Vehicle-mounted power supply wake-up circuit and vehicle-mounted power supply wake-up method

Abstract

The application relates to the technical field of vehicle-mounted charging, in particular to a vehicle-mounted power supply wake-up circuit and a vehicle-mounted power supply wake-up method. The vehicle-mounted power supply wake-up circuit comprises a rectification module, an isolation module and a wake-up driving module. A high-voltage alternating-current signal output by an alternating-current voltage source is obtained, and half-wave rectification processing is performed on the high-voltage alternating-current signal to generate a wake-up signal. The number of components is minimized to realize reliable detection on the access state of the alternating-current power supply. The vehicle-mounted power supply is woken up only when charging, so that the working loss is greatly reduced, and the circuit layout is simplified.

Description

Technical Field

[0001] This application relates to the field of vehicle charging technology, and in particular to a vehicle power wake-up circuit and a vehicle power wake-up method. Background Technology

[0002] In new energy vehicles such as electric vehicles or hybrid vehicles, the on-board power management system is usually in a dormant state to reduce standby power consumption. When the vehicle needs to be connected to an external AC power source such as a charging station for charging, a dedicated wake-up circuit is required to detect the AC power connection status in real time and generate a wake-up signal to activate the on-board power management system, causing it to switch from dormant mode to working mode, thereby initiating the charging process.

[0003] Currently, the above functions are typically achieved using a full-wave bridge rectifier-based vehicle power supply wake-up circuit. This circuit uses a full-wave rectifier bridge composed of four high-voltage rectifier diodes to convert the externally input high-voltage AC power into a DC signal. This DC signal then drives isolation devices such as optocouplers to generate an isolated wake-up signal for the subsequent main control unit, thus waking up the vehicle power supply. However, because the current flows through two diodes during full-wave rectification, there is double the forward voltage drop loss, resulting in higher circuit power consumption. Furthermore, the use of four high-voltage diodes and corresponding matching circuits increases the number of components in the circuit, raising material costs and increasing the circuit board area, which is detrimental to product miniaturization and integration. Therefore, there is room for improvement. Summary of the Invention

[0004] This application provides an on-board power supply wake-up circuit and an on-board power supply wake-up method, which can reduce circuit power consumption and material costs while simplifying circuit layout.

[0005] The first aspect of this application provides an on-board power supply wake-up circuit, including:

[0006] The rectifier module is used to receive the AC signal output from the AC voltage source and detect the AC signal to obtain the output voltage signal.

[0007] An isolation module, connected to the rectifier module, is used to receive the output voltage signal and isolate the output voltage signal to obtain a wake-up signal;

[0008] The wake-up drive module, connected to the isolation module, is used to receive and transmit the wake-up signal to wake up the vehicle power supply for charging.

[0009] By adopting the above technical solution, and using a rectifier module to detect the AC signal, the external power supply connection status can be converted into an internally processable electrical signal, thus providing a reliable judgment basis for the subsequent wake-up logic. Furthermore, by using an isolation module to isolate the output voltage signal, an electrical safety barrier can be established between the high-voltage side and the low-voltage side, effectively protecting the core main control unit of the downstream stage from high-voltage impacts and improving the safety and reliability of the entire machine. By using a wake-up drive module to receive and transmit the isolated signal, the original and potentially unstable signal can be shaped into a standard logic level, thereby ensuring that the downstream power management system can be reliably and error-free, avoiding the risk of wake-up failure or logic disorder.

[0010] Optionally, the isolation module includes an optocoupler U1, wherein the anode and cathode of the light-emitting diode of the optocoupler U1 are connected to the rectifier module as the control side of the isolation module, and the collector and emitter of the optocoupler U1 are connected to the wake-up drive module as the controlled side of the isolation module.

[0011] By adopting the above technical solution and using optocoupler U1 as an isolation module, light can be used as a signal transmission medium to achieve complete physical disconnection between the input and output sides. This ensures effective signal transmission while providing extremely high voltage isolation capability, further enhancing the safety of the circuit in the high-voltage environment of the vehicle.

[0012] Optionally, the wake-up driving module includes: a power wake-up unit and a wake-up control unit;

[0013] The power wake-up unit is connected to the collector of the optocoupler U1, and the wake-up control unit is connected to the emitter of the optocoupler U1.

[0014] By adopting the above technical solution, the wake-up drive module is split into a power wake-up unit connected to the collector and a wake-up control unit connected to the emitter. The power supply and current limiting functions of the circuit are structurally decoupled from the signal generation and output functions. This makes the functional division of each part of the circuit clearer, facilitates targeted design and debugging, and improves the modularity and maintainability of the circuit design.

[0015] Optionally, the power wake-up unit includes: a first power supply, a first resistor R1, and a first capacitor C1;

[0016] The positive terminal of the first power supply is connected to one end of the first resistor R1, the negative terminal of the first power supply is grounded, the other end of the first resistor R1 is connected to the collector of the optocoupler U1, the connection point of the first resistor R1 and the optocoupler U1 is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is grounded.

[0017] By adopting the above technical solution, and by using a power wake-up unit including a first power supply and a first resistor R1, the necessary operating bias and power source can be provided for the phototransistor of the optocoupler U1. At the same time, the first resistor R1 is used to limit the current flowing through the optocoupler, while the first capacitor C1 can effectively bypass these internal noise signals to ground, thereby smoothing the power supply voltage. This ensures that the optocoupler can conduct normally and effectively prevents it from being damaged by surge or overload current, significantly extending the service life and reliability of the device.

