Low level pulse wake-up circuit

Abstract

The utility model discloses a low level pulse awakening circuit, including low level conversion circuit, pulse awakening circuit, awakening detection circuit and MCU self locking circuit, low level conversion circuit receives the low level signal of input and changes it into high level signal to the pulse conversion circuit with high level signal input, the pulse conversion circuit produces pulse signal for awakening power IC, the awakening detection circuit is used for detecting the voltage division value of VCU or BMS internal circuit and CC ground resistance, and the high level is given to the pulse awakening circuit through low level conversion circuit, and the pulse awakening circuit produces awakening enable signal ENP and wakes up power IC, and the system starts normal work, and MCU singlechip GPIO pin output self locking signal, and output to GPIO port makes the EN of power IC enable and keeps. The low level pulse awakening circuit provided by the utility model has the effect that does not influence VCU (or BMS) dormancy, also does not influence the subsequent other awakening source and wakes up VCU or BMS again, reduces the dark current of whole car after charging.

Description

Technical Field

[0001] This utility model relates to the field of automotive control technology, and in particular to a low-level pulse wake-up circuit. Background Technology

[0002] With the increasing popularity of new energy electric vehicles and the continuous growth of their ownership, charging has become a crucial usage scenario and experience point for electric vehicles. To improve user experience and ease of operation, new energy vehicles need to enter the charging process whenever they are plugged in. Therefore, the charging gun provides one or more signals to wake up the vehicle. Currently, some operating conditions of the VCU (or BMS) (such as false wake-up by the wake-up source) can lead to excessive dark current in the vehicle. In severe cases, this may cause the low-voltage battery to drain, or the vehicle may not be able to enter sleep mode after charging is completed, or certain operations may fail to wake up the VCU again, resulting in abnormal vehicle starting or failure to start. Processing the wake-up signals of the charging port cover, charging pile, or charging gun connected to the VCU (or BMS) is key to solving the dark current problem of the VCU (or BMS) and the vehicle starting problem.

[0003] Currently, the conventional practice is that during AC charging, when the OBC and the power supply equipment are properly connected, the OBC outputs a low-voltage auxiliary power source of 14V or 24V to wake up the BMS, VCU, and instrument panel. After waking up the controllers, the vehicle's high-voltage system begins the power-on process. During DC charging, when the off-board charger control system receives the signal indicating that the charging gun is plugged in, the control system outputs low voltage (to prevent charging interruption or failure due to insufficient battery voltage), connecting A+ and A- to supply power to the electric vehicle's low-voltage power supply system to ensure successful charging of the vehicle, while simultaneously waking up the BMS, VCU, and instrument panel.

[0004] The above solution is a commonly used solution for charging wake-up and wake-up detection in the market. The specific charging requirements and charging power matching are all transmitted through the CAN bus. After charging is completed, the entire vehicle's electronic control system will go into sleep or power down. However, if the wake-up signal of the charging pile or OBC is abnormal, the wake-up source of the charging gun plug will continue to connect to the vehicle's VCU (or BMS) through the unplugged charging gun, causing the VCU (or BMS) to be unable to go into sleep. This will result in an excessive dark current in the vehicle, which may lead to the low-voltage battery being drained in severe cases. Alternatively, after charging is completed, certain operations may fail to wake up the VCU (or BMS), causing abnormal vehicle starting or failure to start. Utility Model Content

[0005] To address the aforementioned problems, a low-level pulse wake-up circuit is provided, aiming to solve the issues existing in the prior art.

[0006] The specific technical solution is as follows:

[0007] A low-level pulse wake-up circuit includes a low-level conversion circuit, a pulse wake-up circuit, a wake-up detection circuit, and an MCU self-locking circuit. The low-level conversion circuit receives an input low-level signal, converts it into a high-level signal, and inputs the high-level signal to the pulse conversion circuit. The pulse conversion circuit generates a pulse signal to wake up the Power IC. The wake-up detection circuit detects the voltage division value between the internal circuit of the VCU or BMS and the CC grounding resistor. The MCU self-locking circuit receives a self-locking signal output by the MCU, enabling and maintaining the EN signal of the Power IC.

