Switching circuit, battery management system and vehicle

Abstract

The embodiment of the utility model provides a switch circuit, a battery management system and a vehicle, the switch circuit comprises a switch module, and the switch module is suitable for being connected with a battery and a power management chip; when the signal input by the switch module is a turn-off signal, the switch module is turned off, so that the positive electrode of the battery is disconnected from the power supply end of the power supply management chip; and under the condition that the signal input by the switch module is a conduction signal, the switch module is conducted, so that the battery supplies power to the power supply end of the power supply management chip. According to the embodiment of the invention, the quiescent current of the power management chip can be reduced.

Description

Technical Field

[0001] This application relates to the technical field of electronic circuits, and particularly to a switching circuit, a battery management system, and a vehicle. Background Art

[0002] Due to the development of vehicle electrification, there are more and more electrical appliances on the vehicle. And due to limitations such as size and materials of the battery capacity, the total battery power is limited. Therefore, when the vehicle is turned off, the electrical appliances that are still connected consume battery power, and it is very important to manage this consumption. Otherwise, the vehicle will fail to start the next time due to battery power depletion, resulting in the vehicle being unable to start. Currently, the power supply of the power management chip directly draws power from the battery. After the vehicle is turned off, the power supply is not physically cut off, and the power management chip controls itself to enter the sleep or low-power mode to reduce power consumption, but there is still a relatively large static current in the power management chip. Summary of the Utility Model

[0003] Embodiments of this application provide a switching circuit, a battery management system, and a vehicle, which can reduce the static current of the power management chip.

[0004] In a first aspect of the embodiments of this application, a switching circuit is provided, including a switching module, and the switching module is adapted to be connected to a battery and a power management chip;

[0005] When the signal input to the switching module is an off signal, the switching module disconnects, so that the positive electrode of the battery is disconnected from the power supply terminal of the power management chip;

[0006] When the signal input to the switching module is an on signal, the switching module conducts, so that the battery supplies power to the power supply terminal of the power management chip.

[0007] In the embodiments of this application, when the signal input to the switching module is an off signal, the switching module disconnects, so that the positive electrode of the battery is disconnected from the power supply terminal of the power management chip, physically cutting off the battery from the power management chip, thereby reducing the static current of the power management chip.

[0008] Optionally, the input end of the switching module is adapted to be connected to the output end of an output module; the output module is used to input the off signal or the on signal to the input end of the switching module through the output end.

[0009] Optionally, the switching module includes at least one switching tube.

[0010] Optionally, the switching module includes a first switching unit and a second switching unit, and the control end of the second switching unit is connected to the first end of the first switching unit.

[0011] Optionally, the first end of the second switch unit is connected to the positive electrode of the battery, the second end of the second switch unit is connected to the power supply terminal of the power management chip, the control terminal of the first switch unit is connected to the output terminal of the output module, and the second end of the first switch unit is grounded.

[0012] Optionally, the first switch unit includes a first semiconductor switch. The first end of the first semiconductor switch is connected to the control terminal of the second switch unit, and the second end of the first semiconductor switch is grounded.

[0013] Optionally, the first switch unit further includes a first resistor and a second resistor. The output terminal of the output module is connected to the first end of the first resistor. The second end of the first resistor is connected to the first end of the second resistor and the control terminal of the first semiconductor switch, and the second end of the second resistor is grounded.

[0014] Optionally, the first switch unit further includes a first diode. The output terminal of the output module is connected to the first end of the first resistor through the first diode; the output terminal of the output module is connected to the positive electrode of the first diode, and the negative electrode of the first diode is connected to the first end of the first resistor.

[0015] Optionally, the second switch unit includes a second semiconductor switch. The positive electrode of the battery is connected to the first end of the second semiconductor switch, the second end of the second semiconductor switch is connected to the power supply terminal of the power management chip, and the control terminal of the second semiconductor switch is connected to the first end of the first semiconductor switch.

[0016] Optionally, the second switch unit further includes a third resistor. The control terminal of the second semiconductor switch is connected to the first end of the first semiconductor switch through the third resistor. The control terminal of the second semiconductor switch is connected to the first end of the third resistor, and the second end of the third resistor is connected to the first end of the first semiconductor switch.