[0018] Optionally, the wake-up control unit includes: a second resistor R2 and a second capacitor C2;

[0019] One end of the second resistor R2 is connected to the emitter of the optocoupler U1, and the other end of the second resistor R2 is grounded. The connection between the second resistor R2 and the optocoupler U1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

[0020] By adopting the above technical solution, and by using a wake-up control unit including a second resistor R2 and a second capacitor C2, the current signal of the optocoupler can be converted into a clear voltage signal by the second resistor R2. At the same time, the second capacitor C2 connected in parallel is used to perform low-pass filtering on the voltage signal, thereby effectively filtering out high-frequency noise and glitches in the signal, making the final output wake-up signal waveform smoother and more stable, and greatly reducing the probability of misjudgment caused by signal jitter in the subsequent main control unit.

[0021] Optionally, the rectifier module includes: a second diode D2, a third diode D3, a third resistor R3, and a fourth resistor R4;

[0022] The anode of the second diode D2 is connected to the positive side of the AC voltage source as the positive input terminal of the rectifier module. The cathode of the second diode D2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the anode of the light-emitting diode of the optocoupler U1. One end of the fourth resistor R4 is connected to the cathode of the light-emitting diode of the optocoupler U1, and the other end of the fourth resistor R4 is connected to the anode of the third diode D3. The cathode of the third diode D3 is connected to the negative side of the AC voltage source as the negative input terminal of the rectifier module.

[0023] By adopting the above technical solution, and by using a rectifier module composed of a second diode D2, a third diode D3, and corresponding resistors, half-wave rectification of high-voltage AC power can be achieved with a simplified structure of only two diodes. Compared with the traditional four-tube full-wave rectifier bridge, this significantly reduces the number of components, directly lowers hardware costs and PCB footprint, and enhances the product's cost competitiveness and integration.

[0024] Optionally, the rectifier module includes: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8;

[0025] One end of the seventh resistor R7 is connected to the positive side of the AC voltage source as the positive input terminal of the rectifier module. The other end of the seventh resistor R7 is connected to one end of the fifth resistor R5. The other end of the fifth resistor R5 is connected to the anode of the light-emitting diode of the optocoupler U1. One end of the sixth resistor R6 is connected to the cathode of the light-emitting diode of the optocoupler U1. The other end of the sixth resistor R6 is connected to one end of the eighth resistor R8. The other end of the eighth resistor R8 is connected to the negative side of the AC voltage source as the negative input terminal of the rectifier module.

[0026] By adopting the above technical solution, and by using a rectifier module composed of the fifth, sixth, seventh, and eighth resistors, the high-voltage AC input can be pre-divided using a pure resistor network, thereby significantly reducing the voltage stress applied to the subsequent rectifier and isolation components. This allows the subsequent circuits to use lower-cost, low-voltage components, fundamentally optimizing the cost structure of the entire circuit.

[0027] Optionally, the isolation module further includes: a first diode D1;

[0028] The connection between the fifth resistor R5 and the anode of the LED of the optocoupler U1 is connected to the cathode of the first diode D1, and the connection between the sixth resistor R6 and the cathode of the LED of the optocoupler U1 is connected to the anode of the first diode D1.

[0029] By adopting the above technical solution and adding a first diode D1 in parallel in the isolation module, half-wave rectification can be completed using this single diode in the low-voltage AC signal environment after voltage division, thereby reducing the number of core rectifier components to one, further simplifying the circuit design and reducing costs.

[0030] The second aspect of this application provides a vehicle power supply wake-up method, applied to the vehicle power supply wake-up circuit of the first aspect, including:

[0031] Acquire the AC signal output from the AC voltage source, and perform half-wave rectification on the AC signal to generate a driving voltage signal;

[0032] Determine whether the driving voltage signal meets the driving voltage condition for waking up the vehicle power supply;

[0033] If the driving voltage condition is met, a wake-up signal is generated based on the driving voltage signal, and the wake-up signal is used to wake up the vehicle power supply.

[0034] By adopting the above technical solution, and by performing half-wave rectification on the AC signal to generate a drive voltage signal, the detection of AC power connection status can be completed with lower power consumption, thus meeting the energy-saving design requirements of vehicle equipment. By judging whether the drive voltage signal meets the drive voltage conditions, the validity of the signal can be accurately identified, and noise interference can be filtered out, thereby avoiding false wake-ups caused by invalid signals and improving the stability of the system. By generating a wake-up signal when the conditions are met, it can be ensured that the wake-up command is only issued when the external power supply is confirmed to be validly connected, thus ensuring the rigor and reliability of the entire wake-up process.

[0035] Optionally, the step of determining whether the driving voltage signal meets the driving voltage condition for waking up the vehicle power supply includes:

[0036] Obtain the voltage amplitude of the driving voltage signal and determine whether the voltage amplitude is less than the conduction threshold voltage in the driving voltage condition;

[0037] If the amplitude of the driving voltage signal is greater than or equal to the conduction threshold voltage, then the driving voltage condition is determined to be satisfied.

[0038] If the amplitude of the driving voltage signal is less than the conduction threshold voltage, then the driving voltage condition is determined not to be met.

[0039] By adopting the above technical solution, the voltage amplitude of the driving voltage signal is obtained and compared with the conduction threshold voltage, making the judgment of the signal validity more objective and the result more reliable. By determining that the condition is met when the amplitude is greater than or equal to the threshold and that the condition is not met when it is less than the threshold, a clear logic gate switch can be provided for the continuation or termination of the wake-up process, making the entire execution process more rigorous and stable and eliminating the risk of misjudgment in critical states.

[0040] In summary, this application includes at least one of the following beneficial technical effects:

[0041] 1. By using a rectifier module to detect AC signals, the external power supply connection status can be converted into an internally processable electrical signal, thus providing a reliable basis for subsequent wake-up logic. Furthermore, by using an isolation module to isolate the output voltage signal, an electrical safety barrier can be established between the high-voltage side and the low-voltage side, effectively protecting the core control unit of the downstream stage from high-voltage impact and improving the safety and reliability of the entire machine. By using a wake-up drive module to receive and transmit the isolated signal, the original and potentially unstable signal can be shaped into a standard logic level, thereby ensuring reliable and error-free triggering of the downstream power management system and avoiding the risk of wake-up failure or logic disorder.

