Secondary battery charging and discharging control circuit and battery module

Abstract

This utility model discloses a secondary battery charging and discharging control circuit and a battery module, including a secondary battery circuit, a load detection circuit, and a discharge mode switching circuit. The secondary battery circuit is used to output a first voltage. The load detection circuit is used to connect to a load connection terminal and to detect a load signal. The discharge mode switching circuit is connected to the secondary battery circuit, the load detection circuit, and the load connection terminal, and is used to switch different voltage adjustment modes to adjust the first voltage according to the load signal, and output a second voltage to the load connection terminal. This allows the secondary battery charging and discharging control circuit to adjust the first voltage and output a corresponding second voltage according to the load signal of different loads, thereby adapting to different electrical loads and improving the load-carrying performance of the secondary battery charging and discharging control circuit.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a secondary battery charging and discharging control circuit and battery module. Background Technology

[0002] A rechargeable battery to dry cell battery converter is a device that converts the output voltage and interface of a rechargeable battery to be compatible with dry cell batteries. Its main purpose is to replace traditional dry cell batteries with rechargeable batteries to provide higher energy density, longer lifespan, and the convenience of recharging.

[0003] Existing rechargeable battery to dry cell battery converters generally consist of three parts: a charging module, a step-down module, and a rechargeable battery module. The charging module is the charging terminal for the rechargeable battery, charging and storing energy when the battery is low. The rechargeable battery module is the power supply terminal for the load, serving both energy storage and load-carrying functions. The step-down module converts the rechargeable battery voltage to a lower voltage for use in dry cell battery applications. However, existing rechargeable battery to dry cell battery converters only consider the voltage reduction and conversion of the rechargeable battery to a dry cell battery, neglecting to consider the load-carrying performance of the converter under different load conditions. Utility Model Content

[0004] This utility model provides a secondary battery charging and discharging control circuit and a battery module to solve the problem of poor load-carrying performance of existing secondary battery to dry battery conversion devices.

[0005] A secondary battery charging and discharging control circuit includes a secondary battery circuit, a load detection circuit, and a discharge mode switching circuit; The secondary battery circuit is used to output the first voltage; The load detection circuit is used to connect to the load connection terminal and to detect the load signal; The discharge mode switching circuit is connected to the secondary battery circuit, the load detection circuit and the load connection terminal, and is used to switch different voltage adjustment modes to adjust the first voltage according to the load signal, and output the second voltage to the load connection terminal.

[0006] Furthermore, the secondary battery charging and discharging control circuit also includes a mode selection switch; The mode selection switch is connected to the discharge mode switching circuit. When triggered, it outputs a mode selection signal to the discharge mode switching circuit, so that the discharge mode switching circuit switches to different voltage adjustment modes to adjust the first voltage and outputs a second voltage to the load connection terminal.

[0007] Furthermore, the discharge mode switching circuit includes a signal processing circuit, a switching circuit, a linear buck circuit, a switching buck circuit, and a boost circuit; The signal processing circuit is connected to the load detection circuit and the switching circuit, and is used to output a mode switching signal to the switching circuit according to the load signal. The switching circuit is connected to the secondary battery circuit, the linear buck circuit, the switching buck circuit, and the boost circuit, and is used to select one of the linear buck circuit, the switching buck circuit, and the boost circuit to be connected to the secondary battery circuit according to the mode switching signal. The linear step-down circuit is connected to the load connection terminal and is used to linearly step down the first voltage when the secondary battery circuit is turned on, and output the second voltage to the load connection terminal. The switching step-down circuit is connected to the load connection terminal and is used to perform switching step-down processing on the first voltage when it is connected to the secondary battery circuit, and output the second voltage to the load connection terminal. The boost circuit is connected to the load connection terminal and is used to boost the first voltage when the secondary battery circuit is turned on, and output the second voltage to the load connection terminal.

[0008] Furthermore, the switching circuit includes a first switch, a second switch, and a third switch; The first terminal of the first switch is connected to the secondary battery circuit, the second terminal of the first switch is connected to the linear step-down circuit, and the third terminal of the first switch is connected to the signal processing circuit. The first terminal of the second switch is connected to the secondary battery circuit, the second terminal of the second switch is connected to the linear step-down circuit, and the third terminal of the second switch is connected to the signal processing circuit. The first terminal of the third switch is connected to the secondary battery circuit, the second terminal of the third switch is connected to the linear step-down circuit, and the third terminal of the third switch is connected to the signal processing circuit.

