Low quiescent current control circuit based on multiple wake-up signal sources

Abstract

The utility model discloses a low quiescent current control circuit based on multiple wake-up signal sources, and relates to the field of automobile low quiescent current control, in which a whole vehicle storage battery is used for providing a power supply for a CAN bus transceiver and a low dropout regulator LDO; the CAN bus transceiver is used for accessing an external wake-up signal and a CAN network signal, and outputting a high level signal to the low dropout regulator LDO when detecting the external wake-up signal or the CAN network signal; the low dropout regulator LDO is activated after receiving the high level signal, and is used for converting a power supply provided by a storage battery of the whole vehicle into a logic level voltage in an activated state and outputting the logic level voltage to the MCU controller; in other words, the control circuit can intelligently activate or close the LDO according to the external wake-up signal or the CAN network signal, the mechanism ensures that electric energy is provided for the MCU controller only at the necessary moment, and quiescent current consumption when the system is in a standby state is effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of low static current control in automobiles, and in particular to a low static current control circuit based on multiple wake-up signal sources. Background Technology

[0002] After a car is turned off, although most electronic devices disconnect power to save energy, some control devices need to remain in standby mode to respond to user commands at any time. These devices include remote unlocking systems and alarm systems, which rely on battery power to maintain standby mode. The current consumed during this standby mode is called quiescent current. During prolonged parking, the continuous consumption of quiescent current can deplete the battery, preventing the vehicle from starting. Therefore, reducing quiescent current consumption when the vehicle is locked is crucial for extending vehicle standby time and is a key factor in improving user experience and product competitiveness.

[0003] Traditional methods for reducing quiescent current mainly include selecting low-power chips and increasing resistor values ​​to limit the current in the circuit. However, this approach has certain limitations: on the one hand, the quiescent power consumption of the chip must be strictly considered when selecting it, which may limit design flexibility; on the other hand, while reducing current by increasing resistors is effective, it may require additional components and complex circuit designs, thereby increasing costs and development time. Utility Model Content

[0004] To reduce the static current consumption when the vehicle is locked, this invention proposes a low static current control circuit based on multiple wake-up signal sources, including:

[0005] The vehicle battery, CAN bus transceiver, low dropout linear regulator (LDO), and MCU controller; among which:

[0006] The vehicle battery is used to provide power to the CAN bus transceiver and the low dropout linear regulator (LDO).

[0007] The CAN bus transceiver is used to access external wake-up signals and CAN network signals, and outputs a high-level signal to the low dropout linear regulator (LDO) when an external wake-up signal or CAN network signal is detected.

[0008] The low-dropout linear regulator (LDO) is activated upon receiving the high-level signal. In the activated state, it converts the power supply provided by the vehicle battery into a logic level voltage and outputs it to the MCU controller.

[0009] Furthermore, the external wake-up signal includes:

[0010] Ignition signal IGN and body control module wake-up signal KL87.

[0011] Furthermore, the CAN network signals include:

[0012] The CAN bus transmits differential signal pairs: CAN_H signal and CAN_L signal; where:

[0013] The CAN_H signal is a high-level signal on the CAN bus;

[0014] The CAN_L signal is a low-level signal on the CAN bus.

[0015] Furthermore, the CAN bus transceiver includes:

[0016] The first chip U1 and the voltage divider unit, wherein:

[0017] The voltage divider unit is used to receive an external wake-up signal and input the voltage level of the external wake-up signal to the first chip U1 after adjusting the voltage level of the external wake-up signal.

[0018] The first chip U1 is used to access CAN network signals and outputs a high-level signal to the low-dropout linear regulator LDO when an external wake-up signal or CAN network signal is detected.

[0019] Furthermore, the voltage divider unit includes:

[0020] The system consists of a first diode D1, a second diode D2, a second resistor R2, a fourth resistor R4, and a sixth resistor R6. The positive terminal of the first diode D1 is connected to the ignition signal IGN, and the negative terminal is connected to one end of the second resistor R2. The positive terminal of the second diode D2 is connected to the body control module wake-up signal KL87, and the negative terminal is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the other end of the second resistor R2 and one end of the sixth resistor R6, and then connected to the first chip U1. The other end of the sixth resistor R6 is grounded to the negative terminal of the vehicle battery.