[0042] 2. By performing half-wave rectification on the AC signal to generate a drive voltage signal, the detection of AC power connection status can be completed with lower power consumption, thus meeting the energy-saving design requirements of vehicle equipment. By judging whether the drive voltage signal meets the drive voltage conditions, the validity of the signal can be accurately identified, and noise interference can be filtered out, thereby avoiding false wake-ups caused by invalid signals and improving system stability. By generating a wake-up signal when the conditions are met, it can be ensured that the wake-up command is only issued when the external power supply is confirmed to be validly connected, thus ensuring the rigor and reliability of the entire wake-up process. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of a vehicle power supply wake-up circuit provided in an embodiment of this application;

[0044] Figure 2 Here is a circuit diagram of the first type of vehicle power supply wake-up circuit provided in this application embodiment:

[0045] Figure 3 This is a circuit diagram of the second type of vehicle power supply wake-up circuit provided in the embodiments of this application;

[0046] Figure 4 This is a circuit diagram of the third type of vehicle power supply wake-up circuit provided in the embodiments of this application;

[0047] Figure 5 This is a circuit diagram of the fourth type of vehicle power supply wake-up circuit provided in the embodiments of this application;

[0048] Figure 6 This application provides a schematic diagram of a wake-up signal waveform when there is AC power input.

[0049] Figure 7 This application provides a schematic diagram of a wake-up signal waveform when there is no AC power input.

[0050] Figure 8This is a flowchart illustrating a vehicle power supply wake-up method provided in an embodiment of this application. Detailed Implementation

[0051] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0052] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0053] The present application will be further described in detail below with reference to the accompanying drawings.

[0054] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle power supply wake-up circuit provided in an embodiment of this application. The vehicle power supply wake-up circuit includes a rectifier module 1, an isolation module 2, and a wake-up driver module 3. The isolation module 2 is connected to the rectifier module 1, and the wake-up driver module 3 is connected to the rectifier module 1.

[0055] Rectifier module 1 is used to receive the AC signal output from the AC voltage source and rectify the AC signal to obtain the output voltage signal;

[0056] Isolation module 2, connected to rectifier module 1, is used to receive the output voltage signal and isolate the output voltage signal to obtain a wake-up signal;

[0057] The wake-up drive module 3, connected to the isolation module 2, is used to receive and transmit wake-up signals to wake up the vehicle power supply for charging.

[0058] The rectifier module 1 receives the AC signal output from the AC voltage source and rectifies the AC signal to obtain an output voltage signal. The isolation module 2 is connected to the rectifier module 1 and is used to receive the output voltage signal and isolate the output voltage signal to obtain a wake-up signal. The wake-up drive module 3 is connected to the isolation module 2 and is used to receive and transmit the wake-up signal to wake up the vehicle power supply for charging.

[0059] Specifically, existing wake-up circuits for detecting AC power connection generally employ full-wave rectification. Direct application in the cost- and power-sensitive automotive environment would result in high overall circuit cost and significant standby power consumption, contradicting the design principles of new energy vehicles. Therefore, this embodiment optimizes the traditional design using a simplified rectification and driving method, correcting inherent defects in existing technologies. While ensuring wake-up reliability, it significantly reduces circuit complexity and hardware cost, thereby optimizing the overall performance of the vehicle power management system. Thus, a high-efficiency and low-cost wake-up circuit is constructed using rectification module 1, isolation module 2, and wake-up driver module 3. This structure enables accurate detection and safe wake-up of external AC power connection status.

[0060] More specifically, when an external AC power source, such as the charging gun of a charging station, is connected to the vehicle, the rectifier module 1, as the signal sensing front end of the circuit, receives an AC sine wave signal of up to several hundred volts, i.e., the AC signal V_SIN. Through its internal half-wave rectification function, the rectifier module 1 performs a non-linear processing on the AC signal, for example, allowing only the positive or negative half-cycle of the signal to pass through, thereby generating a pulsating and unidirectional voltage signal at the output end, i.e., the output voltage signal. This completes the initial detection of the high-voltage AC power connection status. The isolation module 2, as the safety core of the circuit, receives the output voltage signal generated by the rectifier module 1 and achieves electrical isolation of several thousand volts through a non-electrically contact signal transmission method, such as optical coupling. This results in a safe wake-up signal that can be used by subsequent circuits. The wake-up drive module 3 receives the wake-up signal output by the isolation module 2 and, through its internal filtering, amplification, and level shaping circuits, finally outputs a standardized wake-up signal V_AC_WAKE_UP with a stable waveform and sufficient driving capability. This signal is then transmitted to the main control unit of the vehicle power supply to reliably trigger the vehicle power management system to switch from sleep mode to working mode.

[0061] Based on the above embodiments, as an optional embodiment, such as... Figure 2 As shown, Figure 2 A circuit diagram of an on-board power supply wake-up circuit is shown. The isolation module 2 includes an optocoupler U1. The anode and cathode of the light-emitting diode of the optocoupler U1 are connected to the rectifier module 1 as the control side of the isolation module 2, and the collector and emitter of the optocoupler U1 are connected to the wake-up drive module 3 as the controlled side of the isolation module 2.