[0017] Optionally, the second switch unit further includes a second diode. The positive electrode of the battery is connected to the first end of the second semiconductor switch through the second diode. The positive electrode of the battery is connected to the positive electrode of the second diode, and the negative electrode of the second diode is connected to the first end of the second semiconductor switch.

[0018] Optionally, the wake-up terminal of the power management chip is connected to the output terminal of the output module or the negative electrode of the first diode. When a conduction signal is output at the output terminal of the output module, the power management chip is powered on.

[0019] Optionally, the power supply terminal of the power management chip is connected to the power supply terminal of the main control chip, and the wake-up terminal of the power management chip is connected to the first output terminal of the main control chip and the negative electrode of the first diode; the main control chip is a chip for controlling the switching module and the power management chip;

[0020] When the power management chip is powered on, the main control chip is powered on;

[0021] When the main control chip is powered on, the first output terminal of the main control chip outputs a self-locking signal to keep the first semiconductor switch continuously conducting.

[0022] Optionally, the switching circuit further includes a fourth resistor and a third diode. The positive electrode of the third diode is connected to the first output terminal of the main control chip, the negative electrode of the third diode is connected to the first end of the fourth resistor and the negative electrode of the first diode, and the second end of the fourth resistor is grounded.

[0023] Optionally, the switching circuit further includes a third switching unit. The third switching unit includes a third semiconductor switch and an AND gate. The first end of the third semiconductor switch is connected to the positive electrode of the second diode, the second end of the third semiconductor switch is connected to the main circuit module, the control end of the third semiconductor switch is connected to the output end of the AND gate, the first input end of the AND gate is connected to the output end of the power management chip, and the second input end of the AND gate is connected to the second output terminal of the main control chip; the main circuit module is used to control the rotation of the motor.

[0024] Optionally, the semiconductor switch includes a triode or a field effect transistor.

[0025] The second aspect of the embodiments of the present application provides a battery management system, including a power management chip and the switching circuit according to any one of the first aspect of the embodiments of the present application.

[0026] The third aspect of the embodiments of the present application provides a vehicle, including a battery and the battery management system according to any one of the second aspect of the embodiments of the present application. The battery management system may include an electric power steering (EPS) system. EPS is a power steering system that directly relies on a motor to provide auxiliary torque and can determine the rotation direction of the motor and the magnitude of the assist current according to the signals of the vehicle speed sensor and the torque sensor, thereby achieving real-time control of the power steering.

[0027] The switch circuit of the embodiment of the present application includes a switch module, and the switch module is adapted to be connected to a battery and a power management chip; when the signal input to the switch module is an off signal, the switch module is turned off to disconnect the positive electrode of the battery from the power supply terminal of the power management chip; when the signal input to the switch module is an on signal, the switch module is turned on to supply power from the battery to the power supply terminal of the power management chip. In the embodiment of the present application, when the signal input to the switch module is an off signal, the switch module is turned off to disconnect the positive electrode of the battery from the power supply terminal of the power management chip, physically cutting off the battery and the power management chip, thereby reducing the static current of the power management chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0029] Figure 1 is a schematic structural diagram of a switch circuit provided by an embodiment of the present application;

[0030] Figure 2 is a schematic structural diagram of another switch circuit provided by an embodiment of the present application;

[0031] Figure 3 is a schematic structural diagram of another switch circuit provided by an embodiment of the present application;

[0032] Figure 4 is a schematic structural diagram of another switch circuit provided by an embodiment of the present application;

[0033] Figure 5 is a schematic structural diagram of another switch circuit provided by an embodiment of the present application;

[0034] Figure 6 is a schematic structural diagram of another switch circuit provided by an embodiment of the present application;

[0035] Figure 7 is a schematic structural diagram of another switch circuit provided by an embodiment of the present application;

[0036] Figure 8 is a schematic circuit diagram of a direct connection between the output terminal KL15 of an output module and the wake-up terminal WAK of a power management chip provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0038] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, products or devices.

[0039] Referring to "embodiment" in the present application means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments.

[0040] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a switching circuit provided by an embodiment of the present application. As Figure 1 shown, the switching circuit may include a switching module, and the switching module is adapted to connect a battery and a power management chip; when the signal input to the switching module is an off signal, the switching module disconnects, so that the positive electrode of the battery is disconnected from the power supply terminal of the power management chip; when the signal input to the switching module is an on signal, the switching module conducts, so that the battery supplies power to the power supply terminal of the power management chip.