[0008] The aforementioned low-level pulse wake-up circuit also has the following characteristics: the low-level conversion circuit includes a MOSFET Q1, a capacitor C1, resistors R1, R2, RC, R12, a switch S, and a switch S1. The source of the MOSFET Q1 is electrically connected to the external power supply VDD. The source of the MOSFET Q1 is electrically connected to its gate through the capacitor C1. The resistor R1 is connected in parallel across the capacitor C1. The gate of the MOSFET Q1 is grounded after passing through the resistor R2 and the switch S in sequence. The resistor RC and the switch S1 are connected in series and then in parallel across the switch S. The resistor R12 is connected in parallel across the switch S1. The drain of the MOSFET Q1 serves as the output terminal and is electrically connected to the input terminal of the pulse wake-up circuit.

[0009] The aforementioned low-level pulse wake-up circuit also has the following characteristics: the pulse wake-up circuit includes a MOSFET Q2, a diode D1, resistors R3 and R4, MOSFETs Q3 and Q4, resistors R5, R6, R7, and R8, capacitors C2 and C3. The drain of the MOSFET Q1 serves as the output terminal and is electrically connected to the drain of the MOSFET Q4 through resistor R5. The drain of the MOSFET Q1 is also sequentially electrically connected to the gate of the MOSFET Q4 through resistors R6 and R7. The common terminal of resistors R6 and R7 is electrically connected to the source of the MOSFET Q4 through capacitor C2. Capacitor C3 is connected in parallel with the diode. The drain of the MOSFET Q4 is electrically connected to its source via resistor R8. The source of MOSFET Q4 is grounded. The drain of MOSFET Q4 is electrically connected to the gate of MOSFET Q3. The source of MOSFET Q4 is electrically connected to the source of MOSFET Q3. The drain of MOSFET Q3 is electrically connected to the source of MOSFET Q2 via resistor R3. The drain of MOSFET Q3 is also electrically connected to the gate of MOSFET Q2 via resistor R4. The drain of MOSFET Q2 is electrically connected to the anode of diode D1. The cathode of diode D1 serves as the pulse signal output terminal. The source of MOSFET Q2 is electrically connected to the enable terminal of Power IC.

[0010] The aforementioned low-level pulse wake-up circuit also has the following features: the wake-up detection circuit includes a resistor R9, a diode D2, a resistor R10, and a capacitor C4. The anode of the diode D2 is electrically connected to the external power supply VCC through the capacitor C9. The anode of the diode D2 is also grounded after passing through the resistor R10 and the capacitor C4 in sequence. The cathode of the diode D2 is used to receive the signal from the charging port cover switch S. The common terminal of the resistor R10 and the capacitor C4 is used as a signal output terminal and electrically connected to the ADC terminal of the MCU.

[0011] The aforementioned low-level pulse wake-up circuit also has the following features: the MCU self-locking circuit includes a diode D3 and a resistor R11. The anode of the diode D3 is grounded through the resistor R11. The anode of the diode D3 serves as the input terminal and is electrically connected to the MCU. The cathode of the diode D3 serves as the output terminal and is electrically connected to the Power IC.

[0012] In summary, the beneficial effects of this scheme are:

[0013] In the low-level pulse wake-up circuit provided by this invention, a high-level signal is generated by a low-level conversion circuit and sent to the pulse wake-up circuit. The pulse wake-up circuit generates a wake-up enable signal ENP to wake up the Power IC, and the system begins normal operation. The MCU microcontroller outputs a self-locking signal on its GPIO pin, which is output to the GPIO port to enable and maintain the EN signal of the Power IC. The low-level pulse wake-up circuit provided by this invention does not affect the VCU (or BMS) sleep mode, nor does it affect subsequent wake-up sources from waking up the VCU or BMS, thus reducing the dark current of the entire vehicle after charging. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the low-level conversion circuit structure of the low-level pulse wake-up circuit of this utility model;