[0062] Specifically, in a high-voltage vehicle environment, ensuring electrical safety isolation between the low-voltage control circuit and the high-voltage input circuit is the primary design principle. Inadequate isolation measures can lead to direct damage to the downstream main control chip from abnormal fluctuations on the high-voltage side. Therefore, this embodiment proposes a specific circuit implementation scheme using an optocoupler U1 as the core device. This scheme utilizes the optical conductivity of the optocoupler to construct a physically disconnected but signal-connected safe channel. This ensures high safety and reliability of the entire system while achieving reliable wake-up functionality, meeting the safety design requirements of vehicle electronic equipment. Therefore, a complete and implementable wake-up circuit is constructed using the rectifier module 1, the optocoupler U1 as the isolation module 2, and the wake-up drive module 3. This structure is used to complete the entire process from AC signal detection to DC wake-up signal output under absolutely safe isolation conditions.

[0063] More specifically, by receiving the output voltage signal generated by the rectifier module 1, the output voltage signal is applied to the two ends of the light-emitting diode on the control side of the optocoupler U1. When the amplitude of the voltage signal exceeds the conduction threshold of the light-emitting diode, it will drive it to emit light, converting electrical energy into light energy. Otherwise, it will not emit light, thus translating the presence or absence of an electrical signal into the presence or absence of a light signal. On the controlled side, the base region of the phototransistor continuously monitors the light signal from the light-emitting diode. Once it receives light, the phototransistor will switch from the cutoff state to the conduction state, allowing current to flow between its collector and emitter. Otherwise, it will remain cut off. In this way, it converts the received light signal back into a synchronous electrical signal, i.e., a wake-up signal, and transmits it to the wake-up drive module 3 in the subsequent steps.

[0064] Based on the above embodiments, as an optional embodiment, the wake-up driving module 3 includes: a power wake-up unit 31 and a wake-up control unit 32; the power wake-up unit 31 is connected to the collector of the optocoupler U1, and the wake-up control unit 32 is connected to the emitter of the optocoupler U1.

[0065] Specifically, although the wake-up signal output by the preceding isolation module 2 is logically correct, its driving capability is weak and it may contain electrical noise. If it is directly used to drive the subsequent main control unit, it may cause wake-up failure or logic disorder due to unstable level or insufficient driving current. Therefore, this embodiment proposes a dedicated signal conditioning circuit. By receiving and purifying the original wake-up signal, it can be shaped into a standard, stable logic level signal with sufficient driving capability, thereby ensuring reliable matching with the subsequent digital circuit interface and achieving the purpose of stable and efficient wake-up of the vehicle power supply. Therefore, a complete signal conditioning and driving circuit is constructed by using the power wake-up unit 31 and the wake-up control unit 32. This structure is used to perform the final optimization processing of the isolated wake-up signal and is the last link to ensure the reliability of the entire wake-up process.

[0066] More specifically, the power wake-up unit 31 is connected to the collector of the optocoupler U1, mainly serving as a power supply and current limiting channel. It provides the necessary operating voltage for the phototransistor to conduct and limits its operating current within a safe range. The wake-up control unit 32 is connected to the emitter of the optocoupler U1, serving as the core for generating and outputting the final wake-up signal. It converts the current signal flowing through the emitter into a voltage signal through an internal pull-down resistor. That is, it outputs a high level when the phototransistor is on and a low level when it is off. At the same time, the filter capacitor in this unit is responsible for smoothing and filtering the output voltage signal, removing noise and glitches, thereby ensuring that the final wake-up signal V_AC_WAKE_UP output to the vehicle power supply is clean and stable.

[0067] Based on the above embodiments, as an optional embodiment, the power wake-up unit 31 includes: a first power supply, a first resistor R1 and a first capacitor C1; the positive terminal of the first power supply is connected to one end of the first resistor R1, the negative terminal of the first power supply is grounded, the other end of the first resistor R1 is connected to the collector of the optocoupler U1, the connection between the first resistor R1 and the optocoupler U1 is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is grounded.

[0068] Specifically, since the phototransistor on the controlled side of the optocoupler U1 does not generate energy, an external power supply must be provided to convert its switching state into an effective voltage signal. However, if a power supply is directly connected, a huge inrush current may be generated at the moment of conduction due to the low circuit resistance, which could burn out the device. Therefore, this embodiment proposes a circuit unit that combines power supply and protection functions. By providing a stable operating voltage to the phototransistor while presetting a safe maximum operating current, it ensures that the subsequent signal conversion circuit can operate normally and is absolutely safe, achieving the design requirements of high reliability. Therefore, a basic bias and current limiting circuit is constructed using the first power supply, the first resistor R1, and the first capacitor C1. This structure is used to provide the necessary power to the signal output stage of the isolation module 2 and is an indispensable energy source in the entire wake-up signal generation chain.

[0069] More specifically, the first power supply, such as a 12V DC regulated power supply taken from the vehicle's constant power supply, serves as the source of driving energy and provides the necessary potential difference for establishing a voltage signal after the phototransistor is turned on. The first capacitor C1 is a power supply bypass capacitor, directly connected in parallel across the first power supply. The first resistor R1 is connected in series between the first power supply and the collector of the optocoupler U1 as a current-limiting resistor. It is a core component that ensures the safety of the optocoupler. The resistance value can be 20Ω, ensuring that even when the phototransistor is fully turned on and tends to be short-circuited, the current flowing through the entire circuit is limited to a safe value far less than its maximum rated value, such as tens of milliamps. This effectively prevents the device from being thermally damaged due to overcurrent and ensures the long-term stable operation of the entire wake-up circuit.

[0070] Based on the above embodiments, as an optional embodiment, the wake-up control unit 32 includes: a second resistor R2 and a second capacitor C2; one end of the second resistor R2 is connected to the emitter of the optocoupler U1, the other end of the second resistor R2 is grounded, the connection between the second resistor R2 and the optocoupler U1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

[0071] Specifically, since the original voltage signal output from the emitter of optocoupler U1, i.e., the wake-up signal, may contain unstable transients or high-frequency noise, directly using this unprocessed voltage as a logic signal could lead to misjudgments at the input stage of subsequent digital circuits. Therefore, this embodiment proposes a circuit unit integrating potential clamping and voltage filtering functions to ensure that the voltage at the emitter node can be stably maintained at clear high and low logic levels and to filter out voltage fluctuations, thereby generating a clean, reliable, and directly recognizable final wake-up signal V_AC_WAKE_UP by the microcontroller MCU's input pins, thus improving system stability and anti-interference capabilities. Therefore, an RC low-pass filter and level stabilization network is constructed using the second resistor R2 and the second capacitor C2. This structure is used for the final optimization and output of the original and unprocessed emitter voltage signal.