[0041] In the embodiments of the present application, the battery may be a storage battery on a vehicle. For example, it may be a 12V storage battery, and the battery can provide 12V direct current.

[0042] When the switching module is disconnected, the power management chip is powered off; when the switching module is conducting, the power management chip is powered on.

[0043] After the power management chip is powered on, it is used to supply power to each module on the vehicle.

[0044] After the power management chip is powered down, since the switching module is disconnected, the battery and the power management chip are physically disconnected, thereby reducing the static current of the power management chip.

[0045] In the embodiment of the present application, when the signal input to the switching module is a turn-off signal, the switching module is disconnected, so that the positive electrode of the battery is disconnected from the power supply terminal of the power management chip, and the battery and the power management chip are physically disconnected, thereby reducing the static current of the power management chip.

[0046] Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of another switching circuit provided by the embodiment of the present application. Figure 2 It is obtained on the basis of Figure 1 , as shown in Figure 2 , the input end of the switching module is adapted to be connected to the output end of the output module; the output module is used to input the turn-off signal or the conduction signal to the input end of the switching module through the output end.

[0047] Among them, the output module is used to control the switching module to be disconnected or conducted. The output module can be an ignition system of a vehicle. When the ignition system is turned off, the output module can output a turn-off signal (for example, a turn-off signal), and when the ignition system is ignited, the output module can output a conduction signal (for example, an ignition signal).

[0048] Among them, the switching module includes at least one switching tube. The switching tube can be a semiconductor switch.

[0049] Please refer to Figure 3 , Figure 3 which is a schematic structural diagram of another switching circuit provided by the embodiment of the present application. Figure 3 It is obtained on the basis of Figure 2 , as shown in Figure 3 , the switching module includes a first switching unit and a second switching unit, and the control end of the second switching unit is connected to the first end of the first switching unit.

[0050] Optionally, as shown in Figure 3 , the output end (the output end of the ignition system) KL15 of the output module is connected to the control end of the first switching unit, the first end of the second switching unit is connected to the positive electrode KL30 of the battery, and the second end of the second switching unit is connected to the power supply terminal VS of the power management chip.

[0051] Wherein, when a turn-on signal is output at the output terminal KL15 of the output module (for example, a turn-off signal is output at the output terminal KL15 of the ignition system), the first switch unit is turned off, so that the second switch unit is turned off, so that the positive electrode of the battery is disconnected from the power supply terminal of the power management chip, and at this time the power management chip is powered down.

[0052] In the embodiment of the present application, the turn-off signal may be a signal that triggers the first switch unit to turn off. When the first switch unit is turned off, the control terminal of the second switch unit is disconnected from the ground, and then the second switch unit is turned off. Among them, the first switch unit is turned on when a high-level signal is input to the control terminal of the first switch unit, and the first switch unit is turned off when a low-level signal is input to the control terminal of the first switch unit; the second switch unit is turned off when the first switch unit is turned off, and the second switch unit is turned on when the first switch unit is turned on.

[0053] Exemplarily, the turn-off signal is a low-level signal. When a low-level signal is input to the control terminal of the first switch unit, the first switch unit is turned off, and no signal is input to the control terminal of the second switch unit, and the second switch unit is also turned off. When the second switch unit is turned off, the power supply terminal of the power management chip is disconnected from the positive electrode of the battery, and the power management chip loses power supply, so that the power management chip is powered down.

[0054] Figure 3 In, the negative electrode KL31 of the battery is grounded.

[0055] In the embodiment of the present application, after the vehicle is turned off, the output module outputs a turn-off signal (for example, a turn-off signal), the first switch unit is turned off, so that the second switch unit is turned off, and the power management chip is powered down. After the vehicle is turned off, the positive electrode of the battery is disconnected from the power supply terminal of the power management chip through the second switch unit, so that the static current of the power management chip can be reduced after the vehicle is turned off.

[0056] The battery may be a storage battery on the vehicle. For example, it may be a 12V storage battery, and the battery can provide 12V DC power.

[0057] Optionally, when a turn-on signal (for example, an ignition signal) is output at the output terminal KL15 of the output module, the first switch unit is turned on, so that the second switch unit is turned on, so that the battery supplies power to the power supply terminal of the power management chip, and at this time the power management chip is powered on.

