Chip power supply protection circuit and vehicle-mounted control device

Abstract

This application discloses a chip power supply protection circuit and an on-board control device, applied in the field of automotive electronics technology, to solve the problem of poor reliability of chip power supply short-circuit protection in the prior art. Specifically: a current sampling module is connected in series in the power supply circuit between the external power supply and the protected chip to collect the power supply current in the power supply circuit and convert it into a corresponding sampling voltage; when the sampling voltage exceeds a preset threshold, the short-circuit detection module generates a drive enable signal and outputs it to the on / off control module; the on / off control module is connected in series in the power supply circuit between the current sampling module and the protected chip to cut off the power supply circuit when the drive enable signal is received; after the drive enable signal disappears, the power supply circuit is automatically restored, realizing fast overcurrent shutdown and fault self-recovery, forming a hardware-level protection mechanism without external intervention, significantly improving the reliability of chip power supply short-circuit protection.

Description

Technical Field

[0001] This application relates to the field of automotive electronics technology, and in particular to a chip power supply protection circuit and an on-board control device. Background Technology

[0002] With the rapid development of electronic technology, controllers are increasingly widely used in industrial automation, smart homes, automotive electronics, and other fields. As a core component, the reliability and safety of control chips are of paramount importance. In practical applications, external power supply lines are prone to short circuits to ground or power supply due to improper plugging and unplugging, cable wear, device breakdown, or human intervention, causing the chip's logic power supply ports to be subjected to instantaneous current surges far exceeding design specifications.

[0003] Currently, protection against short circuits in chip power supply mainly relies on two types of solutions: one is passive protection based on the physical structure of the PCB (Printed Circuit Board), which involves reducing the width and thickness of the copper foil of the chip's logic power supply traces and increasing the distance between it and the surrounding ground loops, using the Joule heat accumulation of the copper foil under overcurrent to achieve melting and thus cut off the faulty circuit; the other is active protection relying on the overcurrent detection and shutdown circuit integrated inside the control chip, which monitors the supply current in real time and triggers the MOSFET or driver to turn off. However, both of the above solutions have inherent limitations: For the first solution, the fusing characteristics of PCB traces are significantly affected by copper thickness, trace width, temperature rise path, and environmental heat dissipation conditions. Especially in short-circuit scenarios with currents below 20A, the local high temperature generated at the short-circuit point often causes the PCB dielectric layer (such as FR-4 or high-frequency PP resin) to carbonize or even ignite first, while the power supply copper foil has not yet reached the fusing threshold and cannot open the circuit in time, resulting in obvious risks of ablation and fire. For the second solution, its protection action relies entirely on the integrity of the chip's own functions. Once a short-circuit impact causes abnormal chip power supply, internal logic lock-up, or protection module failure, it cannot complete the shutdown response. Even if the protection is successfully triggered, the chip may lose its subsequent recovery capability due to reset failure or firmware stagnation, resulting in an irreversible permanent power outage of the system.

[0004] In summary, existing solutions either risk substrate carbonization and combustion due to delayed physical melting, or completely lose their protective capabilities due to chip malfunction. Neither of these solutions can meet the high reliability requirements of chip power supply short-circuit protection. Summary of the Invention

[0005] This application provides a chip power supply protection circuit and an on-board control device to solve the problem of poor reliability of chip power supply short circuit protection in the prior art.

[0006] The technical solutions provided in this application are as follows: On one hand, embodiments of this application provide a chip power supply protection circuit, including: a current sampling module, a short circuit detection module, and a switching control module; The current sampling module is connected in series in the power supply circuit between the external power supply and the protected chip. The output terminal of the current sampling module is connected to the input terminal of the short circuit detection module. The current sampling module is used to collect the power supply current in the power supply circuit and convert it into the corresponding sampling voltage. The output of the short-circuit detection module is connected to the drive terminal of the on / off control module; the short-circuit detection module is used to generate a drive enable signal and output it to the on / off control module when the sampled voltage exceeds a preset threshold. The on / off control module is connected in series in the power supply circuit between the current sampling module and the protected chip; the on / off control module is used to cut off the power supply circuit when a drive enable signal is received; and automatically restore the power supply circuit after the drive enable signal disappears.

[0007] Optionally, the current sampling module includes: a first resistor; The first end of the first resistor is connected to the external power supply and the first input terminal of the short circuit detection module, respectively. The second end of the first resistor is connected to the protected chip via the on / off control module. The second end of the first resistor is also connected to the second input terminal of the short circuit detection module.

