CN218040820U - Power supply circuit, battery management system, battery pack and electronic device - Google Patents

Abstract

The embodiment of the application provides a power supply circuit, a battery management system, a battery pack and an electronic device. The power supply circuit comprises a controller, a first voltage reduction module, a second voltage reduction module and a third voltage reduction module. The first voltage reduction module is electrically connected with the controller and is configured to be electrically connected with the anode of the external battery cell module. The second voltage reduction module is electrically connected with the first voltage reduction module and the controller respectively. The third voltage reduction module is electrically connected with the controller and the second voltage reduction module respectively and is configured to be electrically connected with a positive electrode of the external battery cell module. The first voltage reduction module is turned off and the third voltage reduction module is turned on in response to the controller outputting a first control signal, or the first voltage reduction module is turned on and the third voltage reduction module is turned off in response to the controller outputting a second control signal.

Description

Power supply circuit, battery management system, battery pack and electronic device

Technical Field

The embodiment of the application relates to the field of electrical technology, in particular to a power supply circuit, a battery management system, a battery pack and an electronic device.

Background

The battery management system can carry out high-efficient management to the battery cell module through parts such as controller, and the battery management system still includes the supply circuit who supplies power to parts such as controller, and supply circuit acquires voltage from the battery cell module, through voltage processing, obtains the supply voltage of parts such as controller.

The existing power supply circuit adopts a direct current to direct current (DC-DC) voltage reduction chip with higher cost, when an electric core module discharges normally, the DC-DC voltage reduction chip reduces the voltage of the electric core module to supply power for a controller and other modules of a battery management system, but when the battery management system is in a dormant state, the DC-DC voltage reduction chip cannot meet the requirement of low power consumption.

SUMMERY OF THE UTILITY MODEL

In view of the above, embodiments of the present disclosure provide a power supply circuit, a battery management system, a battery pack and an electronic device, so as to at least improve the above problems.

According to a first aspect of embodiments herein, a power supply circuit is provided. The power supply circuit includes: the voltage-reducing circuit comprises a controller, a first voltage-reducing module, a second voltage-reducing module and a third voltage-reducing module. The first voltage reduction module is electrically connected with the controller and is configured to be electrically connected with a positive electrode of an external battery cell module and reduce the voltage output by the external battery cell module; the second voltage reduction module is electrically connected with the first voltage reduction module and the controller respectively and is configured to reduce the voltage input to the second voltage reduction module so as to supply power to the controller; the third voltage reduction module is electrically connected with the controller and the second voltage reduction module, is configured to be electrically connected to the positive electrode of the external cell module, reduces the voltage output by the external cell module, and outputs the voltage to the second voltage reduction module. The first voltage reduction module is turned off and the third voltage reduction module is turned on in response to the controller outputting a first control signal; or, in response to the controller outputting the second control signal, the first voltage reduction module is turned on, and the third voltage reduction module is turned off.

In another implementation manner of the embodiment of the present application, the power supply circuit further includes a control module, and the control module is electrically connected to the controller and the third voltage reduction module, respectively. The control module receives the first control signal to enable the third voltage reduction module to be conducted, or the control module receives the second control signal to enable the third voltage reduction module to be conducted.

In another implementation manner of the embodiment of the present application, the first voltage-reducing module includes a triode and a first switch. The base electrode of the triode is electrically connected with the controller, the emitting electrode of the triode is grounded, the collecting electrode of the triode is electrically connected with the control end of the first switch, and the first end of the first switch is electrically connected with the external battery cell module. The responding to the controller outputting the first control signal, the first voltage reduction module being disconnected, further comprising: in response to the base of the transistor receiving the first control signal, the transistor is turned off to turn off the first switch. Or, the responding to the controller outputting the second control signal, the first voltage-reducing module being turned on, further comprising: in response to the base of the transistor receiving the second control signal, the transistor is turned on to turn on the first switch.

