System for reducing wake-up starting current and control method thereof
By employing a two-stage circuit timing control method for current limiting and delayed start-up, the problem of power fluctuations caused by excessive instantaneous current during the wake-up of the vehicle domain controller was solved, thereby improving power stability and functional safety.
Patent Information
- Application Number
- CN202511838368.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-03-03
AI Technical Summary
At the moment the vehicle domain controller wakes up, excessive starting current can cause power supply voltage fluctuations, which may trigger MCU reset, peripheral malfunctions, or data errors, affecting system stability and functional safety.
A two-stage circuit timing control is adopted. The first switching circuit module MOSFET_SW1 performs current-limited pre-charging through series resistor, and the second switching circuit module MOSFET_SW2 is turned on with a delay to ensure power supply stability.
It effectively suppresses surge current, ensures power network stability, achieves smooth and seamless power switching, reduces electromagnetic interference, and meets functional safety and low power consumption requirements.
Smart Images
Figure CN121590448A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of automotive electronics technology. Specifically, this invention relates to a system and control method for reducing wake-up current, thereby improving the reliability of vehicle body domain control. Background Technology
[0002] As automotive electronic architecture evolves towards a domain-centralized approach, body controllers are gradually shifting from traditional distributed modules to regionalized body domain controllers. During this transformation, the functions encompassed by body domain controllers are becoming increasingly diverse, encompassing not only basic body controls such as lights, wipers, and windows, but also integrating a series of complex functions related to comfort, safety, and network management. Therefore, functional safety requirements are particularly important in the application of body system controllers, necessitating corresponding diagnostic, fault-tolerant, and safety mechanisms at both the hardware and software levels. To ensure reliable system operation, related applications often employ PMIC modules with diagnostic capabilities. This module not only supplies power to each subsystem but also monitors the voltage status on the network in real time, detecting potential overvoltage, undervoltage, or voltage fluctuations, thus providing functional safety assurance at the power supply level. Simultaneously, modern body systems also need to support low-power design, i.e., possess robust sleep and wake-up logic. When the vehicle is stationary, the body controller can enter sleep mode to reduce quiescent current; and when it receives a wake-up signal, such as a remote key or door opening trigger, the system must quickly resume normal operation. However, at the moment the body controller is woken up, the MCU and its related logic circuits need to be powered on simultaneously, often resulting in a large inrush current. This current surge can cause momentary voltage fluctuations at the PMIC power output port, which, if not effectively suppressed, may cause a brief drop or rise in the supply voltage. If this voltage anomaly exceeds the normal operating range of the devices, it may lead to MCU reset, peripheral malfunctions, or data errors, thereby affecting the stable startup of the body system and even triggering functional safety-related faults. To solve this problem, effective control of the startup current must be implemented during the system design phase. Common measures include using soft-start circuits, introducing current limiting mechanisms in the power path, optimizing capacitor configuration to buffer momentary current demands, or managing the power-on sequence and slope of each stage of the power supply through the timing control function of the PMIC. These methods can significantly reduce the current peak during the wake-up process, avoid large voltage fluctuations, and thus ensure that the system maintains power stability during the wake-up phase, meeting the stringent functional safety and reliability requirements of the body domain controller.
[0003] In summary, the power supply design of the vehicle domain controller not only needs to focus on the power supply quality under normal conditions, but also must be carefully optimized for special operating conditions such as wake-up transients. Through reasonable current management and voltage monitoring strategies, the system can be guaranteed to operate stably and safely under various operating conditions. Summary of the Invention
[0004] This invention aims to overcome the shortcomings of the prior art and provide a system and control method for reducing wake-up startup current. During circuit wake-up, timing control is achieved through a two-stage circuit. The MCU system power supply is pre-charged with current-limited power through a series resistor switching circuit. Within the system's allowed time window, the control switching circuit is then used to supply power normally, thus solving the problem of excessive startup current causing the power chip to fail to start normally.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a system and control method for reducing wake-up startup current, characterized in that it includes a microcontroller unit module (MCU), a safety function logic power supply module (PMIC_VCC), a wake-up state logic circuit module, a first switching circuit module (MOSFET_SW1), and a second switching circuit module (MOSFET_SW2); the microcontroller unit module (MCU) is connected to the first switching circuit module (MOSFET_SW1) and the second switching circuit module (MOSFET_SW2) respectively; the safety function logic power supply module (PMIC_VCC) is connected to the first switching circuit module (MOSFET_SW1) and the second switching circuit module (MOSFET_SW2) respectively; and the wake-up state logic circuit module is connected to the first switching circuit module (MOSFET_SW1) and the second switching circuit module (MOSFET_SW2) respectively.
