VEHICLE-MOUNTED POWER SUPPLY CIRCUIT AND VEHICLE

Description

Technical Field

[0001] The present invention relates to the technical field of automobile electronic control, and particularly relates to a vehicle-mounted power supply circuit and a vehicle.Prior Art

[0002] Logic circuits (e.g. electronic control units, information processing systems, and other electric equipment) of a vehicle and power motors are all connected to a vehicle-mounted power supply (e.g. a vehicle-mounted battery or a generator). Since the working environment of the vehicle is complex and can be affected by temperature, working conditions and other conditions, an output voltage of the vehicle-mounted power supply may fluctuate. These conditions include a load dump, which refers to sharp changes in the power supply voltage due to sudden changes in a load at the moment when the power supply is disconnected from the load, and the load dump may cause two types of problems: 1. failure to supply power to electronic equipment, and 2. a large voltage spike generated by inductive generators.

[0003] When a load dump occurs to the vehicle-mounted power supply, the vehicle-mounted power supply outputs a large voltage spike, thereby causing other electric equipment connected to the power supply to be damaged. For example, when an alternator (comprising inductive coils and rectifiers) charges a storage battery with a high current, a sharp rise in the output voltage of the alternator will be caused due to the inability of the current of the inductive devices to change abruptly if the storage battery is suddenly disconnected, and this voltage spike can reach 120 V and will last for 400 ms before subsiding.

[0004] DE 101 49 282 A1 discloses a method for generating a supply voltage intended for digital circuits in a motor vehicle. This method involves the use of a DC / DC converter to generate an intermediate voltage from a higher input voltage, specifically more than 12 volts, during normal operation. A linear regulator then generates the supply voltage from this intermediate voltage. In a parking mode, the DC / DC converter is bypassed using a bypass circuit, allowing the supply voltage to be directly generated by the linear regulator.

[0005] EP 3 691 068 A1 discloses a control system comprising a controller and a plurality of power regulating modules, including at least one first power regulating module and at least one second power regulating module. The first power regulating module is activated upon receiving an external wake-up signal and supplies power to the controller, which is connected to its output. The controller, once powered on, can send an internal wake-up signal to activate the second power regulating module, which is connected to a load module.

[0006] CN 207 926248 U discloses a vehicle-mounted power supply system that includes a power factor correction circuit connected to an AC power supply, an inverter circuit, and a transformer with multiple windings. The system incorporates a bidirectional AC / DC circuit linked to a high-voltage battery and a rectifier circuit with a buck circuit connected to a low-voltage storage battery. The invention allows for dual-mode operation, enabling both charging and discharging functions.

[0007] CN 109 649 309 A discloses a control system comprising a controller and multiple power regulation modules including at least one first and one second power regulation module. The first power regulation module is awakenable by an external wake-up signal and, once activated, powers on the controller. After being powered, the controller can issue internal wake-up signals to selectively activate the second power regulation modules, whose outputs are connected to respective load modules.

[0008] CN 108 058 662 A discloses a vehicle 24 V system load-dump transient over-voltage protection circuit comprising a control circuit and a voltage suppression circuit with a low-clamp-voltage TVS diode. The control circuit monitors the input voltage of the electronic device and keeps the suppression circuit inactive within the normal operating range so that negligible current is drawn. When a load-dump or other transient over-voltage occurs, the control circuit activates the suppression circuit, allowing the TVS diode to clamp the input voltage.

[0009] CN 213 817 344 U discloses a multipath power supply device that comprises a controller and at least two identically-structured power supply circuits, each circuit including an input voltage sampling circuit, a power supply branch with an electronic switch, and an electronic switch driving module. The controller monitors the input voltage of every power supply circuit and, upon detecting an abnormal voltage, commands the corresponding electronic switch driving module to disconnect the affected branch while maintaining operation of the remaining branches with normal voltage.

[0010] CN 207 926 248 U discloses a vehicle-mounted power supply that combines a power factor correction stage, an inverter, a multi-winding transformer, and downstream bidirectional AC / DC, rectifier and buck converter stages, all governed by a common control circuit. The system enables AC grid charging of both a high-voltage traction battery via the transformer's secondary winding and a low-voltage auxiliary battery via the tertiary winding, while also permitting energy transfer from the high-voltage battery to the low-voltage battery in discharge mode. By multiplexing the transformer windings and sharing power-conversion stages, the design lowers component count, volume and cost relative to separate charger and DC-DC units.Summary of the Invention

[0011] The present invention provides a vehicle-mounted power supply circuit as recited in independent claim 1 and vehicle (claim 16), to ensure that electronic equipment of the vehicle will not be damaged after a transient overvoltage of a load dump and to meet anti-reverse requirements. Preferred embodiments are recited in dependent claims.Brief Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings, which are required to be used in the embodiments or the prior art, are briefly described below. FIG. 1 is a schematic diagram of a vehicle-mounted power supply circuit of the prior art; FIG. 2 is a schematic diagram of a vehicle-mounted power supply circuit provided in an embodiment of the present invention. Detailed Description of Embodiments

[0013] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the drawings in the present invention. Obviously, the embodiments described are some of the embodiments of the present invention, but not all of the embodiments.