[0008] Optionally, the short-circuit detection module includes: a second resistor, a third resistor, a fourth resistor, a fifth resistor, and a first operational amplifier; The non-inverting input terminal of the first operational amplifier is connected to the first terminal of the first resistor via the second resistor, the inverting input terminal of the first operational amplifier is connected to the second terminal of the first resistor via the third resistor, the output terminal of the first operational amplifier is connected to the driving terminal of the on / off control module, the negative power supply terminal of the first operational amplifier is connected to ground, and the positive power supply terminal of the first operational amplifier is connected to the external power supply via the fourth resistor. The first end of the fifth resistor is connected to the non-inverting input of the first operational amplifier, and the second end of the fifth resistor is connected to the output of the first operational amplifier.

[0009] Optionally, the short-circuit detection module may also include: a transient voltage suppression diode; The positive terminal of the transient voltage suppressor diode is connected to ground, and the negative terminal of the transient voltage suppressor diode is connected between the fourth resistor and the external power supply.

[0010] Optionally, the on / off control module includes: a drive submodule and a switch submodule; The input terminal of the drive submodule is connected to the output terminal of the short-circuit detection module, and the output terminal of the drive submodule is connected to the drive terminal of the switch submodule; the switch submodule is connected in series in the power supply circuit between the current sampling module and the external power supply. When a drive enable signal is received, the drive enable signal is amplified to obtain a shutdown control signal, which is then output to the switch submodule. When the drive enable signal disappears, the drive enable signal is output to the switch submodule. The switch submodule is used to cut off the power supply circuit when a shutdown control signal is received, and to connect the power supply circuit when a conduction control signal is received.

[0011] Optionally, the driver submodule includes: a first transistor; The base of the first transistor is connected to the output terminal of the short-circuit detection module, the collector of the first transistor is connected to the external power supply, and the emitter of the first transistor is connected to the drive terminal of the switch submodule.

[0012] Optionally, the switching submodule includes: a first MOSFET and a sixth resistor; The gate of the first MOSFET is connected to the emitter of the first transistor and the first terminal of the sixth resistor, respectively; the source of the first MOSFET is connected to the current sampling module, and the drain of the first MOSFET is connected to the protected chip; the second terminal of the sixth resistor is connected to ground.

[0013] Optionally, the chip power supply protection circuit may also include: a protection module; The protection module is connected in series in the power supply circuit between the external power supply and the current sampling module; The protection module is used to ensure that the current in the power supply circuit flows in a unidirectional direction according to a preset direction.

[0014] Optionally, the protection module includes: a first diode; The positive terminal of the first diode is connected to an external power supply, and the negative terminal of the first diode is connected to the current sampling module.

[0015] On the other hand, this application provides an in-vehicle control device, including: the above-mentioned chip power supply protection circuit and power management chip; The input terminal of the chip power supply protection circuit is connected to an external power supply, and the output terminal of the chip power supply protection circuit is connected to a power management chip.

[0016] The beneficial effects of the embodiments of this application are as follows: In this embodiment, by connecting the current sampling module in series in the power supply circuit, the current in the power supply circuit can be converted into a sampling voltage in real time, realizing non-destructive monitoring of the power supply status. The short-circuit detection module generates a drive enable signal when the sampling voltage exceeds a preset threshold, so that the on / off control module cuts off the power supply circuit when it receives the drive enable signal, thereby quickly blocking the overcurrent path and preventing the chip from being damaged by overcurrent impact. At the same time, by means of the mechanism of the on / off control module automatically restoring the power supply circuit after the drive enable signal disappears, repeatable and self-recovering hardware-level protection without external intervention is realized, which significantly improves the reliability and system availability of chip power supply short-circuit protection.

[0017] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the first circuit structure of the chip power supply protection circuit in the embodiments of this application; Figure 2 This is a schematic diagram of a second circuit structure for the chip power supply protection circuit in an embodiment of this application; Figure 3 This is a schematic diagram of a third circuit structure for the chip power supply protection circuit in an embodiment of this application; Figure 4 This is a schematic diagram of the fourth circuit structure of the chip power supply protection circuit in the embodiments of this application; Figure 5 This is a schematic diagram of the fifth circuit structure of the chip power supply protection circuit in the embodiments of this application; Figure 6 This is a schematic diagram of the sixth circuit structure of the chip power supply protection circuit in the embodiments of this application; Figure 7 This is a schematic diagram of the circuit structure of the vehicle control device in the embodiments of this application.