[0072] More specifically, the second resistor R2 acts as a pull-down resistor, providing a default and stable low-potential reference for the emitter node. When the phototransistor is in the off state, this resistor reliably clamps the potential of the emitter node to near ground, i.e., a logic low level. When the phototransistor is turned on, it, together with the pull-up resistor of the power wake-up unit 31, determines the final amplitude of the high-level voltage of the emitter node. The second capacitor C2 is connected in parallel across the second resistor R2 as a low-pass filter, which is a key component to ensure the quality of the output voltage. It can present extremely low impedance to fast voltage jumps or high-frequency noise voltages, effectively absorbing their energy and bypassing it to ground. For slowly changing DC voltage levels, it presents high impedance, enabling it to be stably established. In this way, it can smooth the output voltage waveform, ensuring that the final wake-up signal V_AC_WAKE_UP is a clean and stable DC voltage signal without glitches or jitter.

[0073] Based on the above embodiments, as an optional embodiment, the rectifier module 1 includes: a second diode D2, a third diode D3, a third resistor R3, and a fourth resistor R4; the anode of the second diode D2 is connected to the positive side of the AC voltage source as the positive input terminal of the rectifier module 1, the cathode of the second diode D2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to the anode of the light-emitting diode of the optocoupler U1, one end of the fourth resistor R4 is connected to the cathode of the light-emitting diode of the optocoupler U1, the other end of the fourth resistor R4 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is connected to the negative side of the AC voltage source as the negative input terminal of the rectifier module 1.

[0074] Specifically, since traditional full-wave rectifier bridges require four diodes to operate, their application in vehicle wake-up circuits with stringent cost and size requirements would be structurally redundant and costly. Therefore, this embodiment proposes a simplified rectification scheme that achieves effective detection of high-voltage AC power using a minimum number of diodes. By directly reducing the core rectifier components by half, material costs are significantly reduced and valuable circuit board layout space is saved while maintaining functionality, thus optimizing the overall circuit cost and integration. Therefore, a series half-wave rectifier circuit is constructed using the second diode D2, the third diode D3, the third resistor R3, and the fourth resistor R4. This structure simplifies the design while reliably capturing the AC power input status. Since the resistors are used for voltage division, the number of resistors varies depending on their value; no limit is placed on the number of resistors here.

[0075] More specifically, for an AC signal V_SIN, such as a 310V mains voltage, when the AC signal is in one half-cycle (positive at the top, negative at the bottom), the current flows sequentially from the positive side of the AC voltage source through the second diode D2, the third resistor R3, the LED of the subsequent optocoupler U1, the fourth resistor R4, and the third diode D3, finally returning to the negative side of the AC voltage source, forming a complete conducting loop. Here, the third resistor R3 and the fourth resistor R4 together act as current-limiting resistors, protecting the LED from excessive current surges. When the AC signal is in the opposite half-cycle, the second diode D2 and the third diode D3 are reverse biased and cut off, blocking the current path. Thus, current flows only during half a cycle of the AC signal. Through the coordinated work of these four components, the safe detection and half-wave rectification of the high-voltage AC signal are cleverly achieved.

[0076] Based on the above embodiments, as an optional embodiment, such as... Figure 3 As shown, Figure 3 A circuit diagram of the second type of vehicle power supply wake-up circuit is shown. The rectifier module 1 includes: a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8; one end of the seventh resistor R7 serves as the positive input terminal of the rectifier module and is connected to the positive side of the AC voltage source; the other end of the seventh resistor R7 is connected to one end of the fifth resistor R5; the other end of the fifth resistor R5 is connected to the anode of the LED of the optocoupler U1; one end of the sixth resistor R6 is connected to the cathode of the LED of the optocoupler U1; the other end of the sixth resistor R6 is connected to one end of the eighth resistor R8; the other end of the eighth resistor R8 serves as the negative input terminal of the rectifier module and is connected to the negative side of the AC voltage source.

[0077] Specifically, since directly processing high-voltage AC power requires high-voltage-rated and expensive electronic components, effectively reducing the signal voltage before rectification can greatly optimize the circuit's cost structure and design flexibility. Therefore, this embodiment proposes a voltage divider-before-processing architecture. By pre-attenuating the input high-voltage AC power to a safe low voltage range through a pure resistor network before any rectification process, subsequent rectifiers and isolation devices can use low-cost and low-voltage common components, fundamentally reducing hardware costs and improving the overall cost-effectiveness of the circuit. Therefore, a passive resistor voltage divider network is constructed using resistors R5, R6, R7, and R8. This structure is used to proportionally attenuate the input high-voltage signal, which is a key prerequisite for subsequent low-voltage rectification. Since the function of the resistors is to divide voltage, the number of resistors varies depending on the resistor value; no limit is placed on the number of resistors here.

[0078] More specifically, the seventh resistor R7 and the fifth resistor R5 are connected in series to form the upper arm of the voltage divider network, and the sixth resistor R6 and the eighth resistor R8 are connected in series to form the lower arm of the voltage divider network. These four resistors together form a symmetrical bridge voltage divider structure. Its core function is to attenuate the high-voltage AC current applied between the positive and negative input terminals according to the ratio of its resistance value, for example, reducing the peak voltage of 310V to tens of volts. Finally, a low-voltage AC signal with a significantly reduced amplitude but whose waveform and phase are consistent with the source signal is applied to the middle output terminal of the voltage divider network. The LED of the optocoupler at the input terminal of the subsequent isolation module 2 is connected to the middle node of this voltage divider network. This attenuated low-voltage signal is then sent to the subsequent stage for actual rectification. In this way, the difficult problem of high-voltage processing is cleverly transformed into a routine problem of low-voltage processing, laying the foundation for the low-cost implementation of the entire circuit.

