Vehicle-mounted power supply circuit and vehicle

Abstract

The application provides a vehicle-mounted power supply circuit, which comprises a power switch module and a voltage clamping module, and the power switch module and the voltage clamping module are electrically connected with a power supply to receive an input voltage from the power supply; the power switch module outputs a first power supply voltage to a first power supply link based on the received input voltage; the voltage clamping module clamps the received input voltage in a preset voltage range and outputs a second power supply voltage to a second power supply link; wherein the power switch module is electrically connected with a vehicle-mounted controller, and the vehicle-mounted controller can directly trigger the power switch module to turn on or turn off the first power supply voltage through a switch control signal. The application adopts a separation mode of the first power supply voltage and the second power supply voltage and independently controls the turn-on or turn-off of the first power supply voltage, avoids damage of transient large current generated in the case of throwing a load to a subsequent circuit, and provides a good power supply environment for electronic equipment of a vehicle-mounted system.

Description

Technical Field

[0001] This invention relates to the field of automotive electronic control technology, and in particular to an on-board power supply circuit and a vehicle. Background Technology

[0002] The vehicle's logic circuits (such as electronic control units, information processing systems, and other electrical equipment) and drive motor are all connected to the vehicle's power supply (such as a vehicle battery or generator). Due to the complex operating environment of vehicles, which is affected by factors such as temperature and operating conditions, the output voltage of the vehicle's power supply will fluctuate. Load dumping refers to the sudden change in power supply voltage caused by the instant the power supply is disconnected from the load. Load dumping can cause two types of problems: 1. Power failure for electronic devices; 2. Large voltage spikes generated by the inductive generator.

[0003] When a vehicle power supply experiences a load shedding event, it will output a large voltage spike, which can damage other electrical devices connected to that power source. For example, when an alternator (containing an inductive coil and a rectifier) ​​is charging a battery with a large current, if the battery is suddenly disconnected, the alternator's output voltage will rise sharply because the current in the inductive components cannot change abruptly. This voltage spike can reach 120V and takes about 400ms to subside. Summary of the Invention

[0004] This invention provides an on-board power supply circuit and vehicle that ensures that automotive electronic equipment is not damaged after a load dump transient overvoltage and meets anti-reverse requirements.

[0005] This invention provides an on-board power supply circuit, comprising a power switch module and a voltage clamping module. Both the power switch module and the voltage clamping module are electrically connected to a power source to receive an input voltage from the power source. The power switch module outputs a first power supply voltage to a first power supply link based on the received input voltage. The voltage clamping module clamps the received input voltage within a preset voltage range and outputs a second power supply voltage to a second power supply link. The power switch module is electrically connected to an on-board controller to receive a switch control signal from the on-board controller and control the switching on or off of the first power supply voltage based on the switch control signal.

[0006] Furthermore, the first power supply link is a link that supplies power to the vehicle's power motor, and the second power supply link is a link that supplies power to the vehicle's logic circuit.

[0007] Furthermore, the vehicle power supply circuit also includes a filtering module, which receives the raw voltage from the power source and filters the raw voltage to output the input voltage. The filtering module includes a first output terminal and a second output terminal, the first output terminal outputting the input voltage and the second output terminal grounded.

[0008] Further, the power switching module includes a first control unit, a first power switching transistor, and a second power switching transistor; the first control unit includes an output pin and two control voltage signal pins, the source of the first power switching transistor is electrically connected to the first output terminal of the filter module, the drain of the first power switching transistor is electrically connected to the drain of the second power switching transistor, and the source of the second power switching transistor is electrically connected to the output pin of the first control unit to output the first supply voltage; the gates of the first power switching transistor and the second power switching transistor are respectively electrically connected to two corresponding control voltage signal pins of the first control unit to receive control signals from the first control unit; the first control unit also includes an enable signal pin, which is electrically connected to the vehicle controller to receive the switch control signal from the vehicle controller; wherein, the switch control signal controls the on or off of the first supply voltage.

[0009] Furthermore, the first power switch is an ideal diode, and the second power switch is a MOSEFET device with an integrated diode.

[0010] Furthermore, when the input voltage is greater than the first threshold, if the first control unit receives a switch control signal from the vehicle controller instructing to turn off the first power supply voltage, then it controls the power switch module to turn off the first power supply voltage.

[0011] Furthermore, the power switch module further includes a first resistor and a second resistor, and the first control unit further includes a first functional pin, a second functional pin, a third functional pin, and an overvoltage detection pin. The first functional pin and the second functional pin are both electrically connected to the source of the first power switch transistor. The first resistor and the second resistor are connected in series and then electrically connected between the third functional pin and ground. The third functional pin is internally connected to the second functional pin. The overvoltage detection pin is electrically connected to the intermediate node of the series connection between the first resistor and the second resistor, and is used to detect whether the input voltage is greater than a second threshold. If the first control unit does not receive a switch control signal from the vehicle controller indicating to turn off the first power supply voltage when the input voltage is greater than the second threshold, the first control unit will automatically control the power switch module to turn off the first power supply voltage, wherein the second threshold is greater than the first threshold.