[0058] Exemplarily, the ignition signal is a high-level signal. When a high-level signal is input to the control terminal of the first switch unit, the first switch unit conducts, and the control terminal of the second switch unit is equivalent to being grounded (i.e., a low-level signal is input to the control terminal of the second switch unit), and the second switch unit conducts. When the second switch unit conducts, the power supply terminal of the power management chip is conducted with the positive electrode of the battery, and the power management chip is powered.

[0059] In the embodiment of the present application, after the vehicle is ignited, the output terminal KL15 of the ignition system outputs an ignition signal, and the first switch unit conducts to make the second switch unit conduct, and the power management chip is powered.

[0060] Please refer to Figure 4 , Figure 4 which is a schematic structural diagram of another switch circuit provided by the embodiment of the present application. Figure 4 It is obtained on the basis of Figure 3 , as shown in Figure 4 , the first switch unit includes a first semiconductor switch Q1, the first end of the first semiconductor switch Q1 is connected to the control terminal of the second switch unit, and the second end of the first semiconductor switch Q1 is grounded.

[0061] Optionally, as shown in Figure 4 , the first switch unit further includes a first resistor R1 and a second resistor R2. The output terminal of the output module is connected to the first end of the first resistor R1. The second end of the first resistor R1 is connected to the first end of the second resistor R2 and the control terminal of the first semiconductor switch Q1, and the second end of the second resistor R2 is grounded.

[0062] Optionally, the first switch unit further includes a first diode D1. The output terminal of the output module is connected to the first end of the first resistor R1 through the first diode D1; the output terminal of the output module is connected to the positive electrode of the first diode D1, and the negative electrode of the first diode D1 is connected to the first end of the first resistor R1.

[0063] Among them, the first resistor R1 and the second resistor R2 form a voltage dividing circuit, and the resistance values of the first resistor R1 and the second resistor R2 can be set according to the conduction voltage of the first diode D1 and the voltage of the high level. Taking the ignition system as an example for the output module, the first diode D1 is an anti-reverse diode, which can allow the signal output by the output terminal of the ignition system to pass through the first diode D1 to reach the control terminal of the first semiconductor switch Q1, preventing the signal at the control terminal of the first semiconductor switch Q1 from flowing back to the output terminal of the ignition system and preventing interference with the signal at the output terminal of the ignition system.

[0064] Optionally, as shown in Figure 4As shown, the second switch unit includes a second semiconductor switch Q2. The positive electrode of the battery is connected to the first end of the second semiconductor switch Q2. The second end of the second semiconductor switch Q2 is connected to the power supply terminal of the power management chip. The control terminal of the second semiconductor switch Q2 is connected to the first end of the first semiconductor switch Q1.

[0065] Optionally, as Figure 4 shown, the second switch unit further includes a third resistor R3. The control terminal of the second semiconductor switch Q2 is connected to the first end of the first semiconductor switch Q1 through the third resistor R3. The control terminal of the second semiconductor switch Q2 is connected to the first end of the third resistor R3. The second end of the third resistor R3 is connected to the first end of the first semiconductor switch Q1.

[0066] Optionally, as Figure 4 shown, the second switch unit further includes a second diode D2. The positive electrode of the battery is connected to the first end of the second semiconductor switch Q2 through the second diode D2. The positive electrode of the battery is connected to the positive electrode of the second diode D2. The negative electrode of the second diode D2 is connected to the first end of the second semiconductor switch Q2.

[0067] Among them, the second diode D2 is an anti - reverse diode, which prevents the voltage at the power supply terminal of the power management chip from flowing back to the positive electrode of the battery and prevents damage to the battery.

[0068] Figure 4 In , the first semiconductor switch Q1 and the second semiconductor switch Q2 take triodes as an example. Among them, the first semiconductor switch Q1 is an NPN triode, and the second semiconductor switch is a PNP triode.

[0069] Please refer to Figure 5 , Figure 5 which is a schematic structural diagram of another switch circuit provided by an embodiment of the present application. Figure 5 is obtained on the basis of Figure 4 . The wake - up terminal WAK of the power management chip is connected to the output terminal of the output module or the negative electrode of the first diode D1. When the output module outputs a conduction signal (for example, an ignition signal) at the output terminal, the power management chip is powered on.