[0009] Furthermore, the linear buck circuit includes a first transistor, a first comparator, a first voltage divider circuit, and a first capacitor; The first terminal of the first transistor is connected to the switching circuit, the second terminal of the first transistor is connected to the first terminal of the first capacitor, and the second terminal of the first capacitor is grounded. The first terminal of the first voltage divider circuit is connected to the second terminal of the first transistor and the first terminal of the first capacitor. The second terminal of the first voltage divider circuit is grounded. The third terminal of the first voltage divider circuit is connected to the non-inverting input terminal of the first comparator. The inverting input terminal of the first comparator is connected to the first reference voltage terminal, and the output terminal of the first comparator is connected to the third terminal of the first transistor.

[0010] Furthermore, the switching buck circuit includes a second transistor, a third transistor, a second comparator, a first driving circuit, a second voltage divider circuit, a first inductor, and a first capacitor; The first terminal of the second transistor is connected to the switching circuit, the second terminal of the second transistor is connected to the second terminal of the third transistor, and the first terminal of the third transistor is grounded. The first terminal of the first inductor is connected to the second terminal of the second transistor and the second terminal of the third transistor. The second terminal of the first inductor is connected to the first terminal of the first capacitor. The second terminal of the first capacitor is grounded. The first terminal of the second voltage divider circuit is connected to the second terminal of the first inductor and the first terminal of the first capacitor. The second terminal of the second voltage divider circuit is grounded. The third terminal of the second voltage divider circuit is connected to the non-inverting input terminal of the second comparator. The inverting input of the second comparator is connected to the second reference voltage terminal, and the output of the second comparator is connected to the first driving circuit. The first driving circuit is connected to the third terminal of the second transistor and the third terminal of the third transistor.

[0011] Furthermore, the boost circuit includes a second inductor, a third comparator, a third voltage divider circuit, a fourth transistor, a second driving circuit, a first diode, and a first capacitor; The first end of the second inductor is connected to the switching circuit, the second end of the second inductor is connected to the first end of the fourth transistor and the anode of the first diode, the second end of the fourth transistor is grounded, the cathode of the first diode is connected to the first end of the first capacitor, and the second end of the first capacitor is grounded. The first terminal of the third voltage divider circuit is connected to the cathode of the first diode and the first terminal of the first capacitor; the second terminal of the third voltage divider circuit is grounded; and the third terminal of the third voltage divider circuit is connected to the non-inverting input terminal of the third comparator. The inverting input terminal of the third comparator is connected to the third reference voltage terminal, and the output terminal of the third comparator is connected to the second driving circuit. The second driving circuit is connected to the third terminal of the fourth transistor.

[0012] Furthermore, the secondary battery charge / discharge control circuit also includes a charging module; The charging module is connected to an external power source and the secondary battery circuit, and is used to charge the secondary battery circuit according to the charging voltage provided by the external power source.

[0013] Furthermore, the charging module includes a fourth comparator, a fifth comparator, a fifth transistor, a sixth transistor, a seventh transistor, and a fourth voltage divider circuit; The non-inverting input of the fourth comparator is connected to the secondary battery circuit, and the inverting input of the fourth comparator is connected to the external power supply. The output terminal of the fourth comparator is connected to the third terminal of the fifth transistor, the first terminal of the fifth transistor is connected to the second terminal of the sixth transistor and the external power supply, and the second terminal of the fifth transistor is grounded. The first terminal of the sixth transistor and the first terminal of the seventh transistor are connected together and connected to the first power supply terminal, and the second terminal of the seventh transistor is connected to the secondary battery circuit; The first terminal of the fourth voltage divider circuit is connected to the second terminal of the secondary battery circuit and the seventh transistor, the second terminal of the fourth voltage divider circuit is grounded, and the third terminal of the fourth voltage divider circuit is connected to the non-inverting input terminal of the fifth comparator. The inverting input of the fifth comparator is connected to the fourth reference voltage terminal, and the output of the fifth comparator is connected to the third terminal of the sixth transistor and the third terminal of the seventh transistor.