In another implementation manner of the embodiment of the present application, the first voltage-dropping module further includes a first resistor, a second resistor, a third resistor, and a fourth resistor. The first resistor is connected between the base of the triode and the controller. One end of the second resistor is connected between the first resistor and the base electrode of the triode, and the other end of the second resistor is connected to the emitting electrode of the triode. The third resistor is connected between the control end of the first switch and the collector of the triode. The fourth resistor is connected between the control end and the first end of the first switch.

In another implementation manner of the embodiment of the present application, the power supply circuit further includes a DC-DC chip, and the DC-DC chip is connected between the second end of the first switch and the output end of the first voltage-reducing module.

In another implementation of the embodiment of the present application, the control module includes a second switch. The control end of the second switch is electrically connected with the controller, the first end of the second switch is grounded, and the second end of the second switch is electrically connected with the third voltage reduction module.

In another implementation of the embodiment of the present application, the control module further includes a fifth resistor and a sixth resistor. The fifth resistor is connected between the controller and the control end of the second switch, and the sixth resistor is connected between the control end of the second switch and the first end.

In another implementation manner of the embodiment of the application, the control module further includes a seventh resistor. The seventh resistor is connected between the second end of the second switch and the third voltage reduction module.

In another implementation manner of the embodiment of the present application, the third voltage reduction module includes a third switch. And the control end of the third switch is electrically connected with the second switch. The first end of the third switch is electrically connected with the second voltage reduction module, and the second end of the third switch is electrically connected with the anode of the external battery cell module. In response to the control terminal of the second switch receiving the first signal, the second switch is turned off to turn on the third switch. Or, in response to the control terminal of the second switch receiving the second signal, the second switch is turned on to turn off the third switch.

In another implementation manner of the embodiment of the present application, the third voltage-reducing module further includes an eighth resistor and a ninth resistor. The eighth resistor is connected between the input end of the third voltage reduction module and the first end of the third switch. One end of the ninth resistor is connected between the seventh resistor and the input end of the third voltage reduction module. The other end of the ninth resistor is connected to the control end of the third switch.

In another implementation manner of the embodiment of the present application, the third voltage-reducing module further includes a zener diode. The cathode of the voltage stabilizing diode is connected to the control end of the third switch, and the anode of the voltage stabilizing diode is grounded.

According to a second aspect of embodiments herein, there is provided a battery management system. A battery management system comprises a controller, other functional modules and a power supply circuit according to the first aspect.

According to a third aspect of embodiments herein, there is provided a battery pack. The battery pack comprises a cell module and the battery management system according to the second aspect.

According to a fourth aspect of embodiments herein, there is provided an electronic apparatus. The electronic device includes the battery pack according to the third aspect.

In the scheme of this application embodiment, in response to the controller output first control signal, first step-down module disconnection, the third step-down module switches on, it steps down to the output voltage of electric core module in proper order to have realized third step-down module and second step-down module, in addition, in response to controller output second control signal, first step-down module switches on, the disconnection of third step-down module has realized first step-down module and second step-down module, step down to the output voltage of electric core module in proper order. Compare in the scheme that adopts single step-down chip to carry out the step-down, the first step-down module and the second step-down module of this application make the battery package at awaken state or normal during operation, keep higher work efficiency, the third step-down module and the second step-down module of this application can improve the power consumption of battery package under non-awaken state or dormant mode, make the power consumption of battery package under non-awaken state or dormant mode lower, and first step-down module, second step-down module and third step-down module are general device, reduce cost.

Drawings

Some specific embodiments of the present application will be described in detail hereinafter by way of illustration and not limitation with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

fig. 1A is a schematic diagram of an exemplary battery pack.

Fig. 1B is a schematic diagram of the battery management system of fig. 1A.

FIG. 2 is a schematic diagram of a power supply circuit according to one embodiment of the present application.

Fig. 3 is a schematic diagram of a power supply circuit according to another embodiment of the present application.