[0070] Taking the ignition system as an example for the output module, when the output terminal of the ignition system outputs an ignition signal, the wake - up terminal WAK of the power management chip is awakened, the power supply terminal of the power management chip is conducted with the positive electrode of the battery, and the power management chip is powered.

[0071] Figure 4 and Figure 5In the case where the power supply terminal of the power management chip is connected to the positive electrode of the battery and the wake-up terminal WAK of the power management chip is woken up, the power management chip is powered on.

[0072] After the power management chip is powered on, the power management chip can output a signal through the output terminal and can also output a voltage through the power supply terminal to supply power to other modules.

[0073] Optionally, as Figure 5 shown, the power supply terminal QXX of the power management chip is connected to the power supply terminal of the main control chip, and the wake-up terminal WAK of the power management chip is connected to the first output terminal of the main control chip (as Figure 5 shown) and the negative electrode of the first diode D1; the main control chip is a chip that controls the switching module and the power management chip;

[0074] When the power management chip is powered on, the main control chip is powered on;

[0075] When the power management chip is powered on, the power supply terminal of the power management chip can output a voltage to the power supply terminal of the main control chip, so as to power on the main control chip.

[0076] When the main control chip is powered on, the first output terminal of the main control chip outputs a self-locking signal IO-LOCK to make the first semiconductor switch Q1 continuously conduct.

[0077] In the embodiment of the present application, the output terminal of the ignition system is connected to the positive electrode of the first diode D1 through a plug wire connected by a buckle, and the vehicle will jolt during driving. If the buckle becomes loose, the connection between the output terminal of the ignition system and the positive electrode of the first diode D1 will be disconnected, resulting in the power management chip entering the sleep state and making the power management chip unable to work properly. To avoid the above situation, when the main control chip is powered on, the first output terminal of the main control chip outputs a self-locking signal IO-LOCK to make the first semiconductor switch Q1 continuously conduct. It can prevent the ignition signal output by the output terminal of the ignition system during vehicle driving from being lost due to jitter and prevent system abnormal power-off.

[0078] The self-locking signal can be a high-level signal. As long as the main control chip is powered on, even if the ignition signal output by the output terminal of the ignition system is lost due to jitter, it can ensure that the power management chip and the main control chip will not have abnormal power-off.

[0079] It should be noted that when the main control chip outputs a flameout signal at the first output terminal, the flameout signal will also pull down the self-locking signal, thereby making the power management chip enter the sleep state.

[0080] The main control chip can be a microcontroller Unit (MCU).

[0081] Optionally, as Figure 5 shown, the switch circuit further includes a fourth resistor R4 and a third diode D3. The positive electrode of the third diode D3 is connected to the first output terminal of the main control chip, the negative electrode of the third diode D3 is connected to the first end of the fourth resistor R4 and the negative electrode of the first diode D1, and the second end of the fourth resistor R4 is grounded.

[0082] The first output terminal of the main control chip outputs a self-locking signal IO-LOCK to the positive electrode of the third diode D3. Even if the ignition signal output from the output terminal of the ignition system is lost due to jitter, the first semiconductor switch Q1 can be continuously turned on by the self-locking signal IO-LOCK output from the first output terminal of the main control chip. It can prevent the ignition signal output from the output terminal of the ignition system from being lost due to jitter during vehicle driving, and prevent system abnormal power-off.

[0083] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of another switch circuit provided by an embodiment of the present application. Figure 6 is obtained on the basis of Figure 5 . The switch circuit further includes a third switch unit. The third switch unit includes a third semiconductor switch Q3 and an AND gate U1. The first end of the third semiconductor switch Q3 is connected to the positive electrode of the second diode D2, the second end of the third semiconductor switch Q3 is connected to the main circuit module, the control end of the third semiconductor switch Q3 is connected to the output end of the AND gate U1, the first input end of the AND gate U1 is connected to the output end SS1 of the power management chip, and the second input end of the AND gate U1 is connected to the second output end IO-CTRL of the main control chip; the main circuit module is used to control the rotation of the motor.

[0084] In the embodiment of the present application, IO-CTRL and SS1 are respectively control signals for controlling the third semiconductor switch Q3 output by the main control chip and the power management chip. When both the output end SS1 of the power management chip and the second output end IO-CTRL of the main control chip output high levels, the main circuit module is powered on and starts to work.