[0021] Furthermore, the first chip U1 includes:

[0022] The wake-up pin, WAKE, is connected to the other end of the fourth resistor R4 in the voltage divider unit.

[0023] The CANH pin is used to connect the CAN_H signal;

[0024] The CANL pin is used to connect the CAN_L signal;

[0025] The power supply pin VS is connected to the positive terminal of the vehicle battery.

[0026] The enable control pin INH is connected to the low dropout linear regulator LDO; when the first chip U1 detects an external wake-up signal through the wake-up pin WAKE, or detects a CAN network signal through the CANH and CANL pins, the enable control pin INH is pulled high.

[0027] Furthermore, the low-dropout linear regulator (LDO) includes:

[0028] The second chip U2 includes:

[0029] The input pin IN is connected to the positive terminal of the vehicle's battery.

[0030] The output pin VOUT is connected to the power supply pin VCC of the third chip U3 in the MCU controller;

[0031] The enable pin EN is connected to the enable control pin INH in the first chip U1.

[0032] Furthermore, when the enable control pin INH is pulled high, it outputs a high-level signal to the enable pin EN. At this time, the output pin VOUT of the second chip U2 outputs a logic level voltage to the power supply pin VCC of the third chip U3 in the MCU controller.

[0033] Furthermore, the third chip U3 also includes:

[0034] The AD pin is connected to one end of both the first resistor R1 and the third resistor R3; the other end of the first resistor R1 is connected to the positive terminal of the vehicle battery, and the other end of the third resistor R3 is connected to the negative terminal of the vehicle battery and grounded.

[0035] Furthermore, the GND pins of the first chip U1, the second chip U2, and the third chip U3 are all grounded to the negative terminal of the vehicle battery.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] (1) In this utility model, the vehicle battery is used to provide power to the CAN bus transceiver and the low dropout linear regulator (LDO); the CAN bus transceiver is used to access external wake-up signals and CAN network signals, and outputs a high-level signal to the LDO when it detects an external wake-up signal or a CAN network signal; the LDO is activated after receiving the high-level signal, and in the activated state, it converts the power supply provided by the vehicle battery into a logic level voltage and outputs it to the MCU controller; that is, the control circuit can intelligently activate or deactivate the LDO according to the external wake-up signal or the CAN network signal. This mechanism ensures that the MCU controller is provided with power only when necessary, effectively reducing the static current consumption when the system is in standby mode.

[0038] (2) This utility model integrates a CAN bus transceiver to process different types of wake-up signals (including ignition signals and body control module signals), which increases the flexibility and adaptability of the circuit, enabling the control circuit to respond to diverse operating scenarios and enhancing the user experience.

[0039] (3) This utility model avoids the traditional method of reducing static current by requiring the selection of specific low-power chips or the increase of resistance value to limit the current, simplifies the circuit design process, reduces the number of required components, and thus reduces the research and development and production costs.

[0040] (4) This utility model uses a low dropout linear regulator (LDO) to convert the battery voltage into a stable logic level voltage, ensuring that the MCU controller can be provided with a stable operating voltage even when the input voltage fluctuates, thus improving the reliability of the entire circuit. Attached Figure Description

[0041] Figure 1 This is a circuit diagram for a low static current control system based on multiple wake-up signal sources. Detailed Implementation

[0042] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0043] To reduce the static current consumption when the vehicle is locked, such as Figure 1 As shown, this utility model proposes a low quiescent current control circuit based on multiple wake-up signal sources, including:

[0044] The vehicle battery, CAN bus transceiver, low dropout linear regulator (LDO), and MCU controller; among which:

[0045] The vehicle battery is used to provide power to the CAN bus transceiver and the low dropout linear regulator (LDO).

[0046] The CAN bus transceiver is used to access external wake-up signals and CAN network signals, and outputs a high-level signal to the low dropout linear regulator (LDO) when an external wake-up signal or CAN network signal is detected.