Fig. 4A is a schematic diagram of a power supply circuit according to another embodiment of the present application.

Fig. 4B is a schematic diagram of a first buck module of one example of the embodiment of fig. 4A.

FIG. 4C is a schematic diagram of a third voltage reduction module of one example of the embodiment of FIG. 4A.

Detailed Description

In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be described below in detail and clearly with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application shall fall within the scope of protection of the embodiments in the present application.

The following further describes specific implementations of embodiments of the present application with reference to the drawings of the embodiments of the present application.

With the development of battery technology, lithium ion batteries such as lithium iron phosphate batteries, lithium manganate batteries, ternary polymer lithium batteries, lead acid batteries, sodium ion batteries, and the like may be used as the energy storage battery. The energy storage battery is widely applied in various scenes, and can be used as a power battery in electric equipment such as unmanned aerial vehicles, electric tools, electric bicycles, electric motorcycles, energy storage systems and the like.

The energy storage Battery can provide electric energy for the electric equipment in the form of a Battery pack, and a Battery Management System (BMS) can monitor the Battery pack in different application scenes, manage the charging and discharging of the Battery pack, and improve the working efficiency and the service life of the Battery pack. Specifically, the battery management system may perform control management such as battery state monitoring, battery state analysis, battery safety protection, energy control management, and battery information management. The battery management system can be connected with the battery cell module and is arranged in the battery pack to manage charging and discharging of the battery cell module, wherein the battery cell module comprises a plurality of battery cells, and series connection, parallel connection or series-parallel connection can be realized between the battery cells.

Fig. 1A is a schematic diagram of an exemplary battery pack. The battery pack 100 of fig. 1A includes a cell module 110 and a battery management system 120. The battery management system 120 includes a power supply circuit 130, a wake-up circuit 140, a controller 150, and other functional circuits 160. The power supply circuit 130 is electrically connected to the controller 150 and the other functional circuits 160 for supplying power to the controller 150 and the other functional circuits 160. The voltage required by the controller 150 is smaller than the voltage provided by the cell module 110, and generally, the power supply circuit 130 steps down the voltage output by the B + side of the cell module 110, and supplies power to the controller 150 based on the stepped-down voltage. The wake-up circuit 140 is electrically connected to the controller 150, and is configured to send a control signal to the controller 150 to enable the battery management system 120 to enter a wake-up state or a non-wake-up state. Fig. 1B is a schematic diagram of the battery management system of fig. 1A. In a specific implementation manner, the power supply circuit 130 includes a Low Dropout Regulator (LDO) chip 131, and the LDO chip 131 is electrically connected between the B + side of the cell module 110 and the controller 150, and is configured to step down a voltage output from the B + side, and input the stepped-down power supply voltage to the controller 150 and the other functional circuits 160. In another specific implementation, LDO chip 131 may be replaced with a DC-DC integrated chip.

In some examples, the other functional circuitry 160 includes, but is not limited to, communication circuitry, peripheral circuitry (e.g., digital input output circuitry), etc., and the other functional circuitry 160 and the controller 150 are each different modules in the battery management system.

Specifically, the controller may be implemented as a Micro Controller Unit (MCU) for receiving a control signal from the wake up circuit 140 to enable the battery management system 120 to enter a wake up state or a non-wake up state. The awake state indicates that the battery management system 120 is in the working state, and the non-awake state indicates a low power consumption state of the battery management system 120, and the non-awake state includes, but is not limited to, a sleep state, a standby state, a power-off state, and the like. Specifically, in the low power consumption state of the battery management system 120, the functions of some circuits in the battery management system 120 may not be used, and accordingly, in the non-wake-up state, the power supply of some circuits is turned off, so that the power consumption of the battery cell module is reduced, and the power consumption of the battery pack is reduced. In one specific embodiment, when the battery management system 120 is in the awake state or the non-awake state, the power supply voltage of the power supply circuit 130 is continuously output to the controller, so that the power supply circuit 130 provides a stable power supply voltage for the controller when the controller is started to be powered on or when the controller is abnormally reset, thereby ensuring the reliability of the battery management system 120.

