional conducting device is connected to the output terminal of the DC-DC step-down circuit, and the second connection terminal of the first unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The first unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the first connection terminal to the second connection terminal, and to block the voltage from being transmitted from the second connection terminal to the first connection terminal.
[0061] The DC-DC step-down circuit is used to reduce the voltage to the range applicable to the T-BOX. When the main power supply is normal, it provides a stable main power supply to the T-BOX.
[0062] In some embodiments, a power supply unit may be provided on the main power supply branch at the front end of the DC-DC step-down circuit. The power supply unit is used to perform power preprocessing on the main power supply (such as an on-board power supply). The power supply unit may include input protection circuitry, such as EMC filtering.
[0063] In some embodiments, the power supply unit further includes an LC filter circuit located at the input terminal of the DC-DC buck circuit. The LC filter circuit includes a power inductor and a filter capacitor.
[0064] The voltage output from the main power supply, such as the vehicle battery, is filtered by an inductor and a large capacitor, and then stepped down by a DC-DC step-down circuit to obtain the main power supply voltage for the minimum system of the T-BOX control unit.
[0065] In some embodiments, the first unidirectional conducting device is a diode D1, wherein the anode of diode D1 is the first connection terminal and the cathode of diode D1 is the second connection terminal. Diode D1 can prevent reverse current.
[0066] In some embodiments, the switching control circuit includes a main power supply detection circuit and a switching logic circuit. The switching logic circuit has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the switching logic circuit is connected to the output terminal of the main power supply detection circuit. The second input terminal of the switching logic circuit is used to receive an externally input valid level signal. The output terminal of the switching logic circuit is the output terminal of the switching control circuit.
[0067] The main power supply detection circuit is configured to detect the input status of the main power supply and output a valid level signal when the main power supply input is abnormal.
[0068] The switching logic circuit is configured to output a valid level signal through its output terminal when both its first and second input terminals are input with valid level signals, so as to close the switching unit.
[0069] In some embodiments, the second input terminal of the switching logic circuit is used to receive a valid level signal input from the MCU. Using the above scheme, the function of switching the backup power supply can be turned off or on by the MCU.
[0070] In some embodiments, the main power supply detection circuit includes a second transistor Q1. The control electrode of the second transistor Q1 is connected to the main power supply via a first resistor R1. The control electrode of the second transistor Q1 is grounded via a second resistor R2. The first electrode of the second transistor Q1 is grounded. The second electrode of the second transistor Q1 is connected to the backup power supply voltage via a third resistor R3. The second electrode of the second transistor Q1 is the output terminal of the main power supply detection circuit.
[0071] In some embodiments, the second transistor Q1 is a transistor, such as an NPN transistor. Of course, the second transistor is not limited to an NPN transistor and can be adaptively adjusted as needed.
[0072] In some embodiments, the switching logic circuit is a NAND gate circuit Q2. In this embodiment, the NAND gate circuit Q2 outputs a low level only when both inputs are high; otherwise, it outputs a high level.
[0073] Switching logic circuits are not limited to NAND gates; they can also be adaptively adjusted according to functional requirements.
[0074] In some embodiments, see Figure 4 The power supply circuit of the T-BOX of the present invention further includes a second backup power supply branch. One end of the second backup power supply branch is connected to a backup power source, and the other end of the second backup power supply branch is connected to the power input terminal of the T-BOX control unit. The second backup power supply branch includes a DC-DC boost circuit, and the control terminal of the DC-DC boost circuit is connected to the control terminal of the switching unit.
[0075] In some embodiments, the second backup power supply branch includes a third unidirectional conducting device. The third unidirectional conducting device has a fifth connection terminal and a sixth connection terminal. The fifth connection terminal of the third unidirectional conducting device is connected to the output terminal of the DC-DC boost circuit, and the input terminal of the DC-DC boost circuit is connected to the backup power supply. The sixth connection terminal of the third unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The third unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the fifth connection terminal to the sixth connection terminal and to block the voltage from being transmitted from the sixth connection terminal to the fifth connection terminal.