[0015] Figure 2 This is a schematic diagram of the pulse wake-up circuit structure of the low-level pulse wake-up circuit of this utility model;

[0016] Figure 3 This is a schematic diagram of the wake-up detection circuit structure of the low-level pulse wake-up circuit of this utility model;

[0017] Figure 4 This is a schematic diagram of the MCU self-locking circuit structure of the low-level pulse wake-up circuit of this utility model. Detailed Implementation

[0018] The technical solution of this utility model will be clearly and completely described below with reference to its embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0020] The present invention will be further described below with reference to specific embodiments, but this is not intended to limit the present invention.

[0021] Figure 1 This is a schematic diagram of the low-level conversion circuit structure of the low-level pulse wake-up circuit of this utility model. Figure 2 This is a schematic diagram of the pulse wake-up circuit structure of the low-level pulse wake-up circuit of this utility model. Figure 3 This is a schematic diagram of the wake-up detection circuit structure of the low-level pulse wake-up circuit of this utility model. Figure 4 This is a schematic diagram of the MCU self-locking circuit structure of the low-level pulse wake-up circuit of this utility model, as shown below. Figures 1-4 As shown, the low-level pulse wake-up circuit provided in this embodiment includes a low-level conversion circuit, a pulse wake-up circuit, a wake-up detection circuit, and an MCU self-locking circuit. The low-level conversion circuit receives the input low-level signal, converts it into a high-level signal, and inputs the high-level signal to the pulse conversion circuit. The pulse conversion circuit generates a pulse signal to wake up the Power IC. The wake-up detection circuit is used to detect the voltage division value between the internal circuit of the VCU or BMS and the CC grounding resistor. The MCU self-locking circuit receives the self-locking signal output by the MCU, enabling and maintaining the EN of the Power IC.

[0022] In the above embodiment, the low-level conversion circuit includes a MOSFET Q1, a capacitor C1, resistors R1, R2, RC, R12, a switch S, and a switch S1. The source of the MOSFET Q1 is electrically connected to the external power supply VDD. The source of the MOSFET Q1 is electrically connected to its gate through the capacitor C1. The resistor R1 is connected in parallel across the capacitor C1. The gate of the MOSFET Q1 is grounded after passing through the resistor R2 and the switch S in sequence. The resistor RC and the switch S1 are connected in series and then in parallel across the switch S. The resistor R12 is connected in parallel across the switch S1. The drain of the MOSFET Q1 is used as the output terminal and is electrically connected to the input terminal of the pulse wake-up circuit.

[0023] It should be noted that when S(CC) is low-level input (i.e. S is closed), resistors R1 and R2 and power supply VDD form a voltage divider circuit. At this time, MOSFET Q1 is in saturation conduction state, and the WKCTL terminal outputs a high level to provide power to the pulse wake-up circuit.

[0024] In the above embodiment, the pulse wake-up circuit includes a MOSFET Q2, a diode D1, resistors R3 and R4, MOSFETs Q3 and Q4, resistors R5, R6, R7, and R8, capacitors C2 and C3. The drain of MOSFET Q1 serves as the output terminal and is electrically connected to the drain of MOSFET Q4 via resistor R5. The drain of MOSFET Q1 is also sequentially connected to the gate of MOSFET Q4 via resistors R6 and R7. The common terminal of resistors R6 and R7 is electrically connected to the source of MOSFET Q4 via capacitor C2. Capacitor C3 is connected in parallel with capacitor C3. At terminals C2, the drain of MOSFET Q4 is electrically connected to its source via resistor R8. The source of MOSFET Q4 is grounded. The drain of MOSFET Q4 is electrically connected to the gate of MOSFET Q3. The source of MOSFET Q4 is electrically connected to the source of MOSFET Q3. The drain of MOSFET Q3 is electrically connected to the source of MOSFET Q2 via resistor R3. The drain of MOSFET Q3 is also electrically connected to the gate of MOSFET Q2 via resistor R4. The drain of MOSFET Q2 is electrically connected to the anode of diode D1. The cathode of diode D1 serves as the pulse signal output terminal. The source of MOSFET Q2 is electrically connected to the enable terminal of the Power IC.