[0014] The terms "first", "second" and the like in the specification, claims, and above drawings of the present invention are used to distinguish similar objects and need not to be used to describe a specific sequence or precedence order. It should be understood that the data used in this way may be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0015] FIG. 1 is a schematic diagram of a vehicle-mounted power supply circuit of the prior art. Most current power supply circuits use a transient voltage suppressor (TVS) to suppress transient voltages under load-dump working conditions, etc. As shown in FIG. 1, the vehicle-mounted power supply circuit comprises a capacitor C1, a capacitor C2, a resistor R, a transient voltage suppressor (TVS), an anti-reverse diode D1, an inductor L4, a capacitor C3, a capacitor C4 and an electronic control unit (ECU), wherein the capacitor C1 and the capacitor C2 are connected in series and electrically connected between a positive electrode and a negative electrode of a power supply; the resistor R is electrically connected to an anode of the anti-reverse diode D1; a terminal on one side of the transient voltage suppressor (TVS) is connected to an intermediate node of the resistor R and the anti-reverse diode D1, and a terminal on the other side of the transient voltage suppressor (TVS) is electrically connected to a grounding terminal GND; a terminal on one side of the inductor L4 is electrically connected to a cathode of the anti-reverse diode D1, and a terminal on the other side of the inductor L4 is electrically connected to the electronic control unit (ECU); a terminal on one side of the capacitor C3 is connected to an intermediate node of the anti-reverse diode D1 and the inductor L4, and a terminal on the other side of the capacitor C3 is electrically connected to the grounding terminal GND; and a terminal on one side of the capacitor C4 is connected to an intermediate node of the inductor L4 and the electronic control unit, and a terminal on the other side of the capacitor C4 is electrically connected to the grounding terminal GND.

[0016] In the vehicle-mounted power supply circuit in FIG. 1, the capacitor C1, the capacitor C2, the resistor R, the transient voltage suppressor (TVS) and the anti-reverse diode D1 form an anti-surge circuit. At the moment of startup, the anti-reverse diode D1 is not conducting due to the presence of C3 and C4, and the current forms a loop with the transient voltage suppressor (TVS) through the resistor R. Although a control method of the above technical solution is simple, it is only applicable to low-current situations because the anti-reverse diode D1 is in the vehicle-mounted power supply circuit, the anti-reverse diode D1 is a low-power device that cannot be applied to h-current circuits, or it will be easily broken down; and moreover, the anti-reverse diode D1 is not capable of being separated when a high voltage is input at the input end (Vin).

[0017] FIG. 2 is a schematic diagram of a vehicle-mounted power supply circuit provided in an embodiment of the present invention. As shown in FIG. 2, the vehicle-mounted power supply circuit according to an embodiment of the present invention comprises a power switch module 100 and a voltage clamp module 200, and the power switch module 100 and the voltage clamp module 200 are both electrically connected to a power supply to receive an input voltage from the power supply; on the basis of the received input voltage, the power switch module 100 outputs a first power supply voltage to the first power supply link; and the voltage clamp module 200 clamps the received input voltage within a preset voltage range and outputs a second power supply voltage to the second power supply link, wherein the power switch module 100 is electrically connected to a microcontroller unit (MCU) to receive a switch control signal from the microcontroller unit (MCU) and controls the turn-on and turn-off of the first power supply voltage based on the switch control signal.

[0018] As can be seen from the above, in the vehicle-mounted power supply circuit provided by the embodiment of the present invention, the first power supply voltage is output to the first power supply link, and the second power supply voltage is output to the second power supply link, that is, the first power supply link and the second power supply link are independent of each other; and the power switch module is electrically connected to the microcontroller unit, and the microcontroller unit, by means of the switch control signal, may directly trigger the power switch module to turn on or turn off the first power supply voltage. Therefore, since the present invention adopts a way that the first power supply voltage and the second power supply voltage are separately controlled and the turn-on or turn-off of the first power supply voltage is independently controlled, the damage to a backward stage circuit caused by a transient high current generated when the load dump occurs is avoided, and a good power supply environment is provided for the electronic equipment of the vehicle-mounted system.

[0019] For example, the first power supply link is a link for supplying power to the vehicle-mounted power motor, and the second power supply link is a link for supplying power to the vehicle-mounted logic circuit. The first power supply voltage output by the first power supply link is used as a working voltage of high-power power equipment, e.g., a power motor or the like, and the second power supply voltage output by the second power supply link is used as a working voltage of the vehicle-mounted logic circuit, e.g., a logic control circuit, vehicle-mounted electronic equipment, an information processing system, etc.

[0020] Further, the vehicle-mounted power supply circuit further comprises a filtering module 300, and the filtering module 300 receives an original voltage from the power supply and filters the original voltage to output the input voltage, wherein the filtering module 300 comprises a first output end and a second output end, the first output end outputs the input voltage, and the second output end is grounded. The filtering module 300 mainly suppresses the electromagnetic noise and clutter signals of the input power supply to prevent interference with the power supply, and also that with the backward stage circuit by the power supply generated high-frequency clutters. The filtering module 300 may be implemented using conventional filtering circuits, such as various complex filtering circuits formed by connecting capacitors in parallel at both ends of the load resistor, or connecting inductors in series with the load, as well as combining capacitors and inductors, which will not be limited herein by the present invention.