Specifically, when the battery management system 120 is in the wake-up state, the voltage output by the B + side may be the total voltage of the cell module, and the total voltage may be in a wide voltage range, for example, the voltage output by the B + side of the cell module is between 30V and 60V. The voltage is stepped down through LDO chip 131 to lower voltages U1 and U2, e.g., 3.3V and 5V, respectively, and U1 and U2 power controller 150 and other functional circuitry 160, respectively.

The LDO chip 131 directly steps down a higher voltage (e.g., 30-60V) to lower voltages U1 and U2, and the LDO chip 131 needs to have a specific circuit configuration, so that when the battery pack is in an awake state or normally operates, the LDO chip 131 is adopted, and the operating efficiency is low.

Compared with the LDO chip 131, the DC-DC integrated chip has higher working efficiency, generally, the working efficiency of the battery pack can reach 70% when the battery pack works normally, but when the battery pack is in a non-awakening state or a dormant state, the power consumption of the DC-DC chip is higher, and when the dormant state is difficult to meet, the power consumption of the battery management system is kept in the microampere-level application working condition.

FIG. 2 is a schematic diagram of a power supply circuit according to one embodiment of the present application. The power supply circuit 230 of fig. 2 is electrically connected between the B + side of the battery cell module 110 and the controller 150, and is configured to supply power to the controller 150. The power supply circuit 230 receives the output voltage U0 of the battery cell module 110, and after voltage reduction processing, provides the output voltages U1 and U2 to the controller 150 and the other functional circuits 160, respectively. As an example, U0 may be at a wide voltage range, e.g., between 30V-60V, with U1 and U2 being approximately 3.3V and 5V, respectively.

Specifically, the power supply circuit 230 includes a first voltage-reducing module 231 and a second voltage-reducing module 232. Specifically, the first voltage dropping module 231 or the second voltage dropping module 232 may be implemented as a linear voltage dropping circuit composed of discrete devices such as a switching tube of a field effect transistor or a triode, a resistor, a capacitor, and the like, or as a low power consumption voltage dropping module or a chip including the linear voltage dropping circuit. For example, the first buck module 231 may include a direct current buck (DC-DC) chip and the second buck module 232 may include an LDO chip.

The first voltage reduction module 231 is configured to reduce the output voltage U0 of the cell module to U2, where U2 is smaller than 20V as an example. The output terminal of the first voltage-decreasing module 231 is connected to the other functional circuit 160, and U2 is input to the other functional circuit 160. The output terminal of the first voltage-reducing module 231 is further connected to the input terminal of the second voltage-reducing module 232, the output terminal of the second voltage-reducing module 232 is connected to the controller 150, and the second voltage-reducing module 232 further reduces the voltage of U2 to U1, which is input to the controller 150, so as to provide reliable dc voltage for the controller 150 and other functional circuits 160, respectively. First voltage reduction module 231's work efficiency is higher, is favorable to improving supply circuit 230's work efficiency, and in addition, first voltage reduction module 231 steps down the output voltage U0 of electric core module to U2, compares with the LDO chip 131 of fig. 1B, and the cost of the first voltage reduction module 231 of this embodiment is lower, is favorable to selecting more general chip model.

Fig. 3 is a schematic diagram of a power supply circuit according to another embodiment of the present application. In the embodiment of fig. 3, the power supply circuit 230 further includes a third voltage step-down module 233 and a control module 235.

The first voltage-reducing module 231 is connected to the controller 150, and is configured to receive a control signal sent by the controller 150, where the control signal enables or disables the first voltage-reducing module 231. In one specific implementation, the controller 150 sends a first signal (an example of a second control signal) when the battery management system 120 is in the wake-up state, and accordingly operates the first voltage reduction module 231. The controller 150 sends a second signal (an example of a first control signal) when the battery management system 120 is in the non-awake state, and accordingly disables the first voltage reduction module 231, i.e., causes the first voltage reduction module 231 to stop supplying power to the other functional circuits 160.