[0019] Icons: 100 - Chip power supply protection circuit; 110 - Current sampling module; 120 - Short circuit detection module; 130 - On / off control module; R1 - First resistor; R2 - Second resistor; R3 - Third resistor; R4 - Fourth resistor; R5 - Fifth resistor; U1 - First operational amplifier; TVS1 - Transient voltage suppression diode; 131 - Driver submodule; 132 - Switch submodule; P1 - First transistor; Q1 - First MOSFET; R6 - Sixth resistor; 140 - Protection module; D1 - First diode; 200 - Vehicle control device; 210 - Power management chip. Detailed Implementation

[0020] To make the objectives, technical solutions, and beneficial effects of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] This application provides a chip power supply protection circuit, see below. Figure 1 As shown, the chip power supply protection circuit 100 includes at least: a current sampling module 110, a short circuit detection module 120, and an on / off control module 130; The current sampling module 110 is connected in series in the power supply circuit between the external power supply and the protected chip. The output terminal of the current sampling module 110 is connected to the input terminal of the short circuit detection module 120. The current sampling module 110 is used to collect the power supply current in the power supply circuit and convert it into the corresponding sampling voltage. The output terminal of the short circuit detection module 120 is connected to the drive terminal of the on / off control module 130; the short circuit detection module 120 is used to generate a drive enable signal and output it to the on / off control module 130 when the sampled voltage exceeds a preset threshold. The on / off control module 130 is connected in series in the power supply circuit between the current sampling module 110 and the protected chip; the on / off control module 130 is used to cut off the power supply circuit when a drive enable signal is received; and automatically restore the power supply circuit after the drive enable signal disappears.

[0022] exist Figure 1In the chip power supply protection circuit 100 shown, the current sampling module 110 is directly connected in series in the main power supply circuit between the external power supply and the protected chip. The external power supply is the lead-acid battery power supply of the vehicle. The protected chip is a power management chip. The current sampling module 110 can collect the supply current flowing from the external power supply to the protected chip. The core function of the current sampling module 110 is to realize the current-to-voltage conversion, that is, to collect the supply current in the power supply circuit and convert it into the corresponding sampling voltage. The sampling voltage can directly reflect the magnitude of the supply current of the protected chip. The input terminal of the short-circuit detection module 120 is electrically connected to the output terminal of the current sampling module 110. The short-circuit detection module 120 is used to receive the sampling voltage. Since the supply current requirement of the protected chip in the later stage is usually in the milliampere level, the sampling voltage is very weak and cannot be directly used to reliably drive the subsequent control logic. Therefore, the main function of the short-circuit detection module 120 is to accurately linearly amplify the weak sampling voltage and compare it with a preset threshold; when the sampling voltage exceeds the preset threshold, a drive enable signal is generated and output to the on / off control module 130. This preset threshold directly corresponds to the critical current value at which protective action is required, i.e., the voltage level triggered by the drive enable signal. The on / off control module 130 is the execution unit for the protective action. The drive terminal of the on / off control module 130 is connected to the output terminal of the short-circuit detection module 120 to receive the drive enable signal; the main power switch path of the on / off control module 130 is connected in series in the power supply circuit between the current sampling module 110 and the protected chip. When the on / off control module 130 receives the drive enable signal, it cuts off the power supply circuit; after the drive enable signal disappears, it automatically restores the power supply circuit.

[0023] In this way, by connecting the current sampling module in series in the power supply circuit, the current in the power supply circuit can be converted into a sampling voltage in real time, realizing non-destructive monitoring of the power supply status. The short-circuit detection module generates a drive enable signal when the sampling voltage exceeds a preset threshold, so that the on / off control module cuts off the power supply circuit when it receives the drive enable signal, thereby quickly blocking the overcurrent path and preventing the chip from being damaged by overcurrent impact. At the same time, with the mechanism of the on / off control module automatically restoring the power supply circuit after the drive enable signal disappears, repeatable and self-recovering hardware-level protection without external intervention is realized, which significantly improves the reliability and system availability of the chip power supply short-circuit protection.

[0024] In one possible implementation, see [reference] Figure 2 As shown, the current sampling module 110 includes: a first resistor R1; The first end of the first resistor R1 is connected to the external power supply and the first input terminal of the short circuit detection module 120, respectively. The second end of the first resistor R1 is connected to the protected chip via the on / off control module 130. The second end of the first resistor R1 is also connected to the second input terminal of the short circuit detection module 120.

[0025] exist Figure 2 In the chip power supply protection circuit 100 shown, the first end of the first resistor R1 is connected to both the positive terminal of the external power supply and one input terminal of the short-circuit detection module 120. The second end of the first resistor R1 is divided into two paths: one path flows to the protected chip through the subsequent on / off control module 130, forming the main power supply current path; the other path is directly connected to the other input terminal of the short-circuit detection module 120. As a precision resistor with a small resistance value, the voltage difference between the first and second ends of the first resistor R1 serves as the sampling voltage, strictly following Ohm's law and proportional to the power supply current flowing through it. The sampling voltage across the first resistor R1 can be directly provided as a differential signal to the short-circuit detection module 120.

[0026] In this way, by using a discrete resistor as the sampling element, the simplest, most direct, and lowest-cost current detection scheme is achieved. By carefully selecting the resistance value of the first resistor R1 (typically in the milliohm range), a balance can be struck between two objectives: on the one hand, the resistance value is small enough that the voltage drop across it is minimal during normal operation, thereby minimizing the impact on the supply voltage of subsequent chips and the power loss of the circuit itself; on the other hand, the resistance value is sufficient to generate a sampling voltage signal that can be clearly identified and amplified by subsequent circuitry during a short circuit. This design provides reliable and linear raw current information for the entire protection circuit.