[0025] It should be noted that after a high-level input, MOSFET Q3 and MOSFET Q2 are both in saturation, waking up the Power IC. Simultaneously, the pulse wake-up circuit, upon inputting a high-level WKCTL to the level conversion circuit, charges capacitors C2 and C3 through resistor R6. After a time τ = R × C, the charging voltage at the gate of MOSFET Q4 reaches the conduction threshold, at which point MOSFET Q4 turns on, and MOSFET Q3 changes from on to off. At the same time, the voltage at the gate of MOSFET Q2 is pulled high by resistors R3 and R4, causing Q2 to change from on to off, and ENP changes from high to low. During this process, a wide pulse is generated, waking up the VCU or BMS.

[0026] In the above embodiment, the wake-up detection circuit includes a resistor R9, a diode D2, a resistor R10, and a capacitor C4. The anode of the diode D2 is electrically connected to the external power supply VCC through the capacitor C9. The anode of the diode D2 is also grounded after passing through the resistor R10 and the capacitor C4 in sequence. The cathode of the diode D2 is used to receive the signal from the charging port cover switch S. The common terminal of the resistor R10 and the capacitor C4 is used as the signal output terminal and electrically connected to the ADC terminal of the MCU.

[0027] It should be noted that the wake-up detection circuit can perform two functions: first, to detect the source of the wake-up; and second, to detect the resistance value of the CC signal wake-up resistor RC.

[0028] When the charging port cover S signal (or CC signal) is not connected (S disconnected), the VCU (or BMS) cannot be woken up, the microcontroller does not start working, and the wake-up detection function cannot be performed.

[0029] When the charging port cover is connected to the S signal (S closed), the VCU (or BMS) is awakened, VCC=5V is supplied normally, and the system works; the microcontroller's IO and ADC ports function normally. After S is closed, the power supply VCC=5V, resistor R9=1K, resistor R10=20K, and capacitor C4=100nF form a series filter circuit. The voltage V1 at detection point 1 is pulled down to GND by switch S, so V1=Vd2=0.3V;

[0030] When another wake-up source wakes up the VCU (or BMS), the power supply VCC=5V, resistor R9=1K, resistor R10=20K, and capacitor C4=100nF form a series filter circuit, and the voltage at detection point 1 is V1=VCC=5V.

[0031] When the CC signal is input (S1 closed), that is, when the charging gun is fully inserted and the connection is reliable, the CC signal switch S1 closes, grounding the resistor RC. For VCU (or BMS) detection, the grounding resistance of the CC signal changes from floating to RC. The RC resistance value for slow charging is specified by national standards and can be 100Ω, 220Ω, 680Ω, or 1.5kΩ (RC accuracy is ±3%). At the same time, the VCU (or BMS) is awakened, VCC=5V is supplied normally, and the system works; the microcontroller IO and ADC ports function normally. After S is closed, the power supply VCC=5V, resistor R9=1K, diode D2, and resistor RC form a series circuit, so the voltage at detection point 1 V1 = (5V-Vd2)*RC / (RC+R9) + Vd2 = (5V*RC+1000Vd2) / (RC+1000).

[0032] In the above embodiment, the MCU self-locking circuit includes a diode D3 and a resistor R11. The anode of the diode D3 is grounded through the resistor R11. The anode of the diode D3 is electrically connected to the MCU as an input terminal, and the cathode of the diode D3 is electrically connected to the PowerIC as an output terminal.

[0033] It should be noted that after the VCU or BMS is woken up, the GPIO outputs a high level to the wake-up source ENP, keeping the power supply VCC continuously output, thus achieving a self-holding function. Specifically, the GPIO outputs a high-level (self-locking) signal, diode D3 is turned on, meaning the Power IC ENP pin is at a high level. At this time, regardless of whether other wake-up source input signals are present or lost, this high-level signal is maintained by the MCU's output GPIO. When charging is complete and the vehicle needs to be powered down or put into sleep mode, this can be controlled by software. When the VCU (or BMS) needs to be woken up again, or when multiple wake-up sources wake up the VCU (or BMS), the pulse wake-up circuit works again, repeating the above wake-up process.