[0014] A battery module includes the aforementioned secondary battery charging and discharging control circuit.

[0015] This utility model provides a secondary battery charging and discharging control circuit and a battery module. The secondary battery charging and discharging control circuit includes a secondary battery circuit, a load detection circuit, and a discharge mode switching circuit. The secondary battery circuit is used to output a first voltage. The load detection circuit is used to connect to a load connection terminal and to detect load signals. The discharge mode switching circuit is connected to the secondary battery circuit, the load detection circuit, and the load connection terminal, and is used to switch different voltage adjustment modes to adjust the first voltage according to the load signal, and output a second voltage to the load connection terminal. This allows the secondary battery charging and discharging control circuit to adjust the first voltage and output a corresponding second voltage according to the load signals of different loads, thereby adapting to different electrical loads and improving the load-carrying performance of the secondary battery charging and discharging control circuit. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a circuit diagram of a secondary battery charging and discharging control circuit in one embodiment of this utility model; Figure 2 This is a circuit diagram of a linear step-down circuit in one embodiment of the present invention; Figure 3 This is a circuit diagram of a switching step-down circuit in one embodiment of the present invention; Figure 4 This is a circuit diagram of a boost circuit in one embodiment of the present invention; Figure 5 This is a circuit diagram of a charging module in one embodiment of the present invention.

[0018] In the diagram: 1. Secondary battery circuit; 2. Load detection circuit; 3. Discharge mode switching circuit; 31. Signal processing circuit; 32. Switching circuit; 321. First switch; 322. Second switch; 323. Third switch; 33. Linear buck circuit; 331. First voltage divider circuit; 34. Switching buck circuit; 341. First drive circuit; 342. Second voltage divider circuit; 35. Boost circuit; 351. First drive circuit; 352. Second voltage divider circuit; 4. Mode selection switch; 5. Charging module; 51. Fourth voltage divider circuit. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0020] It should be understood that this invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0021] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this utility model, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0022] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. When used herein, the singular forms “a,” “an,” and “ / the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “comprising,” when used in this specification, identify the presence of features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0024] To fully understand this utility model, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0025] This embodiment provides a secondary battery charging and discharging control circuit, including a secondary battery circuit 1, a load detection circuit 2, and a discharge mode switching circuit 3; the secondary battery circuit 1 is used to output a first voltage; the load detection circuit 2 is used to connect to a load connection terminal and to detect a load signal; the discharge mode switching circuit 3 is connected to the secondary battery circuit 1, the load detection circuit 2, and the load connection terminal, and is used to switch different voltage adjustment modes to adjust the first voltage according to the load signal, and output a second voltage to the load connection terminal.

[0026] As an example, the secondary battery circuit 1 includes a secondary battery module. The secondary battery circuit 1 outputs a first voltage based on the energy stored in the secondary battery module. The secondary battery module may be a lithium-ion battery module or a sodium-ion battery module.

[0027] As an example, load detection circuit 2 is used to connect to the load connection terminal and to detect the load signal. In this example, the load connection terminal is used to connect to an electrical load. The load signal includes load current and load voltage.

[0028] As an example, the discharge mode switching circuit 3 is connected to the secondary battery circuit 1, the load detection circuit 2, and the load connection terminal. It is used to switch between different voltage adjustment modes to adjust the first voltage according to the load signal, and output a second voltage to the load connection terminal. When the secondary battery charge / discharge control circuit simulates a dry cell battery discharging, the discharge mode switching circuit 3 adjusts the first voltage according to the default discharge mode, and receives the load signal fed back from the load detection circuit 2. Based on the load signal, it switches between different voltage adjustment modes to adjust the first voltage and outputs a second voltage to the load connection terminal. Exemplarily, this voltage adjustment mode includes linear buck adjustment, switching buck adjustment, and boost adjustment.

[0029] Specifically, when the load connection is determined to be in a light-load, low-voltage state based on the load current and load voltage of the load signal, the first voltage is adjusted by linear step-down to smoothly output the second voltage, while ensuring low noise and low power consumption. When the load connection is determined to be in a heavy-load, low-voltage state, the first voltage is adjusted by switching step-down to achieve a step-down function where the second voltage is lower than the first voltage, thereby improving the step-down efficiency of the switch and reducing heat generation. When the load connection is determined to be in a heavy-load, high-voltage state, the first voltage is adjusted by step-up to adapt to the high-voltage load.

