Battery switching circuit and vehicle-mounted controller

Abstract

The utility model provides a battery switching circuit and a vehicle-mounted controller, the battery switching circuit is applied to the vehicle-mounted controller, the vehicle-mounted controller comprises a microcontroller, a working power supply and a battery, and the vehicle-mounted controller is at least connected with one load; the battery switching circuit comprises a first triode, a first PMOS (P-channel Metal Oxide Semiconductor) transistor, a second PMOS transistor and a boosting chip, a base electrode of the first triode is connected with a starting enable signal of the microcontroller, and a collector electrode of the first triode is connected with a grid electrode of the first PMOS transistor; the source electrode of the first PMOS transistor is connected with the battery; the drain electrode of the first PMOS transistor is connected with the source electrode of the second PMOS transistor; the grid electrode of the second PMOS transistor is connected with the output end of the working power supply; the drain electrode of the second PMOS transistor is connected with the voltage input pin of the boost chip, and the voltage output pin of the boost chip is connected with a load. According to the battery switching circuit, timely and rapid switching of the system power supply and the battery can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle-mounted controllers, and in particular to a battery switching circuit and a vehicle-mounted controller. Background Art

[0002] When a vehicle breaks down or an accident occurs, the onboard controller needs to make a one-button alarm and upload the vehicle's current status and alarm information to obtain rescue. However, when the vehicle power network fails, it is necessary to switch to the backup battery; since the backup battery is used very rarely, in order to ensure that it will not fail during the switch, a backup battery switching management circuit needs to be set up to manage the charging, discharging and switching of the backup battery.

[0003] Most of the current backup battery switching circuits do not have a factory mode, that is, the backup battery powers the device for a period of time before leaving the factory. Even if the device is in a low-power state, the backup battery is in a long-term discharge state, causing the backup battery to be in a feeding state, affecting its service life and affecting the normal discharge of the battery. In particular, when a vehicle breaks down, the backup battery switching will fail, resulting in the inability of people in the car to implement one-click rescue in time. Utility Model Content

[0004] In view of this, the present application proposes a battery switching circuit and a vehicle-mounted controller, which can realize the normal switching of the system power supply and the backup battery, and can also prevent the backup battery from discharging before being installed on the vehicle, causing damage to the battery power supply, affecting the normal operation of the equipment, and improving the stability and reliability of the vehicle-mounted controller.

[0005] In a first aspect, an embodiment of the present application provides a battery switching circuit, which is applied to a vehicle-mounted controller, wherein the vehicle-mounted controller includes a microcontroller, a working power supply and a battery, and the vehicle-mounted controller is connected to at least one load; the battery switching circuit includes: a first transistor, a first PMOS transistor, a second PMOS transistor and a boost chip, wherein the base of the first transistor is connected to the start enable pin of the microcontroller, and the collector of the first transistor is connected to the gate of the first PMOS transistor; the source of the first PMOS transistor is connected to the battery; the drain of the first PMOS transistor is connected to the source of the second PMOS transistor; the gate of the second PMOS transistor is connected to the output end of the working power supply; the drain of the second PMOS transistor is connected to the voltage input pin of the boost chip, and the voltage output pin of the boost chip is connected to the load, wherein the first voltage output by the battery is less than the second voltage output by the working power supply.

[0006] In one possible implementation, when the on-board controller is in a power-off state, the startup enable pin of the microcontroller does not output a signal, the first transistor is not turned on, the first PMOS transistor is not turned on, and the battery does not supply power.

[0007] In one possible implementation, when the on-board controller is in a powered-on state, the startup enable pin of the microcontroller outputs a high voltage, the first transistor is turned on, the first PMOS transistor is turned on, the second PMOS transistor is not turned on, and the battery is not powered.

[0008] In one possible implementation, when the second voltage output by the working power supply drops to 0V, the first transistor is turned on, the first PMOS transistor is turned on, the second PMOS transistor is turned on, the first voltage of the battery enters the boost chip, and the voltage output pin of the boost chip outputs the second voltage.