[0021] Further, the power switch module 100 comprises a first control unit 101, a first power switch tube Q 1 , and a second power switch tube Q 2 ; the first control unit 101 comprises an output pin (OUT) and two control voltage signal pins (DGATE and HGATE); a source electrode of the first power switch tube Q 1 is electrically connected to the first output end of the filtering module 300; a drain electrode of the first power switch tube Q 1 is electrically connected to a drain electrode of the second power switch tube Q 2 ; a source electrode of the second power switch tube Q 2 is electrically connected to the output pin of the first control unit 101 in order to output the first power supply voltage; a gate electrode of the first power switch tube Q 1 and a gate electrode of the second power switch tube Q 2 are connected to the two corresponding control voltage signal pins of the first control unit 100, respectively so as to receive a control signal from the first control unit 100; and the first control unit 101 further comprises an enable signal pin (EN), and the enable signal pin (EN) is electrically connected to the microcontroller unit (MCU) to receive the switch control signal from the microcontroller unit (MCU), wherein the switch control signal controls the turn-on or turn-off of the first power supply voltage.

[0022] Specifically, the first power switch tube Q 1 and the second power switch tube Q 2 are electrically connected in a mirror-symmetrical manner, and the first power switch tube Q 1 and the second power switch tube Q 2 constitute a mirror current source; since the drain and gate electrodes of the first power switch tube Q 1 are connected, as long as the input voltage VIN is greater than Vthl (the threshold voltage of Q 1 ), the first power switch tube Q 1 operates in a saturation region; if the characteristics of the first and second power switch tubes Q 1 , Q 2 are the same, the output voltage V 0 can be large enough so that the second power switch tube Q 2 is also in the saturation region; by means of the first power switch tube Q 1 and the second power switch tube Q 2 constituting the mirror current source, the width-to-length ratio of the MOSEFET switch device in the power switch module is respectively increased, which helps increase the saturation current and the current carrying capacity of the MOSEFET switch device; in addition, a voltage clamp effect is achieved, preventing the power switch module 100 from being damaged by instantaneous high current.

[0023] Further, the first power switch tube Q 1 is an ideal diode, and the second power switch tube Q 2 is a MOSEFET switch device integrating a diode. It should be noted that a source electrode-drain electrode current (I DS ) and a source electrode-drain electrode voltage (V DS ) of the first power switch tube Q 1 need to be kept within safe operating area (SOA) boundaries when the first power switch tube Q 1 accumulates energy from the applied voltage and current. A sudden load drop can occur when a load on the first link to which the power supply is supplying power is suddenly disconnected, at which point the other loads will experience a surge of the power supply voltage (e.g. greater than 60 V) or a fairly high transient current (e.g. greater than 80 A). For example, in one implementation of the present application, the first power switch tube Q 1 is designed to be an ideal diode, which has a higher operating efficiency than an ordinary diode. This is because, for the ordinary diode, there is a voltage drop of about 0.7 V for a silicon tube and a voltage drop of about 0.2 V for a germanium tube when it is in forward conduction, whereas for the ideal diode, this voltage drop for the tube is almost absent, so that it can be used for inverse test circuits; and the ideal diode is more sensitive than the ordinary diode when the load drops suddenly, and is capable of clamping a large voltage input by the power supply into its safe operation area boundaries to protect the backward stage circuit. Therefore, through the combined action of the above first power switch tube Q 1 and the above second power switch tube Q 2 , the received input voltage can be clamped in a preset voltage range and the reverse connection of the direct current voltage can be prevented, so that the load dump and anti-reverse requirements of the vehicle-mounted power supply circuit can be met.

[0024] In addition, in this embodiment, the turn-on and turn-off of the first power supply voltage can be controlled individually by the microcontroller unit (MCU). When the input voltage is greater than the first threshold, the power switch module 100 is controlled to turn off the first power supply voltage if the first control unit 101 receives the switch control signal from the microcontroller unit (MCU) indicating turn-off of the first power supply voltage. At this time, the power switch module 100 can be controlled to turn off the first power supply voltage directly by means of internal software operation of the microcontroller unit (MCU) so as to avoid the impact of a transient large voltage. Among these, the microcontroller unit (MCU) may be powered by the second power supply voltage as a logic power supply; the microcontroller unit (MCU) sends a switch control signal to the first control unit 101, a high value of the enable signal (EN) triggers the power switch module 100 to turn on, in order to supply power to the first power supply link, and a low value of the enable signal (EN) triggers the power switch module 100 to turn off, in order to cut off power supplied to the first power supply link. In addition, if the microcontroller unit (MCU) detects a vehicle fault (e.g. a power failure, a system fault) or an input voltage being an overvoltage, the first control unit 101 will be triggered to turn off the first power supply voltage.