[0012] Furthermore, the power switch module further includes a first capacitor, which includes a first terminal and a second terminal; the first control unit further includes a fourth functional pin, a fifth functional pin, and a sixth functional pin. The first terminal of the first capacitor is electrically connected to the intermediate node of the first power switch and the second power switch, the fourth functional pin, and the fifth functional pin. The second terminal of the first capacitor is electrically connected to the sixth functional pin of the first control unit, for forming a charge pump circuit to raise the voltage of the control terminal of the first power switch and the control terminal of the second power switch, respectively.

[0013] Furthermore, the voltage clamping module includes a TVS device, a voltage clamping control subcircuit, and a feedback unit; the TVS device is electrically connected between the first output terminal of the filter module and ground; the voltage clamping control subcircuit is electrically connected to the first output terminal of the filter module and the feedback unit respectively, and is used to detect the magnitude of the input voltage and clamp the received input voltage within a preset voltage range to output the second power supply voltage to the second power supply link; the feedback unit is used to feed back the magnitude of the second power supply voltage to the voltage clamping control subcircuit.

[0014] Furthermore, the voltage clamping control sub-circuit includes a second control unit, which includes a switching assembly comprising a third power switch and a fourth power switch. The third and fourth power switches are electrically connected to clamp the received input voltage within a preset voltage range and to prevent reverse connection of DC voltage. The source of the third power switch is electrically connected to the first output terminal of the filter unit, the drain of the third power switch is electrically connected to the drain of the fourth power switch, and the source of the fourth power switch is electrically connected to the output pin of the second control unit to output the second supply voltage to the second power supply link.

[0015] Furthermore, the second control unit also includes an undervoltage lockout pin, which is electrically connected to the first output terminal of the filter module, for detecting whether the input voltage is lower than the threshold voltage at which the second control unit is activated, and if the input voltage is lower than the threshold voltage at which the second control unit is activated, the second control unit automatically shuts down.

[0016] Furthermore, the second control unit also includes: a slope setting pin for setting the slope of the output internal voltage; a mode selection pin for selecting an overload error response mode; and an RTN function pin as a reference voltage for the internal control circuit; wherein the mode selection pin is electrically connected to the RTN function pin.

[0017] Furthermore, the voltage clamping control sub-circuit also includes a second capacitor, one end of which is electrically connected to the slope setting pin, and the other end of which is electrically connected to the mode selection pin and the RTN function pin.

[0018] Furthermore, the second control unit also includes a fault condition detection pin for an external device to detect whether the second control unit has malfunctioned; the fault condition detection pin is connected to the output pin of the second control unit via a resistor.

[0019] Furthermore, the second control unit also includes a shutdown pin that can be pulled low by a low-current trigger to put the device into a low-power shutdown mode.

[0020] Furthermore, the second control unit also includes a current monitoring output pin; the current monitoring output pin is electrically connected to the RTN function pin via a resistor, and the current monitoring output pin is also connected to an external load monitor.

[0021] Furthermore, the second control unit also includes a limit current setting pin; the limit current setting pin is electrically connected to the RTN function pin via a resistor.

[0022] Furthermore, the feedback unit includes a third resistor, a fourth resistor, and an overvoltage protection device. The third resistor and the fourth resistor are connected in series and electrically connected between the output pin of the second control unit and the RTN function pin. One end of the overvoltage protection device is electrically connected to the intermediate node of the series connection between the third resistor and the fourth resistor, and the other end of the overvoltage protection device is electrically connected to the overvoltage protection signal pin of the second control unit, which is used to provide voltage reduction protection for the second control unit when the DC voltage is too high.

[0023] Furthermore, the voltage clamping control sub-circuit also includes a third capacitor, one end of which is electrically connected to the first output terminal of the filter module and the switching assembly, and the other end of which is grounded.

[0024] Furthermore, the feedback unit also includes a fourth capacitor, one end of which is electrically connected to the output pin of the voltage clamping control sub-circuit, and the other end of which is grounded.

[0025] The present invention also provides a vehicle including any of the above-described vehicle power supply circuits.

[0026] In the vehicle power supply circuit and vehicle provided in this embodiment of the invention, a first power supply voltage is output to the first power supply link, and a second power supply voltage is output to the second power supply link. That is, the first and second power supply links are independently controlled. Furthermore, the power switch module is connected to the vehicle controller, which can directly trigger the power switch module to turn the first power supply voltage on or off via a switch control signal. As can be seen, because this invention adopts a method of separate control of the first and second power supply voltages, it avoids damage to downstream circuits caused by transient large currents generated under load dump conditions, providing a good power supply environment for the electronic equipment of the vehicle system. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this invention. For those skilled in the art, other implementation methods can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of an existing vehicle power supply circuit;