[0027] In one possible implementation, the current sampling module can be implemented using a Hall effect current sensor. The power supply terminal of the Hall sensor is connected to an external power source via a resistor, the ground terminal of the Hall sensor is connected to ground, the Hall sensor is mounted on the power supply line, and the output terminal of the Hall sensor is connected to the input terminal of the short-circuit detection module. Based on the Hall effect principle, the Hall sensor detects the magnetic field strength generated by the current in the power supply circuit and converts it into a voltage signal output proportional to the current. Because the Hall sensor and the power supply circuit are non-contact magnetically coupled, electrical isolation between the power circuit and the control circuit is achieved, eliminating the insertion loss and heat generation problems caused by the sampling resistor.

[0028] In one possible implementation, see [reference] Figure 3 As shown, the short-circuit detection module 120 includes: a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a first operational amplifier U1; The non-inverting input terminal of the first operational amplifier U1 is connected to the first terminal of the first resistor R1 via the second resistor R2. The inverting input terminal of the first operational amplifier U1 is connected to the second terminal of the first resistor R1 via the third resistor R3. The output terminal of the first operational amplifier U1 is connected to the driving terminal of the on / off control module 130. The negative power supply terminal of the first operational amplifier U1 is connected to ground. The positive power supply terminal of the first operational amplifier U1 is connected to an external power supply via the fourth resistor R4. The first end of the fifth resistor R5 is connected to the non-inverting input of the first operational amplifier U1, and the second end of the fifth resistor R5 is connected to the output of the first operational amplifier U1.

[0029] exist Figure 3 In the chip power supply protection circuit 100 shown, the non-inverting input of the first operational amplifier U1 is connected to the first terminal of the first resistor R1 via the second resistor R2. The inverting input of the first operational amplifier U1 is connected to the second terminal of the first resistor R1 via the third resistor R3. The second resistor R2 and the third resistor R3 have the same resistance value. The main functions of the second resistor R2 and the third resistor R3 are current limiting and filtering, while ensuring impedance balance at the differential input terminals. This is crucial for improving the common-mode rejection ratio of the operational amplifier and suppressing common-mode noise from the power supply line. The fifth resistor R5 is connected between the non-inverting input and the output of the first operational amplifier U1. The fifth resistor R5 and the second resistor R2 together form part of the negative feedback network of the first operational amplifier U1. By selecting the resistance ratio of the second resistor R2 and the fifth resistor R5, the amplification factor of the entire short-circuit detection module 120 can be precisely set. The output of the first operational amplifier U1 is the output of the short-circuit detection module 120, which outputs a drive enable signal and connects to the drive terminal of the on / off control module 130. The first operational amplifier U1 adopts a single power supply mode. Its negative power supply terminal is grounded, while the positive power supply terminal is connected to an external power supply through the fourth resistor R4. The fourth resistor R4 plays a current limiting protection role.

[0030] In this way, the differential amplifier circuit structure in the short-circuit detection module 120 can accurately and stably extract the small differential sampling voltage signal across the first resistor R1 and strongly suppress any noise interference common to the two sampling points. By adjusting the resistor network, the amplification factor can be flexibly set, thereby linearly amplifying the millivolt-level sampling voltage to a volt-level drive enable signal, providing high-precision, configurable analog signal processing capabilities, and ensuring the accuracy and reliability of overcurrent detection.

[0031] In one possible implementation, see [reference] Figure 3 As shown, the short-circuit detection module 120 also includes: a transient voltage suppression diode (TVS1); The positive terminal of the transient voltage suppressor diode TVS1 is connected to ground, and the negative terminal of the transient voltage suppressor diode TVS1 is connected between the fourth resistor R4 and the external power supply.