[0009] In one possible implementation, the battery switching circuit also includes: a second transistor, a third PMOS transistor, a charging management chip and a battery voltage acquisition circuit; the gate of the second transistor is connected to the charging enable pin of the microcontroller; the collector of the second transistor is connected to the gate of the third PMOS transistor; the source of the third PMOS transistor is connected to the output end of the working power supply; the drain of the third PMOS transistor is connected to the voltage input pin of the charging management chip; the battery pin of the charging management chip is connected to the battery; and the battery voltage acquisition circuit is respectively connected to the battery and the microcontroller.

[0010] In one possible implementation, the battery voltage acquisition circuit includes: a first resistor and a second resistor, wherein the first end of the first resistor is connected to the battery, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the battery ADC pin of the microcontroller.

[0011] In one possible implementation, when the battery is in a charging state, the microcontroller obtains the battery voltage through the battery ADC pin, and determines whether the battery voltage is less than a preset voltage threshold. If not, the charging enable pin of the microcontroller is set to a low voltage so that the second transistor and the third PMOS transistor are not turned on, thereby stopping charging of the battery.

[0012] In one possible implementation, the battery is connected to the vehicle controller via a plug-in, and a battery NTC pin of the microcontroller is connected to the plug-in.

[0013] In one possible implementation, when the battery is in a charging state, the microcontroller obtains the temperature of the battery through the battery NTC pin, and determines whether the temperature of the battery is greater than a preset temperature threshold. If so, the charging enable pin of the microcontroller is set to a low voltage so that the second transistor and the third PMOS transistor are not turned on, thereby stopping charging of the battery.

[0014] In a second aspect, an embodiment of the present application provides a vehicle-mounted controller, including: a battery switching circuit of an embodiment of the present application.

[0015] The battery switching circuit of the present application can realize timely and rapid switching between system power supply and battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the working principle of the battery and power supply of the existing vehicle-mounted controller of the embodiment of the present application;

[0017] Figure 2 A schematic diagram of a battery switching circuit according to an embodiment of the present application;

[0018] Figure 3 A schematic diagram of a battery charging circuit according to an embodiment of the present application;

[0019] Figure 4 Schematic diagram of a battery temperature acquisition circuit according to an embodiment of the present application.

[0020] Figure ID:

[0021] D1: first diode; D2: second diode;

[0022] Q1: first transistor; Q2: first PMOS transistor; Q3: second PMOS transistor;

[0023] U1: boost chip; Q4: second transistor; Q5: third PMOS transistor;

[0024] U2: charging management chip; R1: first resistor; R2: second resistor; JP1: plug-in. DETAILED DESCRIPTION

[0025] Various aspects and features of the present application are described herein with reference to the accompanying drawings.

[0026] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present application will occur to those skilled in the art.

[0027] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0028] These and other characteristics of the present application will become apparent from the following description of a preferred form of embodiment given as a non-limiting example with reference to the accompanying drawings.

[0029] It should also be understood that although the present application has been described with reference to some specific examples, those skilled in the art will be able to readily implement many other equivalent forms of the present application.

[0030] The above and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings.

[0031] Specific embodiments of the present application are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments applied for are merely examples of the present application, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that obscure the present application. Therefore, the specific structural and functional details applied for herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present application in a variety of ways with substantially any suitable detailed structure.

[0032] This specification may use the phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present application.

[0033] First, the design concept of the embodiments of the present application is briefly introduced.

[0034] The backup battery of the vehicle controller is used very rarely. To ensure that it does not fail when power switching is required, a backup battery switching management circuit needs to be set up to implement backup battery switching. Figure 1 As shown, the current switching between the backup battery and the system power network is achieved through two parallel diodes. The anti-reverse characteristics of the diodes are used to achieve that when the main power supply is cut off, the backup battery directly takes over the power network, so that the equipment is powered by the backup battery without affecting the normal operation of the equipment.

[0035] Most of the current backup battery switching circuits do not have a factory mode, that is, the backup battery is powering the device for a period of time before leaving the factory. Even if the device has a low-power function, the backup battery is in a long-term discharge state. If the device does not have a factory mode and has been placed in the warehouse for a long time without being installed on the vehicle to charge the battery in time, the backup battery is in a long-term feeding state, which seriously affects the service life and the normal discharge of the battery. When a vehicle fails, the backup battery switching fails, and the people in the car will not be able to request rescue in time with one click.