[0076] In some embodiments, the third unidirectional conducting device is a diode D3, wherein the positive terminal of diode D3 is the fifth connection terminal and the negative terminal of diode D3 is the sixth connection terminal.
[0077] The working principle of this invention is as follows: The voltage of the battery B+ is used to determine whether to switch to the backup battery. When B+ is disconnected, the voltage across Q1 is adjusted using voltage divider resistors R1 / R2. When B+ is normal, the NPN transistor Q1 is turned on, and input 1 of the NAND gate is low. When B+ is abnormally low below a certain voltage, Q1 is turned off, and input 1 of the NAND gate is high. Simultaneously, the signal at input 2 of the NAND gate, controlled by the MCU output, is also checked. Only when input 2 is high and input 1 is also high can Q2 output a low level, turning on the P-MOSFET Q3. Unlike existing designs, the backup battery directly powers the minimum system integrated with the TBOX, rather than the entire system. The minimum system only needs to ensure the normal transmission of communication signals; other functions such as the display screen, camera, and corresponding serializer / deserializer chips, radio, and USB do not need to operate normally. Switching to backup battery power only ensures the operation of the minimum system, isolating other unnecessary chips from power management. This design also adds a redundant design for switching backup batteries, namely a first backup power supply branch and a second backup power supply branch, to prevent switching failure during the switching process. The first backup power supply branch directly supplies power to the minimum system of the T-BOX control unit with the voltage of the backup battery, while the second backup power supply branch supplies power to the minimum system of the T-BOX control unit after boosting the voltage of the backup battery through a DC-DC boost circuit.
[0078] The power supply circuit for the T-BOX provided by this disclosure can switch the integrated TBOX controller's backup battery using a small-capacity battery, meeting the required requirements. It employs a redundant circuit design to ensure the controller's normal operation under abnormal power conditions. If the switching circuit design proposed in this invention is used, only three 600mAh batteries are needed to complete the switching.
[0079] Based on the same inventive concept, this disclosure also provides an in-vehicle domain controller, including the power supply circuit of the T-BOX provided in any of the preceding embodiments. The description of the power supply circuit of the T-BOX can be found in the content of the preceding embodiments, and will not be repeated here.
[0080] In some embodiments, the vehicle domain controller is a cockpit domain controller with an integrated TBOX. Of course, the vehicle domain controller is not limited to a cockpit domain controller; it can also be other normally functioning domain controllers with high loads.
[0081] The power supply circuit of the T-BOX is configured to provide power to the minimum system of the T-BOX control unit.
[0082] Integrated TBOX Cockpit Domain Controller: The TBOX controller is integrated into the cockpit domain controller, which can not only drive the screen display and collect camera data, but also communicate with the cloud to upload vehicle information and make emergency calls.
[0083] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.
Claims
1. A power supply circuit for a T-BOX, characterized in that, include: The system includes a main power supply branch, a first backup power supply branch, and a switching control circuit. One end of the main power supply branch is connected to the main power supply, and one end of the first backup power supply branch is connected to the backup power supply. The other ends of both the main power supply branch and the first backup power supply branch are connected to the power input terminal of the T-BOX control unit. A switching unit is connected in series on the first backup power supply branch, and the control terminal of the switching unit is connected to the output terminal of the switching control circuit. The main power supply branch is configured to output the main power supply voltage to power the T-BOX control unit when the main power supply input is normal. The switching control circuit is configured to generate a level signal for controlling the closing or opening of the switching unit based on the main power supply input state. The switching unit is configured to perform an on or off action according to the level signal, so as to realize the switching of the first backup power supply branch.