[0047] The external wake-up signal includes:

[0048] Ignition signal IGN and body control module wake-up signal KL87.

[0049] The CAN network signals include:

[0050] The CAN bus transmits differential signal pairs: CAN_H signal and CAN_L signal; where:

[0051] The CAN_H signal is a high-level signal on the CAN bus;

[0052] The CAN_L signal is a low-level signal on the CAN bus.

[0053] The differential signal pairs transmitted by the CAN bus represent the data and commands exchanged between various electronic control units within the vehicle.

[0054] The CAN bus transceiver includes:

[0055] The first chip U1 and the voltage divider unit, wherein:

[0056] The voltage divider unit is used to receive an external wake-up signal and input the voltage level of the external wake-up signal to the first chip U1 after adjusting the voltage level of the external wake-up signal.

[0057] The voltage divider unit includes:

[0058] The system consists of a first diode D1, a second diode D2, a second resistor R2, a fourth resistor R4, and a sixth resistor R6. The positive terminal of the first diode D1 is connected to the ignition signal IGN, and the negative terminal is connected to one end of the second resistor R2. The positive terminal of the second diode D2 is connected to the body control module wake-up signal KL87, and the negative terminal is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the other end of the second resistor R2 and one end of the sixth resistor R6, and then connected to the first chip U1. The other end of the sixth resistor R6 is grounded to the negative terminal of the vehicle battery.

[0059] The main function of the second resistor R2 and the fourth resistor R4 in the voltage divider unit is to adjust the voltage levels of the IGN and KL87 signals to a suitable range for the input pins (Wake pin) of the CAN bus transceiver. For example, if the voltage of the IGN or KL87 signal is too high, the second resistor R2 and the fourth resistor R4 can reduce the voltage of the signal to meet the requirements of the CAN bus transceiver. The sixth resistor R6 is used to stabilize the IGN or KL87 signal in the presence of fluctuations.

[0060] Additionally, in the voltage divider unit:

[0061] D1: Used to protect the circuit from reverse voltage of the IGN signal.

[0062] D2: Used to protect the circuit from reverse voltage of the KL87 signal.

[0063] The first chip U1 is used to access CAN network signals and outputs a high-level signal to the low-dropout linear regulator LDO when an external wake-up signal or CAN network signal is detected.

[0064] The first chip U1 includes:

[0065] The wake-up pin, WAKE, is connected to the other end of the fourth resistor R4 in the voltage divider unit.

[0066] The CANH pin is used to connect the CAN_H signal;

[0067] The CANL pin is used to connect the CAN_L signal;

[0068] The power supply pin VS is connected to the positive terminal of the vehicle battery.

[0069] The enable control pin INH is connected to the low dropout linear regulator LDO; when the first chip U1 detects an external wake-up signal through the wake-up pin WAKE, or detects a CAN network signal through the CANH and CANL pins, the enable control pin INH is pulled high.

[0070] The low-dropout linear regulator (LDO) is activated upon receiving the high-level signal. In the activated state, it converts the power supply provided by the vehicle battery into a logic level voltage and outputs it to the MCU controller.

[0071] The low-dropout linear regulator (LDO) includes:

[0072] The second chip U2 includes:

[0073] The input pin IN is connected to the positive terminal of the vehicle battery; it is used to connect an unregulated input voltage. In this application scenario, this pin is connected to the 9-16V power supply provided by the vehicle battery.

[0074] The output pin VOUT is connected to the power supply pin VCC of the third chip U3 in the MCU controller; that is, it is used to provide a stable output voltage (logic level voltage) after being regulated by the LDO. In this embodiment, the LDO converts the input voltage into a 5V voltage for use by the MCU controller.

[0075] The enable pin EN is connected to the enable control pin INH in the first chip U1.

[0076] The third chip U3 also includes:

[0077] The AD pin is connected to one end of both the first resistor R1 and the third resistor R3; the other end of the first resistor R1 is connected to the positive terminal of the vehicle battery, and the other end of the third resistor R3 is connected to the negative terminal of the vehicle battery and grounded.