[0029] Figure 2 This is a schematic diagram of the vehicle power supply circuit provided in an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0032] Figure 1This is a schematic diagram of an existing vehicle power supply circuit. Currently, most power supply circuits use a transient voltage suppressor (TVS) to suppress transient voltages under conditions such as load dumping, such as... Figure 1 As shown, the vehicle power supply circuit includes capacitor C1, capacitor C2, resistor R, transient voltage suppressor (TVS), reverse protection diode D1, inductor L4, capacitor C3, capacitor C4, and control unit (ECU). Capacitors C1 and C2 are connected in series and electrically between the positive and negative terminals of the power supply. Resistor R is electrically connected to the anode of reverse protection diode D1. One terminal of the TVS is connected to the midpoint between resistor R and reverse protection diode D1, and the other terminal of the TVS is electrically connected to ground terminal GND. One terminal of inductor L4 is electrically connected to the cathode of reverse protection diode D1, and the other terminal of inductor L4 is electrically connected to the control unit (ECU). One terminal of capacitor C3 is connected to the midpoint between reverse protection diode D1 and inductor L4, and the other terminal of capacitor C3 is electrically connected to ground terminal GND. One terminal of capacitor C4 is connected to the midpoint between inductor L4 and the control unit, and the other terminal of capacitor C4 is electrically connected to ground terminal GND.

[0033] Figure 1 The vehicle power supply circuit in the example consists of capacitors C1 and C2, resistor R, a transient voltage suppressor (TVS), and a reverse protection diode D1, forming a surge protection circuit. At startup, due to the presence of capacitors C3 and C4, the reverse protection diode D1 is not conducting, and the current flows through resistor R and the TVS to form a loop. While the control method described above is simple, it is only suitable for low-current applications. This is because the reverse protection diode D1 is a low-power device and cannot be used in high-current circuits, otherwise it is easily damaged. Furthermore, when a high voltage is applied to the input terminal (Vin), the reverse protection diode D1 cannot be disconnected.

[0034] Figure 2 This is a schematic diagram of the vehicle power supply circuit provided in an embodiment of the present invention. (As shown...) Figure 2As shown, the vehicle power supply circuit of this embodiment includes a power switch module 100 and a voltage clamping module 200. Both the power switch module 100 and the voltage clamping module 200 are electrically connected to a power source to receive an input voltage from the power source. The power switch module 100 outputs a first power supply voltage to a first power supply link based on the received input voltage. The voltage clamping module 200 clamps the received input voltage within a preset voltage range and outputs a second power supply voltage to a second power supply link. The power switch module 100 is electrically connected to a vehicle controller (Microcontroller Unit, MCU) to receive a switch control signal from the vehicle controller (MCU) and control the opening or closing of the first power supply voltage based on the switch control signal.

[0035] As can be seen from the above, in the vehicle power supply circuit provided in this embodiment of the invention, a first power supply voltage is output to the first power supply link, and a 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. The power switch module is electrically connected to the vehicle controller, and the vehicle controller can directly trigger the power switch module to turn on or off the first power supply voltage through a switch control signal. Therefore, since this invention adopts a method of separating and controlling the first power supply voltage and the second power supply voltage and independently controlling the turning on or off of the first power supply voltage, it avoids the damage to downstream circuits caused by transient large currents generated under load dump conditions, and provides a good power supply environment for the electronic equipment of the vehicle system.

[0036] For example, the first power supply link is a link that supplies power to the vehicle's power motor, and the second power supply link is a link that supplies power to the vehicle's logic circuit. The first power supply voltage output from the first power supply link serves as the operating voltage for high-power equipment, such as the power motor, and the second power supply voltage output from the second power supply link serves as the operating voltage for the vehicle's logic circuit, such as logic control circuits, vehicle electronic devices, and information processing systems.

[0037] Furthermore, the vehicle power supply circuit also includes a filtering module 300. The filtering module 300 receives the raw voltage from the power supply and filters it to output the input voltage. The filtering module 300 includes a first output terminal and a second output terminal. The first output terminal outputs the input voltage, and the second output terminal is grounded. The filtering module 300 primarily suppresses electromagnetic noise and spurious signals from the input power supply to prevent interference with the power supply itself, and also prevents high-frequency noise generated by the power supply itself from interfering with subsequent circuits. The filtering module 300 can be implemented using conventional filtering circuits, such as a capacitor connected in parallel across the load resistor, an inductor connected in series with the load, or various complex filtering circuits composed of capacitors and inductors. This invention does not impose any limitations on these methods.

[0038] Further, the power switch module 100 includes a first control unit 101, a first power switch Q1, and a second power switch Q2; the first control unit 101 includes an output pin (OUT) and two control voltage signal pins (DGATE and HGATE), the source of the first power switch Q1 is electrically connected to the first output terminal of the filter module 300, the drain of the first power switch Q1 is electrically connected to the drain of the second power switch Q2, and the source of the second power switch Q2 is electrically connected to the output pin (OUT) of the first control unit 101 to output the first supply voltage; the gates of the first power switch Q1 and the second power switch Q2 are respectively electrically connected to two corresponding control voltage signal pins of the first control unit 100 to receive control signals from the first control unit 100; the first control unit 101 also includes an enable signal pin (EN), which is electrically connected to the vehicle controller (MCU) to receive the switch control signal from the vehicle controller (MCU); wherein the switch control signal controls the on or off of the first supply voltage.