[0030] In this embodiment, the secondary battery charging and discharging control circuit includes a secondary battery circuit 1, a load detection circuit 2, and a discharge mode switching circuit 3. The secondary battery circuit 1 is used to output a first voltage. The load detection circuit 2 is used to connect to the load connection terminal and to detect the load signal. The discharge mode switching circuit 3 is connected to the secondary battery circuit 1, the load detection circuit 2, and the load connection terminal. It is used to switch different voltage adjustment modes to adjust the first voltage according to the load signal and output a second voltage to the load connection terminal. This allows the secondary battery charging and discharging control circuit to adjust the first voltage and output a corresponding second voltage according to the load signal of different loads, thereby adapting to different electrical loads and improving the load-carrying performance of the secondary battery charging and discharging control circuit.

[0031] In one embodiment, the secondary battery charging and discharging control circuit further includes a mode selection switch 4; the mode selection switch 4 is connected to the discharge mode switching circuit 3, and when triggered, outputs a mode selection signal to the discharge mode switching circuit 3, so that the discharge mode switching circuit 3 switches to different voltage adjustment modes to adjust the first voltage and outputs a second voltage to the load connection terminal.

[0032] In this embodiment, the user can also manually select the voltage adjustment mode of the discharge mode switching circuit 3 by triggering the mode selection switch 4, thereby adjusting the first voltage according to the user's needs and outputting a second voltage that matches the electrical load, ensuring the load-carrying performance of the secondary battery charging and discharging control circuit.

[0033] In one embodiment, the discharge mode switching circuit 3 includes a signal processing circuit 31, a switching circuit 32, a linear buck circuit 33, a switching buck circuit 34, and a boost circuit 35. The signal processing circuit 31 is connected to the load detection circuit 2 and the switching circuit 32, and is used to output a mode switching signal to the switching circuit 32 according to the load signal. The switching circuit 32 is connected to the secondary battery circuit 1, the linear buck circuit 33, the switching buck circuit 34, and the boost circuit 35, and is used to select the linear buck circuit 33, the switching buck circuit 34, and the boost circuit 35 according to the mode switching signal. One of the voltage-reducing circuits 35 is connected to the secondary battery circuit 1; the linear buck circuit 33 is connected to the load connection terminal and is used to linearly reduce the first voltage when connected to the secondary battery circuit 1, and output the second voltage to the load connection terminal; the switching buck circuit 34 is connected to the load connection terminal and is used to switch the first voltage when connected to the secondary battery circuit 1, and output the second voltage to the load connection terminal; the boost circuit 35 is connected to the load connection terminal and is used to boost the first voltage when connected to the secondary battery circuit 1, and output the second voltage to the load connection terminal.

[0034] As an example, the signal processing circuit 31 is connected to the load detection circuit 2 and the switching circuit 32, and is used to output a mode switching signal to the switching circuit 32 according to the load signal. Exemplarily, the signal processing circuit 31 is used to determine the current state of the electrical load based on the magnitude of the load current and the magnitude of the load voltage. A large load current indicates a heavy load, and a small load current indicates a light load. A large load voltage indicates a high voltage, and a small load voltage indicates a low voltage. Understandably, the signal processing circuit 31 determines whether it is a heavy or light load based on a preset current threshold, and determines whether it is a high or low voltage based on a preset voltage threshold. When the load connection is in a light load and low voltage state, the signal processing circuit 31 instructs the switching circuit 32 to turn on the secondary battery circuit 1 and the linear step-down circuit 33 via the mode switching signal, so as to linearly reduce the voltage to adjust the first voltage and smoothly output the second voltage.

[0035] When the load connection is under heavy load and low voltage, the signal processing circuit 31 instructs the switching switch circuit 32 to turn on the secondary battery circuit 1 and the switching step-down circuit 34 through the mode switching signal, so as to adjust the first voltage by switching step-down, thereby realizing the step-down function that the second voltage is lower than the first voltage.