[0006] When the vehicle domain controller receives a wake-up request, the microcontroller unit module (MCU) controls the integrated circuit enable IC_EN to output an enable signal to the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2; the safety function logic power supply module PMIC_VCC transmits power to the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2; the wake-up state logic circuit module executes the wake-up logic response response output related to the power supply response of the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2.
[0007] The safety function logic power module PMIC_VCC receives instruction output from the power management integrated circuit chip PMIC and provides power to the wake-up state logic circuit module.
[0008] The first switching circuit module MOSFET_SW1 includes a field-effect transistor and a current-limiting resistor; the second switching circuit module MOSFET_SW2 includes a resistor, a capacitor, and a field-effect transistor.
[0009] In the first switching circuit module MOSFET_SW1, the gate of the field-effect transistor is controlled by the integrated circuit enable IC_EN, the drain is connected to the safety function logic power supply module PMIC_VCC, and the source is the power supply for the subsequent circuit. In the second switching circuit module MOSFET_SW2, the resistor and capacitor are connected in parallel between the gate of the field-effect transistor and ground. The gate of the field-effect transistor is controlled by the integrated circuit enable IC_EN, the drain is connected to the safety function logic power supply module PMIC_VCC, and the source is connected to the power supply for the subsequent circuit.
[0010] The first switching circuit module MOSFET_SW1 precharges the subsequent system circuit after current limiting by the series resistor; the second switching circuit module MOSFET_SW2 turns on after a delay, and when the voltage of the subsequent circuit rises to a certain level, it turns on the normal function of the subsequent circuit to perform normal operation.
[0011] The first switching circuit module MOSFET_SW1 is directly powered and charged during system startup, with current limited by a resistor. At this time, the charging only charges the subsequent circuits and does not enable them to work. The second switching circuit module MOSFET_SW2 is powered on after a delay during system startup. The delay can be achieved by connecting resistors and capacitors in series or in parallel. After the delay, it directly powers the subsequent circuits.
[0012] A system for reducing wake-up startup current and a control method thereof, characterized in that the method includes the following steps:
[0013] S1: When the vehicle domain controller receives a wake-up request, the microcontroller unit module (MCU) controls the integrated circuit to enable IC_EN and outputs an enable signal.
[0014] S2: Safety function logic power module PMIC_VCC transmits power to the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2;
[0015] S3: The first switching circuit module MOSFET_SW1 limits the current of the series resistor and precharges the subsequent system circuit. The second switching circuit module MOSFET_SW2 turns on after a delay. When the voltage of the subsequent circuit rises to a certain level, the normal function of the subsequent circuit of the measurement channel is turned on and it works normally.
[0016] S4: The wake-up state logic circuit module receives power from the first switch circuit module MOSFET_SW1 and the second switch circuit module MOSFET_SW2, and performs relevant wake-up logic execution response output.
[0017] The technical advantages of this invention are: effectively suppressing surge current, ensuring power network stability, avoiding abnormal operating conditions, achieving smooth and seamless power switching, simple and reliable circuit, low cost, and effectively supporting functional safety and low power management. Attached Figure Description
[0018] This manual includes the following figures, which illustrate the following:
[0019] Figure 1 This is a block diagram of the logical structure of the system of the present invention;
[0020] Figure 2 This is the circuit schematic diagram of the present invention. Detailed Implementation
[0021] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.
[0022] Figure 1 The logical structure block diagram of the present invention includes a microcontroller unit module (MCU), a safety function logic power supply module (PMIC_VCC), a wake-up state logic circuit module, a first switch circuit module (MOSFET_SW1), and a second switch circuit module (MOSFET_SW2). The microcontroller unit module (MCU) is connected to the first switch circuit module (MOSFET_SW1) and the second switch circuit module (MOSFET_SW2), respectively. The safety function logic power supply module (PMIC_VCC) is connected to the first switch circuit module (MOSFET_SW1) and the second switch circuit module (MOSFET_SW2), respectively. The wake-up state logic circuit module is connected to the first switch circuit module (MOSFET_SW1) and the second switch circuit module (MOSFET_SW2), respectively.