[0039] Specifically, the first power switch Q1 and the second power switch Q2 are electrically connected in a mirror symmetric manner, forming a mirror current source. Since the drain and gate of the first power switch Q1 are connected, as long as the input voltage VIN is greater than Vth1 (the threshold voltage of Q1), the first power switch Q1 will operate in the saturation region. If the characteristics of the second power switch Q2 are the same as those of the first power switch Q1, the output voltage V0 can be made large enough to make the second power switch Q2 also saturate. By using the mirror current source formed by the first power switch Q1 and the second power switch Q2, it is approximately equivalent to increasing the width-to-length ratio of the MOSEFET switching device in the power switch module. This is beneficial to increasing the saturation current of the MOSEFET switching device and improving its current carrying capacity. At the same time, it has a voltage clamping effect to prevent the power switch module 100 from being damaged by a sudden large current.

[0040] Furthermore, the first power switch Q1 is an ideal diode, and the second power switch Q2 is a MOSEFET switching device with an integrated diode. It should be noted that when the first power switch Q1 accumulates energy from the applied voltage and current, its source-drain current (Io)... DS ) and source-drain voltage (V DSIt is necessary to keep the power switch Q1 within the safe operating area (SOA) boundary. A load sag can occur when the load on the first link to which the power supply is providing power is suddenly disconnected, causing other loads to experience power supply voltage surges (e.g., greater than 60V) or considerably high transient currents (e.g., greater than 80A). For example, in one embodiment of this application, the first power switch Q1 is designed as an ideal diode, which has higher efficiency than a conventional diode. This is because, for a conventional diode, a silicon diode has a voltage drop of approximately 0.7V during forward conduction, and a germanium diode has a voltage drop of approximately 0.2V, while for an ideal diode, this voltage drop is almost non-existent, making it suitable for reverse testing circuits. Furthermore, this ideal diode is more sensitive to load sags than a conventional diode, clamping the large voltage input to the safe operating area boundary to protect downstream circuitry. Therefore, through the combined action of the first power switch Q1 and the second power switch Q2, the received input voltage can be clamped within a preset voltage range and the reverse connection of DC voltage can be prevented, thus meeting the load dumping and reverse protection requirements of the vehicle power supply circuit.

[0041] Furthermore, in this embodiment, the on / off state of the first power supply voltage can be controlled independently by the vehicle controller (MCU). When the input voltage is greater than a first threshold, if the first control unit 101 receives a switch control signal from the vehicle controller (MCU) instructing to turn off the first power supply voltage, it controls the power switch module 100 to turn off the first power supply voltage. At this time, the power switch module 100 can be directly controlled to turn off the first power supply voltage using the internal software of the vehicle controller (MCU) to avoid the impact of transient high voltage. The vehicle controller (MCU) can be powered by a second power supply voltage that serves as a logic power supply. The vehicle controller (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, supplying power to the first power supply link. A low value of the enable signal (EN) triggers the power switch module 100 to turn off, cutting off power supply to the first power supply link. Furthermore, if the vehicle controller MCU detects a vehicle malfunction (e.g., power failure, system failure) or an overvoltage input, it will trigger the first control unit 101 to shut off the first power supply voltage.

[0042] Furthermore, the power switch module 100 further includes a first resistor R1 and a second resistor R2, and the first control unit 101 further includes 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 of the first power switch Q1. The first resistor R1 and the second resistor R2 are connected in series between the third functional pin (SW) and ground, and the third functional pin (SW) and the second functional pin (VSNS) are electrically connected inside the first control unit 101. The overvoltage detection pin (OV) is electrically connected to the intermediate node of the series connection between the first resistor R1 and the second resistor R2, and is used to detect whether the input voltage is greater than a second threshold. If the first control unit 101 does not receive a switch control signal from the vehicle controller (MCU) indicating to turn off the first power supply voltage when the input voltage is greater than the second threshold, the first control unit 101 controls the power switch module 100 to turn off the first power supply voltage, wherein the second threshold is greater than the first threshold.

[0043] Specifically, the second functional pin (VSNS) of the first control unit 101 is electrically connected to the first output terminal of the filter module 300. The first resistor R1 and the second resistor R2 are used as voltage divider resistors. The first resistor R1 is connected to the third functional pin (SW) of the first control unit 101, and the second resistor R2 is grounded. This allows the input bus power supply voltage (i.e., the filtered DC voltage) to be divided by the first resistor R1 and the second resistor R2 to obtain a sampled voltage. This sampled voltage is monitored using the overvoltage detection pin (OV) of the first control unit 101. If the input power supply voltage is detected to be too high, the first control unit 101 is controlled to shut down to protect the downstream circuitry from damage by high current. Figure 2 In this context, the first control unit 101 is an integrated circuit (IC) chip including one or more circuits. Alternatively, the first control unit 101 may be implemented using hardware logic, machine-readable instructions, hardware-implemented state machines, and / or any combination thereof.