[0085] Among them, the main circuit module can be a component of the battery management system, and the main circuit module can be used to control the rotation of the motor.

[0086] Optionally, the semiconductor switch includes a triode or a field effect transistor.

[0087] The above Figures 4 to 6 first semiconductor switch Q1 and second semiconductor switch Q2 are both triodes, and the third semiconductor switch Q3 is a field effect transistor.

[0088] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of another switching circuit provided by an embodiment of the present application. Compared with Figure 6 , Figure 7 the first semiconductor switch Q1 and the second semiconductor switch Q2 of Figure 7 are replaced from triodes with field effect transistors. The field effect transistor may include a metal-oxide-semiconductor field effect transistor (MOSFET), and the MOSFET may also be simply referred to as a MOS transistor. The MOS transistor may include an N-channel MOS transistor (abbreviated as NMOS) or a P-channel MOS transistor (abbreviated as PMOS). Exemplarily, Figure 7 the first semiconductor switch Q1 of

[0089] Please refer to Figure 8 , Figure 8 which is a schematic circuit diagram of the direct connection between the output terminal KL15 of an output module and the wake-up terminal WAK of a power management chip provided by an embodiment of the present application. Figure 8 In Figure 8 , the positive electrode KL30 of the battery is connected to the power supply terminal VS of the power management chip through the second diode D2. When the power management chip is in the sleep state, the positive electrode KL30 of the battery is connected to the power supply terminal VS of the power management chip through the second diode D2, and the power management chip generates a certain static current, about 70 microamperes (μA). When the vehicle shuts off, compared with the circuit solution of Figure 6

[0090] As shown in Figure 6 , an embodiment of the present application adds a switching circuit at the front end of the power management chip, and uses the ignition signal as the input of this switching circuit. In this way, the static current of the entire electric power steering system EPS is converted from the static current of the power management chip of Figure 8 to the leakage current of the second semiconductor switch Q2 of the switching circuit of Figure 6 , greatly reducing the static current of the system. In the off state, the power consumption of the power management chip for the vehicle power supply (battery) is minimized, and almost no vehicle power supply is consumed.

[0091] After the electric power steering system EPS is powered on, the self-locking signal output by the main control chip through the first output port forms the self-locking of the ignition signal, ensuring that the ignition signal will not cause the system to abnormally lose power due to jitter loss during vehicle driving.

[0092] When the vehicle is turned off, due to the absence of the self-locking signal, the power management chip and the vehicle power supply are disconnected, and the main circuit is also disconnected through the third semiconductor switch Q3. At this time, the static current of the electric power steering system EPS is almost zero, minimizing the static current of the electric power steering system EPS to the greatest extent.

[0093] When the vehicle is ignited, the output terminal of the output module outputs a conduction signal (for example, the ignition signal). The output terminal of the ignition signal outputs a high-level signal. The first semiconductor switch Q1 is turned on through the switch control loop composed of the ignition signal, the first resistor R1, and the second resistor R2. The second semiconductor switch Q2 is turned on through the conduction of the first semiconductor switch Q1 and the third resistor R3. At this time, the power supply terminal VS of the power management chip is powered on, and the QXX power supply is output to supply power to each module of the system. The first output terminal of the main control chip outputs a self-locking signal to continuously turn on the first semiconductor switch Q1, preventing the ignition signal from being lost due to jitter during vehicle driving and causing the system to abnormally lose power.

[0094] The embodiment of the present application also provides a battery management system, including Figures 1 to 7 Any of the switch circuits as described above. The battery management system may further include a power management chip, a control chip, and a main circuit module. The battery management system may be an electric power steering system EPS.

[0095] The embodiment of the present application also provides a vehicle, including the above battery management system.

[0096] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0097] In several embodiments provided by the present application, it should be understood that the disclosed switch circuit, battery management system, and vehicle can be implemented in other ways. For example, the switch circuit embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

Claims

1. A switching circuit, characterized in that: A switch module is included, and the switch module is suitable for connecting a battery and a power management chip; When the signal input to the switch module is a shutdown signal, the switch module is disconnected to disconnect the positive electrode of the battery from the power supply terminal of the power management chip; When the signal input to the switch module is a conduction signal, the switch module is turned on so that the battery supplies power to the power supply end of the power management chip.