The input end of the third voltage reduction module 233 is connected to the B + side of the battery cell module 110, and is configured to receive the voltage output by the B + side. An output of the third voltage-decreasing module 233 may be connected to an input of the second voltage-decreasing module 232. The control module 235 is electrically connected to the third voltage-reducing module 233 and the controller 150. In a specific implementation manner, the controller 150 sends a third signal to the control module 235 when the battery management system 120 is in the wake-up state, so that the third voltage-reducing module 233 is disabled; the controller 150 sends a fourth signal to the control module 235 when the battery management system 120 is in the non-awake state, and accordingly operates the third voltage decreasing module 233. The controller 150 controls the first voltage dropping module 231 and the third voltage dropping module 233 to alternately operate. The third voltage-reducing module 233 reduces the output voltage U0 of the cell module, and the second voltage-reducing module 232 is configured to further reduce the voltage and output U1 to supply power to the controller 150. The third voltage reduction module 233 can be implemented as a low-power voltage reduction device, and when the battery management system is in a non-wake-up state, the third voltage reduction module 233 starts to operate, so that the battery cell module is turned off to supply power to other functional circuits 160, and power consumption of the battery pack is reduced.

In addition, the power supply circuit 230 further includes diodes D1 and D2. The cathode of the diode D1 is connected to the input terminal of the second voltage-dropping module 232, and the anode of the diode D1 is connected to the output terminal of the third voltage-dropping module 233. An anode of the diode D2 is connected to the output terminal of the first voltage-dropping module 231, and a cathode of the diode D2 is connected to a cathode of the diode D1 and an input terminal of the second voltage-dropping module 232.

When the battery management system 120 is in the wake-up state, the controller 150 activates the first voltage reduction module 231 according to the first signal. At this time, the output voltage U2 of the first voltage-decreasing module 231 is input to the other functional circuit 160. The output voltage U2 of the first voltage-reducing module 231 is also input into the diode D2, the anode voltage of the diode D2 is higher than the cathode voltage, and the diode D2 is turned on. Then, the output voltage U3 of the cathode of the diode D2 is input to the second step-down module 232 for further step-down. For example, the output terminal of the first voltage-reducing module 231 outputs 5V (in the case of U2), the voltage drop generated across the diode D2 is approximately 0.7V, and thus the diode D2 inputs 4.3V (5V-0.7V) (in the case of U3) to the second voltage-reducing module 232, and further reduces the voltage to 3.3V (in the case of U1). In addition, in the wake-up state, the third step-down module 233 is disabled, and D1 prevents a current from reversely flowing into the third step-down module 233.

When the battery management system 120 enters the non-awake state from the awake state, the third voltage reduction module 233 starts to operate, so that the anode voltage of the diode D1 is higher than the cathode voltage, and the diode D1 is turned on. At this time, the voltage at the anode of the diode D1 is substantially U4, and U5 is output to the second voltage-dropping module 232 through the voltage drop across the diode D1, and the second voltage-dropping module 232 further drops U5 to U1, and inputs U1 to the controller 150. For example, the third voltage-dropping module 233 drops the output voltage U0 of the cell module to 13.5V (an example of U4) and outputs the voltage to the anode of the diode D1, the voltage drop across the diode D1 is approximately 0.7V, and thus the cathode of the diode D1 outputs 12.8V (an example of U5) to the second voltage-dropping module 232. The second buck module 232 then buck 12.8V to 3.3V. In addition, when the battery management system 120 is in the non-wake-up state, the first voltage reduction module 231 is disabled, the cathode voltage of the diode D2 is higher than the anode voltage, the diode D2 is not turned on, and the power supply to the other functional circuits 160 is stopped.

