Low-voltage detection circuit and system in sleep scene

Abstract

The utility model discloses a low-voltage detection circuit and system in a dormant scene, and the circuit comprises a voltage division circuit which is connected with the voltage input of a storage battery, obtains a divided voltage after the voltage is reduced through a resistor voltage division circuit, and outputs the divided voltage to a comparison circuit; the comparison circuit is used for receiving the input reference voltage, comparing the reference voltage with the divided voltage and outputting a comparison state to the MCU detection circuit; and the MCU detection circuit is connected with the comparison circuit and is used for detecting the comparison state output by the comparison circuit. After the electronic equipment is dormant, the voltage of the storage battery of the vehicle can be detected without waking up the electronic equipment, and once the voltage reaches the threshold value set by the comparator, IO interruption wakes up the electronic equipment, so that the problem that the low voltage of the vehicle cannot be detected after the electronic equipment is dormant is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle voltage detection, in particular to a low-voltage detection circuit and system in a dormant scenario. Background Art

[0002] Currently, many automotive electronic devices will detect the vehicle's battery voltage. When low voltage is detected, they will optimize their own power usage, such as reducing the power of the entire machine to reduce the impact on the entire vehicle; or notify the user to charge in time.

[0003] To prevent the vehicle from being unable to start after being parked for a long time, the car manufacturer will control the sleep current of the electrical equipment (electronic equipment) on the vehicle. For example, after sleep, the current cannot exceed 3mA and other requirements. However, this does not mean that the electrical equipment (electronic equipment) on the vehicle is not consuming power, but it consumes less power. Usually, the way electronic equipment detects the voltage of the entire vehicle is through resistor voltage division, and then gives it to the MCU for AD acquisition, and then converts it to the actual voltage. However, after the electronic equipment is in sleep, the AD acquisition function is usually not used. After sleep, if you want to know the current voltage of the entire vehicle, you must first wake up the electronic equipment, then perform AD acquisition, and finally convert it to the actual vehicle voltage. However, once the electronic equipment is woken up, the operating current is relatively large. If it happens too many times, the vehicle battery is more likely to fail, which is obviously inappropriate. Utility Model Content

[0004] The main purpose of the utility model is to propose a low voltage detection circuit and system in a sleep scenario, which overcomes the shortcomings of the existing technology and solves the problem that the electronic device cannot detect low voltage in the vehicle after sleep.

[0005] The utility model adopts the following technical solutions:

[0006] In one aspect, a low voltage detection circuit in a sleep scenario includes:

[0007] The voltage divider circuit is connected to the battery voltage input, and the voltage is reduced by the resistor voltage divider circuit to obtain the divided voltage, which is output to the comparison circuit;

[0008] The comparison circuit receives the input reference voltage, compares the reference voltage with the divided voltage, and outputs the comparison status to the MCU detection circuit;

[0009] The MCU detection circuit is connected to the comparison circuit and detects the comparison state output by the comparison circuit.

[0010] Preferably, the voltage divider circuit includes: a first resistor and a second resistor; one end of the first resistor is connected to the level voltage input, and the connection point between the other end of the first resistor and one end of the second resistor is connected to an input end of the comparison circuit; the other end of the second resistor is grounded.

[0011] Preferably, the voltage divider circuit further includes: a first capacitor; the first capacitor is connected in parallel with the second resistor.

[0012] Preferably, the comparison circuit includes: a comparator; the positive input terminal of the comparator is connected to the voltage divider circuit, and the reverse input terminal of the comparator is connected to the reference voltage, or the reverse input terminal of the comparator is connected to the voltage divider circuit, and the positive input terminal of the comparator is connected to the reference voltage; the output terminal of the comparator is connected to the MCU detection circuit.

[0013] Preferably, the voltage divider circuit further includes: a fourth resistor; one end of the fourth resistor is connected to the DC voltage, and the other end is connected to the comparator.

[0014] Preferably, the voltage divider circuit further includes: a third resistor and a second capacitor; the third resistor is connected in parallel with the second capacitor; one end of the third resistor is grounded, and the other end of the third resistor and the connection point of the fourth resistor are connected to the comparator.