[0036] When the load connection is under heavy load and high voltage, the signal processing circuit 31 uses the mode switching signal to indicate the switching switch circuit 32 to turn on the secondary battery circuit 1 and the boost circuit 35, and adjusts the first voltage to adapt to the high voltage load.

[0037] In this embodiment, the signal processing circuit 31, the switching circuit 32, the linear buck circuit 33, the switching buck circuit 34, and the boost circuit 35 are used to switch different voltage adjustment modes according to the load signal to adjust the first voltage and output the second voltage to the load connection terminal. This allows the secondary battery charging and discharging control circuit to adjust the first voltage and output the corresponding second voltage according to the load signal of different loads, so as to adapt to different electrical loads. The structure is simple and the cost is low.

[0038] In one embodiment, the switching circuit 32 includes a first switch 321, a second switch 322, and a third switch 323; the first terminal of the first switch 321 is connected to the secondary battery circuit 1, the second terminal of the first switch 321 is connected to the linear step-down circuit 33, and the third terminal of the first switch 321 is connected to the signal processing circuit 31; the first terminal of the second switch 322 is connected to the secondary battery circuit 1, the second terminal of the second switch 322 is connected to the linear step-down circuit 33, and the third terminal of the second switch 322 is connected to the signal processing circuit 31; the first terminal of the third switch 323 is connected to the secondary battery circuit 1, the second terminal of the third switch 323 is connected to the linear step-down circuit 33, and the third terminal of the third switch 323 is connected to the signal processing circuit 31.

[0039] Optionally, the first switch 321, the second switch 322 and the third switch 323 are all MOSFETs, which have a faster switching speed.

[0040] For example, the first switch 321 is a first PMOS transistor, the second switch 322 is a second PMOS transistor, and the third switch 323 is a third PMOS transistor. The source of the first switch 321 is connected to the secondary battery circuit 1, the drain of the first switch 321 is connected to the linear buck circuit 33, and the gate of the first switch 321 is connected to the signal processing circuit 31; the source of the second switch 322 is connected to the secondary battery circuit 1, the drain of the second switch 322 is connected to the linear buck circuit 33, and the gate of the second switch 322 is connected to the signal processing circuit 31; the source of the third switch 323 is connected to the secondary battery circuit 1, the drain of the third switch 323 is connected to the linear buck circuit 33, and the gate of the third switch 323 is connected to the signal processing circuit 31. The signal processing circuit 31 inputs different level signals to the gates of the first switch 321, the second switch 322, and the third switch 323 respectively to control the first switch 321, the second switch 322, and the third switch 323 to be turned on or off.

[0041] In this embodiment, by using the first switch 321, the second switch 322, and the third switch 323, different voltage regulation modes can be switched by turning the first switch 321, the second switch 322, and the third switch 323 on or off. The structure is simple and the cost is low.

[0042] In one embodiment, the linear buck circuit 33 includes a first transistor PMOS1, a first comparator CMP1, a first voltage divider circuit 331, and a first capacitor C1. The first terminal of the first transistor PMOS1 is connected to the switching circuit 32, the second terminal of the first transistor PMOS1 is connected to the first terminal of the first capacitor C1, and the second terminal of the first capacitor C1 is grounded. The first terminal of the first voltage divider circuit 331 is connected to the second terminal of the first transistor PMOS1 and the first terminal of the first capacitor C1, the second terminal of the first voltage divider circuit 331 is grounded, and the third terminal of the first voltage divider circuit 331 is connected to the non-inverting input terminal of the first comparator CMP1. The inverting input terminal of the first comparator CMP1 is connected to the first reference voltage terminal, and the output terminal of the first comparator CMP1 is connected to the third terminal of the first transistor PMOS1.

[0043] As an example, the first transistor PMOS1 can be a MOSFET or a bipolar transistor. In this example, the first transistor PMOS1 is preferably a MOSFET.

[0044] For example, the first transistor PMOS1 is a PMOS transistor. The source of the first transistor PMOS1 is connected to the switching circuit 32, the drain of the first transistor PMOS1 is connected to the first terminal of the first capacitor C1, and the gate of the first transistor PMOS1 is connected to the output terminal of the first comparator CMP1.

