Switching circuit, whole vehicle power supply system and vehicle

Abstract

The utility model relates to the technical field of whole vehicle power supply systems, in particular to a switching circuit, a whole vehicle power supply system and a vehicle, which comprises a field effect transistor unit, a voltage dividing unit and a filtering unit, the field effect transistor unit comprises at least one P-type field effect transistor and at least one N-type field effect transistor; a source electrode of the P-type field effect transistor is used for being connected with a power supply of a whole vehicle power supply system, and a drain electrode of the P-type field effect transistor is grounded through the filtering unit and used for controlling on-off of the power supply. A drain electrode of the N-type field effect transistor is connected to a power supply after passing through the voltage dividing unit, the voltage dividing unit is connected with a grid electrode of the P-type field effect transistor, and a grid electrode of the N-type field effect transistor is used for being connected with an MCU chip of a whole vehicle power supply system and used for receiving an enable signal sent by the MCU chip and controlling the on-off state of the P-type field effect transistor according to the enable signal. According to the utility model, power management is simplified, and stability and reliability are improved.

Description

Technical Field

[0001] This utility model relates to the technical field of vehicle power supply systems, specifically to a switching circuit, a vehicle power supply system, and a vehicle. Background Technology

[0002] With the rapid development of new energy vehicle technology, the performance requirements for controllers, as core components of new energy vehicles, are increasing. In new energy vehicle controllers, the power supply system plays a crucial role, providing a stable and reliable power supply. However, the power supply system faces numerous challenges in the current development of new energy vehicle controller technology.

[0003] First, the complexity of power trees is increasing. As controller functions diversify, the types and quantities of power supplies required are also constantly increasing, leading to increasingly complex power tree structures. This complexity not only increases the difficulty of power management but may also cause interference and conflicts between power supplies, affecting the stability and reliability of the controller.

[0004] Secondly, insufficient isolation between power supplies leads to significant interference propagation issues. In complex power systems, electromagnetic interference and coupling effects often exist between power supplies. If isolation measures are inadequate, these interferences can propagate between them, affecting the normal operation of the power supplies. This interference problem is particularly severe under high voltage and high current environments, potentially leading to controller performance degradation or even damage.

[0005] Furthermore, preventing reverse power connection is a major challenge that urgently needs to be addressed in current new energy vehicle controller technology. If the power supply polarity is reversed during connection, it will not only cause the power supply to malfunction but may also severely damage the controller. Therefore, effectively preventing reverse power connection and ensuring the safe and stable operation of the controller is a key issue that needs to be considered in current technological development.

[0006] To address the aforementioned issues, existing technologies have proposed several solutions, such as using SJ-MOS transistors (superjunction power MOSFETs) to build a full-bridge circuit and employing MOS switching power supplies. However, these solutions still have some shortcomings in practical applications. For example, SJ-MOS transistors suffer from parasitic diode reverse recovery during freewheeling, making them prone to damage; while MOS switching power supplies require complex circuit design and control strategies to achieve reliable power switching and reverse protection.

[0007] In summary, new energy vehicle controller technology still faces many challenges in terms of power systems, requiring continuous exploration and innovation to meet the high requirements of the new energy vehicle industry for controller performance and safety. Utility Model Content

[0008] The purpose of this invention is to provide a switching circuit, a vehicle power supply system, and a vehicle that can simplify power management and improve stability and reliability.

[0009] In a first aspect, the switching circuit described in this utility model includes a field-effect transistor unit, a voltage divider unit, and a filter unit;

[0010] The field-effect transistor unit includes at least one P-type field-effect transistor and at least one N-type field-effect transistor;

[0011] The source of the P-type field-effect transistor is used to connect to the power supply of the vehicle power supply system, and the drain of the P-type field-effect transistor is grounded through a filter unit to control the on / off state of the power supply.

[0012] The drain of the N-type field-effect transistor is connected to the power supply via a voltage divider unit, and the voltage divider unit is connected to the gate of the P-type field-effect transistor. The gate of the N-type field-effect transistor is used to connect to the MCU chip of the vehicle power supply system, to receive the enable signal sent by the MCU chip, and to control the switching state of the P-type field-effect transistor according to the enable signal.