[0015] Preferably, the MCU detection circuit includes: an MCU; an input end of the MCU is connected to an output end of a voltage divider circuit; and an output end of the MCU is connected to an electronic device and / or a communication module.

[0016] On the other hand, a low voltage detection system in a sleep scenario includes the low voltage detection circuit and an electronic device; the MCU detection circuit is connected to the electronic device to interrupt and wake up the electronic device when a change in the status of the MCU's IO port is detected.

[0017] Preferably, the low voltage detection system in the sleep scenario further includes a communication module; the MCU detection circuit is connected to the communication module.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] The utility model can detect the vehicle battery voltage without waking up the electronic device after the electronic device is dormant. Once the threshold value set by the comparator is reached, the IO interrupt wakes up the electronic device, solving the problem that the electronic device cannot detect low vehicle voltage after dormant.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention so that it can be implemented in accordance with the contents of the specification, and to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below.

[0021] Based on the following detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other purposes, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a low voltage detection circuit diagram in a sleep scenario according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic structural diagram of a low voltage detection system in a sleep scenario according to an embodiment of the present invention;

[0024] Description of labels:

[0025] 1. Low voltage detection circuit; 10. Voltage divider circuit; 11. Comparison circuit; 12. MCU detection circuit; 2. Communication module; 3. MPU. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0028] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "sleeved / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be a connection between the two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] See also Figure 1 As shown, the utility model provides a low voltage detection circuit 1 in a sleep scenario, comprising:

[0031] The voltage divider circuit 10 is connected to BAT_IN, and the voltage is reduced by the resistor voltage divider circuit to obtain the divided voltage, which is output to the comparison circuit 11;

[0032] The comparison circuit 11 receives the input reference voltage Ref, compares the reference voltage Ref with the divided voltage, and outputs the comparison status to the MCU detection circuit 12;

[0033] The MCU detection circuit 12 is connected to the comparison circuit 11 and detects the comparison state output by the comparison circuit 11 .

[0034] Specifically, the voltage divider circuit 10 includes: a first resistor R1 and a second resistor R2; one end of the first resistor R1 is connected to BAT_IN, and the connection point between the other end of the first resistor R1 and one end of the second resistor R2 is connected to an input end of the comparison circuit 11; the other end of the second resistor R2 is grounded.

[0035] Furthermore, the voltage divider circuit 10 further includes: a first capacitor C1; the first capacitor C1 is connected in parallel with the second resistor R2.

[0036] Specifically, the comparison circuit 11 includes: a comparator U1; the positive input terminal of the comparator U1 is connected to the voltage divider circuit 10, and the reverse input terminal of the comparator U1 is connected to the reference voltage Ref, or the reverse input terminal of the comparator U1 is connected to the voltage divider circuit 10, and the positive input terminal of the comparator U1 is connected to the reference voltage Ref; the output terminal of the comparator U1 is connected to the MCU detection circuit 12.

[0037] Furthermore, the voltage divider circuit 10 further includes: a fourth resistor R4; one end of the fourth resistor R4 is connected to the DC voltage MCU_3V3, and the other end is connected to the comparator U1.

[0038] Furthermore, the voltage divider circuit 10 also includes: a third resistor R3 and a second capacitor C2; the third resistor R3 and the second capacitor C2 are connected in parallel; one end of the third resistor R3 is grounded, and the other end of the third resistor R3 and the connection point of the fourth resistor R4 are connected to the comparator U1.

[0039] Specifically, the MCU detection circuit 12 includes: an MCU; an input end of the MCU is connected to an output end of the voltage divider circuit 10; and an output end of the MCU is connected to an electronic device and / or a communication module.

[0040] As described above, after the vehicle BAT_IN, the low-voltage detection circuit 1 of the present invention is stepped down by the resistor divider circuit 10 and then fed to the voltage comparator U1 (op amp). If the divided voltage is lower than the reference voltage Ref, the output state of the comparator U1 is flipped, and the MCU detects that the IO port state has changed (the rising edge trigger or the falling edge trigger can also be set according to the actual situation), and an interrupt is triggered to wake up the electronic device.

