An MCU sleep / wake-up circuit
By implementing hierarchical control of signal circuits and transistors, low-power sleep mode and reliable wake-up of the MCU are achieved, solving the problems of increased current and system instability in the MCU sleep mode, extending battery life and improving system reliability and automation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JHETECH
- Filing Date
- 2025-05-29
- Publication Date
- 2026-05-26
Smart Images
Figure CN224277067U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle control circuits, specifically to an MCU sleep / wake-up circuit. Background Technology
[0002] Currently, in-vehicle devices such as dashboard lighting and in-vehicle communication systems, which need to operate when the car is not running and have low power consumption, are typically powered by the vehicle's low-voltage battery. These electronic devices are controlled by a control unit (MCU). The MCU is powered by a low-dropout regulator (LDO) connected to the battery. Activating the MCU to control in-vehicle devices when the vehicle enters sleep mode is essential for achieving automated and intelligent vehicle control.
[0003] Currently used vehicle MCUs, even in sleep mode, require their monitoring modules to remain partially operational to ensure timely response to vehicle control signals. This increases the MCU's sleep current, putting a strain on the vehicle battery and impacting its lifespan. Other methods for achieving MCU sleep performance require complex circuitry or control software logic, increasing the risk of MCU errors, reducing system reliability, and sometimes preventing the MCU from resuming operation from sleep mode, rendering the vehicle unresponsive. Summary of the Invention
[0004] The purpose of this application is to overcome the shortcomings of the prior art and provide an MCU sleep-wake-up circuit that can reduce system complexity and achieve low-power sleep and reliable wake-up of the control unit MCU.
[0005] Another technical solution to achieve the above objective is: an MCU sleep / wake-up circuit, including a signal circuit, a second sleep control transistor Q2, a first hierarchical sleep control transistor Q1, an LDO chip U, and a control unit MCU;
[0006] The output terminal of the signal circuit outputs a wake-up signal.
[0007] The second sleep control transistor Q2 is an NPN transistor. The base of the second sleep control transistor Q2 is connected to the output terminal of the signal circuit through the current limiting resistor R4 to receive the wake-up signal, grounded through the voltage divider resistor R9, and connected to the enable terminal ENA through the current limiting resistor R3. The enable terminal ENA is also connected to the control unit MCU. The emitter of the second sleep control transistor Q2 is grounded. The collector of the second sleep control transistor Q2 outputs a control signal to control the conduction and shutdown of the first stage sleep control transistor Q1.
[0008] The first hibernation control transistor Q1 is a PNP transistor. The control signal output by the second hibernation control transistor Q2 is input to the first hibernation control transistor Q1 through a bias voltage divider circuit composed of the first bias voltage divider resistor R1 and the second bias voltage divider resistor R2. The emitter of the first hibernation control transistor Q1 is connected to the power supply VIN. The collector of the first hibernation control transistor Q1 outputs the power supply voltage to the input pin IN of the LDO chip U to control the start and stop of the LDO chip U.
[0009] The LDO chip U outputs the operating voltage to the control unit MCU via its output pin OUT, which powers the control unit MCU. When the control unit MCU is working, it outputs a high level to the enable pin ENA.
[0010] The above technical solution achieves hierarchical MCU sleep control through the second sleep control transistor Q2 and the first hierarchical sleep control transistor Q1. In sleep mode, the MCU is completely powered off, ensuring low power consumption and extending battery life. When the vehicle equipment generates a signal, the vehicle equipment signal triggers a wake-up signal that turns on the second sleep control transistor Q2, which in turn controls the first hierarchical sleep control transistor Q1 to power on the MCU. This enables reliable and efficient triggering of vehicle signals and vehicle wake-up. After waking up, the MCU, now in working mode, sends a high level to the enable terminal ENA to take over the conduction control of the entire sleep-wake-up circuit, achieving autonomous control and thus completing the system wake-up.
[0011] Preferably, the signal circuit includes several signal input channels, each of which is connected to a corresponding signal input terminal. When any signal input channel sends a signal to the signal input terminal, the signal circuit outputs a wake-up signal.