[0079] Based on the above embodiments, as an optional embodiment, such as... Figure 4 As shown, Figure 4 A circuit diagram of the third type of vehicle power supply wake-up circuit is shown. The sixth resistor R6 and the eighth resistor R8 in rectifier module 1 can also be replaced with the second diode D2. The cathode of the second diode D2 serves as the negative input terminal of the rectifier module and is connected to the negative side of the AC voltage source. The cathode of the second diode D2 is connected to the cathode of the light-emitting diode in optocoupler U1.

[0080] Furthermore, based on the above embodiment, a ninth resistor R9 can be added; the connection point between the fifth resistor R5 and the anode of the LED of the optocoupler U1 is connected to one end of the ninth resistor R9, and the connection point between the anode of the second diode D2 and the cathode of the LED of the optocoupler U1 is connected to the other end of the ninth resistor R9.

[0081] Specifically, to ensure high reliability and anti-interference capabilities in complex automotive environments, cost and power consumption can be reduced by minimizing core rectifier components, such as a single diode. Simultaneously, an auxiliary parallel resistor is added to enhance noise suppression, achieving an ideal balance between low cost and high reliability, thus optimizing the design. Therefore, a highly robust half-wave rectifier detection front-end is constructed using a single diode, a series current-limiting resistor, and a parallel resistor. This structure is used to accurately and reliably detect the AC power connection status even in harsh operating environments.

[0082] More specifically, the seventh resistor R7 and the fifth resistor R5, connected in series in the main circuit, together serve as high-voltage current-limiting resistors. Their core function is to limit the operating current generated under the input high voltage of several hundred volts to a safe microampere level. The second diode D2, connected in series in the return path of the circuit, serves as the core half-wave rectifier element. By utilizing its unidirectional conduction characteristic, it ensures that the entire circuit conducts only during half a cycle of the AC current, thereby achieving the rectification function. The ninth resistor R9, connected in parallel across the LED of the optocoupler U1, serves as a noise suppression element. Its core function is to provide a bypass path for any weak interference current that may exist in the line and to effectively increase the signal threshold required to drive the LED of the optocoupler U1, preventing it from being accidentally lit by noise. Finally, these components work together to ensure that only real and effective AC signals can drive the optocoupler and to safely and reliably transmit this state to the subsequent wake-up drive module.

[0083] Based on the above embodiments, as an optional embodiment, refer to... Figure 3 The isolation module 2 also includes: a first diode D1; the connection between the fifth resistor R5 and the anode of the light-emitting diode of the optocoupler U1 is connected to the cathode of the first diode D1; and the connection between the sixth resistor R6 and the cathode of the light-emitting diode of the optocoupler U1 is connected to the anode of the first diode D1.

[0084] Specifically, since the preceding resistor network only attenuates the AC signal voltage, this low-voltage AC signal must be converted into a unidirectional pulsating signal to drive the subsequent isolation device. Therefore, this embodiment adds a core rectifier element to complete this step. By adding only one diode with the minimum number of components to achieve half-wave rectification, the final goal of the voltage divider-then-rectifier design strategy is perfectly achieved, realizing the ultimate compression of circuit cost and complexity while ensuring functionality. Therefore, the first diode D1 and the light-emitting diode of the optocoupler U1 are cleverly connected in parallel. This structure is used to efficiently complete the final rectification task under low-voltage conditions.

[0085] More specifically, the first diode D1, as the sole rectifier, is connected in reverse parallel with the LED of the optocoupler U1. Together, they operate under the low-voltage AC signal provided by the preceding voltage divider network. When the low-voltage AC signal is in one half-cycle, for example, positive at the top and negative at the bottom, the current preferentially selects to pass through the forward-biased, low-impedance LED of the optocoupler, thereby driving it to emit light and generating a driving light signal. At this time, the first diode D1 is cut off due to reverse bias and has no effect on the main circuit. When the AC signal is in the other opposite half-cycle, the first diode D1 becomes forward-biased, providing a path with extremely low impedance to bypass the current directly. This prevents the reverse voltage from damaging the LED with weak voltage withstand capability and ensures that no current can drive the LED to emit light during this half-cycle, thus protecting the optocoupler from high voltage damage. In this way, relying solely on the unidirectional conduction characteristic of a single ordinary diode, the half-wave rectification function of the AC signal is completed efficiently and reliably.

[0086] Based on the above embodiments, as an optional embodiment, such as... Figure 5 As shown, Figure 5 A circuit diagram of the fourth type of vehicle power supply wake-up circuit is shown. Isolation module 2 also includes: a tenth resistor R10;

[0087] The connection between the anode of the first diode D1 and the cathode of the light-emitting diode of the optocoupler U1 is connected to one end of the tenth resistor R10, and the connection between the cathode of the first diode D1 and the anode of the light-emitting diode of the optocoupler U1 is connected to the other end of the tenth resistor R10.

[0088] Specifically, in complex electromagnetic environments, or when the control signal comes from a turn-off state with a weak leakage current, a very small noise current may flow through the LED. While this current is insufficient to fully illuminate the LED, it may cause it to emit a faint light, resulting in an uncertain semi-conducting state for the phototransistor on the other side, thus triggering erroneous conduction. Therefore, a resistor can be connected in parallel between the anode and cathode of the LED in optocoupler U1. This parallel resistor provides a bypass for these weak noise currents or leakage currents, as these small currents will preferentially flow through the relatively low-resistance parallel resistor rather than illuminating the LED, which requires a certain turn-on voltage. Thus, only when a real, effective drive signal arrives will the larger current be sufficient to illuminate the LED, thereby improving the circuit's anti-interference capability.

