An electric power management circuit for a power tailgate

Abstract

The utility model provides a kind of electric tailgate power management circuit, including control module, drive chip, bracing bar motor and anti-reverse connection MOS switch tube, control module and drive chip electric connection, drive chip is connected with bracing bar motor by drive circuit drive, the source electrode of anti-reverse connection MOS switch tube is connected power supply, its drain electrode and the drive circuit electric connection of bracing bar motor, its gate electrode connects the charge pump voltage output end of drive chip;Its characterized in that, it further includes first switch module;First switch module electric connection is between the gate electrode of anti-reverse connection MOS switch tube and charge pump voltage output end, and first switch module and control module control connection, control module controls the on-off of first switch module.The utility model can effectively avoid the possibility that the output voltage of charge pump is exported to other controller for power supply when bracing bar motor generates electricity due to rapidly pulling tailgate when control module is not powered.

Description

Technical Field

[0001] This utility model relates to the field of circuit design technology, specifically to a power management circuit for an electric tailgate. Background Technology

[0002] In today's automotive electronics technology, power tailgate systems have become standard equipment in many models due to their convenience. The core of this system consists of a power tailgate controller, a strut motor, sensors, and other components. The controller receives control commands from the vehicle's CAN bus or direct hardwired signals, which in turn drive the strut motor to rotate forward or reverse, thus achieving automatic opening and closing of the tailgate.

[0003] Currently, the power architecture of mainstream electric tailgate controllers in the industry typically follows the principle of low power consumption design. When the vehicle is in "locked sleep" or "not powered on" state, although the controller's main power supply is physically connected, its internal main controller and drive circuit are in a low-power or completely de-energized state to reduce static current and prevent the battery from being depleted when the vehicle is parked.

[0004] However, an anomaly was observed in the practical application of this design: when the vehicle is not powered on, if the user rapidly pulls the tailgate, the strut motor generates electricity. This generated energy is fed back to the motor drive bridge circuit of the electric tailgate controller through the motor wiring harness, and the current direction is as follows: Figure 1 As shown.

[0005] The reason is that a motor drive bridge typically consists of a driver chip and multiple power MOSFETs. The driver chip requires a certain supply voltage to operate normally. Once it receives power from the generator, even if the main controller MCU is not working, the charge pump circuit integrated within the driver chip will start operating as long as the supply voltage is sufficient. The charge pump's function is to generate a high voltage to fully turn on the N-MOSFETs in the upper half of the drive bridge. To protect the downstream circuitry, a reverse-connection protection NMOS transistor is usually connected in series with the motor drive bridge for reverse connection protection and sleep isolation. Its gate is controlled by the charge pump power output of the main controller MCU or the driver chip, ensuring it is only turned on when the system is operating normally.

[0006] When the vehicle is not powered on, if the user rapidly pulls the tailgate, the strut motor will generate electricity, leading to the aforementioned abnormal situation. In this case, the high voltage generated by the charge pump is unexpectedly applied to the gate of the reverse polarity protection NMOS transistor, causing it to fully conduct. Once this reverse polarity protection NMOS transistor is turned on, it provides a low-impedance path for the current generated by the strut motor, preventing it from being confined to the controller's internal consumption and instead allowing it to flow back through the controller's power input port to the vehicle's low-voltage power network.

[0007] This backflow current is sufficient to wake up or partially power other electronic control units or modules connected to this power network, causing them to malfunction, record fault codes, or even cause a brief "pseudo-power-on" phenomenon in some of the vehicle's electrical systems. This not only violates the management regulations for the vehicle's low-voltage power network and leads to unpredictable system behavior, but may also cause potential damage to the delicate circuitry of the electric tailgate controller or other ECUs due to current backflow. Utility Model Content

[0008] In order to overcome the defects existing in the prior art, the purpose of this utility model is to provide an electric tailgate power management circuit.

[0009] To achieve the above-mentioned objectives of this utility model, this utility model provides an electric tailgate power management circuit, including a control module, a drive chip, a strut motor, and a reverse-connection-protected MOS switch. The control module is electrically connected to the drive chip, and the drive chip is driven by the strut motor through a drive circuit. The source of the reverse-connection-protected MOS switch is connected to the power supply, its drain is electrically connected to the drive circuit driving the strut motor, and its gate is connected to the charge pump voltage output terminal of the drive chip. It also includes a first switch module.

[0010] The first switch module is electrically connected between the gate of the reverse-connection protected MOS switch and the voltage output terminal of the charge pump, and the first switch module is controlled by the control module, which controls the on / off state of the first switch module.

[0011] The power control circuit of the electric tailgate controller sets a first switch module between the gate of the reverse-connection MOS switch and the voltage output terminal of the charge pump. By controlling the first switch module to turn on, the drive circuit of the strut motor is powered. By controlling the first switch module to turn off, the possibility of the strut motor generating electricity when the tailgate is pulled rapidly when the control module is not powered on, which would cause the output voltage of the charge pump to jump out of the port and power other controllers.