[0041] This embodiment provides a low-voltage detection system in a dormant state, comprising the low-voltage detection circuit 1 and an electronic device. The MCU detection circuit 12 is connected to the electronic device to interrupt and wake up the electronic device upon detecting a change in the status of an MCU IO port. After waking up, the electronic device can optimize its power usage, such as shutting down all controllable power supplies or even its own power consumption.

[0042] Furthermore, the low voltage detection system in the sleep scenario further includes a communication module 2 ; the MCU detection circuit 12 is connected to the communication module 2 .

[0043] See also Figure 2 Figure 1 shows a low-voltage detection system for a multimedia screen in a sleep state. The MCU detection circuit 12 is connected to the multimedia screen's MPU 3 via serial communication. Upon detecting a change in the MCU's IO port status, the MPU 3 is interrupted and woken up. After waking up, the multimedia screen can optimize its power usage, such as shutting down all controllable power supplies or even its own power consumption.

[0044] In addition, the MCU detection circuit 12 is connected to the communication module 2 via serial communication to remotely notify the user to charge in time to avoid the vehicle being unable to start.

[0045] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any person skilled in the art who, within the technical scope disclosed in the present invention, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of the present invention shall be covered by the scope of protection of the present invention.

Claims

1. A low voltage detection circuit in a sleep scenario, characterized in that: include: The voltage divider circuit is connected to the battery voltage input, and the voltage is reduced by the resistor voltage divider circuit to obtain the divided voltage, which is output to the comparison circuit; The comparison circuit receives the input reference voltage, compares the reference voltage with the divided voltage, and outputs the comparison status to the MCU detection circuit; The MCU detection circuit is connected to the comparison circuit and detects the comparison state output by the comparison circuit.

2. The low voltage detection circuit in a sleep scenario according to claim 1, characterized in that: The voltage divider circuit includes: a first resistor and a second resistor; one end of the first resistor is connected to the level voltage input, and the connection point between the other end of the first resistor and one end of the second resistor is connected to an input end of the comparison circuit; the other end of the second resistor is grounded.

3. The low voltage detection circuit in a sleep scenario according to claim 2, characterized in that: The voltage divider circuit further includes: a first capacitor; the first capacitor is connected in parallel with the second resistor.

4. The low voltage detection circuit in a sleep scenario according to claim 1, characterized in that: The comparison circuit includes: a comparator; the positive input terminal of the comparator is connected to the voltage divider circuit, and the reverse input terminal of the comparator is connected to the reference voltage, or the reverse input terminal of the comparator is connected to the voltage divider circuit, and the positive input terminal of the comparator is connected to the reference voltage; the output terminal of the comparator is connected to the MCU detection circuit.

5. The low voltage detection circuit in a sleep scenario according to claim 4, characterized in that: The voltage divider circuit further includes: a fourth resistor; one end of the fourth resistor is connected to the DC voltage, and the other end is connected to the comparator.

6. The low voltage detection circuit in a sleep scenario according to claim 5, characterized in that: The voltage divider circuit further includes: a third resistor and a second capacitor; the third resistor and the second capacitor are connected in parallel; one end of the third resistor is grounded, and the other end of the third resistor and the connection point of the fourth resistor are connected to the comparator.

7. The low voltage detection circuit in a sleep scenario according to claim 1, characterized in that: The MCU detection circuit includes: an MCU; an input end of the MCU is connected to an output end of a voltage divider circuit; and an output end of the MCU is connected to an electronic device and / or a communication module.

8. A low voltage detection system in a dormant scenario, characterized in that: The low voltage detection circuit comprises the low voltage detection circuit as claimed in any one of claims 1 to 7, and also comprises an electronic device; the MCU detection circuit is connected to the electronic device to interrupt and wake up the electronic device when a change in the state of the MCU's IO port is detected.

9. The low voltage detection system in a sleep scenario according to claim 8, characterized in that: It also includes a communication module; the MCU detection circuit is connected to the communication module.

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