2. The switch circuit according to claim 1, characterized in that: The input end of the switch module is suitable for connecting to the output end of the output module; the output module is used to input the shutdown signal or the conduction signal to the input end of the switch module through the output end.

3. The switch circuit according to claim 1 or 2, characterized in that: The switch module includes at least one switch tube.

4. The switch circuit according to claim 2, characterized in that: The switch module includes a first switch unit and a second switch unit, wherein a control end of the second switch unit is connected to a first end of the first switch unit.

5. The switch circuit according to claim 4, characterized in that: The first end of the second switch unit is connected to the positive electrode of the battery, the second end of the second switch unit is connected to the power end of the power management chip, the control end of the first switch unit is connected to the output end of the output module, and the second end of the first switch unit is grounded.

6. The switch circuit according to claim 5, characterized in that: The first switch unit includes a first semiconductor switch, a first end of the first semiconductor switch is connected to a control end of the second switch unit, and a second end of the first semiconductor switch is grounded.

7. The switch circuit according to claim 6, characterized in that: The first switch unit also includes a first resistor and a second resistor, the output end of the output module is connected to the first end of the first resistor, the second end of the first resistor is connected to the first end of the second resistor and the control end of the first semiconductor switch, and the second end of the second resistor is grounded.

8. The switch circuit according to claim 7, characterized in that: The first switch unit also includes a first diode, and the output end of the output module is connected to the first end of the first resistor through the first diode; the output end of the output module is connected to the anode of the first diode, and the cathode of the first diode is connected to the first end of the first resistor.

9. The switch circuit according to claim 8, characterized in that: The second switch unit includes a second semiconductor switch, the positive electrode of the battery is connected to the first end of the second semiconductor switch, the second end of the second semiconductor switch is connected to the power end of the power management chip, and the control end of the second semiconductor switch is connected to the first end of the first semiconductor switch.

10. The switch circuit according to claim 9, characterized in that: The second switch unit also includes a third resistor, the control end of the second semiconductor switch is connected to the first end of the first semiconductor switch through the third resistor, the control end of the second semiconductor switch is connected to the first end of the third resistor, and the second end of the third resistor is connected to the first end of the first semiconductor switch.

11. The switch circuit according to claim 9 or 10, characterized in that: The second switch unit also includes a second diode, the positive electrode of the battery is connected to the first end of the second semiconductor switch through the second diode, the positive electrode of the battery is connected to the positive electrode of the second diode, and the cathode of the second diode is connected to the first end of the second semiconductor switch.

12. The switch circuit according to claim 11, characterized in that: The wake-up end of the power management chip is connected to the output end of the output module or the cathode of the first diode. When the output end of the output module outputs a conduction signal, the power management chip is powered on.

13. The switch circuit according to claim 12, characterized in that: The power supply end of the power management chip is connected to the power supply end of the main control chip, and the wake-up end of the power management chip is connected to the first output end of the main control chip and the cathode of the first diode; the main control chip is a chip that controls the switch module and the power management chip; When the power management chip is powered on, the main control chip is powered on; When the main control chip is powered on, the first output terminal of the main control chip outputs a self-locking signal to keep the first semiconductor switch turned on continuously.

14. The switch circuit according to claim 13, characterized in that: The switching circuit also includes a fourth resistor and a third diode, the anode of the third diode is connected to the first output end of the main control chip, the cathode of the third diode is connected to the first end of the fourth resistor and the cathode of the first diode, and the second end of the fourth resistor is grounded.

15. The switch circuit according to claim 14, characterized in that: The switch circuit also includes a third switch unit, which includes a third semiconductor switch and an AND gate. The first end of the third semiconductor switch is connected to the anode of the second diode, the second end of the third semiconductor switch is connected to the main circuit module, the control end of the third semiconductor switch is connected to the output end of the AND gate, the first input end of the AND gate is connected to the output end of the power management chip, and the second input end of the AND gate is connected to the second output end of the main control chip; the main circuit module is used to control the rotation of the motor.

16. The switch circuit according to any one of claims 6 to 10 and 12 to 15, characterized in that: The semiconductor switch includes a triode or a field effect transistor.

17. A battery management system, characterized in that: It comprises a power management chip and the switch circuit according to any one of claims 1 to 16.

18. A vehicle, characterized in that: The invention comprises a battery and the battery management system as claimed in claim 17.

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