[0012] Optionally, the first switching module includes a PNP transistor;

[0013] The collector of the PNP transistor is electrically connected to the gate of the reverse-connection MOS switch, the emitter of the PNP transistor is electrically connected to the voltage output terminal of the charge pump, and the base of the PNP transistor is connected to the control module.

[0014] The first switch module has a simple structure, which makes the power control circuit of the tailgate controller inexpensive.

[0015] Optionally, the first switching module may also include an NPN transistor;

[0016] The collector of the NPN transistor is electrically connected to the base of the PNP transistor and the charge pump voltage output terminal. The base of the NPN transistor is connected to the control module, and its emitter is grounded.

[0017] This first switch module not only has a simple structure, but also further improves safety performance.

[0018] Optionally, the collector of the NPN transistor is connected to one end of a fourth resistor, the other end of the fourth resistor is connected to the base of a PNP transistor, and the other end of the fourth resistor is also connected to the charge pump voltage output terminal.

[0019] The beneficial effects of this utility model are:

[0020] This utility model has a simple circuit structure, requires minimal modification to the original circuit, is easy to implement, has low production costs, high safety performance, improves the safety of the entire vehicle, and avoids potential damage to the electric tailgate controller or other ECU's precision circuits caused by current backflow.

[0021] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is the schematic diagram of the power control circuit for an existing electric tailgate controller;

[0024] Figure 2 This is the circuit schematic diagram of this utility model;

[0025] Figure 3 This is a circuit diagram of another alternative embodiment of this utility model. Detailed Implementation

[0026] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0027] In the description of this utility model, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0028] like Figure 2 As shown, this utility model provides a power control circuit for an electric tailgate controller, including a control module MCU, a driver chip, a strut motor, a reverse polarity-protected MOS switch Q1, and a first switch module.

[0029] The control module MCU is electrically connected to the driver chip. Specifically, the enable signal output pin of the control module MCU is electrically connected to the enable terminal of the driver chip. The control module MCU is also connected to the driver chip through the SPI communication bus, and the PWM signal output terminal of the control module MCU is connected to the control terminal of the driver chip.

[0030] The driver chip and the strut motor are electrically connected via a driver circuit. The source of the reverse-connection MOS switch Q1 is connected to the power supply BAT1, and the drain of the reverse-connection MOS switch Q1 is electrically connected to the driver circuit driving the strut motor. The drain of the reverse-connection MOS switch Q1 is also connected to the power supply pin VCP of the driver chip. A seventh resistor R7 is connected in series between the two. The current provided by the power supply BAT1 flows through the diode connected between the source and drain of the reverse-connection MOS switch Q1, and a small current flows into the power supply pin VCP of the driver chip. The first switch module is electrically connected between the gate of the reverse-connection MOS switch Q1 and the charge pump voltage output terminal CP of the driver chip. The first switch module is also connected to the control module MCU for control, and the control module MCU controls the on / off state of the first switch module.

[0031] When the strut motor needs to be driven, the control module MCU powers on and outputs a control signal (such as a high level) to the first switch module to control the first switch module to conduct. The control module MCU also enables the driver chip through the EN signal. The charge pump in the driver chip generates a voltage higher than the power supply BAT1 voltage. Due to the conduction of the first switch module, this voltage directly acts on the gate of the reverse polarity protection MOS switch Q1, thereby driving the gate of the reverse polarity protection MOS switch Q1 and making the reverse polarity protection MOS switch Q1 fully conduct. After the reverse polarity protection MOS switch Q1 is fully conducted, its on-resistance is extremely small, and electrical energy flows efficiently from its gate to its drain, supplying power to the drive circuit of the strut motor.

[0032] When the strut motor is not needed or the vehicle is not powered on, the control module MCU is not working, and the first switch module is open. If the electric tailgate is pulled rapidly at this time, the strut motor will generate electricity, and its voltage will be directly input to the power supply pin VCP of the driver chip through the seventh resistor R7. This voltage is sufficient to make the charge pump work even when the control module MCU is not working. At this time, the charge pump outputs voltage, but because the first switch module is in the open state, the voltage output by the charge pump cannot act on the gate of the reverse connection protection MOS switch Q1. The reverse connection protection MOS switch Q1 remains in the off state, preventing the electricity generated by the strut motor from leaking out of the port to power other controllers.

[0033] In one optional embodiment, the first switching module includes a PNP transistor Q2. The collector of the PNP transistor Q2 is electrically connected to the gate of the reverse-connection-protected MOS switch Q1, the emitter of the PNP transistor Q2 is electrically connected to the charge pump voltage output terminal CP, and the base of the PNP transistor Q2 is connected to the control module MCU.