[0078] The GND pins of the first chip U1, the second chip U2, and the third chip U3 are all grounded to the negative terminal of the vehicle battery.

[0079] When the enable control pin INH is pulled high, it outputs a high-level signal to the enable pin EN. At this time, the output pin VOUT of the second chip U2 outputs a logic level voltage to the power supply pin VCC of the third chip U3 in the MCU controller.

[0080] This invention proposes a low quiescent current control circuit based on multiple wake-up signal sources, aiming to reduce the quiescent current consumption of a vehicle when locked. The control circuit includes a vehicle battery, a low-dropout linear regulator (LDO), an MCU controller, and a CAN bus transceiver. The vehicle battery provides a power supply of 9 to 16 volts, while the LDO converts this voltage to a stable 5-volt output for the MCU controller. By recognizing external wake-up signals or CAN network signals, the circuit can intelligently control the LDO's enable pin (EN), thereby effectively managing the power supply to the MCU controller and its subsequent circuits, ultimately reducing the overall quiescent current of the controller.

[0081] Specifically, the IGN and KL87 signals pass through anti-reverse diodes D1 and D2, respectively, and are then adjusted by a voltage divider unit composed of resistors R2, R4, and R6 before being transmitted to the WAKE pin of the CAN bus transceiver (model SIT1043QT). Simultaneously, the CANH and CANL pins of the CAN bus transceiver are connected to the CAN bus to receive and transmit CAN network signals. When the WAKE pin of the CAN bus transceiver detects a high-level signal, or when its CANH and CANL pins receive a CAN network signal, the INH pin of U1 is pulled high, outputting a high-level signal to the EN pin of the LDO. This activates the LDO, and its output pin VOUT outputs a 5-volt voltage, powering the MCU controller and waking up the entire control circuit to enter operating mode.

[0082] Conversely, if the WAKE pin of the CAN bus transceiver fails to detect a high-level signal, and its CANH and CANL pins do not receive any CAN network signal within a set time, the INH pin of U1 will be pulled low, causing the EN pin of the LDO to go low. At this time, the VOUT pin of the LDO stops outputting 5 volts, cutting off the power supply to the MCU controller and its subsequent drive circuit modules, effectively shutting down the current consumption of these devices, and achieving the goal of significantly reducing the static current consumption of the entire circuit in sleep mode. This design not only improves the reliability and adaptability of the circuit, but also significantly reduces the risk of battery depletion due to static current consumption during long-term parking.

[0083] In the low quiescent current control circuit of this embodiment, a drive module is also provided, which is communicatively connected to the MCU controller. For details of the connection relationship, please refer to [link to relevant documentation]. Figure 1 This driver module is a downstream circuit of the MCU controller. It executes instructions issued by the MCU controller, such as controlling various actuators in a vehicle (e.g., relays, motors). It amplifies signals or provides the necessary power output to achieve effective control of specific equipment.

[0084] This invention addresses the problems in the prior art by intelligently managing power supply in standby mode. Specifically, it utilizes the coordinated operation of the vehicle battery, CAN bus transceiver, low-dropout linear regulator (LDO), and MCU controller. Based on external wake-up signals or CAN network signals, it dynamically controls the LDO's enable pin (EN), thereby effectively managing the power supply to the MCU controller and its subsequent circuits. When no external wake-up signal or CAN network signal is detected, the LDO stops outputting voltage, cutting off power to the MCU controller and subsequent circuits, significantly reducing static current consumption. This method not only avoids the design limitations and increased costs associated with using low-static-power chips in traditional solutions but also eliminates the need for methods such as increasing resistor values, simplifying circuit design, reducing the number of components used, lowering R&D and production costs, and simultaneously improving system reliability and flexibility.