[0023] When the vehicle domain controller receives a wake-up request, the microcontroller unit module (MCU) controls the integrated circuit enable IC_EN to output an enable signal to the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2; the safety function logic power supply module PMIC_VCC transmits power to the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2; the wake-up state logic circuit module executes the wake-up logic response response output related to the power supply response of the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2.
[0024] The safety function logic power module PMIC_VCC receives instruction output from the power management integrated circuit chip PMIC and provides power to the wake-up state logic circuit module.
[0025] The Safety Function Logic Power Module (PMIC_VCC) is a power supply line or submodule that powers digital logic circuits performing safety tasks. It is typically specially identified and designed for high reliability within the system. The Power Management Integrated Circuit (PMIC) chip is a highly integrated, dedicated chip that features voltage conversion, power timing management, dynamic voltage and frequency regulation, charging management, and provides overvoltage, undervoltage, overcurrent, and overheat protection. It receives input power and outputs multiple controlled power supplies of different specifications to other components in the system.
[0026] The first switching circuit module MOSFET_SW1 includes a field-effect transistor and a current-limiting resistor; the second switching circuit module MOSFET_SW2 includes a resistor, a capacitor, and a field-effect transistor.
[0027] The field-effect transistor used in this invention is a MOSFET, or metal-oxide-semiconductor field-effect transistor. The advantages of using a MOSFET include extremely high input impedance, extremely low drive number, fast switching speed, suitability for high-frequency operation, mature manufacturing process, and ease of miniaturization. The MOSFET is one of the specific implementations of a FET; its metal-oxide-semiconductor structure, especially the intermediate insulating layer, makes it an ideal voltage-controlled electronic switch.
[0028] In the first switching circuit module MOSFET_SW1, the gate of the field-effect transistor is controlled by the integrated circuit enable IC_EN, the drain is connected to the safety function logic power supply module PMIC_VCC, and the source is the power supply for the subsequent circuit. In the second switching circuit module MOSFET_SW2, the resistor and capacitor are connected in parallel between the gate of the field-effect transistor and ground. The gate of the field-effect transistor is controlled by the integrated circuit enable IC_EN, the drain is connected to the safety function logic power supply module PMIC_VCC, and the source is connected to the power supply for the subsequent circuit.
[0029] The IC_EN enable signal is a digital control signal issued by a microcontroller unit (MCU). Its sole purpose is to command another integrated circuit to start working or enter sleep mode. It enables the main controller to manage the power or function of lower-level functional modules. Physically, the IC_EN enable signal is a physical connection line from a general-purpose input / output pin of the MCU to a specific enable pin of the controlled IC. Logically, it is a digital level signal, typically following these conventions: high level executes an "on" or "on" command; low level executes a "off" or "sleep" command. The IC_EN enable signal is used for dynamic power management, reducing system power consumption. When a function is not needed, its power supply is directly turned off or it is put into sleep mode, rather than being allowed to idle and consume power. It can control the timing of power-on and power-off. Some complex systems require chips to be powered on in a specific order to avoid conflicts or latch-up effects. The MCU can precisely pull the IC_EN enable signals of each integrated circuit high sequentially to achieve this timing control. Furthermore, the IC_EN enable function also has functional isolation and fault-safe functions. When a peripheral IC malfunctions, such as a short circuit or communication failure, the microcontroller unit module (MCU) can force a reset or completely shut it down by pulling its IC_EN enable function low, preventing the problem from spreading and improving system reliability.
[0030] The first switching circuit module MOSFET_SW1 precharges the subsequent system circuit after current limiting by the series resistor; the second switching circuit module MOSFET_SW2 turns on after a delay, and when the voltage of the subsequent circuit rises to a certain level, it turns on the normal function of the subsequent circuit to perform normal operation.
[0031] The first switching circuit module MOSFET_SW1 is directly powered and charged during system startup, with current limited by a resistor. At this time, the charging only charges the subsequent circuits and does not enable them to work. The second switching circuit module MOSFET_SW2 is powered on after a delay during system startup. The delay can be achieved by connecting resistors and capacitors in series or in parallel. After the delay, it directly powers the subsequent circuits.
[0032] For the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2, the first switching circuit module MOSFET_SW1 precharges the subsequent system circuit after current limiting by a series resistor of a set of MOSFET switching circuits. The second switching circuit module MOSFET_SW2 turns on after a delay. When the voltage of the subsequent circuit rises to a certain level, the normal function of the subsequent circuit is turned on and normal operation is performed. This method can control and prevent the voltage fluctuation caused by excessive current at the moment of startup, thus ensuring the stability of the power supply and improving the stability of the vehicle body system.