[0089] Based on the above embodiments, in order to more clearly illustrate the working mechanism of the vehicle power wake-up circuit, within a complete AC power cycle, if the rectifier module 1 adopts the first vehicle power wake-up circuit scheme, when the AC voltage source enters the positive half-cycle, for example, the input terminal is positive at the top and negative at the bottom, the current flows sequentially through the second diode D2, the third resistor R3, the light-emitting diode of the optocoupler U1, the fourth resistor R4, and the third diode D3, forming a conducting loop and lighting up the light-emitting diode. When the AC voltage source enters the negative half-cycle, the input terminal becomes negative at the top and positive at the bottom, the second diode D2 and the third diode D3 are reverse cut off, there is no current in the circuit, and the light-emitting diode is turned off. If the rectifier module 1 adopts the second vehicle power wake-up circuit scheme, when the AC voltage source enters the positive half-cycle, its high voltage is divided by the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8, and the resulting low-voltage AC signal drives the light-emitting diode of the optocoupler U1 to conduct in the forward direction and emit light. The first diode D1 connected in parallel with it is reverse cut off. During the negative half-cycle of the AC voltage source, the polarity of the low-voltage AC signal after voltage division is reversed, causing the first diode D1 to conduct in the forward direction and bypassing the current, thereby protecting and ensuring that the light-emitting diode remains off during this period.

[0090] Since the two vehicle power supply wake-up circuit schemes mentioned above are consistent in their subsequent circuitry, for both schemes, during the positive half-cycle of the AC input, the LED of the optocoupler U1 is lit, and the phototransistor on its controlled side conducts accordingly. Current flows from the first power supply through the first resistor R1 and the phototransistor, generating a voltage drop at the second resistor R2, which serves as the output terminal. This pulls the wake-up signal V_AC_WAKE_UP output terminal high. During the negative half-cycle, although the LED is off, the high level at the output terminal is maintained due to the energy storage and filtering effect of the second capacitor C2. Finally, through the accumulation and smoothing of multiple cycles, the circuit outputs a stable high-level DC wake-up signal V_AC_WAKE_UP. The voltage waveform of the wake-up signal is as follows: Figure 6 As shown, Figure 6 This is a schematic diagram of a wake-up signal waveform when there is AC power input, provided as an embodiment of this application.

[0091] Throughout the standby time, since no valid voltage signal is received at the AC input terminal of the circuit, the amplitude of the drive signal output to the LED of the optocoupler U1 remains constant at zero, regardless of whether it's the first or second vehicle power supply wake-up circuit scheme. Because the LED is always off, the phototransistor also remains in a high-impedance cutoff state. Ultimately, the second resistor R2 in the wake-up drive module 3, i.e., the pull-down resistor, plays a crucial potential clamping role, forcibly and continuously clamping the wake-up signal output terminal to a near-ground potential of 0V. At this time, the voltage waveform of the wake-up signal is as follows: Figure 7As shown, Figure 7 This is a schematic diagram of a wake-up signal waveform when there is no AC power input, provided as an embodiment of this application.

[0092] Please refer to Figure 8 , Figure 8 This is a flowchart illustrating a vehicle power supply wake-up method applied to the aforementioned vehicle power supply wake-up circuit, provided in an embodiment of this application. The vehicle power supply wake-up method includes:

[0093] S1: Obtain the AC signal output from the AC voltage source and perform half-wave rectification on the AC signal to generate a drive voltage signal.

[0094] Specifically, the AC signal refers to the raw input power provided by the external power source when the vehicle is connected to a charging pile or external power grid. This power source has alternating polarity and a relatively high voltage amplitude, such as a peak value of 310V. Through half-wave rectification of this signal, only one half of the AC signal waveform, such as the positive half-cycle, is allowed to pass, while the other half, such as the negative half-cycle, is blocked. In this way, the bidirectional alternating AC power is converted into a unidirectional and pulsating DC power signal. Based on this processing, a driving voltage signal is generated. This driving voltage signal is a voltage pulse synchronized with the half-cycle of the AC power, which represents the access status of the external AC power and serves as the direct driving source for subsequent judgment and wake-up actions, providing a judgment basis for the entire wake-up process.

[0095] S2: Determine whether the drive voltage signal meets the drive voltage condition for waking up the vehicle power supply.

[0096] Specifically, when performing this judgment step, a preset driving condition is introduced, such as a specific voltage threshold. This threshold is set according to the turn-on characteristics of the downstream circuit components. For example, it may be the minimum turn-on voltage required for the LED inside the downstream optocoupler to emit light. Only when the amplitude of the driving voltage signal reaches this standard line is it considered to meet the driving condition for waking up the power supply. Only then can the subsequent wake-up action be triggered, thereby effectively avoiding misjudgments caused by invalid signals such as line noise.

[0097] S3; If the driving voltage condition is met, a wake-up signal is generated based on the driving voltage signal. The wake-up signal is used to wake up the vehicle power supply.

[0098] Specifically, when the drive voltage signal meets the drive voltage condition, the drive voltage signal can drive the isolation module 2 to work. Therefore, a wake-up signal is generated based on the drive voltage signal. However, since the unprocessed wake-up signal may contain electrical noise, if it is directly used to drive the subsequent main control unit, it may cause wake-up failure or logic disorder due to unstable level or insufficient drive current. Therefore, the wake-up signal is processed, usually including level shaping and filtering, to obtain a stable high level such as +12V or low level such as 0V wake-up signal V_AC_WAKE_UP, to ensure that it can effectively drive the wake-up interrupt pin of the subsequent microcontroller MCU and complete the final wake-up of the vehicle power supply.