[0013] Optionally, the filtering unit includes at least a filter capacitor C1 and a filter capacitor C2, which are connected in parallel between the drain of the P-type field-effect transistor and ground to filter out ripple and noise at the power output terminal.

[0014] Optionally, the voltage divider unit includes at least resistors R1 and R2. The power supply is connected to the drain of the N-type field-effect transistor via resistors R1 and R2 in sequence, and the connection point of resistors R1 and R2 is connected to the gate of the P-type field-effect transistor to provide the divided voltage to the gate of the P-type field-effect transistor.

[0015] Optionally, the switching circuit further includes:

[0016] Pull-down resistor R4 is connected between the gate of the N-type field-effect transistor and ground to ensure that the N-type field-effect transistor is in the off state when it does not receive a control signal from the MCU chip.

[0017] Optionally, the switching circuit further includes:

[0018] The current-limiting resistor R3 is connected between the gate of the N-type field-effect transistor and the enable signal output terminal of the MCU chip to limit the current output from the MCU chip to the gate of the N-type field-effect transistor.

[0019] Optionally, the switching circuit further includes:

[0020] Zener diodes D1 and D2 are used. The positive terminal of Zener D1 is connected to the gate of the N-type field-effect transistor (NMOSFET), and the negative terminals of both Zener D1 and D2 are connected. The positive terminal of Zener D2 is grounded. Zener D1 and D2 together form a voltage stabilization and protection network. Zener D1 primarily limits excessive voltage to the gate of the NMOSFET Q2, while Zener D2 works in conjunction with D1 to ensure that other parts of the circuit are not subjected to excessive voltage surges. This configuration helps improve the reliability and stability of the circuit.

[0021] Optionally, the P-type field-effect transistor is a PMOS transistor Q1. The PMOS transistor Q1 has low resistance in the on-state, which is very suitable for applications requiring high current and provides strong anti-interference capability; at the same time, the PMOS transistor Q1 has strong anti-interference capability, making it suitable for harsh environmental conditions. However, its operating speed is relatively low, which is just right for preventing power supply overshoot ripple.

[0022] Optionally, the N-type field-effect transistor is an NMOS transistor Q2. The NMOS transistor Q2 has a relatively fast response speed and conducts when the voltage level is high. Therefore, using a combination of NMOS transistor Q2 and PMOS transistor Q1 to switch the power supply achieves both efficient control and full conduction.

[0023] Secondly, the vehicle power supply system described in this utility model includes:

[0024] power supply;

[0025] SBC chip, connected to power supply;

[0026] An MCU chip, connected to an SBC chip; characterized in that it further includes:

[0027] Multiple switching circuits as described in this utility model are provided, with the power input terminal of each switching circuit connected to a power source, the power output terminal of each switching circuit connected to different vehicle subsystems, and the control terminal of each switching circuit connected to an MCU chip. The MCU chip controls the on / off state of each switching circuit to provide DC power to different vehicle subsystems.

[0028] Thirdly, the vehicle described in this utility model adopts the vehicle power supply system described in this utility model.

[0029] The beneficial effects of this utility model are:

[0030] (1) This utility model simplifies power management and improves stability and reliability;

[0031] By introducing a switching circuit that includes P-type field-effect transistors (such as PMOS transistor Q1) and N-type field-effect transistors (such as NMOS transistor Q2), flexible control of different power supply branches in the vehicle power supply system is achieved. This design simplifies the complex power tree structure, making power management more intuitive and efficient. By controlling the on / off state of each switching circuit through the MCU chip, the required DC power supply can be precisely provided to different vehicle subsystems, reducing interference and conflicts between power supplies and improving the stability and reliability of the power supply system.

[0032] (2) This utility model improves power isolation and reduces interference transmission;

[0033] The design of the filter unit, especially the parallel use of filter capacitors C1 and C2, effectively filters out high-frequency noise and interference in the power supply, improving the purity of the power signal.