[0033] Figure 2 This is the circuit schematic of the present invention. As shown in the figure, VCC_3V3 is the PMIC_VCC power supply, and VCC_3V3_MCU_SW is the system peripheral power supply of the MCU. When the system wakes up, the system prioritizes controlling IC_EN to be active high, Q29 is turned on to ground, and M16 turns on VCC_3V3 to supply power to the subsequent circuit through R661. However, the resistance of R661 is 10 ohms, which limits the current of VCC_3V3 to prevent overcurrent. At the same time, when IC_EN is active, C476 is charged through R668. TP551 will reach the Q28 turn-on voltage after a certain time T1. At this time, VCC_3V3_MCU_SW has been pre-charged to a certain voltage by M16. After Q28 turns on, M15 directly turns on VCC_3V3 to directly supply power to VCC_3V3_MCU_SW. Through this process, VCC_3V3 performs voltage regulation and switching power supply to VCC_3V3_MCU_SW.
[0034] A system for reducing wake-up startup current and a control method thereof, characterized in that the method includes the following steps:
[0035] S1: When the vehicle domain controller receives a wake-up request, the microcontroller unit module (MCU) controls the integrated circuit to enable IC_EN and outputs an enable signal.
[0036] S2: Safety function logic power module PMIC_VCC transmits power to the first switching circuit module MOSFET_SW1 and the second switching circuit module MOSFET_SW2;
[0037] S3: The first switching circuit module MOSFET_SW1 limits the current of the series resistor and precharges the subsequent system circuit. The second switching circuit module MOSFET_SW2 turns on after a delay. When the voltage of the subsequent circuit rises to a certain level, the normal function of the subsequent circuit of the measurement channel is turned on and it works normally.
[0038] S4: The wake-up state logic circuit module receives power from the first switch circuit module MOSFET_SW1 and the second switch circuit module MOSFET_SW2, and performs relevant wake-up logic execution response output.
[0039] The role and effect of the embodiments
[0040] The core objective of this embodiment is to solve the problem of power supply voltage fluctuation caused by excessive startup current of downstream circuits when the system is woken up from hibernation, thereby improving system reliability and functional safety. Figure 2The first switching circuit, MOSFET_SW1, performs pre-charging. Due to the presence of R661, the charging current of the large-capacity filter capacitor in the subsequent circuit is limited, avoiding huge inrush currents. The second switching circuit module, MOSFET_SW2, is delayed in activation. When M15 is turned on, the capacitor in the subsequent circuit has already been pre-charged to a voltage close to VCC_3V3 by the M16 / R661 path. Therefore, the conduction of M15 will not generate a large inrush current, achieving a seamless and smooth switching from "current-limited pre-charging" to "full-voltage direct supply." In other words, this invention suppresses inrush current and avoids voltage slump. Subsequent circuits such as MCUs, memory, and peripheral ICs have a large number of decoupling capacitors to ground on their power pins during sleep mode. Direct power-on is equivalent to a momentary short circuit of these capacitors, generating an extremely high current change rate. This solution uses a 10Ω resistor to limit the current, controlling the peak capacitor charging current to a normal level, far lower than the several ampere surges that a direct short circuit might cause. This prevents the PMIC_VCC network from experiencing a sudden voltage drop due to instantaneous heavy load. Furthermore, this solution ensures the stable operation of the power management integrated circuit chip (PMIC) to meet functional safety requirements. The PMIC chip possesses overvoltage and undervoltage diagnostic functions. If the PMIC_VCC experiences drastic fluctuations due to current surges during wake-up, it may falsely trigger overvoltage and undervoltage protection, causing the system to fail to start normally or enter an erroneous state, violating automotive functional safety requirements. This solution maintains a stable output voltage for the PMIC chip, ensuring the reliability of its monitoring logic. This invention achieves "soft start," reducing electromagnetic interference (EMI). Rapid current changes are a major source of EMI. The smooth charging process significantly reduces high-frequency noise in the power supply circuit, which is beneficial for passing the stringent EMC testing standards of automobiles.
[0041] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.