Fig. 4A is a schematic diagram of a power supply circuit according to another embodiment of the present application. In the power supply circuit 230 of fig. 4A, the control module 235 includes switching devices including, but not limited to, switching tubes such as field effect transistors, relays, optocoupler devices, etc. As an example, the switching device is a field effect transistor Q1 (an example of a second switch), a gate of the field effect transistor Q1 is connected to the controller 150, a source is grounded, and a drain is connected to the third step-down module 233.

As an example, the field effect transistor Q1 shown in fig. 4A is an NMOS transistor, the third signal is a high level signal for turning on Q1, and the third voltage-reducing module 233 inhibits the operation with the turning on of Q1. The fourth signal is a low level signal, which is used to turn off Q1, and the third voltage-reducing module 233 starts to operate along with the turn-off of Q1. The drain of Q1 is connected to the third voltage dropping module 233 through a current limiting resistor R0 (an example of a seventh resistor).

Alternatively, unlike the example of fig. 4, the field effect transistor Q1 may also be a PMOS transistor, in which case the third signal is a low level signal for turning on Q1; the fourth signal is a high level signal for turning off Q1.

In addition, a resistor R2 (an example of a sixth resistor) may be disposed between the source and the gate of the field effect transistor Q1 to provide a stable gate-source voltage for the field effect transistor Q1, so as to stabilize a control signal such as the third signal or the fourth signal. In addition, a resistor R1 (an example of a fifth resistor) may be disposed between the gate of the fet Q1 and the controller 150, where R1 is connected in series with R2 to further provide a stable gate-source voltage to the fet Q1, and the arrangement of R1 may further improve the input impedance of the control signal output from the controller 150, and reduce the influence of the inrush current on the stability of the control signal.

The power supply circuit 230 further includes a filter composed of a resistor R3 and a capacitor C1, one end of R3 is connected to the B + side of the battery cell module 110, and the other end is connected to the first voltage-reducing module 231 and the third voltage-reducing module 233. One end of the capacitor C1 is grounded, and the other end of the capacitor C1 may be connected to either end of the resistor R3. The filter can stabilize the output voltage from the B + side of the cell module 110, filter out an alternating current component in the input voltage, and reduce the inflow of surge current. The output voltage of the B + side of the battery cell module 110 is filtered by a filter to obtain a voltage Vin, and is input to the first voltage reduction module 231 and the third voltage reduction module 233.

The power supply circuit 230 further includes an anti-reverse diode D3, the other end of the resistor R3 is electrically connected to the first voltage-reducing module 231 and the third voltage-reducing module 233 through the anti-reverse diode D3, that is, the other end of the resistor R3 is electrically connected to the anode of the anti-reverse diode D3, and the cathode of the anti-reverse diode D3 is electrically connected to the input end of the first voltage-reducing module 231 and the input end of the third voltage-reducing module 233, so that the current in the power supply circuit 230 is prevented from reversely flowing into the B + side of the battery cell module 110.

Further, as shown in fig. 4B, the first voltage-reducing module 231 includes switching tubes Q2 (an example of a first switch) and Q3, a filtering module 2311, and a DC-DC chip 2312. For example, the transistor Q2 may be a transistor, the transistor Q3 may be a PMOS transistor, and a base of the transistor Q2 is connected to the control terminal of the controller 150 for receiving the first signal or the second signal. The emitter of the triode Q2 is grounded, the collector of the triode Q2 is connected to the gate of the PMOS transistor Q3 for sending a control signal to the PMOS transistor Q3, the source of the PMOS transistor Q3 is connected to the voltage Vin, and the drain of the PMOS transistor Q3 is connected to the filtering module 2311.