[0012] Preferably, each signal input terminal is connected to an anti-reverse diode.
[0013] The above technical solution enables the input terminal of the signal circuit to accept various types of vehicle signals, achieving diversified and multimodal wake-up signals. Furthermore, multiple signal input channels provide expansion space for the vehicle system; other vehicle signals can be included in the signal circuit as needed, thereby increasing the signal sources for waking up the vehicle. Anti-reverse diodes are used for isolation to prevent transient reverse voltage.
[0014] Preferably, a filter capacitor C8 is connected between the output terminal of the signal circuit and the emitter of the second sleep control transistor Q2.
[0015] Preferably, an input filter capacitor is connected between the collector of the first stage sleep control transistor Q1 and the input pin IN of the LDO chip U; an output filter capacitor is connected between the output pin OUT of the LDO chip U and the control unit MCU.
[0016] The above technical solutions achieve AC filtering, smooth DC output, and suppress noise and interference.
[0017] Preferably, the control unit MCU includes a timer module. The control unit MCU is connected to the output terminal of the signal circuit. The timer module records the time during which the signal circuit does not output a wake-up signal and the control unit MCU stops working. This time is recorded as the sleep time. If the sleep time reaches a preset limit, the control unit MCU outputs a low level to the enable terminal ENA.
[0018] The above technical solution enables the automatic shutdown of the second sleep control transistor Q2 after the MCU stops working and no new vehicle signal input generates a wake-up signal, thereby shutting off the first sleep control transistor Q1 and stopping power supply to the MCU. This achieves automated sleep mode without manual control or software program control.
[0019] In summary, this application includes at least one of the following beneficial technical effects:
[0020] 1. The MCU sleep-wake circuit of this application can realize hierarchical control of the MCU sleep-wake. The MCU in sleep state can completely stop power supply, which reduces the operating current of the system, reduces the power burden of the vehicle battery, and improves the life of the vehicle battery.
[0021] 2. This application implements sleep and wake-up control of the control unit MCU based on a simple circuit structure. The control is achieved entirely through the signal connection of circuit devices, without the need for software programs, algorithms or manual control, thus improving the reliability of the sleep and wake-up circuit.
[0022] 3. This application provides expansion space for the vehicle system, and the newly added vehicle signal system can be easily woken up and controlled by the control unit MCU through the signal circuit.
[0023] 4. This application can automatically enter sleep mode after the MCU stops working and no new vehicle signal input generates a wake-up signal, thereby improving the automation and intelligence of the vehicle system. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of an MCU sleep / wake-up circuit according to an embodiment of this application. Detailed Implementation
[0025] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of this application.
[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that in the optional embodiments of this application, the object information and other related data involved require the permission or consent of the object when the embodiments of this application are applied to specific products or technologies, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. That is to say, if the embodiments of this application involve data related to the object, it needs to be obtained with the authorization and consent of the object, the authorization and consent of the relevant departments, and in compliance with the relevant laws, regulations, and standards of the country and region. If personal information is involved in the embodiments, the acquisition of all personal information requires the consent of the individual. If sensitive information is involved, the separate consent of the information subject is required, and the embodiments also need to be implemented with the authorization and consent of the object.
[0027] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.
[0028] Please see Figure 1 The present application discloses an MCU sleep / wake-up circuit, which includes a signal circuit, a second sleep control transistor Q2, a first hierarchical sleep control transistor Q1, an LDO chip U, and a control unit MCU (not shown in the figure).
[0029] The output terminal of the signal circuit outputs a wake-up signal.
[0030] More specifically, in the embodiments of this application, the signal circuit consists of six signal input channels, namely Input1, Input2, Input3, Input4, Input5, and Input6. Each signal channel receives a different vehicle signal to trigger the wake-up of the control unit MCU. The signal can be a normally high or normally low level signal or a PWM signal. Unused signal channels can serve as backup channels for the vehicle system. When a new vehicle system signal is connected, it can be accessed through the backup channel to the signal circuit.
[0031] More specifically, the signal circuit includes integrated diodes D1 and D2, each of which integrates an independent diode. The diodes are configured to correspond one-to-one with the signal input terminals of the Input1, Input2, Input3, Input4, Input5, and Input6 signal channels, serving as anti-reverse diodes for the signal channels.