[0032] exist Figure 3 In the chip power supply protection circuit 100 shown, the transient voltage suppressor diode TVS1 can be a unidirectional suppressor diode. The positive terminal of the transient voltage suppressor diode TVS1 is connected to ground, and the negative terminal is connected between the fourth resistor R4 and the external power supply. In the case where the external power supply is a car battery, the car battery power supply circuit is a typical harsh electrical environment, easily induced by events such as sudden load shedding, inductive load disconnection, or electromagnetic interference, resulting in voltage spikes or surges with amplitudes far exceeding the normal battery voltage and short durations. If such transient high voltages are not suppressed, they will be directly conducted to the positive power supply pin of the first operational amplifier U1 through the fourth resistor R4. During normal operation, the external power supply voltage is within its rated range, and the reverse voltage across the transient voltage suppressor diode TVS1 is lower than its breakdown voltage. At this time, the transient voltage suppressor diode TVS1 presents extremely high impedance, with only microamp-level leakage current, which has almost no impact on the power supply of the first operational amplifier U1, and the circuit function is unaffected. Once a transient overvoltage occurs on the external power line, causing the voltage at that node to momentarily exceed the preset breakdown voltage of the transient voltage suppressor diode (TVS1), the TVS1 will rapidly transition from a high-resistance state to a low-resistance state within nanoseconds, resulting in avalanche breakdown. In this state, the TVS1 provides an extremely low-impedance path, bypassing the excessive transient current from the power line to ground, thereby forcibly clamping the voltage on the positive power supply pin of the first operational amplifier U1 at the breakdown voltage of the TVS1. When the transient overvoltage event disappears and the power supply voltage returns to normal, the TVS1 automatically returns to its high-resistance state, and the first operational amplifier U1 continues to operate normally. Furthermore, the TVS1 can also be a bidirectional suppressor diode. In this case, one end of the TVS1 is connected to ground, and the other end is connected between the fourth resistor R4 and the external power supply.

[0033] In this way, the transient voltage suppressor diode TVS1 provides power supply protection for the first operational amplifier U1, preventing it from suffering permanent breakdown or damage due to overvoltage stress on the power supply pins, thus ensuring the long-term reliability of the signal conditioning function. This significantly enhances the adaptability and robustness of the chip power supply protection circuit 100 in complex automotive or industrial electromagnetic environments.

[0034] In one possible implementation, the short-circuit detection module can be implemented by reusing idle operational amplifier resources in the motor control circuit of a BLDC (Brushless Direct Current Motor). In the BLDC motor control circuit, a two-phase current sampling scheme based on Kirchhoff's current law is typically used to calculate the third-phase current using the two-phase sampled values, thereby freeing up the operational amplifier for the third-phase sampling channel. This idle operational amplifier for the third-phase sampling channel is then used as the first operational amplifier U1 of the short-circuit detection module, while retaining the other device settings and connections of the short-circuit detection module. By reusing idle analog front-end resources in the motor control chip, the functionality and response speed of the short-circuit detection module are maintained without the need for an additional independent operational amplifier, significantly reducing hardware costs and PCB footprint, and improving the system integration functional density.

[0035] In one possible implementation, see [reference] Figure 4 As shown, the on / off control module 130 includes: a drive submodule 131 and a switch submodule 132; The input terminal of the drive submodule 131 is connected to the output terminal of the short circuit detection module 120, and the output terminal of the drive submodule 131 is connected to the drive terminal of the switch submodule 132; the switch submodule 132 is connected in series in the power supply circuit between the current sampling module 110 and the protected chip. When a drive enable signal is received, the drive enable signal is amplified to obtain a shutdown control signal, and the shutdown control signal is output to the switch submodule 132; when the drive enable signal disappears, the drive enable signal is output to the switch submodule 132. The switch submodule 132 is used to cut off the power supply circuit when a shutdown control signal is received, and to connect the power supply circuit when a conduction control signal is received.

[0036] exist Figure 4In the chip power supply protection circuit 100 shown, the input terminal of the drive submodule 131 is directly connected to the output terminal of the short-circuit detection module 120 to receive the drive enable signal. The output terminal of the drive submodule 131 is connected to the drive terminal of the switch submodule 132 to output a turn-off control signal or a turn-on control signal to the switch submodule 132. The main power path of the switch submodule 132 is connected in series in the power supply circuit between the current sampling module 110 and the protected chip, and its physical location allows it to directly control the on / off of the power supply current. The core function of the drive submodule 131 is as a power amplifier and logic drive unit. When the drive enable signal is received, the drive submodule 131 amplifies the drive enable signal to obtain a turn-off control signal; when the drive enable signal disappears, it outputs a turn-on control signal. When the drive enable signal is received, the drive submodule 131 outputs a turn-off control signal to the switch submodule 132 to cut off the power supply circuit; when the drive enable signal disappears, it outputs a turn-on control signal to the switch submodule 132 to automatically restore the power supply circuit. The switching submodule 132 acts as a controlled power switching execution unit. It directly responds to the turn-off or turn-on control signals from the drive submodule 131 and controls the state of its internal power switching devices according to the corresponding control signals. When a turn-on control signal is received, the switching submodule 132 connects the power supply circuit, allowing external power to supply power to the protected chip. When a turn-off control signal is received, the switching submodule 132 disconnects the power supply circuit, achieving rapid power-off protection.