[0034] The voltage divider unit provides a stable control voltage to the gate of the P-type field-effect transistor through the voltage division effect of resistors R1 and R2, further reducing electromagnetic interference and coupling effects between power supplies.

[0035] (3) This utility model realizes the power supply anti-reverse function to ensure safe and stable operation;

[0036] In switching circuit design, precise control of the power supply process is achieved by controlling the gate of the N-type field-effect transistor through the MCU chip. When the power supply polarity is reversed, the MCU chip can quickly cut off the power supply branch, preventing damage to the controller caused by reverse power connection.

[0037] In addition, the addition of Zener diodes D1 and D2 provides an extra protection mechanism for the circuit, further enhancing the system's ability to withstand reverse connection.

[0038] In summary, this invention significantly improves the stability, reliability, and safety of the power supply system for new energy vehicle controllers by introducing a switching circuit containing P-type and N-type field-effect transistors, optimizing filtering and voltage divider design, implementing power supply reverse protection, and adopting modular design, thus providing strong technical support for the development of the new energy vehicle industry. Attached Figure Description

[0039] Figure 1 This is a circuit diagram of the switching circuit described in the embodiments of this application;

[0040] Figure 2 This is a schematic block diagram of the vehicle power supply system described in the embodiments of this application;

[0041] Figure 3 This is a flowchart illustrating the processing of the vehicle power supply system described in the embodiments of this application;

[0042] Figure 4 This is a schematic diagram of the vehicle power supply system described in the embodiments of this application;

[0043] In the diagram: 1-Power supply, 2-Field effect transistor unit, 3-Filter unit, 4-Voltage divider unit, 5-Switching circuit, 6-Vehicle subsystem, 7-SBC chip, 8-MCU chip. Detailed Implementation

[0044] The embodiments of this utility model will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be understood that the preferred embodiments are only for illustrating this utility model and not for limiting the scope of protection of this utility model.

[0045] like Figure 1 As shown in the embodiment of this application, a switching circuit includes a field-effect transistor (FET) unit 2, a voltage divider unit 4, and a filter unit 3. The FET unit 2 includes at least one P-type FET and at least one N-type FET. The source of the P-type FET is connected to the power supply 1 of the vehicle power supply system, and the drain of the P-type FET is grounded through the filter unit 3 to control the switching on and off of the power supply 1. The drain of the N-type FET is connected to the power supply 1 through the voltage divider unit 4, and the voltage divider unit 4 is connected to the gate of the P-type FET. The gate of the N-type FET is connected to the MCU chip 8 of the vehicle power supply system to receive an enable signal from the MCU chip 8 and control the switching state of the P-type FET according to the enable signal.

[0046] like Figure 1 As shown, in one possible embodiment, the filter unit 3 includes at least a filter capacitor C1 and a filter capacitor C2, which are connected in parallel between the drain of the P-type field-effect transistor and ground, for filtering out ripple and noise at the power output terminal.

[0047] like Figure 1 As shown, in one possible embodiment, the voltage divider unit 4 includes at least resistors R1 and R2. The power supply 1 is connected to the drain of the N-type field-effect transistor via resistors R1 and R2 in sequence, and the connection point of resistors R1 and R2 is connected to the gate of the P-type field-effect transistor to provide the divided voltage to the gate of the P-type field-effect transistor.

[0048] like Figure 1As shown, in one possible embodiment, a switching circuit further includes a pull-down resistor R4 connected between the gate of the N-type field-effect transistor and ground, to ensure that the N-type field-effect transistor is in the off state when it does not receive a control signal from the MCU chip 8.

[0049] like Figure 1 As shown, in one possible embodiment, a switching circuit further includes a current-limiting resistor R3, which is connected between the gate of the N-type field-effect transistor and the enable signal output terminal of the MCU chip 8, and is used to limit the current output from the MCU chip 8 to the gate of the N-type field-effect transistor.