[0025] Further, the power switch module 100 further comprises a first resistor R 1 and a second resistor R 2 ; the first control unit 101 further comprises a first functional pin (A), a second functional pin (VSNS), a third functional pin (SW), and an overvoltage detection pin (OV); the first functional pin (A) and the second functional pin (VSNS) are both electrically connected to the source electrode of the first power switch tube Q 1 ; and the first resistor R 1 and the second resistor R 2 are connected in series and then electrically connected between the third functional pin (SW) and ground, the third functional pin (SW) and the second functional pin (VSNS) are electrically connected inside the first control unit 101, and the overvoltage detection pin (OV) is electrically connected to an intermediate node formed after the first resistor R 1 and the second resistor R 2 are connected in series, for detecting whether the input voltage is greater than a second threshold, wherein when the input voltage is greater than the second threshold, the first control unit 101 automatically controls the power switch module 100 to turn off the first power supply voltage if the first control unit 101 does not receive a switch control signal from the microcontroller unit (MCU) indicating turn-off of the first power supply voltage, wherein the second threshold is greater than the first threshold.

[0026] Specifically, the second functional pin (VSNS) of the first control unit 101 is electrically connected to the first output end of the filtering module 300. The first resistor R 1 and the second resistor R 2 are used as divider resistors, wherein the first resistor R 1 is connected to the third functional pin (SW) of the first control unit 101, and the second resistor R 2 is grounded, thereby dividing an input bus power supply voltage (i.e. the filtered direct current voltage) through the first resistor R 1 and the second resistor R 2 to obtain a sampling voltage, and monitoring the sampling voltage using the overvoltage detection pin (OV) of the first control unit 101. Once the input power supply voltage is monitored to be too high, the first control unit 101 is controlled to be turned off to protect the backward stage circuit from being damaged by the high current. In FIG. 2, the first control unit 101 is an integrated circuit (IC) chip comprising one or more circuits, and alternatively, the first control unit 101 may be implemented using hardware logic, machine-readable instructions, hardware-implemented state machines and / or any combination thereof.

[0027] When the input voltage is greater than a first threshold, if the microcontroller unit (MCU) does not send a switch control signal all the time, that is, the microcontroller unit (MCU) fails to control the power switch module 100 to turn off the first power supply voltage all the time when the input voltage is greater than the first threshold, the input voltage will continue to rise, and the overvoltage detection pin (OV) of the first control unit 101 will detect that the input voltage has become greater than the second threshold, and then will perform a corresponding turn-off operation when the input voltage is greater than a second threshold (wherein the second threshold is greater than the first threshold). Specifically, the second threshold value of the input voltage can be set according to the safe operation area (SOA) boundary value of the first power switch tube Q 1 and the second power switch tube Q 2 . The power switch module 100 is controlled to turn off the first power supply voltage through the overvoltage detection circuit (hardware circuit) carried by the first control unit 101 itself. It should be understood that the first control unit 101 itself can monitor the overvoltage by means of the overvoltage detection circuit (hardware circuit), and can compensate for the implementation of load dump transient overvoltage protection in the event of the microcontroller unit (MCU) detecting a failure, so as to further improve the safety of the vehicle power supply system.

[0028] Further, the power switch module 100 further comprises a first capacitor C 1 , and the first capacitor C 1 comprises a first end and a second end; the first control unit 101 further comprises a fourth functional pin (C), a fifth functional pin (VS) and a sixth functional pin (CAP); and the first end of the first capacitor C 1 is electrically connected to an intermediate node of the first power switch tube Q 1 and the second power switch tube Q 2 , the fourth functional pin (C) and the fifth functional pin (VS), and the second end of the first capacitor C 1 is electrically connected to the sixth functional pin (CAP) of the first control unit 101, so as to be used for forming a charge pump circuit to respectively increase a voltage of the control end of the first power switch tube Q 1 and a voltage of the control end of the second power switch tube Q 2 .

[0029] For example, a gate electrode of the first power switch tube Q 1 is electrically connected to one control voltage signal pin (DGATE) on the first control unit 101, and a gate electrode of the second power switch tube Q 2 is electrically connected to the other control voltage signal pin (HGATE) on the first control unit 101.

[0030] In the embodiment of the present invention, when the first control unit 101 is powered on, the first capacitor C 1 begins to be charged, that is, the first power switch tube Q 1 , the fourth functional pin (C) and the fifth functional pin (VS) charge the first end of the first capacitor C 1 . The sixth functional pin (CAP) is a capture pin, the sixth functional pin (CAP) is electrically connected to the second end of the first capacitor C 1 , and the sixth functional pin (CAP) outputs a high level to control the charging of the first capacitor C 1 , thereby enabling the voltage positive end V CAP of the energy-storing first capacitor C 1 to slowly rise to be close to a turn-on voltage of the first power switch tube Q 1 and the second power switch tube Q 2 . Even when the vehicle-mounted power supply is powered off, V CAP can serve as VIN to continue supplying power to the powered system (the first power supply link), which can also continue maintaining the operation of the first power supply link.