[0099] In one embodiment, step S2, namely the step of determining whether the driving voltage signal meets the driving voltage condition for waking up the vehicle power supply, includes:

[0100] S21: Obtain the voltage amplitude of the drive voltage signal and determine whether the voltage amplitude is less than the conduction threshold voltage in the drive voltage condition.

[0101] Specifically, by measuring the drive voltage signal using a voltmeter, a specific voltage value is obtained, which is the voltage amplitude. This voltage amplitude is then compared with a pre-set turn-on threshold voltage, which is a voltage threshold pre-set based on the physical characteristics of the light-emitting diode in the subsequent isolation device, such as an optocoupler, for example, 0.7V. The result of this comparison will serve as the basis for subsequent steps to determine whether the drive conditions are met.

[0102] S22: If the amplitude of the driving voltage signal is greater than or equal to the conduction threshold voltage, then the driving voltage condition is satisfied.

[0103] Specifically, when the amplitude of the driving voltage signal exceeds the preset turn-on threshold voltage, the method determines that it is a real and valid input signal, rather than accidental noise interference. At this point, the conclusion that the driving voltage condition is met is established, and the entire process will continue to execute to trigger the final wake-up action, ensuring the timeliness of wake-up.

[0104] S23: If the amplitude of the driving voltage signal is less than the conduction threshold voltage, then the driving voltage condition is not met.

[0105] Specifically, when the amplitude of the driving voltage signal fails to reach the preset turn-on threshold voltage, it indicates that the signal may be weak noise or other interference on the line. In this case, it is determined to be an invalid input and the driving voltage condition is not met. The entire circuit will remain in a silent or sleep state, thereby avoiding unnecessary power consumption and system abnormalities.

[0106] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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. Such 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 this application, and should all be included within the protection scope of this application.

Claims

1. A vehicle power supply wake-up circuit, characterized in that, The vehicle power supply wake-up circuit includes: a rectifier module, an isolation module, and a wake-up driver module; The isolation module includes an optocoupler U1. The anode and cathode of the light-emitting diode of the optocoupler U1 are connected to the rectifier module as the control side of the isolation module, and the collector and emitter of the optocoupler U1 are connected to the wake-up drive module as the controlled side of the isolation module. The rectifier module includes a pure resistor voltage divider network composed of multiple resistors, which is used to attenuate the high-voltage AC signal received from the AC voltage source into a low-voltage AC signal before performing half-wave rectification. The isolation module also includes a first diode D1, which is connected in reverse parallel with the light-emitting diode of the optocoupler U1 and connected to the output of the pure resistor voltage divider network. The first diode D1 is used to turn on the light-emitting diode during the positive half-cycle of the low-voltage AC signal and provide a bypass channel for the low-voltage AC signal during the negative half-cycle, thereby realizing half-wave rectification of the low-voltage AC signal and generating a pulsating DC signal. The wake-up drive module includes an RC low-pass filter network consisting of a second resistor R2 and a second capacitor C2. The RC low-pass filter network is connected to the emitter of the optocoupler U1 and is used to smooth the pulsating DC signal so that the energy stored in the second capacitor C2 is used to maintain the output wake-up signal at an effective level during the negative half-cycle of the high-voltage AC signal, thereby waking up the vehicle power supply.

2. The vehicle power supply wake-up circuit according to claim 1, characterized in that, The wake-up driver module includes: a power wake-up unit and a wake-up control unit; The power wake-up unit is connected to the collector of the optocoupler U1, and the wake-up control unit is connected to the emitter of the optocoupler U1.

3. The vehicle power supply wake-up circuit according to claim 2, characterized in that, The power wake-up unit includes: a first power supply, a first resistor R1, and a first capacitor C1; The positive terminal of the first power supply is connected to one end of the first resistor R1, the negative terminal of the first power supply is grounded, the other end of the first resistor R1 is connected to the collector of the optocoupler U1, the connection point of the first resistor R1 and the optocoupler U1 is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is grounded.

4. The vehicle power supply wake-up circuit according to claim 1, characterized in that, The rectifier module includes: a second diode D2, a third diode D3, a third resistor R3, and a fourth resistor R4; The anode of the second diode D2 is connected to the positive side of the AC voltage source as the positive input terminal of the rectifier module. The cathode of the second diode D2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the anode of the light-emitting diode of the optocoupler U1. One end of the fourth resistor R4 is connected to the cathode of the light-emitting diode of the optocoupler U1, and the other end of the fourth resistor R4 is connected to the anode of the third diode D3. The cathode of the third diode D3 is connected to the negative side of the AC voltage source as the negative input terminal of the rectifier module.

5. A vehicle power supply wake-up method, applied to the vehicle power supply wake-up circuit as described in any one of claims 1-4, characterized in that, The vehicle power supply wake-up method includes: Acquire the AC signal output from the AC voltage source, and perform half-wave rectification on the AC signal to generate a driving voltage signal; Determine whether the driving voltage signal meets the driving voltage condition for waking up the vehicle power supply; If the driving voltage condition is met, a wake-up signal is generated based on the driving voltage signal, and the wake-up signal is used to wake up the vehicle power supply.

6. The vehicle power supply wake-up method according to claim 5, characterized in that, The step of determining whether the driving voltage signal meets the driving voltage condition for waking up the vehicle power supply includes: Obtain the voltage amplitude of the driving voltage signal and determine whether the voltage amplitude is less than the conduction threshold voltage in the driving voltage condition; If the amplitude of the driving voltage signal is greater than or equal to the conduction threshold voltage, then the driving voltage condition is determined to be satisfied. If the amplitude of the driving voltage signal is less than the conduction threshold voltage, then the driving voltage condition is determined not to be met.

Images