[0037] In this way, the driver submodule, acting as a buffer stage, provides the necessary current drive capability, ensuring reliable control of the power switch. The driver submodule can utilize fast, precise small-signal devices to focus on power amplification and rapid logic response; while the switch submodule can independently utilize low on-resistance, high-voltage power devices to focus on handling main circuit power and withstanding short-circuit stress. The two operate independently, each at its optimal state. This modular design makes the circuit logic clearer and facilitates fault analysis, testing, and maintenance. For example, the signal amplification capability of the driver submodule and the switching action of the switch submodule can be tested separately, ensuring the determinism and reliability of the entire on / off control function.

[0038] In one possible implementation, see [reference] Figure 5 As shown, the driver submodule 131 includes: a first transistor P1; The base of the first transistor P1 is connected to the output terminal of the short-circuit detection module 120, the collector of the first transistor P1 is connected to an external power supply, and the emitter of the first transistor P1 is connected to the drive terminal of the switch submodule 132.

[0039] exist Figure 5In the chip power supply protection circuit 100 shown, the base of the first transistor P1 serves as the signal input terminal, directly connected to the output terminal of the short-circuit detection module 120 to receive the drive enable signal. The collector of the first transistor P1 is connected to an external power supply, which makes the external power supply not only the energy source to be monitored and controlled, but also the operating voltage source for the drive submodule 131 itself. The emitter of the first transistor P1 serves as the output terminal of the turn-off control signal or the turn-on control signal, directly connected to the drive terminal of the switch submodule 132. The first transistor P1 is a PNP bipolar transistor, performing both voltage comparison and power amplification functions. Under normal power supply conditions, the supply current is small, and the short-circuit detection module 120 outputs a low level indicating an invalid state. At this time, the voltage applied to the base of the first transistor P1 is insufficient to forward bias and conduct its base-emitter junction, and the first transistor P1 is in a reliable off state. In this state, its emitter output terminal exhibits high impedance characteristics, outputting a low-level turn-on control signal to the switch submodule 132 to maintain the conduction of the power supply circuit. When an overcurrent or short-circuit fault occurs, the short-circuit detection module 120 outputs a high-level drive enable signal. The first transistor P1 amplifies the drive enable signal and outputs a high-level shutdown control signal to the switch submodule 132, so that the switch submodule 132 cuts off the power supply circuit.

[0040] In this way, threshold comparison and power amplification are simultaneously achieved using a single discrete first transistor, resulting in a simple circuit structure that significantly reduces complexity and cost. Secondly, the conduction threshold, based on the physical characteristics of semiconductors, is highly stable, providing a reliable and adjustment-free protection trigger point. The transistor's switching response is extremely fast, completing state transitions within microseconds, ensuring rapid overcurrent protection, which is crucial for preventing fault escalation.

[0041] In one possible implementation, see [reference] Figure 5 As shown, the switching submodule 132 includes: a first MOSFET Q1 and a sixth resistor R6; The gate of the first MOSFET Q1 is connected to the emitter of the first transistor P1 and the first terminal of the sixth resistor R6, respectively; the source of the first MOSFET Q1 is connected to the current sampling module 110, and the drain of the first MOSFET Q1 is connected to the protected chip; the second terminal of the sixth resistor R6 is connected to ground.

[0042] exist Figure 5In the chip power supply protection circuit 100 shown, the first MOSFET Q1 is a P-channel enhancement-mode metal-oxide-semiconductor field-effect transistor. The gate of the first MOSFET Q1 is connected to the emitter of the first transistor P1 in the drive submodule 131 to receive a turn-off control signal or a turn-on control signal. The gate of the first MOSFET Q1 is also connected to the first terminal of the sixth resistor R6, the source of the first MOSFET Q1 is connected to the second terminal of the first resistor R1, and the drain of the first MOSFET Q1 is connected to the power input terminal of the protected chip. The second terminal of the sixth resistor R6 is connected to the circuit ground. The source and drain paths of the first MOSFET Q1 are connected in series in the power supply loop between the current sampling module 110 and the protected chip, which is used to cut off the power supply loop when a turn-off control signal is received and to turn on the power supply loop when a turn-on control signal is received. The sixth resistor R6, as a gate resistor, has the functions of pull-down, current limiting, and voltage division.