[0031] Based on the two-stage effect of the flat capacitor, the voltages of the control voltage signal pin DGATE and the control voltage signal pin HGATE of the first control unit 101 continuously rise after the first capacitor C 1 begins to be charged. For example, the first power switch tube Q 1 and the second power switch tube Q 2 are both N-type channel MOSFETs. When a high level is input into the gate electrodes of the first power switch tube Q 1 and the second power switch tube Q 2 , due to the presence of the first capacitor C 1 , the voltages of the DGATE and the HGATE rise, so that the first power switch tube Q 1 and the second power switch tube Q 2 can be turned on. The filtered power supply voltage is input to the source electrode of the first power switch tube Q 1 , and the first capacitor C 1 is connected to the intermediate nodes of the first power switch tube Q 1 and the second power switch tube Q 2 , so that the first end of the first capacitor C 1 continues to be charged. The second end of the first capacitor C 1 is electrically connected to the sixth functional pin (CAP) of the first control unit 101, and the voltage positive end V CAP of the energy storage first capacitor C 1 slowly rises to be close to a turn-on voltage of the first power switch tube Q 1 and the second power switch tube Q 2 , so as to achieve the turn-on (conduction) of the first power switch tube Q 1 and the second power switch tube Q 2 . Alternatively, a MOSFET with one or more P-type channels may also be used to replace the first power switch tube Q 1 and the second power switch tube Q 2 , which is not limited in the present invention.

[0032] Further, in an embodiment of the present invention, the voltage clamp module 200 comprises a transient voltage suppressor (TVS) 210, a voltage clamp control sub-circuit 220, and a feedback unit 230. The TVS 210 is electrically connected between the first output end of the filtering module 300 and ground (GND); the voltage clamp control sub-circuit 220 is electrically connected to the first output end of the filtering module 300 and the feedback unit 230, respectively, for detecting a magnitude of the input voltage and clamping the received input voltage within a preset voltage range so as to output the second power supply voltage to the second power supply link; and the feedback unit 230 is used for feeding back the magnitude of the second power supply voltage to the voltage clamp control sub-circuit 220.

[0033] Specifically, the TVS 210 is connected in parallel with the voltage clamp control sub-circuit 220. The TVS 210 is composed of one or more TVS tubes, one pole of the TVS tube is electrically connected to the first output end of the filtering module, and the other pole of the TVS tube is grounded. The working principle of the TVS 210 is: the TVS 210 is connected in parallel into the voltage clamp control sub-circuit 220; when the circuit operates normally, it is in the cutoff state (high-resistance state), which does not affect the normal operation of the line; and when the circuit has a load-dump abnormal overvoltage and reaches its breakdown voltage, that is, when the two poles of the TVS tube are subjected to an instantaneous high-energy shock, it can abruptly reduce the high impedance between the two poles to low impedance at a very high speed (up to 1 / (10^12) seconds), and absorb up to several kilowatts of surge power (high current) to clamp the voltage between the two poles at a predetermined value, thereby ensuring that the circuit components and parts behind it are prevented from being damaged by the transient high-energy impact. When the load dump abnormal overvoltage disappears, it returns to the high resistance state and the circuit operates normally. When the voltage exceeds the turn-on voltage of the TVS 210, it is turned on and grounded to release the voltage. Since the normal signal voltage generally does not reach the turn-on voltage of the TVS 210, it will not be turned on and grounded so as to avoid loss. In the case of a sudden drop in load, the output voltage, which generally exceeds the turn-on voltage of the TVS 210, causes the TVS 210 to turn on, and the surge voltage (high current) is released through grounding, thereby protecting the backward stage circuit and not damaging the electronic equipment connected to the second link. Optionally, the TVS 210 is a bi-directional TVS tube so as to prevent a high alternating current from damaging the components and parts of the backward stage circuit.

[0034] Further, the voltage clamp control sub-circuit 220 comprises a second control unit 221; the second control unit 221 comprises a switch assembly, and the switch assembly comprises a third power switch tube Q 3 and a fourth power switch tube Q 4 ; and the third power switch tube Q 3 is electrically connected to the fourth power switch tube Q 3 for clamping the received input voltage within a preset voltage range and for preventing reverse connection of the direct current voltage, wherein a source electrode of the third power switch tube Q 3 is electrically connected to the first output end of the filtering unit 300, a drain electrode of the third power switch tube Q 3 is electrically connected to a drain electrode of the fourth power switch tube Q 4 , and a source electrode of the fourth power switch tube Q 4 is electrically connected to an output pin (OUT) of the second control unit 221 so as to output the second power supply voltage to the second power supply link.

[0035] Similarly, the third power switch tube Q 3 and the fourth power switch tube Q 4 are electrically connected in a mirror-symmetrical manner to constitute a mirror current source; by means of the third power switch tube Q 1 and the fourth power switch tube Q 2 constituting the mirror current source, the width-to-length ratio of the MOSEFET switch device in the second control unit 221 is respectively increased, which helps increase the saturation current and the current carrying capacity of the MOSEFET switch device; in addition, a voltage clamp effect is achieved, preventing the second control unit 221 from being damaged by instantaneous high current. Therefore, through the joint action of the third power switch tube Q 3 and the fourth power switch tube Q 4 , the received input voltage can be clamped within a preset voltage range and the reverse connection of the direct current voltage can be prevented.