Specifically, when the battery management system 120 is in the wake-up state, the first signal input to the base of the transistor Q2 by the controller 150 is at a high level, and the collector of the transistor Q2 outputs a low level to the gate of the PMOS transistor Q3, so that the source and the drain of the PMOS transistor Q3 are turned on, and thus the voltage Vin with the voltage U0 can be input to the filtering module 2311 to filter the ac component. The voltage filtered is input to the DC-DC chip 2312 to perform a step-down process, for example, a step-down from U0 to U2.

When the battery management system 120 is in the non-awake state, the second signal input to the base of the transistor Q2 by the controller 150 is at a low level, and the collector of the transistor Q2 outputs a high level to the gate of the PMOS transistor Q3, so that the source and the drain of the PMOS transistor Q3 are turned off, and thus the voltage Vin having the voltage U0 is prohibited from being input to the filtering module 2311 and the DC-DC chip 2312, that is, the first voltage reduction module 231 is prohibited from operating.

In addition, a resistor R21 (an example of a first resistor) may be electrically connected between the base of the transistor Q2 and the controller 150, and a resistor R22 (an example of a second resistor) may be electrically connected between the base and the emitter of the transistor Q2 for stabilizing the dc voltage of the first signal or the second signal.

In addition, a resistor R31 (an example of a third resistor) may be electrically connected between the collector of the transistor Q2 and the gate of the PMOS transistor Q3, and a resistor R32 (an example of a fourth resistor) may be electrically connected between the gate and the source of the PMOS transistor Q3, for enabling the transistor Q2 to provide a more stable control signal to the PMOS transistor Q3.

Further, as shown in fig. 4C, the third voltage-reducing module 233 includes a switch Q4 (an example of a third switch) and a resistor R42 (an example of an eighth resistor), and the switch Q4 may be an NMOS transistor. Specifically, the gate of the NMOS transistor Q4 may be connected to the control module 235 for receiving the fifth signal or the sixth signal. When the control module 235 receives the third signal, Q1 is turned on, the resistor R42 is connected between the source of the NMOS transistor Q4 and Vin, and the drain of the NMOS transistor Q4 is connected to the diode D1.

Referring to the example of fig. 4A, when the battery management system 120 is in the wake-up state, the control module 235 receives the third signal as high level, the NMOS transistor Q1 in the control module 235 is turned on according to the third signal, and the gate of the NMOS transistor Q4 receives low level (for example, the gate voltage of the NMOS transistor Q4 is lower than the source voltage), so that the source and the drain of the NMOS transistor Q4 are turned off, and thus the third voltage-dropping module 233 inhibits operation.

When the battery management system 120 is in the non-awake state, the control module 235 receives the fourth signal as the low level, the NMOS transistor Q1 in the control module 235 is turned off according to the fourth signal, and outputs the high level to the gate of the NMOS transistor Q4 (for example, the gate voltage of Q4 is higher than the source voltage), so that the source and the drain of the NMOS transistor Q4 are connected, and the voltage reduction processing of the third voltage reduction module 233 is realized by the voltage drop across the resistor R42, that is, the voltage of Vin is reduced from U0 to U4.

In addition, the third voltage dropping module 233 may further include a diode D4 (an example of a zener diode) and a resistor R41 (an example of a ninth resistor), wherein a cathode of the diode D4 is connected to the gate of the NMOS transistor Q4 and the control module 235, an anode of the diode D4 is grounded, and the resistor R41 is connected between the gate and the source of the NMOS transistor Q4, so as to stabilize a dc voltage of a control signal of the control module 235.

Thus, particular embodiments of the present subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may be advantageous.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of other like elements in a process, method, article, or apparatus comprising the element.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, as for the system embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and reference may be made to the partial description of the method embodiment for relevant points.