[0032] When a vehicle model is sent to the signal input terminal through any signal input channel, the signal circuit outputs a wake-up signal through the anti-reverse diode.
[0033] It should be noted that this embodiment is merely an illustrative example of the technical solution of this application and is not intended to limit the number of signal channels, their configuration, or the configuration of the anti-reverse diodes. In practical applications, technicians can modify the configuration as needed, and any circuit architecture that uses signal circuits for vehicle wake-up signal output falls within the protection scope of this application.
[0034] The second sleep control transistor Q2 is an NPN transistor. Its base is connected to the output of the signal circuit via a current-limiting resistor R4 to receive the wake-up signal, grounded via a voltage divider resistor R9, and connected to the enable terminal ENA via a current-limiting resistor R3. The enable terminal ENA is then connected to the control unit MCU. The emitter of the second sleep control transistor Q2 is grounded. The collector of the second sleep control transistor Q2 outputs a control signal to control the on / off state of the first stage sleep control transistor Q1. More specifically, a filter capacitor C8 is connected between the output of the signal circuit and the emitter of the second sleep control transistor Q2.
[0035] When the signal circuit outputs a wake-up signal, the signal passes through the current-limiting resistor R4 and the voltage-dividing resistor R9, which turns on the second sleep control transistor Q2 and outputs a control signal to the outside.
[0036] The first-stage sleep control transistor Q1 is a PNP transistor. The wake-up signal output by the second sleep control transistor Q2 is input to the first-stage sleep control transistor Q1 through a bias voltage divider circuit composed of the first bias voltage divider resistor R1 and the second bias voltage divider resistor R2. The emitter of the first sleep control transistor Q1 is connected to the power supply VIN, and the collector of the first sleep control transistor Q1 outputs the supply voltage to the input pin IN of the LDO chip U, controlling the turn-on and turn-off of the LDO chip U. More specifically, input filter capacitors C10, C11, C12, and C13 are connected between the collector of the first-stage sleep control transistor Q1 and the input pin IN of the LDO chip U. Each capacitor has a different capacitance, realizing multi-stage filtering.
[0037] After receiving power, the LDO chip U begins normal operation, outputting a stable operating voltage to the control unit MCU via its output pin OUT. In this embodiment, this is a 5V operating voltage. At this time, the control unit MCU is awakened. More specifically, output filter capacitors C15, C16, and C17 are connected between the output pin OUT of the LDO chip U and the control unit MCU. Each capacitor has a different capacitance, achieving multi-stage filtering.
[0038] Furthermore, the enable terminal ENA is connected to the I / O port of the control unit MCU. After the control unit MCU starts working, it outputs a high level to the enable terminal ENA, thereby taking over the entire circuit system, ensuring the conduction of the second sleep control transistor Q2, which in turn turns on the first stage sleep control transistor Q1, ensuring that the LDO continuously outputs the working voltage to the MCU, thus achieving autonomous control.
[0039] In another embodiment, the control unit MCU includes a timer module. The control unit MCU is connected to the output terminal of the signal circuit. During operation, it monitors the wake-up signal output of the signal circuit. The timer module records the duration during which the signal circuit continuously outputs no wake-up signal and the control unit MCU stops working; this is recorded as the sleep time. In this embodiment, the sleep time is 2 seconds. In practical applications, the sleep time can be customized and adjusted according to actual needs. When Input1, Input2, Input3, Input4, Input5, and Input6 have no input signals, there is no wake-up signal output, and the timer module starts timing from the point where no signal is detected. Simultaneously, if the control unit MCU has no working process and stops working, the timer module also starts timing. If, at any point during the sleep time, the signal circuit generates a wake-up signal and / or the control unit MCU starts working, the timing restarts. If there is no wake-up signal output and the MCU of the control unit stops working for 2 seconds, the MCU outputs a low level to the enable terminal ENA after 2 seconds. Since there is no wake-up signal output from the signal circuit at the same time, it is also at a low level. Therefore, the second sleep control transistor Q2 does not conduct, which in turn causes the first sleep control transistor Q1 to also not conduct. The LDO chip U has no power input and stops working, so it does not output a 5V working voltage. This causes the MCU to lose power and stop working. At this point, all circuits are shut down and enter sleep mode until a new vehicle signal input signal circuit outputs a wake-up signal.