[0044] If the vehicle controller (MCU) fails to send a switch control signal when the input voltage exceeds a first threshold, meaning the MCU fails to control the power switch module 100 to turn off the first supply voltage when the input voltage exceeds the first threshold, the input voltage will continue to rise. When the input voltage exceeds a second threshold (wherein the second threshold is greater than the first threshold), the overvoltage detection pin (OV) of the first control unit 101 will detect that the input voltage exceeds the second threshold and perform a corresponding shutdown operation. Specifically, the second threshold of the input voltage can be set according to the safe operating area (SOA) boundary values ​​of the first power switch Q1 and the second power switch Q2. The overvoltage detection circuit (hardware circuit) carried by the first control unit 101 itself can be used to control the power switch module 100 to turn off the first supply voltage. It should be understood that the first control unit 101 itself can monitor overvoltage through the overvoltage detection circuit (hardware circuit), which can compensate for the failure detected by the vehicle controller (MCU) and implement load dump transient overvoltage protection to further improve the safety of the vehicle power system.

[0045] Furthermore, the power switch module 100 also includes a first capacitor C1, which has a first terminal and a second terminal; the first control unit 101 also includes a fourth functional pin (C), a fifth functional pin (VS), and a sixth functional pin (CAP). The first terminal of the first capacitor C1 is electrically connected to the intermediate node of the first power switch Q1 and the second power switch Q2, the fourth functional pin (C), and the fifth functional pin (VS). The second terminal 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 raise the voltage of the control terminal of the first power switch Q1 and the control terminal of the second power switch Q2, respectively.

[0046] For example, the gate of the first power switch Q1 is electrically connected to a control voltage signal pin (DGATE) on the first control unit 101, and the gate of the second power switch Q2 is electrically connected to another control voltage signal pin (HGATE) on the first control unit 101.

[0047] In this embodiment of the invention, when the first control unit 101 is powered on, the first capacitor C1 begins to charge, that is, the first power switch Q1, the fourth functional pin (C), and the fifth functional pin (VS) charge the first terminal of the first capacitor C1. The sixth functional pin (CAP) is a capture pin, which is electrically connected to the second terminal of the first capacitor C1. The sixth functional pin (CAP) outputs a high level to control the charging of the first capacitor C1, thereby increasing the voltage at the positive terminal V of the energy-storing first capacitor C1. CAP The voltage gradually increases to near the turn-on voltage of the first power switch Q1 and the second power switch Q2. Even when the vehicle power supply fails, the voltage is maintained by V. CAP It acts as VIN to continuously supply power to the powered system (first power supply link) and can also continue to maintain the operation of the first power supply link.

[0048] Based on the two-stage effect of a parallel-plate capacitor, after the first capacitor C1 begins charging, the voltages of the control voltage signal pins DGATE and HGATE of the first control unit 101 are continuously raised. For example, both the first power switch Q1 and the second power switch Q2 are N-channel MOSFETs. When the gates of the first power switch Q1 and the second power switch Q2 are input with a high level, due to the presence of the first capacitor C1, the voltages of DGATE and HGATE are raised, enabling the first power switch Q1 and the second power switch Q2 to conduct. The filtered power supply voltage is input to the source of the first power switch Q1. The first capacitor C1 is connected to the midpoint between the first power switch Q1 and the second power switch Q2. The first terminal of the first capacitor C1 continues to charge, and the second terminal of the first capacitor C1 is electrically connected to the sixth functional pin (CAP) of the first control unit 101, transferring the voltage of the energy-storing first capacitor C1 to the positive terminal V. CAP The voltage is gradually increased to near the turn-on voltage of the first power switch Q1 and the second power switch Q2 to turn on (conduct) the first power switch Q1 and the second power switch Q2. Alternatively, one or more P-channel MOSFETs can be used instead of the first power switch Q1 and the second power switch Q2, which is not a limitation of this invention.

[0049] Further, in this embodiment of the invention, the voltage clamping module 200 includes a TVS (Transient Voltage Suppressor) device 210, a voltage clamping control sub-circuit 220, and a feedback unit 230; the TVS device 210 is electrically connected between the first output terminal of the filter module 300 and ground (GND); the voltage clamping control sub-circuit 220 is electrically connected to the first output terminal of the filter module 300 and the feedback unit 230, respectively, for detecting the 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; the feedback unit 230 is used to feed back the magnitude of the second power supply voltage to the voltage clamping control sub-circuit 220.