[0034] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the content of the present utility model specification should be included within the protection scope of the present utility model.

Claims

1. A low-level pulse wake-up circuit, characterized in that: It includes a low-level conversion circuit, a pulse wake-up circuit, a wake-up detection circuit, and an MCU self-locking circuit. The low-level conversion circuit receives the input low-level signal, converts it into a high-level signal, and inputs the high-level signal to the pulse conversion circuit. The pulse conversion circuit generates a pulse signal to wake up the Power IC. The wake-up detection circuit is used to detect the voltage division value between the internal circuit of the VCU or BMS and the CC grounding resistor. The MCU self-locking circuit receives the self-locking signal output by the MCU, enabling and maintaining the EN of the Power IC.

2. The low-level pulse wake-up circuit according to claim 1, characterized in that: The low-level conversion circuit includes a MOSFET Q1, a capacitor C1, resistors R1, R2, RC, R12, a switch S, and a switch S1. The source of the MOSFET Q1 is electrically connected to the external power supply VDD. The source of the MOSFET Q1 is electrically connected to its gate through the capacitor C1. The resistor R1 is connected in parallel across the capacitor C1. The gate of the MOSFET Q1 is grounded after passing through the resistor R2 and the switch S. The resistor RC and the switch S1 are connected in series and then in parallel across the switch S. The resistor R12 is connected in parallel across the switch S1. The drain of the MOSFET Q1 serves as the output terminal and is electrically connected to the input terminal of the pulse wake-up circuit.

3. The low-level pulse wake-up circuit according to claim 2, characterized in that: The pulse wake-up circuit includes a MOSFET Q2, a diode D1, resistors R3 and R4, MOSFET Q1, resistors R5, R6, R7, and R8, capacitors C2 and C3. The drain of MOSFET Q1 serves as the output terminal and is electrically connected to the drain of MOSFET Q4 via resistor R5. The drain of MOSFET Q1 is also sequentially connected to the gate of MOSFET Q4 via resistors R6 and R7. The common terminal of resistors R6 and R7 is electrically connected to the source of MOSFET Q4 via capacitor C2. Capacitor C3 is connected in parallel across capacitor C2. The drain of MOSFET Q4 is electrically connected to its source through resistor R8. The source of MOSFET Q4 is grounded. The drain of MOSFET Q4 is electrically connected to the gate of MOSFET Q3. The source of MOSFET Q4 is electrically connected to the source of MOSFET Q3. The drain of MOSFET Q3 is electrically connected to the source of MOSFET Q2 through resistor R3. The drain of MOSFET Q3 is also electrically connected to the gate of MOSFET Q2 through resistor R4. The drain of MOSFET Q2 is electrically connected to the anode of diode D1. The cathode of diode D1 serves as the pulse signal output terminal. The source of MOSFET Q2 is electrically connected to the enable terminal of Power IC.

4. The low-level pulse wake-up circuit according to claim 2, characterized in that: The wake-up detection circuit includes a resistor R9, a diode D2, a resistor R10, and a capacitor C4. The anode of the diode D2 is electrically connected to the external power supply VCC through the capacitor C9. The anode of the diode D2 is also grounded after passing through the resistor R10 and the capacitor C4 in sequence. The cathode of the diode D2 is used to receive the signal from the charging port cover switch S. The common terminal of the resistor R10 and the capacitor C4 is used as a signal output terminal and electrically connected to the ADC terminal of the MCU.

5. A low-level pulse wake-up circuit according to claim 4, characterized in that: The MCU self-locking circuit includes a diode D3 and a resistor R11. The anode of the diode D3 is grounded through the resistor R11. The anode of the diode D3 serves as the input terminal and is electrically connected to the MCU. The cathode of the diode D3 serves as the output terminal and is electrically connected to the Power IC.

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