[0043] Specifically, under normal power supply conditions, the supply current is small, the short-circuit detection module 120 outputs a low level indicating an invalid state, and the first transistor P1 is in the off state. The emitter of the first transistor P1 outputs a turn-on control signal: at this time, the emitter output is high impedance, and the sixth resistor R6 acts as a pull-down resistor, stably pulling the gate potential of the first MOSFET Q1 down to ground potential, forming a low-level turn-on control signal. Since the source of the first MOSFET Q1 is connected to the power supply side and has a high positive voltage, after the gate is pulled low, its gate-source voltage is a large negative value, which is much lower than the turn-on threshold voltage of the first MOSFET Q1. Therefore, the first MOSFET Q1 is fully and reliably driven to the turn-on state, and a low resistance is presented between the source and drain of the first MOSFET Q1. The power supply circuit is connected, and the external power supply supplies power to the protected chip normally through the current sampling module 110 and the turn-on first MOSFET Q1. When an overcurrent or short-circuit fault occurs, the short-circuit detection module 120 outputs a high-level drive enable signal, triggering the first transistor P1 to enter the saturation turn-on state. The first transistor P1 amplifies the drive enable signal to obtain a turn-off control signal. At this time, the emitter potential of the first transistor P1 is rapidly pulled up to near the external power supply voltage, forming a high-level turn-off control signal. This turn-off control signal is applied to the gate of the first MOSFET Q1. The sixth resistor R6 mainly functions as a current limiter and voltage divider at this moment. It, together with the internal resistance of the conducting first transistor P1, forms a voltage divider network to ensure that the voltage applied to the gate is a controlled high potential. At this time, the gate potential of the first MOSFET Q1 is very close to its source potential, and the absolute value of the gate-source voltage of the first MOSFET Q1 rapidly decreases to near zero or even becomes a positive voltage. This causes the first MOSFET Q1 to immediately exit the conduction region and enter the cut-off state. The impedance between the source and drain of the first MOSFET Q1 becomes extremely high, thereby physically forcibly cutting off the power supply circuit and achieving rapid isolation of the fault. When the fault is cleared and the drive enable signal disappears, the first transistor P1 is turned off, the sixth resistor R6 pulls the gate low, the first MOSFET Q1 is turned on again, and the power supply circuit is automatically restored.

[0044] In this way, by utilizing the voltage control characteristics of the MOSFET, the goal of safely controlling a high-current power supply circuit with a small-current control signal is achieved. The sixth resistor, acting as a pull-down resistor, provides a clear low-level reference for the MOSFET gate when the driving transistor is off, completely eliminating the risk of false turn-on due to a floating gate. As a current-limiting resistor, the sixth resistor protects the emitter output of the first transistor and the sensitive gate oxide layer of the first MOSFET, preventing damage from excessive current charging and discharging during switching. The inclusion of the sixth resistor ensures the determinism and reliability of the control logic and enables the automatic reconnection of the power supply circuit.

[0045] In one possible implementation, see [reference] Figure 6As shown, the chip power supply protection circuit 100 also includes: a protection module 140; The protection module 140 is connected in series in the power supply circuit between the external power supply and the current sampling module 110; The protection module 140 is used to ensure that the current in the power supply circuit flows unidirectionally in a preset direction.

[0046] exist Figure 6 In the chip power supply protection circuit 100 shown, the protection module 140 is deployed in series in the power supply loop between the external power supply and the current sampling module 110, specifically located at the upstream input terminal of the power supply loop. The protection module 140 is used to ensure that the current in the power supply loop flows strictly in a preset direction, that is, to achieve reverse connection protection of the power supply. The protection module 140 is essentially a unidirectional current-conducting unit based on the unidirectional conductivity characteristic of semiconductors. When the protection module 140 is connected in series to the positive power supply path, it has the ability to distinguish the polarity of the external power supply. In the correct connection state, that is, when the positive terminal of the external power supply is connected to the input terminal of the protection module 140 and the negative terminal is connected to the system ground, the module presents a low impedance state to forward current due to its internal structure, allowing the current to flow smoothly to the subsequent current sampling module 110 and the entire circuit. However, when the external power supply is accidentally reverse-connected, that is, when the positive terminal of the power supply is mistakenly connected to the system ground and the negative terminal is mistakenly connected to the input terminal of the protection module 140, the voltage applied to the protection module 140 is a reverse voltage. The protection module 140 switches from a low impedance state to a high impedance state, effectively preventing the formation and flow of current in the opposite direction to the preset direction. This ensures the safety of other components in its subsequent overcurrent protection circuit and ensures that the core components will not fail in the event of a pre-existing fault such as reverse power connection.

[0047] In one possible implementation, see [reference] Figure 6 As shown, the protection module 140 includes: a first diode D1; The positive terminal of the first diode D1 is connected to an external power supply, and the negative terminal of the first diode D1 is connected to the current sampling module 110.

[0048] exist Figure 6 In the chip power supply protection circuit 100 shown, the anode of the first diode D1 is connected to the positive terminal of the external power supply, and the cathode of the first diode D1 is connected to the first terminal of the first resistor R1. When the external power supply is correctly connected, i.e., when the positive terminal of the external power supply is connected to the anode of the first diode D1, the first diode D1 is forward biased and conducts, allowing current to flow smoothly into the subsequent circuit. When the external power supply is reverse-biased, the diode is cut off due to reverse bias, which is equivalent to disconnecting the subsequent circuit. In this way, reverse connection protection is achieved by utilizing the inherent unidirectional conductivity of the diode, which is determined by its physical properties. There is no active control or reliance on external conditions, the operation is definite and error-free, and the reliability is extremely high.