[0036] In order to solve the above problems, this application provides a vehicle controller backup battery switching circuit with a factory mode, which can not only meet the switching function of the system power supply and the backup battery, but also prevent the backup battery from discharging before being installed on the vehicle, causing damage to the battery feed and affecting the normal operation of the equipment. This circuit improves the charge and discharge management of the backup battery, adds a factory mode, can effectively improve the stability and safety of the vehicle controller, effectively protect the health of the battery, effectively avoid possible economic losses, and increase product competitiveness.

[0037] After introducing the application scenarios and design concepts of the embodiments of the present application, the technical solutions provided by the embodiments of the present application are described below.

[0038] like Figure 2 As shown, an embodiment of the present application provides a battery switching circuit, which is applied to an on-board controller, wherein the on-board controller includes a microcontroller MCU, a working power supply and a battery, and the on-board controller is connected to at least one load; the battery switching circuit includes: a first transistor Q1, a first PMOS (positive channel Metal Oxide Semiconductor, P-channel metal oxide semiconductor) transistor Q2, a second PMOS transistor Q3 and a boost chip U1, wherein the base of the first transistor Q1 is connected to the startup enable (MCU_BOOST_EN) pin of the microcontroller, and the collector of the first transistor Q1 is connected to the gate of the first PMOS transistor Q2; the source of the first PMOS transistor Q2 is connected to the battery ( Figure 2 The drain of the first PMOS transistor Q2 is connected to the source of the second PMOS transistor Q3; the gate of the second PMOS transistor Q3 is connected to the output end of the working power supply ( Figure 2 5VDCDC); the drain of the second PMOS transistor Q3 is connected to the voltage input (VIN) pin of the boost chip U1, and the voltage output (VOUT) pin of the boost chip U1 is connected to the load, wherein the first voltage output by the battery is less than the second voltage output by the working power supply.

[0039] Exemplarily, the first voltage output by the battery is 3.6V, and the second voltage output by the working power supply is 5V.

[0040] When the vehicle controller is in a power-off state (not powered on), the startup enable pin of the microcontroller does not output a signal, the first transistor Q1 is not turned on, the first PMOS transistor Q2 is in a state, and the battery does not supply power.

[0041] When the on-board controller is in the power-on state, the startup enable pin of the microcontroller outputs a high voltage, the first transistor Q1 is turned on, the first PMOS transistor Q2 is turned on, and because the first voltage output by the battery is less than the second voltage output by the working power supply, the second PMOS transistor Q3 is disconnected and the battery does not supply power.

[0042] When the second voltage output by the working power supply drops to 0V, the first transistor Q1 is turned on, the first PMOS transistor Q2 is turned on, and since the first voltage output by the battery is greater than 0, the second PMOS transistor Q3 is turned on, the first voltage of the battery enters the boost chip U1, and the voltage output pin of the boost chip U1 outputs the second voltage.

[0043] like Figure 3 As shown, the battery switching circuit also includes: a second transistor Q4, a third PMOS transistor Q5, a charging management chip U2 and a battery voltage acquisition circuit; the gate of the second transistor is connected to the charging enable (MCU_Charge_EN) pin of the microcontroller; the collector of the second transistor Q4 is connected to the gate of the third PMOS transistor Q5; the source of the third PMOS transistor Q5 is connected to the working power supply ( Figure 3 The output end of the 5VDCDC in the charging management chip; the drain of the third PMOS transistor is connected to the voltage input (VIN) pin of the charging management chip; the battery (BAT) pin of the charging management chip is connected to the battery; the battery voltage acquisition circuit is respectively connected to the battery ( Figure 3 3.6V_BAT) and the microcontroller in the .

[0044] like Figure 3 As shown, the battery voltage acquisition circuit includes: a first resistor R1 and a second resistor R2, the first end of the first resistor R1 is connected to the battery 3.6V_BAT, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the battery ADC (Battery_MCU_ADC) pin of the microcontroller.

[0045] When the battery is in a charging state; the microcontroller obtains the battery voltage through the battery ADC pin, and determines whether the battery voltage is less than a preset voltage threshold. If not, the charging enable pin of the microcontroller is set to a low voltage so that the second transistor Q4 and the third PMOS transistor Q5 are both not turned on, so that the battery stops charging.

[0046] In this embodiment, the battery voltage acquisition circuit and the microcontroller control the voltage of the charging enable pin, thereby effectively preventing the battery from being overcharged.