[0036] Further, the second control unit 221 further comprises an undervoltage lockout pin (UVLO), and the undervoltage lockout pin (UVLO) is electrically connected to the first output end of the filtering module 300, for detecting whether the input voltage is lower than a threshold voltage for turning on the second control unit 221; and if the input voltage is lower than the threshold voltage for turning on the second control unit 221, the second control unit 221 is automatically turned off.

[0037] Further, the second control unit 221 further comprises: a slope setting pin (dvdT) used for setting a slope of an output internal voltage; a mode selection pin (MODE) used for selecting an overload error response mode; and an RTN functional pin used as a reference voltage of the internal control circuit, wherein the mode selection pin (MODE) is electrically connected to the RTN functional pin. For example, when reverse input polarity protection is not required, the RTN functional pin can be used for ground, and the mode selection pin (MODE) and the RTN functional pin are electrically connected to the same node via an external lead.

[0038] Further, the voltage clamp control sub-circuit 220 further comprises a second capacitor (C dvdT ). One end of the second capacitor (C dvdT ) is electrically connected to the slope setting pin (dvdT), and the other end of the second capacitor (C dvdT ) is electrically connected to the mode selection pin (MODE) and the RTN functional pin.

[0039] Further, the second control unit 221 further comprises a fault condition detection pin (FLT), for external equipment to detect whether the second control unit has a fault; and the fault condition detection pin (FLT) is connected to the output pin of the second control unit through a resistor R FLTb .

[0040] Further, the second control unit 221 further comprises a turn-off pin (SHDN), and the turn-off pin (SHDN) can be pulled down through the trigger of the low current, so that the equipment enters a low-power-consumption shutdown mode.

[0041] Further, the second control unit 221 further comprises a current monitoring output pin (IMON) that is electrically connected to the RTN functional pin via a resistor R IMON and further connected to an external load monitor. For example, the resistor R IMON is 5.36 KΩ. It should be noted that the resistor R IMON for connection is disposed between the current monitoring output pin (IMON) and the RTN functional pin, which can convert the current into a proportional voltage for monitoring. In addition, the current monitoring output pin (IMON) can be left floating if it is not used.

[0042] Further, the second control unit 221 further comprises a limit current setting pin (ILIM), and the limit current setting pin (ILIM) is electrically connected to the RTN functional pin via a resistor R ILIM . For example, the resistor R ILIM is 20 kΩ. It should be noted that the resistor R ILIM for connection is disposed between the limit current setting pin (ILIM) and the RTN functional pin, which can be used for overload and short-circuit current limiting.

[0043] Further, the feedback unit 230 comprises a third resistor R 3 , a fourth resistor R 4 , and an overvoltage protection device. The third resistor R 3 and the fourth resistor R 4 are connected in series and then electrically connected between the output pin of the second control unit 221 and the RTN functional pin; and one end of the overvoltage protection device is electrically connected to the intermediate node formed after the third resistor R 3 and the fourth resistor R 4 are connected in series, and the other end of the overvoltage protection device is electrically connected to the overvoltage protection signal (OVP) pin of the second control unit 221, for performing voltage reduction protection on the second control unit 221 when the direct current voltage is too high.

[0044] Further, the voltage clamp control sub-circuit 220 further comprises a third capacitor. One end of the third capacitor (C IN ) is electrically connected to the first output end of the filtering module 300 and the switch assembly, and the other end of the third capacitor (C IN ) is grounded. The third capacitor (C IN ) is used for the input direct current voltage after filtering.

[0045] Further, the feedback unit 230 further comprises a fourth capacitor (C OUT ). One end of the fourth capacitor (C OUT ) is electrically connected to the output pin of the voltage clamp control sub-circuit, and the other end of the fourth capacitor is grounded. The fourth capacitor (C OUT ) is used for filtering the output direct current voltage.

[0046] As can be seen from the above, in the vehicle-mounted power supply circuit provided by the embodiment of the present invention, the first power supply voltage is output to the first power supply link, and the second power supply voltage is output to the second power supply link, that is, the first power supply link and the second power supply link are independent of each other; and the power switch module is electrically connected to the microcontroller unit, wherein the microcontroller unit, by means of the switch control signal, may directly trigger the power switch module to turn on or turn off the first power supply voltage. As described above, as the mode of separating the first and second power supply voltages is adopted and the turn-on or turn-off of the first power supply voltage is independently controlled, damage to the backward stage circuit by a transient high current generated when load dump occurs is avoided. Therefore, the load dump and anti-reverse requirements of the vehicle-mounted power supply circuit are met, and a good power supply environment is provided for the electronic equipment of the vehicle-mounted system.

[0047] The embodiment of the present invention also provides a vehicle, and the vehicle comprises any one of the above vehicle-mounted power supply circuits described herein.

[0048] The device embodiments described above herein are only illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one location, or they can be distributed across multiple network units. Some or all of the modules can be selected according to the actual needs for achieving the purpose of the solution of this embodiment.