Claims
1. A system and control method for reducing wake-up startup current, characterized in that: It includes a microcontroller unit module (MCU), a safety function logic power supply module (PMIC_VCC), a wake-up state logic circuit module, a first switch circuit module (MOSFET_SW1), and a second switch circuit module (MOSFET_SW2); the microcontroller unit module (MCU) is connected to the first switch circuit module (MOSFET_SW1) and the second switch circuit module (MOSFET_SW2) respectively; the safety function logic power supply module (PMIC_VCC) is connected to the first switch circuit module (MOSFET_SW1) and the second switch circuit module (MOSFET_SW2) respectively; the wake-up state logic circuit module is connected to the first switch circuit module (MOSFET_SW1) and the second switch circuit module (MOSFET_SW2) respectively.
2. The system and control method for reducing wake-up startup current as described in claim 1, characterized in that: When the vehicle domain controller receives a wake-up request, the microcontroller unit module (MCU) controls the integrated circuit enable (IC_EN) to enable and output to the first switching circuit module (MOSFET_SW1) and the second switching circuit module (MOSFET_SW2); the safety function logic power supply module (PMIC_VCC) transmits power to the first switching circuit module (MOSFET_SW1) and the second switching circuit module (MOSFET_SW2); the wake-up state logic circuit module receives the power supply response from the first switching circuit module (MOSFET_SW1) and the second switching circuit module (MOSFET_SW2) and executes the wake-up logic response output.
3. The system and control method for reducing wake-up startup current as described in claim 1, characterized in that: The safety function logic power module (PMIC_VCC) is powered by instructions from the power management integrated circuit chip (PMIC) to provide power to the wake-up state logic circuit module.
4. The system and control method for reducing wake-up startup current as described in claim 1, characterized in that: The first switching circuit module (MOSFET_SW1) includes a field-effect transistor and a current-limiting resistor; the second switching circuit module (MOSFET_SW2) includes a resistor, a capacitor, and a field-effect transistor.
5. The system and control method for reducing wake-up startup current as described in claim 4, characterized in that: In the first switching circuit module (MOSFET_SW1), the gate of the field effect transistor is controlled by the integrated circuit enable (IC_EN), the drain is connected to the safety function logic power supply module (PMIC_VCC), and the source is the power supply for the subsequent circuit.
6. The system and control method for reducing wake-up startup current as described in claim 4, characterized in that: In the second switching circuit module (MOSFET_SW2), the resistor and capacitor are connected in parallel between the gate of the field-effect transistor and ground. The gate of the field-effect transistor is controlled by the integrated circuit enable (IC_EN), the drain is connected to the safety function logic power supply module (PMIC_VCC), and the source is connected to the power supply of the subsequent circuit.
7. The system and control method for reducing wake-up startup current as described in claim 5, characterized in that: The first switching circuit module (MOSFET_SW1) precharges the subsequent system circuit after current limiting by the series resistor; the second switching circuit module (MOSFET_SW2) turns on after a delay, and when the voltage of the subsequent circuit rises to a certain level, it turns on the normal function of the subsequent circuit of the measurement channel and performs normal operation.
8. The system and control method for reducing wake-up startup current as described in claim 6, characterized in that: The first switching circuit module (MOSFET_SW1) is directly powered and charged when the system starts up, and the power supply is limited by a resistor. At this time, the charging only charges the subsequent circuit and cannot make the subsequent circuit work. The second switching circuit module (MOSFET_SW2) is powered on after a delay when the system starts up. The delay can be achieved by connecting resistors and capacitors in series or in parallel. After the delay, it directly powers the subsequent stage.
9. A system and control method for reducing wake-up startup current as described in any one of claims 1-8, characterized in that, The method includes the following steps: S1: When the vehicle domain controller receives a wake-up request, the microcontroller unit module (MCU) controls the integrated circuit enable (IC_EN) to output an enable signal; S2: The safety function logic power module (PMIC_VCC) transmits power to the first switching circuit module (MOSFET_SW1) and the second switching circuit module (MOSFET_SW2); S3: The first switching circuit module (MOSFET_SW1) limits the current of the series resistor and precharges the subsequent system circuit. The second switching circuit module (MOSFET_SW2) turns on after a delay. When the voltage of the subsequent circuit rises to a certain level, the normal function of the subsequent circuit of the measurement channel is turned on, and normal operation is performed. S4: The wake-up state logic circuit module receives power from the first switch circuit module (MOSFET_SW1) and the second switch circuit module (MOSFET_SW2) and performs relevant wake-up logic execution response output.