[0050] like Figure 1 As shown, in one possible embodiment, a switching circuit further includes Zener diodes D1 and D2. The positive terminal of Zener diode D1 is connected to the gate of the N-type field-effect transistor (NMOSFET), and the negative terminals of Zener diodes D1 and D2 are connected. The positive terminal of Zener diode D2 is grounded. Zener diodes D1 and D2 together form a voltage stabilization and protection network. Zener diode D1 is primarily responsible for limiting excessively high voltages at the gate of the NMOS transistor Q2, while Zener diode D2 works in conjunction with Zener diode D1 to ensure that other parts of the circuit are not subjected to excessively high voltage surges. This configuration helps improve the reliability and stability of the circuit.

[0051] like Figure 1 As shown, in one possible embodiment, the P-type field-effect transistor is a PMOS transistor Q1, and the N-type field-effect transistor is an NMOS transistor Q2.

[0052] like Figure 1 As shown in the example, the following description uses a switching circuit including PMOS transistor Q1, NMOS transistor Q2, resistors R1, R2, R3, and R4, filter capacitors C1 and C2, and Zener diodes D1 and D2. The connection relationships of these components are as follows:

[0053] The source of PMOS transistor Q1 is connected to power supply 1 (i.e., Figure 1 The PWR (12V) of the PMOS transistor Q1 is connected to ground via filter capacitor C1; the drain of PMOS transistor Q1 is also connected to ground via filter capacitor C2; power supply 1 is connected to the drain of NMOS transistor Q2 via resistors R1 and R2, and the connection point of resistors R1 and R2 is connected to the gate of PMOS transistor Q1. The gate of NMOS transistor Q2 is connected to ground via resistor R4; the source of NMOS transistor Q2 is connected to ground; the gate of NMOS transistor Q2 is also connected to the enable signal output terminal of MCU chip 8 via resistor R3; the positive terminal of Zener diode D1 is connected to the gate of NMOS transistor Q2, the negative terminal of Zener diode D1 is connected to the negative terminal of Zener diode D2, and the positive terminal of Zener diode D2 is grounded.

[0054] like Figure 1 As shown, in one possible embodiment, PMOS transistor Q1 is selected as the power supply switch, mainly based on the following considerations:

[0055] The PMOS transistor Q1 exhibits low resistance when turned on, which is ideal for applications requiring high current. It also boasts excellent noise immunity, enabling stable operation in complex or harsh environments. Notably, the relatively slow operating speed of the PMOS transistor Q1 helps suppress power supply overshoot ripple, ensuring stable power output.

[0056] Meanwhile, NMOS transistor Q2 is chosen as the switch to drive PMOS transistor Q1 because:

[0057] NMOS transistor Q2 has a fast response speed, enabling it to respond quickly to control signals. It also conducts under high-level conditions, making it compatible with the logic levels of most digital control systems. Therefore, by combining NMOS transistor Q2 and PMOS transistor Q1, efficient and precise power supply control is achieved, while ensuring low resistance and stability of the power supply in the on-state. This combination scheme balances control efficiency with the integrity of the power output.

[0058] like Figure 2 As shown in the embodiments of this application, a vehicle power supply system includes a power supply 1, an SBC chip 7, an MCU chip 8, and multiple switching circuits 5 as described in the embodiments of this application. The SBC chip 7 is connected to the power supply 1. The MCU chip 8 is connected to the SBC chip 7. The power input terminal of each switching circuit 5 is connected to the power supply 1, and the power output terminal of each switching circuit 5 is connected to different vehicle subsystems 6. The control terminal of each switching circuit 5 is connected to the MCU chip 8, and the MCU chip 8 controls the on / off state of each switching circuit 5 to provide DC power to different vehicle subsystems 6.

[0059] In this embodiment of the application, a vehicle employs a vehicle power supply system as described in this embodiment of the application.