[0049] With the description of the above implementations, it is clear to those skilled in the art that the implementations can be realized with the assistance of software plus the requisite common hardware platform, or of course by hardware. Based on this understanding, the portion of the above technical solutions that is essential or contributes to the prior art may be embodied in the form of a software product that may be stored in a computer-readable storage medium, such as a ROM / RAM, a disk, a CD-ROM, or the like, and that comprises a number of instructions to enable a piece of computer equipment (which may be a personal computer, a server, network equipment, or the like) to carry out the method described in the various embodiments or in some portions of the embodiments.

Claims

1. A vehicle-mounted power supply circuit, wherein the vehicle-mounted power supply circuit comprises a power switch module (100) and a voltage clamp module (200),the power switch module (100) and the voltage clamp module (200) both being electrically connected to a power supply to receive an input voltage from the power supply; on the basis of the received input voltage, the power switch module (100) is configured to output a first power supply voltage to a first power supply link; and the voltage clamp module (200) is configured to clamp the received input voltage within a preset voltage range and to output a second power supply voltage to a second power supply link, wherein the power switch module (100) is electrically connected to a microcontroller unit (MCU) to receive a switch control signal from the microcontroller unit (MCU) and configured to control the turn-on or turn-off of the first power supply voltage based on the switch control signal, characterized in that the power switch module (100) comprises a first control unit (101), a first power switch tube (Q1), and a second power switch tube (Q2);the first control unit (101) comprises an output pin (OUT) and two control voltage signal pins (DGATE, HGATE);a source electrode of the first power switch tube (Q1) is electrically connected to the first output end of the filtering module (300);a drain electrode of the first power switch tube (Q1) is electrically connected to a drain electrode of the second power switch tube (Q2);a source electrode of the second power switch tube (Q2) is electrically connected to the output pin (OUT) of the first control unit (101) in order to output the first power supply voltage; a gate electrode of the first power switch tube (Q1) and a gate electrode of the second power switch tube (Q2) are electrically connected to two corresponding control voltage signal pins (DGATE, HGATE) of the first control unit (101), respectively, so as to receive a control signal from the first control unit (101);and the first control unit (101) further comprises an enable signal pin (EN), and the enable signal pin (EN) is electrically connected to the microcontroller unit (MCU) to receive the switch control signal from the microcontroller unit (MCU),wherein the switch control signal is configured to control the turn-on or turn-off of the first power supply voltage, wherein the first power switch tube (Q1) is an ideal diode, and the second power switch tube (Q2) is a MOSFET device integrating a diode, wherein when the input voltage is greater than a first threshold, the power switch module (100) is configured to be controlled to turn off the first power supply voltage if the first control unit (101) receives a switch control signal from the microcontroller unit (MCU) indicating turn-off of the first power supply voltage, wherein the power switch module (100) further comprises a first capacitor (C1), and the first capacitor (C1) comprises a first end and a second end; the first control unit (101) further comprises a fourth functional pin (C), a fifth functional pin (VS) and a sixth functional pin (CAP);and the first end of the first capacitor (C1) is electrically connected to an intermediate node of the first power switch tube (Q1) and the second power switch tube (Q2), the fourth functional pin (C) and the fifth functional pin (VS);and the second end of the first capacitor (C1) is electrically connected to the sixth functional pin (CAP) of the first control unit (101), for forming a charge pump circuit to respectively increase a voltage of the control end of the first power switch tube (Q1) and a voltage of the control end of the second power switch tube (Q2),wherein the voltage clamp module (200) comprises a TVS (210), a voltage clamp control sub-circuit (220) and a feedback unit (230);the TVS (210) is electrically connected between the first output end of the filtering module (300) and ground; the voltage clamp control sub-circuit (220) is electrically connected to the first output end of the filtering module (300) and the feedback unit (230), respectively, for detecting a magnitude of the input voltage and clamping the received input voltage within a preset voltage range so as to output the second power supply voltage to the second power supply link;and the feedback unit (230) is used for feeding back the magnitude of the second power supply voltage to the voltage clamp control sub-circuit (220).

2. The vehicle-mounted power supply circuit according to Claim 1,characterized in that the first power supply link is a link for supplying power to a vehicle-mounted power motor, and the second power supply link is a link for supplying power to a vehicle-mounted logic circuit.

3. The vehicle-mounted power supply circuit according to Claim 2,characterized in that the vehicle-mounted power supply circuit further comprises a filtering module (300), and the filtering module (300) is configured to receive an original voltage from the power supply and to filter the original voltage to output the input voltage, wherein the filtering module (300) comprises a first output end and a second output end, the first output end is configured to output the input voltage, and the second output end is grounded.

4. The vehicle-mounted power supply circuitaccording to Claim 1,characterized in that the power switch module (100) further comprises a first resistor (R1) and a second resistor (R2), and the first control unit (101) further comprises a first functional pin (A), a second functional pin (VSNS), a third functional pin (SW) and an overvoltage detection pin (OV),and the first and second functional pins (A, VSNS) are both electrically connected to the source electrode of the first power switch tube (Q1);the first resistor (R1) and the second resistor (R2) are connected in series and then electrically connected between the third functional pin (SW) and ground, the third functional pin (SW) is internally electrically connected to the second functional pin (VSNS),and the overvoltage detection pin (OV) is electrically connected to an intermediate node formed after the first resistor (R1) and the second resistor (R2) are connected in series, for detecting whether the input voltage is greater than a second threshold; wherein when the input voltage is greater than the second threshold, the first control unit (101) is configured to control the power switch module (100) to turn off the first power supply voltage if the first control unit (101) does not receive a switch control signal from the microcontroller unit (MCU) indicating turn-off of the first power supply voltage, wherein the second threshold is greater than the first threshold.