[0050] Specifically, the TVS device 210 is connected in parallel with the voltage clamping control sub-circuit 220. The TVS device 210 consists of one or more TVS transistors. One terminal of the TVS transistor is electrically connected to the first output terminal of the filter module, and the other terminal of the TVS device is grounded. The working principle of the TVS device 210 is as follows: When the TVS device 210 is connected in parallel with the voltage clamping control sub-circuit 220, it is in the cutoff state (high impedance state) when the circuit is working normally, and does not affect the normal operation of the line. When the circuit experiences an abnormal overvoltage due to load dumping and reaches its breakdown voltage, that is, when the two terminals of the TVS transistor are subjected to an instantaneous high energy impact, it can reduce the high impedance between its two terminals to a low impedance at an extremely high speed (up to 1 / (10^12) seconds), absorbing surge power (large current) of up to several kilowatts, so that the voltage between the two terminals is clamped at a predetermined value, thereby ensuring that the subsequent circuit components are protected from damage by transient high energy impact. When the abnormal overvoltage due to load dumping disappears, it returns to the high impedance state, and the circuit works normally. When the voltage exceeds the turn-on voltage of the TVS device 210, it conducts and is grounded to release the voltage. Since normal signal voltages generally do not reach the turn-on voltage of the TVS device 210, no loss is generated through grounding. However, under load drop conditions, the output voltage generally exceeds the turn-on voltage of the TVS device 210, causing the TVS device 210 to conduct. The surge voltage (large current) is then released through grounding, thereby protecting the downstream circuit and preventing damage to electronic devices connected to the second link. Optionally, the TVS device 210 is a bidirectional TVS transistor to prevent damage to components in the downstream circuit from large AC currents.

[0051] Further, the voltage clamping control sub-circuit 220 includes a second control unit 221, which includes a switching assembly comprising a third power switch Q3 and a fourth power switch Q4. The third power switch Q3 and the fourth power switch Q4 are electrically connected to clamp the received input voltage within a preset voltage range and to prevent reverse connection of DC voltage. The source of the third power switch Q3 is electrically connected to the first output terminal of the filter unit 300, the drain of the third power switch Q3 is electrically connected to the drain of the fourth power switch Q4, and the source of the fourth power switch Q4 is electrically connected to the output pin (OUT) of the second control unit 221 to output the second supply voltage to the second power supply link.

[0052] Similarly, the third power switch Q3 and the fourth power switch Q4 are electrically connected in a mirror symmetric manner. The third power switch Q3 and the fourth power switch Q4 constitute a mirror current source. By using the third power switch Q1 and the fourth power switch Q2 to form a mirror current source, it approximates increasing the width-to-length ratio of the MOSEFET switching device in the second control unit 221. This is beneficial for increasing the saturation current of the MOSEFET switching device and improving its current carrying capacity. Simultaneously, it has a voltage clamping effect, preventing the second control unit 221 from being damaged by a sudden large current. Therefore, through the combined action of the third power switch Q3 and the fourth power switch Q4, the received input voltage can be clamped within a preset voltage range, and reverse connection of DC voltage can be prevented.

[0053] Furthermore, the second control unit 221 also includes an undervoltage lockout pin (UVLO), which is electrically connected to the first output terminal of the filter module 300. The UVLO is used to detect whether the input voltage is lower than the threshold voltage at which the second control unit 221 is turned on. If the input voltage is lower than the threshold voltage at which the second control unit 221 is turned on, the second control unit 221 will automatically turn off.

[0054] Furthermore, the second control unit 221 further includes: a slope setting pin (dvdT) for setting the slope of the output internal voltage; a mode selection pin (MODE) for selecting an overload error response mode; and an RTN function pin as a reference voltage for the internal control circuit; wherein the mode selection pin (MODE) is electrically connected to the RTN function pin. For example, when reverse input polarity protection is not required, the RTN function pin can be grounded, and the mode selection pin (MODE) and the RTN function pin are electrically connected to the same node via external leads.

[0055] Furthermore, the voltage clamping control sub-circuit 220 also includes a second capacitor (C). dvdT ), the second capacitor (C) dvdT One end of the capacitor is electrically connected to the slope setting pin (dvdT), and the second capacitor (C) dvdT The other end of the pin is electrically connected to the mode selection (MODE) pin and the RTN function pin.

[0056] Furthermore, the second control unit 221 also includes a fault condition detection pin (FLT) for external devices to detect whether the second control unit has malfunctioned; the fault condition detection pin (FLT) is connected to a resistor R. FLTb The output pin is connected to the second control unit.

[0057] Furthermore, the second control unit 221 also includes a shutdown pin (SHDN) that can be pulled low by a low-current trigger to put the device into a low-power shutdown mode.

[0058] Furthermore, the second control unit 221 also includes a current monitoring output pin (IMON); the current monitoring output pin (IMON) is connected via a resistor R. IMON The resistor R is electrically connected to the RTN function pin, and the current monitoring output pin (IMON) is also connected to an external load monitor. For example, the resistor R... IMON The resistance is 5.36KΩ. It should be noted that a resistor R is connected between the current monitoring output pin (IMON) and the RTN function pin. IMON The current can be converted into a proportional voltage for monitoring. Furthermore, this current monitoring output pin (IMON) can be floated if it is not in use.