[0060] like Figures 2 to 4As shown in this embodiment, when the vehicle power supply system is initially powered on, power supply 1 (i.e., main road power supply) directly supplies power to SBC chip 7 and switching circuit 5. SBC chip 7 initializes the power configuration. Since SBC chip 7 has not yet supplied power to MCU chip 8, i.e., the enable signal output of MCU chip 8 is low, NMOS transistor Q2 is not turned on, and PMOS transistor Q1 is also in the off state. That is, switching circuit 5 is not turned on, so the subsequent power supply is not turned on, thus achieving isolation between power supplies. When SBC chip 7 supplies power to MCU chip 8, i.e., after MCU chip 8 starts working, MCU chip 8 enables switching circuit 5, turning on switching circuit 5 (i.e., NMOS transistor Q2 is turned on, and PMOS transistor Q1 is also turned on), i.e., turning on the corresponding branch to supply power to the subsequent branch (i.e., the corresponding vehicle subsystem 6).

[0061] In this embodiment of the application, a vehicle employs a vehicle power supply system as described in this embodiment of the application.

[0062] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A switching circuit, characterized by, The switch circuit (5) comprises a field effect transistor unit (2), a voltage division unit (4) and a filter unit (3). The field effect transistor unit (2) comprises at least one P-type field effect transistor and at least one N-type field effect transistor. The source of the P-type field effect transistor is connected with a power supply (1) of a whole vehicle power supply system, the drain of the P-type field effect transistor is grounded through the filter unit (3) and is used for controlling the on-off of the power supply (1). The drain of the N-type field effect transistor is connected to the power supply (1) through the voltage division unit (4), the voltage division unit (4) is connected with the gate of the P-type field effect transistor, the gate of the N-type field effect transistor is connected with an MCU chip (8) of the whole vehicle power supply system, is used for receiving an enable signal sent by the MCU chip (8) and controlling the switching state of the P-type field effect transistor according to the enable signal.

2. The switching circuit of claim 1, wherein The filter unit (3) comprises at least a filter capacitor C1 and a filter capacitor C2, the filter capacitor C1 and the filter capacitor C2 are connected in parallel between the drain of the P-type field effect transistor and the ground.

3. The switching circuit of claim 1, wherein The voltage division unit (4) comprises at least a resistor R1 and a resistor R2, the power supply (1) is connected with the drain of the N-type field effect transistor in sequence through the resistor R1 and the resistor R2, and the connection point of the resistor R1 and the resistor R2 is connected with the gate of the P-type field effect transistor.

4. The switching circuit of claim 1, wherein Further comprising: A pull-down resistor R4 connected between the gate of the N-type field effect transistor and the ground.

5. The switching circuit of claim 1, wherein Further comprising: A current limiting resistor R3 connected between the gate of the N-type field effect transistor and an enable signal output end of the MCU chip (8).

6. The switching circuit of claim 1, wherein Further comprising: A voltage stabilizing tube D1 and a voltage stabilizing tube D2, the positive electrode of the voltage stabilizing tube D1 is connected with the gate of the N-type field effect transistor, the negative electrode of the voltage stabilizing tube D1 and the negative electrode of the voltage stabilizing tube D2 are connected, and the positive electrode of the voltage stabilizing tube D2 is grounded.

7. The switching circuit of claim 1, wherein The P-type field effect transistor is a PMOS tube Q1.

8. The switching circuit of claim 1, wherein The N-type field effect transistor is an NMOS tube Q2.

9. A whole vehicle power supply system, comprising: A power supply (1); An SBC chip (7) connected with the power supply (1); An MCU chip (8) connected with the SBC chip (7); characterized in that further comprising: A plurality of switch circuits (5) according to any one of claims 1 to 8, the power supply input ends of the switch circuits (5) are all connected with the power supply (1), the power supply output ends of the switch circuits (5) are respectively connected with different vehicle subsystems (6), and the control ends of the switch circuits (5) are all connected with the MCU chip (8) to control the on-off of the switch circuits (5) through the MCU chip (8) so as to provide branch current power supply to the different vehicle subsystems (6).

10. A vehicle characterized by comprising: The whole vehicle power supply system according to claim 9 is adopted.

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