[0034] When the strut motor needs to be driven, the control module MCU outputs a high-level signal (lower than the voltage output by the charge pump) to the base of the PNP transistor Q2. The charge pump in the drive chip outputs voltage to the emitter of the PNP transistor Q2. At this time, the base voltage of the PNP transistor Q2 is less than the emitter voltage, and the collector voltage is less than the base voltage. The PNP transistor Q2 is turned on, and the charge pump output voltage acts on the gate of the reverse-connection MOS switch Q1, turning on the reverse-connection MOS switch Q1. Electrical energy flows from its gate to its drain, supplying power to the drive circuit of the strut motor.

[0035] When the strut motor is not needed or the vehicle is not powered on, the control module MCU does not work, and the base of the PNP transistor Q2 is left floating. Even if the charge pump output voltage in the driver chip reaches the emitter of the PNP transistor Q2, the PNP transistor Q2 remains in the off state. This prevents the voltage output by the charge pump from acting on the gate of the reverse connection protection MOS switch Q1. The reverse connection protection MOS switch Q1 remains in the off state, preventing the power generated by the strut motor from leaking out of the port and powering other controllers.

[0036] In another alternative solution of this embodiment, such as Figure 3As shown, the first switching module also includes an NPN transistor Q4. The collector of the NPN transistor Q4 is electrically connected to the base of the PNP transistor Q2, and a fourth resistor R4 is connected in series on the connection line between the two. The collector of the NPN transistor Q4 is also electrically connected to the charge pump voltage output terminal CP. Specifically, the collector of the NPN transistor Q4 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the charge pump voltage output terminal CP. The base of the NPN transistor Q4 is connected to the control module MCU, and a fifth resistor R5 is connected in series on the connection line between the two. The emitter of the NPN transistor Q4 is grounded, and a sixth resistor R6 is connected in series between the emitter and base of the NPN transistor Q4.

[0037] When the strut motor needs to be driven, the control module MCU outputs a high-level signal (lower than the voltage output by the charge pump) to the base of the NPN transistor Q4. At this time, the collector voltage of the NPN transistor Q4 is higher than its base voltage, and the NPN transistor Q4 is turned on. Since the emitter of the NPN transistor Q4 is grounded, the collector voltage of the NPN transistor Q4 is pulled down, which causes the base voltage of the PNP transistor Q2 to be pulled down synchronously. Meanwhile, the output voltage of the charge pump makes the emitter voltage of the PNP transistor Q2 higher than the power supply BAT1 voltage. At this time, the base voltage of the PNP transistor Q2 is less than the emitter voltage, and the collector voltage is less than the base voltage, so the PNP transistor Q2 is turned on. The output voltage of the charge pump acts on the gate of the reverse-connection MOS switch Q1, turning on the reverse-connection MOS switch Q1. Electrical energy flows from its gate to its drain, supplying power to the drive circuit of the strut motor.

[0038] When the strut motor is not needed or the vehicle is not powered on, the control module MCU does not work, and the base of NPN transistor Q4 is left floating, thus keeping NPN transistor Q4 in the off state. Even if the charge pump output voltage in the driver chip reaches the emitter of PNP transistor Q2, PNP transistor Q2 remains in the off state. This prevents the voltage output by the charge pump from acting on the gate of the reverse connection protection MOS switch Q1, and the reverse connection protection MOS switch Q1 remains in the off state, preventing the power generated by the strut motor from leaking out of the port to power other controllers.

[0039] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A power management circuit for an electric tailgate, comprising a control module, a drive chip, a strut motor, and a reverse-connection-protected MOS switch, wherein the control module is electrically connected to the drive chip, the drive chip is driven by the strut motor through a drive circuit, the source of the reverse-connection-protected MOS switch is connected to a power supply, its drain is electrically connected to the drive circuit driving the strut motor, and its gate is connected to the charge pump voltage output terminal of the drive chip; characterized in that, It also includes the first switch module; The first switch module is electrically connected between the gate of the reverse-connection protected MOS switch and the voltage output terminal of the charge pump, and the first switch module is controlled by the control module, which controls the on / off state of the first switch module.

2. The power management circuit for the electric tailgate according to claim 1, characterized in that, The first switching module includes a PNP transistor; The collector of the PNP transistor is electrically connected to the gate of the reverse-connection MOS switch, the emitter of the PNP transistor is electrically connected to the voltage output terminal of the charge pump, and the base of the PNP transistor is connected to the control module.

3. The power management circuit for the electric tailgate according to claim 2, characterized in that, The first switching module also includes an NPN transistor; The collector of the NPN transistor is electrically connected to the base of the PNP transistor and the charge pump voltage output terminal. The base of the NPN transistor is connected to the control module, and its emitter is grounded.

4. The power management circuit for the electric tailgate according to claim 3, characterized in that, The collector of the NPN transistor is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to the base of the PNP transistor, and the other end of the fourth resistor is also connected to the charge pump voltage output terminal.

Images