2. The power supply circuit of the T-BOX according to claim 1, characterized in that: The switching unit includes a first transistor, the control electrode of the first transistor is connected to the output terminal of the switching control circuit, the first electrode of the first transistor is the input terminal of the switching unit for connection to the backup power supply, and the second electrode of the first transistor is the output terminal of the switching unit for connection to the power supply input terminal of the T-BOX control unit.
3. The power supply circuit for the T-BOX according to claim 1 or 2, characterized in that: The first backup power supply branch includes a second unidirectional conducting device. The second unidirectional conducting device has a third connection terminal and a fourth connection terminal. The third connection terminal of the second unidirectional conducting device is connected to the output terminal of the switching unit, the input terminal of the switching unit is connected to the backup power supply, and the fourth connection terminal of the second unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The second unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the third connection terminal to the fourth connection terminal and to block the voltage from being transmitted from the fourth connection terminal to the third connection terminal.
4. The power supply circuit of the T-BOX according to claim 1, characterized in that: The main power supply branch includes a DC-DC step-down circuit, which is configured to step down the main power supply voltage and output the main power supply voltage to power the T-BOX control unit. The main power supply branch includes a first unidirectional conducting device. The first unidirectional conducting device has a first connection terminal and a second connection terminal. The first connection terminal of the first unidirectional conducting device is connected to the output terminal of the DC-DC step-down circuit, and the second connection terminal of the first unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The first unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the first connection terminal to the second connection terminal, and to block the voltage from being transmitted from the second connection terminal to the first connection terminal.
5. The power supply circuit for the T-BOX according to claim 1, characterized in that: The switching control circuit includes a main power supply detection circuit and a switching logic circuit. The switching logic circuit has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the switching logic circuit is connected to the output terminal of the main power supply detection circuit. The second input terminal of the switching logic circuit is used to receive an externally input valid level signal. The output terminal of the switching logic circuit is the output terminal of the switching control circuit. The main power supply detection circuit is configured to detect the input status of the main power supply and output a valid level signal when the main power supply input is abnormal. The switching logic circuit is configured to output a valid level signal through its output terminal when both its first and second input terminals are input with valid level signals, so as to close the switching unit.
6. The power supply circuit for the T-BOX according to claim 5, characterized in that: The main power supply detection circuit includes a second transistor. The control electrode of the second transistor is connected to the main power supply through a first resistor. The control electrode of the second transistor is grounded through a second resistor. The first electrode of the second transistor is grounded. The second electrode of the second transistor is connected to the backup power supply voltage through a third resistor. The second electrode of the second transistor is the output terminal of the main power supply detection circuit.
7. The power supply circuit for the T-BOX according to claim 5, characterized in that: The switching logic circuit is a NAND gate circuit.
8. The power supply circuit of the T-BOX according to claim 1, characterized in that: It also includes a second backup power supply branch, one end of which is connected to a backup power source, and the other end of which is connected to the power input terminal of the T-BOX control unit. The second backup power supply branch includes a DC-DC boost circuit, and the control terminal of the DC-DC boost circuit is connected to the control terminal of the switching unit.
9. The power supply circuit for the T-BOX according to claim 8, characterized in that: The second backup power supply branch includes a third unidirectional conducting device. The third unidirectional conducting device has a fifth connection terminal and a sixth connection terminal. The fifth connection terminal of the third unidirectional conducting device is connected to the output terminal of the DC-DC boost circuit, and the input terminal of the DC-DC boost circuit is connected to the backup power supply. The sixth connection terminal of the third unidirectional conducting device is connected to the power supply input terminal of the T-BOX control unit. The third unidirectional conducting device is configured to enable the voltage to be unidirectionally transmitted from the fifth connection terminal to the sixth connection terminal, and to block the voltage from being transmitted from the sixth connection terminal to the fifth connection terminal.
10. A vehicle-mounted domain controller, which integrates a T-BOX control unit, characterized in that, include: The power supply circuit of the T-BOX as described in any one of claims 1 to 9.