[0047] When the battery is not in a charging state, the microcontroller obtains the battery voltage through the battery ADC pin, determines whether the battery voltage is less than a preset voltage threshold, and if so, sets the charging enable pin of the microcontroller to a high voltage, so that the second transistor Q4 and the third PMOS transistor Q5 are both turned on, so that the battery enters charging. Thus, the battery can be charged in time when the battery power is low.

[0048] like Figure 4 As shown, the battery is connected to pin 1 of plug-in JP1, connected to the PCBA (integrated printed circuit board) of the vehicle controller through plug-in JP1, and the battery NTC (Battery_MCU_NTC) pin of the microcontroller is connected to pin 3 of the plug-in.

[0049] When the battery is in a charging state; the microcontroller obtains the battery temperature through the battery NTC pin, and determines whether the battery temperature is greater than a preset temperature threshold. If so, the charging enable pin of the microcontroller is set to a low voltage so that the second transistor Q4 and the third PMOS transistor Q5 are not turned on, so that the battery stops charging.

[0050] In a second aspect, an embodiment of the present application provides a vehicle-mounted controller, including: a battery switching circuit of an embodiment of the present application.

[0051] Since the vehicle-mounted controller of this embodiment includes the battery switching circuit of the embodiment of the present application, it has the technical advantages of high stability and reliability.

[0052] In addition, although illustrative embodiments are described herein, the scope includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., combinations of schemes across various embodiments), adjustments, or variations based on the present disclosure. The elements in the claims are to be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the continuation of this application. In addition, the steps of the disclosed methods may be modified in any way, including by reordering steps or inserting or deleting steps. Therefore, it is intended that the description be viewed merely as an example, with the true scope being represented by the following claims and their full range of equivalents.

[0053] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. After reading the above description, other embodiments may be used by a person of ordinary skill in the art, for example. Moreover, in the above detailed description, various features may be combined together to simplify the present disclosure. This should not be interpreted as intending that the disclosed features that are not requested for protection are essential to any claim. Therefore, the following claims are incorporated into the specific implementation as examples or embodiments, wherein each claim itself is a separate embodiment, and it is expected that these embodiments may be combined with each other in various combinations or permutations. The scope of the present utility model should be determined with reference to the attached claims and the full scope of equivalents given by these claims.

Claims

1. A battery switching circuit, applied to a vehicle-mounted controller, the vehicle-mounted controller comprising a microcontroller, a working power supply and a battery, the vehicle-mounted controller being connected to at least one load; characterized in that: The battery switching circuit includes: a first triode, a first PMOS transistor, a second PMOS transistor and a boost chip, wherein the base of the first triode is connected to the start enable pin of the microcontroller, the collector of the first triode is connected to the gate of the first PMOS transistor; the source of the first PMOS transistor is connected to the battery; the drain of the first PMOS transistor is connected to the source of the second PMOS transistor; the gate of the second PMOS transistor is connected to the output end of the working power supply; the drain of the second PMOS transistor is connected to the voltage input pin of the boost chip, and the voltage output pin of the boost chip is connected to the load, wherein the first voltage output by the battery is less than the second voltage output by the working power supply.

2. The battery switching circuit according to claim 1, characterized in that: The battery switching circuit also includes: a second transistor, a third PMOS transistor, a charging management chip and a battery voltage acquisition circuit; the gate of the second transistor is connected to the charging enable pin of the microcontroller; the collector of the second transistor is connected to the gate of the third PMOS transistor; the source of the third PMOS transistor is connected to the output end of the working power supply; the drain of the third PMOS transistor is connected to the voltage input pin of the charging management chip; the battery pin of the charging management chip is connected to the battery; and the battery voltage acquisition circuit is respectively connected to the battery and the microcontroller.

3. The battery switching circuit according to claim 2, characterized in that: The battery voltage acquisition circuit includes: a first resistor and a second resistor, wherein the first end of the first resistor is connected to the battery, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the battery ADC pin of the microcontroller.

4. The battery switching circuit according to claim 2, characterized in that: The battery is connected to the vehicle-mounted controller via a plug-in, and the battery NTC pin of the microcontroller is connected to the plug-in.

5. A vehicle-mounted controller, characterized in that: include: The battery switching circuit according to any one of claims 1 to 4.

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