[0040] More specifically, the power supply VIN is connected to the positive terminal of the car battery through the BAT terminal, and the ground terminal GND is connected to the negative terminal of the car battery. BAT and GND are always connected to the battery and are continuously energized. The BAT terminal is equipped with protection circuits such as reverse power supply protection circuit, overcurrent protection circuit, EMC protection capacitor, and TVS surge protection circuit.
[0041] Unless otherwise stated, pins not explicitly described in the circuit diagrams of this application (such as power supply pin VCC, ground pin GND, enable pin ENA, etc.) are connected in accordance with the conventional methods used by those skilled in the art, and such connections do not constitute a limitation on the technical solution of this utility model. Passive components such as decoupling capacitors and pull-up / pull-down resistors not shown in the figures are connected in accordance with general specifications for electronic circuit design (such as IEEE standards), and specific parameters can be adjusted according to the actual application scenario.
[0042] Those skilled in the art will understand that Figure 1 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the electronic device to which the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.
[0043] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0044] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model 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 utility model, and should all be included within the protection scope of this utility model.
Claims
1. An MCU sleep wake-up circuit, comprising: Includes signal circuitry, second sleep control transistor Q2, first stage sleep control transistor Q1, LDO chip U, and control unit MCU; The output terminal of the signal circuit outputs a wake-up signal. The second sleep control transistor Q2 is an NPN transistor. The base of the second sleep control transistor Q2 is connected to the output terminal of the signal circuit through the current limiting resistor R4 to receive the wake-up signal, grounded through the voltage divider resistor R9, and connected to the enable terminal ENA through the current limiting resistor R3. The enable terminal ENA is also connected to the control unit MCU. The emitter of the second sleep control transistor Q2 is grounded. The collector of the second sleep control transistor Q2 outputs a control signal to control the conduction and shutdown of the first stage sleep control transistor Q1. The first hibernation control transistor Q1 is a PNP transistor. The control signal output by the second hibernation control transistor Q2 is input to the first hibernation control transistor Q1 through a bias voltage divider circuit composed of the first bias voltage divider resistor R1 and the second bias voltage divider resistor R2. The emitter of the first hibernation control transistor Q1 is connected to the power supply VIN. The collector of the first hibernation control transistor Q1 outputs the power supply voltage to the input pin IN of the LDO chip U to control the start and stop of the LDO chip U. The LDO chip U outputs the operating voltage to the control unit MCU via its output pin OUT, which powers the control unit MCU. When the control unit MCU is working, it outputs a high level to the enable pin ENA.
2. The MCU hibernate wake-up circuit of claim 1, wherein, The signal circuit includes several signal input channels, each of which is connected to a corresponding signal input terminal. When any signal input channel sends a signal to the signal input terminal, the signal circuit outputs a wake-up signal.
3. The MCU hibernate wake-up circuit of claim 2, wherein, For any given signal input terminal, a reverse protection diode is connected.
4. The MCU hibernate wake-up circuit of claim 1, wherein, A filter capacitor C8 is connected between the output terminal of the signal circuit and the emitter of the second sleep control transistor Q2.
5. The MCU hibernate wake-up circuit of claim 1, wherein, An input filter capacitor is connected between the collector of the first-stage sleep control transistor Q1 and the input pin IN of the LDO chip U; an output filter capacitor is connected between the output pin OUT of the LDO chip U and the control unit MCU.
6. The MCU hibernate wake-up circuit of claim 1, wherein, The control unit MCU includes a timer module. The control unit MCU is connected to the output terminal of the signal circuit. The timer module records the time during which the signal circuit does not output a wake-up signal and the control unit MCU stops working. This time is recorded as the sleep time. If the sleep time reaches the preset time limit, the control unit MCU outputs a low level to the enable terminal ENA.