[0059] Furthermore, the second control unit 221 also includes a limit current setting pin (ILIM); the limit current setting pin (ILIM) is connected via a resistor R. ILIM It is electrically connected to the RTN function pin. For example, the resistor R... ILIM The resistance is 20KΩ. It should be noted that the resistor R connected between the current limit setting pin (ILIM) and the RTN function pin is 20KΩ. ILIM It can be used for overload and short-circuit current limiting.

[0060] Furthermore, the feedback unit 230 includes a third resistor R3, a fourth resistor R4, and an overvoltage protection device. The third resistor R3 and the fourth resistor R4 are connected in series and electrically connected between the output pin of the second control unit 221 and the RTN function pin. One end of the overvoltage protection device is electrically connected to the intermediate node of the series connection between the third resistor R3 and the fourth resistor R4, 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, which is used to provide voltage reduction protection for the second control unit 221 when the DC voltage is too high.

[0061] Furthermore, the voltage clamping control sub-circuit 220 also includes a third capacitor, the third capacitor (C IN One end of the third capacitor (C) is electrically connected to the first output terminal of the filter module 300 and the switching assembly. IN The other end of the third capacitor (C) is grounded. IN This is used for the DC voltage input after filtering.

[0062] Furthermore, the feedback unit 230 also includes a fourth capacitor (C). OUT The fourth capacitor (C) OUT One end of the fourth capacitor is electrically connected to the output pin of the voltage clamping control sub-circuit, and the other end of the fourth capacitor is grounded. The fourth capacitor (C) OUT It is used to filter the output DC voltage.

[0063] As can be seen from the above, in the vehicle power supply circuit provided in this embodiment of the invention, a first power supply voltage is output to the first power supply link, and a second power supply voltage is output to the second power supply link, meaning that the first power supply link and the second power supply link are independent of each other. The power switch module is electrically connected to the vehicle controller, wherein the vehicle controller can directly trigger the power switch module to turn on or off the first power supply voltage through a switch control signal. As can be seen from the above, by adopting a method of separating the first and second power supply voltages and independently controlling the turning on or off of the first power supply voltage, damage to downstream circuits caused by transient large currents generated under load dump conditions is avoided. This satisfies the load dump and reverse current protection requirements of the vehicle power supply circuit, providing a good power supply environment for the electronic equipment of the vehicle system.

[0064] This invention also provides a vehicle, which includes any of the above-described on-board power supply circuits.

[0065] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0066] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle-mounted power supply circuit, characterized in that, The vehicle power supply circuit includes a power switch module and a voltage clamping module, both of which are electrically connected to the power supply to receive the input voltage from the power supply. The power switch module outputs a first power supply voltage to the first power supply link based on the received input voltage; The voltage clamping module clamps the received input voltage within a preset voltage range and outputs a second power supply voltage to the second power supply link; The power switch module is electrically connected to the vehicle controller to receive a switch control signal from the vehicle controller and control the opening or closing of the first power supply voltage based on the switch control signal. The power switch module includes a first power switch and a second power switch, which are electrically connected in a mirror-symmetric manner and constitute a mirror current source.

2. The vehicle power supply circuit according to claim 1, characterized in that, The first power supply link is the link that supplies power to the vehicle's power motor, and the second power supply link is the link that supplies power to the vehicle's logic circuit.

3. The vehicle power supply circuit according to claim 2, characterized in that, The vehicle power supply circuit also includes a filtering module, which receives raw power from the power source. The voltage is filtered to output the input voltage. The filtering module includes a first output terminal and a second output terminal. The first output terminal outputs the input voltage, and the second output terminal is grounded.

4. The vehicle power supply circuit according to claim 3, characterized in that, The power switch module also includes a first control unit; The first control unit includes an output pin and two control voltage signal pins. The source of the first power switch is electrically connected to the first output terminal of the filter module, the drain of the first power switch is electrically connected to the drain of the second power switch, and the source of the second power switch is electrically connected to the output pin of the first control unit to output the first supply voltage. The gates of the first power switch and the second power switch are respectively electrically connected to two corresponding control voltage signal pins of the first control unit to receive control signals from the first control unit. The first control unit further includes an enable signal pin, which is electrically connected to the vehicle controller to receive the switch control signal from the vehicle controller; The switch control signal controls the opening or closing of the first power supply voltage.

5. The vehicle power supply circuit according to claim 4, characterized in that, The first power switch is an ideal diode, and the second power switch is a MOSEFET device with integrated diode.

6. The vehicle power supply circuit according to claim 5, characterized in that, When the input voltage is greater than a first threshold, if the first control unit receives a switch control signal from the vehicle controller instructing to turn off the first power supply voltage, then it controls the power switch module to turn off the first power supply voltage.

7. The vehicle power supply circuit according to claim 6, characterized in that, The power switch module further includes a first resistor and a second resistor, and the first control unit further includes a first functional pin, a second functional pin, a third functional pin, and an overvoltage detection pin. The first functional pin and the second functional pin are both electrically connected to the source of the first power switch transistor. The first resistor and the second resistor are connected in series and then electrically connected between the third functional pin and ground. The third functional pin is internally connected to the second functional pin. The overvoltage detection pin is electrically connected to the intermediate node of the first resistor and the second resistor connected in series, and is used to detect whether the input voltage is greater than the second threshold. Wherein, when the input voltage is greater than the second threshold, if the first control unit does not receive a switch control signal from the vehicle controller indicating to turn off the first power supply voltage, the first control unit controls the power switch module to turn off the first power supply voltage on its own, wherein the second threshold is greater than the first threshold.