The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement or the like made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims (14)

1. A power supply circuit, comprising: a controller;

the first voltage reduction module is electrically connected with the controller and is configured to be electrically connected with a positive electrode of an external battery cell module and reduce the voltage output by the external battery cell module;

a second voltage reduction module respectively electrically connected with the first voltage reduction module and the controller and configured to reduce a voltage input to the second voltage reduction module to supply power to the controller;

a third voltage reduction module electrically connected to the controller and the second voltage reduction module, respectively, and configured to be electrically connected to a positive electrode of the external cell module, reduce a voltage output by the external cell module, and output the voltage to the second voltage reduction module;

the first voltage reduction module is turned off and the third voltage reduction module is turned on in response to the controller outputting a first control signal;

or, in response to the controller outputting the second control signal, the first voltage reduction module is turned on, and the third voltage reduction module is turned off.

2. The power supply circuit of claim 1, further comprising: the control module is electrically connected with the controller and the third voltage reduction module respectively;

the control module receives the first control signal to enable the third voltage reduction module to be conducted;

or, the control module receives the second control signal to turn on the third voltage reduction module.

3. The power supply circuit of claim 1, wherein the first voltage-reducing module comprises: a triode and a first switch;

the base electrode of the triode is electrically connected with the controller, the emitting electrode of the triode is grounded, the collector electrode of the triode is electrically connected with the control end of the first switch, and the first end of the first switch is electrically connected with the external battery cell module;

wherein the responding to the controller outputting the first control signal, the first voltage-reducing module being disconnected, further comprises:

in response to the base of the triode receiving the first control signal, the triode is turned off to turn off the first switch;

or, the responding to the controller outputting the second control signal, the first voltage-reducing module being turned on, further comprising:

the transistor is conducted in response to the base of the transistor receiving the second control signal, so that the first switch is conducted.

4. The power supply circuit of claim 3, wherein the first voltage-reducing module further comprises: a first resistor, a second resistor, a third resistor and a fourth resistor,

the first resistor is connected between the base of the triode and the controller,

one end of the second resistor is connected between the first resistor and the base electrode of the triode, the other end of the second resistor is connected to the emitting electrode of the triode,

the third resistor is connected between the control end of the first switch and the collector electrode of the triode,

the fourth resistor is connected between the control end and the first end of the first switch.

5. The power supply circuit of claim 3, further comprising: a DC-DC chip connected between the second terminal of the first switch and the output terminal of the first buck module.

6. The power supply circuit according to any one of claims 2 to 4, wherein the control module comprises: a second switch;

the control end of the second switch is electrically connected with the controller, the first end of the second switch is grounded, and the second end of the second switch is electrically connected with the third voltage reduction module.

7. The power supply circuit of claim 6, wherein the control module further comprises: the second switch comprises a controller, a first resistor and a sixth resistor, wherein the controller is connected between the controller and the control end of the second switch, and the sixth resistor is connected between the control end of the second switch and the first end.

8. The power supply circuit of claim 6, wherein the control module further comprises: a seventh resistor connected between the second terminal of the second switch and the third voltage dropping module.

9. The power supply circuit of claim 8, wherein the third voltage-reducing module comprises a third switch, a control terminal of the third switch is electrically connected to the second switch, a first terminal of the third switch is electrically connected to the second voltage-reducing module, and a second terminal of the third switch is electrically connected to the positive electrode of the external cell module;

wherein in response to the control terminal of the second switch receiving a first signal, the second switch is turned off to turn on the third switch;

or, in response to the control terminal of the second switch receiving a second signal, the second switch is turned on to turn off the third switch.

10. The power supply circuit of claim 9, wherein the third voltage-reducing module further comprises: the third switch is connected between the input end of the third voltage reduction module and the first end of the third switch, one end of the third switch is connected between the seventh switch and the input end of the third voltage reduction module, and the other end of the third switch is connected to the control end of the third switch.

11. The power supply circuit of claim 9, wherein the third voltage-reducing module further comprises: a voltage regulator diode, the cathode of which is connected to the control terminal of the third switch, and the anode of which is grounded.

12. A battery management system comprising a power supply circuit according to any one of claims 1-11.

13. A battery pack comprising a cell module and the battery management system of claim 12.

14. An electronic device comprising the battery pack according to claim 13.

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