[0085] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0086] Furthermore, in this invention, descriptions involving terms such as "first," "second," and "a" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0087] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0088] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A low quiescent current control circuit based on multiple wake-up signal sources, characterized in that, include: The vehicle battery, CAN bus transceiver, low dropout linear regulator (LDO), and MCU controller; among which: The vehicle battery is used to provide power to the CAN bus transceiver and the low dropout linear regulator (LDO). The CAN bus transceiver is used to access external wake-up signals and CAN network signals, and outputs a high-level signal to the low dropout linear regulator (LDO) when an external wake-up signal or CAN network signal is detected. The low-dropout linear regulator (LDO) is activated upon receiving the high-level signal. In the activated state, it converts the power supply provided by the vehicle battery into a logic level voltage and outputs it to the MCU controller.

2. The low quiescent current control circuit based on multiple wake-up signal sources according to claim 1, characterized in that, The external wake-up signal includes: Ignition signal IGN and body control module wake-up signal KL87.

3. The low quiescent current control circuit based on multiple wake-up signal sources according to claim 1, characterized in that, The CAN network signals include: The CAN bus transmits differential signal pairs: CAN_H signal and CAN_L signal; where: The CAN_H signal is a high-level signal on the CAN bus; The CAN_L signal is a low-level signal on the CAN bus.

4. A low quiescent current control circuit based on multiple wake-up signal sources according to any one of claims 2 or 3, characterized in that, The CAN bus transceiver includes: The first chip U1 and the voltage divider unit, wherein: The voltage divider unit is used to receive an external wake-up signal and input the voltage level of the external wake-up signal to the first chip U1 after adjusting the voltage level of the external wake-up signal. The first chip U1 is used to access CAN network signals and outputs a high-level signal to the low-dropout linear regulator LDO when an external wake-up signal or CAN network signal is detected.

5. A low quiescent current control circuit based on multiple wake-up signal sources according to claim 4, characterized in that, The voltage divider unit includes: The system consists of a first diode D1, a second diode D2, a second resistor R2, a fourth resistor R4, and a sixth resistor R6. The positive terminal of the first diode D1 is connected to the ignition signal IGN, and the negative terminal is connected to one end of the second resistor R2. The positive terminal of the second diode D2 is connected to the body control module wake-up signal KL87, and the negative terminal is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the other end of the second resistor R2 and one end of the sixth resistor R6, and then connected to the first chip U1. The other end of the sixth resistor R6 is grounded to the negative terminal of the vehicle battery.

6. A low quiescent current control circuit based on multiple wake-up signal sources according to claim 5, characterized in that, The first chip U1 includes: The wake-up pin, WAKE, is connected to the other end of the fourth resistor R4 in the voltage divider unit. The CANH pin is used to connect the CAN_H signal; The CANL pin is used to connect the CAN_L signal; The power supply pin VS is connected to the positive terminal of the vehicle battery. The enable control pin INH is connected to the low dropout linear regulator LDO; when the first chip U1 detects an external wake-up signal through the wake-up pin WAKE, or detects a CAN network signal through the CANH and CANL pins, the enable control pin INH is pulled high.

7. A low quiescent current control circuit based on multiple wake-up signal sources according to claim 6, characterized in that, The low-dropout linear regulator (LDO) includes: The second chip U2 includes: The input pin IN is connected to the positive terminal of the vehicle's battery. The output pin VOUT is connected to the power supply pin VCC of the third chip U3 in the MCU controller; The enable pin EN is connected to the enable control pin INH in the first chip U1.

8. A low quiescent current control circuit based on multiple wake-up signal sources according to claim 7, characterized in that, When the enable control pin INH is pulled high, it outputs a high-level signal to the enable pin EN. At this time, the output pin VOUT of the second chip U2 outputs a logic level voltage to the power supply pin VCC of the third chip U3 in the MCU controller.

9. A low quiescent current control circuit based on multiple wake-up signal sources according to claim 8, characterized in that, The third chip U3 also includes: The AD pin is connected to one end of both the first resistor R1 and the third resistor R3; the other end of the first resistor R1 is connected to the positive terminal of the vehicle battery, and the other end of the third resistor R3 is connected to the negative terminal of the vehicle battery and grounded.

10. A low quiescent current control circuit based on multiple wake-up signal sources according to claim 8, characterized in that, The GND pins of the first chip U1, the second chip U2, and the third chip U3 are all grounded to the negative terminal of the vehicle battery.

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