8. The vehicle power supply circuit according to claim 4, characterized in that, The power switch module further includes a first capacitor, which has a first terminal and a second terminal. The first control unit further includes a fourth function pin, a fifth function pin, and a sixth function pin. The first end of the first capacitor is electrically connected to the intermediate node of the first power switch and the second power switch, the fourth function pin, and the fifth function pin. The second end of the first capacitor is electrically connected to the sixth function pin of the first control unit, for forming a charge pump circuit to raise the voltage of the control terminal of the first power switch and the voltage of the control terminal of the second power switch, respectively.

9. The vehicle power supply circuit according to claim 4, characterized in that, The voltage clamping module includes a TVS device, a voltage clamping control sub-circuit, and a feedback unit; The TVS device is electrically connected between the first output terminal of the filter module and ground; The voltage clamping control sub-circuit is electrically connected to the first output terminal of the filter module and the feedback unit, respectively, and is used to detect the magnitude of the input voltage and clamp the received input voltage within a preset voltage range so as to output the second power supply voltage to the second power supply link; The feedback unit is used to provide feedback on the magnitude of the second supply voltage to the voltage clamping control subcircuit.

10. The vehicle power supply circuit according to claim 9, characterized in that, The voltage clamping control subcircuit includes a second control unit. The second control unit includes a switching assembly, which includes a third power switch and a fourth power switch. The third power switch and the fourth power switch are electrically connected and are used to clamp the received input voltage within a preset voltage range and to prevent reverse connection of DC voltage. The source of the third power switch is electrically connected to the first output terminal of the filter module, the drain of the third power switch is electrically connected to the drain of the fourth power switch, and the source of the fourth power switch is electrically connected to the output pin of the second control unit to output the second power supply voltage to the second power supply link.

11. The vehicle power supply circuit according to claim 10, characterized in that, The second control unit further includes an undervoltage lockout pin, which is electrically connected to the first output terminal of the filter module. The pin is used to detect whether the input voltage is lower than the threshold voltage at which the second control unit is activated. If the input voltage is lower than the threshold voltage at which the second control unit is activated, the second control unit will automatically shut down.

12. The vehicle power supply circuit according to claim 11, characterized in that, The second control unit also includes: The slope setting pin is used to set the slope of the output internal voltage. The mode selection pin is used to select the overload error response mode; The RTN function pin serves as the reference voltage for the internal control circuitry. The mode selection pin is electrically connected to the RTN function pin.

13. The vehicle power supply circuit according to claim 12, characterized in that, The voltage clamping control subcircuit also includes a second capacitor, one end of which is electrically connected to the slope setting pin, and the other end of which is electrically connected to the mode selection pin and the RTN function pin.

14. The vehicle power supply circuit according to claim 13, characterized in that, The second control unit also includes a fault condition detection pin, which is used by external devices to detect whether the second control unit has malfunctioned; The fault condition detection pin is connected to the output pin of the second control unit via a resistor.

15. The vehicle power supply circuit according to claim 13, characterized in that, The second control unit also includes a shutdown pin that can be pulled low by a low-current trigger to put the device into a low-power shutdown mode.

16. The vehicle power supply circuit according to claim 13, characterized in that, The second control unit also includes a current monitoring output pin; The current monitoring output pin is electrically connected to the RTN function pin via a resistor, and the current monitoring output pin is also connected to an external load monitor.

17. The vehicle power supply circuit according to claim 16, characterized in that, The second control unit also includes a limit current setting pin; The limit current setting pin is electrically connected to the RTN function pin via a resistor.

18. The vehicle power supply circuit according to claim 17, characterized in that, The feedback unit includes a third resistor, a fourth resistor, and an overvoltage protection device. The third resistor and the fourth resistor are connected in series and electrically connected between the output pin of the second control unit and the RTN function pin. One end of the overvoltage protection device is electrically connected to the intermediate node of the series connection between the third resistor and the fourth resistor, and the other end of the overvoltage protection device is electrically connected to the overvoltage protection signal pin of the second control unit, which is used to reduce the voltage of the second control unit when the DC voltage is too high.

19. The vehicle power supply circuit according to claim 17, characterized in that, The voltage clamping control subcircuit also includes a third capacitor, one end of which is electrically connected to the first output terminal of the filter module and the switching assembly, and the other end of which is grounded.

20. The vehicle power supply circuit according to claim 17, characterized in that, The feedback unit also includes a fourth capacitor, one end of which is electrically connected to the output pin of the voltage clamping control sub-circuit, and the other end of which is grounded.

21. A vehicle, characterized in that, The vehicle includes an on-board power supply circuit as described in any one of claims 1-20.

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