[0049] Based on the same concept, this embodiment also provides an in-vehicle control device, see reference. Figure 7 As shown, the vehicle control device 200 includes: a chip power supply protection circuit 100 and a power management chip 210 as described above; The input terminal of the chip power supply protection circuit 100 is connected to an external power supply, and the output terminal of the chip power supply protection circuit 100 is connected to the power management chip 210.

[0050] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0051] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0052] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0053] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A chip power supply protection circuit, characterized in that, include: Current sampling module, short circuit detection module, and on / off control module; The current sampling module is connected in series in the power supply circuit between the external power supply and the protected chip. The output terminal of the current sampling module is connected to the input terminal of the short circuit detection module. The current sampling module is used to collect the power supply current in the power supply circuit and convert it into a corresponding sampling voltage. The output terminal of the short-circuit detection module is connected to the drive terminal of the on / off control module; the short-circuit detection module is used to generate a drive enable signal and output it to the on / off control module when the sampled voltage exceeds a preset threshold. The on / off control module is connected in series in the power supply circuit between the current sampling module and the protected chip; the on / off control module is used to cut off the power supply circuit when the drive enable signal is received; and automatically restore the power supply circuit after the drive enable signal disappears.

2. The chip power supply protection circuit as described in claim 1, characterized in that, The current sampling module includes: a first resistor; The first end of the first resistor is connected to the external power supply and the first input terminal of the short circuit detection module, respectively. The second end of the first resistor is connected to the protected chip via the on / off control module. The second end of the first resistor is also connected to the second input terminal of the short circuit detection module.

3. The chip power supply protection circuit as described in claim 2, characterized in that, The short-circuit detection module includes: a second resistor, a third resistor, a fourth resistor, a fifth resistor, and a first operational amplifier; The non-inverting input terminal of the first operational amplifier is connected to the first end of the first resistor via a second resistor, the inverting input terminal of the first operational amplifier is connected to the second end of the first resistor via a third resistor, the output terminal of the first operational amplifier is connected to the driving terminal of the on / off control module, the negative power supply terminal of the first operational amplifier is connected to ground, and the positive power supply terminal of the first operational amplifier is connected to an external power supply via a fourth resistor. The first end of the fifth resistor is connected to the non-inverting input of the first operational amplifier, and the second end of the fifth resistor is connected to the output of the first operational amplifier.

4. The chip power supply protection circuit according to claim 3, characterized in that, The short-circuit detection module further includes: a transient voltage suppression diode; The positive terminal of the transient voltage suppression diode is connected to ground, and the negative terminal of the transient voltage suppression diode is connected between the fourth resistor and the external power supply.

5. The chip power supply protection circuit according to claim 1, characterized in that, The on / off control module includes: a drive submodule and a switch submodule; The input terminal of the driving submodule is connected to the output terminal of the short-circuit detection module, and the output terminal of the driving submodule is connected to the driving terminal of the switching submodule; the switching submodule is connected in series in the power supply circuit between the current sampling module and the external power supply. The drive submodule is used to amplify the drive enable signal to obtain a shutdown control signal when a drive enable signal is received, and output the shutdown control signal to the switch submodule; when the drive enable signal disappears, it outputs a turn-on control signal to the switch submodule. The switch submodule is used to cut off the power supply circuit when it receives the shutdown control signal, and to turn on the power supply circuit when it receives the turn-on control signal.

6. The chip power supply protection circuit according to claim 5, characterized in that, The driving submodule includes: a first transistor; The base of the first transistor is connected to the output terminal of the short-circuit detection module, the collector of the first transistor is connected to an external power supply, and the emitter of the first transistor is connected to the driving terminal of the switching submodule.

7. The chip power supply protection circuit according to claim 6, characterized in that, The switching submodule includes: a first MOSFET and a sixth resistor; The gate of the first MOS transistor is connected to the emitter of the first transistor and the first terminal of the sixth resistor, respectively; the source of the first MOS transistor is connected to the current sampling module, and the drain of the first MOS transistor is connected to the protected chip; the second terminal of the sixth resistor is connected to ground.

8. The chip power supply protection circuit according to any one of claims 1-7, characterized in that, Also includes: Protection module; The protection module is connected in series in the power supply circuit between the external power supply and the current sampling module; The protection module is used to ensure that the current in the power supply circuit flows unidirectionally in a preset direction.

9. The chip power supply protection circuit according to claim 8, characterized in that, The protection module includes: a first diode; The positive terminal of the first diode is connected to an external power supply, and the negative terminal of the first diode is connected to the current sampling module.

10. A vehicle-mounted control device, characterized in that, include: The chip power supply protection circuit and power management chip as described in any one of claims 1-9; The input terminal of the chip power supply protection circuit is connected to an external power source, and the output terminal of the chip power supply protection circuit is connected to a power management chip.

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