5. The vehicle-mounted power supply circuit according to Claim 1,characterized in that the voltage clamp control sub-circuit (220) comprises a second control unit (221),the second control unit (221) comprises a switch assembly; the switch assembly comprises a third power switch tube (Q3) and a fourth power switch tube (Q4), and the third power switch tube (Q3) is electrically connected to the fourth power switch tube (Q4), for clamping the received input voltage within the preset voltage range and used for preventing reverse connection of the direct current voltage, wherein a source electrode of the third power switch tube (Q3) is electrically connected to the first output end of the filter unit (300);a drain electrode of the third power switch tube (Q3) is electrically connected to a drain electrode of the fourth power switch tube (Q4);and a source electrode of the fourth power switch tube (Q4) is electrically connected to an output pin (OUT) of the second control unit (221), so as to output the second power supply voltage to the second power supply link.

6. The vehicle-mounted power supply circuit according to Claim 5,characterized in that the second control unit (221) further comprises an undervoltage lockout pin (UVLO), and the undervoltage lockout pin (UVLO) is electrically connected to the first output end of the filtering module (300), for detecting whether the input voltage is lower than a threshold voltage for turning on the second control unit (221);and if the input voltage is lower than the threshold voltage for turning on the second control unit (221),the second control unit (221) is automatically turned off.

7. The vehicle-mounted power supply circuit according to Claim 6,characterized in that the second control unit (221) further comprises: a slope setting pin (dvdT) for setting a slope of an output internal voltage; a mode selection pin (MODE) for selecting an overload error response mode; an RTN functional pin (RTN) used as a reference voltage of the internal control circuit; wherein the mode selection pin (MODE) is electrically connected to the RTN functional pin (RTN).

8. The vehicle-mounted power supply circuit according to Claim 7,characterized in that the voltage clamp control sub-circuit (220) further comprises a second capacitor (CdvdT);and one end of the second capacitor (CdvdT) is electrically connected to the slope setting pin (dvdT), and the other end of the second capacitor (CdvdT) is electrically connected to the mode selection pin (MODE) and the RTN functional pin (RTN).

9. The vehicle-mounted power supply circuit according to Claim 8,characterized in that the second control unit (221) further comprises a fault condition detection pin (FLT) for external equipment to detect whether the second control unit (221) breaks down; and the fault condition detection pin (FLT) is connected to the output pin (OUT) of the second control unit (221) through a resistor (RFLT).

10. The vehicle-mounted power supply circuit according to Claim 8,characterized in that the second control unit (221) further comprises a turn-off pin (SHDN), which is configured to be pulled down via the trigger of the low current, so that equipment enters a low-power-consumption shutdown mode.

11. The vehicle-mounted power supply circuit according to Claim 8,characterized in that the second control unit (221) further comprises a current monitoring output pin (IMON);the current monitoring output pin (IMON) is electrically connected to the RTN functional pin (RTN) via a resistor (RIMON);and the current monitoring output pin (IMON) is further connected to an external load monitor.

12. The vehicle-mounted power supply circuit according to Claim 11, characterized in that the second control unit (221) further comprises a limit current setting pin (ILIM);and the limit current setting pin (ILIM) is electrically connected to the RTN functional pin (RTN) via a resistor (RILIM).

13. The vehicle-mounted power supply circuit according to Claim 12,characterized in that the feedback unit (230) comprises a third resistor (R3), a fourth resistor (R4) and an overvoltage protection device (OVP),the third resistor (R3) and the fourth resistor (R4) are connected in series and then electrically connected between the output pin (OUT) of the second control unit (221) and the RTN functional pin (RTN), one end of the overvoltage protection device (OVP) is electrically connected to an intermediate node formed after the third resistor (R3) and the fourth resistor (R4) are connected in series, and the other end of the overvoltage protection device (OVP) is electrically connected to an overvoltage protection signal pin (OVP) of the second control unit (221), for performing voltage reduction protection on the second control unit (221) when the direct current voltage is too high.

14. The vehicle-mounted power supply circuit according to Claim 12,characterized in that the voltage clamp control sub-circuit (220) further comprises a third capacitor (CIN);and one end of the third capacitor (CIN) is electrically connected to the first output end of the filtering module (300) and the switch assembly, and the other end of the third capacitor (CIN) is grounded.

15. The vehicle-mounted power supply circuit according to Claim 12,characterized in that the feedback unit (230) further comprises a fourth capacitor (COUT);and one end of the fourth capacitor (COUT) is electrically connected to the output pin of the voltage clamp control sub-circuit (220), and the other end of the fourth capacitor (COUT) is grounded.

16. A vehicle, characterized in that the vehicle comprises a vehicle-mounted power supply circuit according to any one of Claims 1 to 15.