[0045] As an example, the first voltage divider circuit 331 includes a first resistor R1 and a second resistor R2, which are connected in series. The connection node between the first resistor R1 and the second resistor R2 is connected to the non-inverting input of the first comparator CMP1.

[0046] As an example, when the load connection is under light load and low voltage conditions, the source voltage of the first transistor PMOS1 is greater than its gate voltage, so the first transistor PMOS1 is turned on. The first voltage, after being divided by the first resistor R1 and the second resistor R2, forms a divided voltage V3 = VOUT * R2 / (R1 + R2) at the non-inverting input of the first amplifier, where VOUT is the second voltage. The divided voltage V3 and the first reference voltage Vref1 provided by the first reference voltage terminal are then processed by the first comparator CMP1. The output of the first comparator CMP1 controls the gate voltage of the first transistor PMOS1, causing it to conduct in different states within the linear region, providing a stable power supply to the subsequent stages. The first capacitor C1 serves to charge and discharge and smooth the output voltage throughout the process. Understandably, the value of the first reference voltage Vref1 can be set based on practical experience.

[0047] In this embodiment, linear voltage reduction can be achieved through the first transistor PMOS1, the first comparator CMP1, the first voltage divider circuit 331, and the first capacitor C1. The structure is simple and the circuit complexity is reduced.

[0048] In one embodiment, the switching buck circuit 34 includes a second transistor PMOS2, a second transistor NMOS3, a second comparator CMP2, a first driving circuit 351341, a second voltage divider circuit 352342, a first inductor L1, and a first capacitor C1; the first terminal of the second transistor PMOS2 is connected to the switching circuit 32, the second terminal of the second transistor PMOS2 is connected to the second terminal of the second transistor NMOS3, and the first terminal of the second transistor NMOS3 is grounded; the first terminal of the first inductor L1 is connected to the second terminal of the second transistor PMOS2 and the second terminal of the second transistor NMOS3, and the second terminal of the first inductor L1 is connected to the second terminal of the second transistor PMOS2 and the second terminal of the second transistor NMOS3. The first terminal of capacitor C1 is connected to ground; the second terminal of capacitor C1 is grounded; the first terminal of the second voltage divider circuit 352342 is connected to the second terminal of the first inductor L1 and the first terminal of capacitor C1; the second terminal of the second voltage divider circuit 352342 is grounded; the third terminal of the second voltage divider circuit 352342 is connected to the non-inverting input terminal of the second comparator CMP2; the inverting input terminal of the second comparator CMP2 is connected to the second reference voltage terminal; the output terminal of the second comparator CMP2 is connected to the first driving circuit 351341; the first driving circuit 351341 is connected to the third terminal of the second transistor PMOS2 and the third terminal of the second transistor NMOS3.

[0049] The second transistor PMOS2 and the second transistor NMOS3 can be either MOSFETs or bipolar transistors. Preferably, the second transistor PMOS2 and the second transistor NMOS3 are MOSFETs to ensure a faster switching speed. For example, the second transistor PMOS2 is a PMOS transistor, the second transistor NMOS3 is an NMOS transistor, and the first terminal of the second transistor PMOS2 or the second transistor NMOS3 is the source, the second terminal is the drain, and the third terminal is the gate.

[0050] As an example, the second voltage divider circuit 352342 includes a third resistor R3 and a fourth resistor R4. The third resistor R3 and the fourth resistor R4 are connected in series, and the connection node between the third resistor R3 and the fourth resistor R4 is connected to the non-inverting input of the second comparator CMP2.

[0051] As an example, when the load connection is under heavy load and low voltage, the second transistor PMOS2 and the second transistor NMOS3 can be turned on respectively to form a switching buck function. Specifically, the second voltage VOUT is divided by the third resistor R3 and the fourth resistor R4, forming a divided voltage V4 = VOUT * R4 / (R3 + R4) at the non-inverting input of the second comparator CMP2. This divided voltage V4 is compared with the second reference voltage Vref2 provided by the second reference voltage terminal. When the divided voltage V4 is greater than the second reference voltage Vref2, the second comparator CMP2 outputs a high level, which enters the first drive circuit 351341, turning off the second transistor PMOS2 and turning on the second transistor NMOS3. The first capacitor C1 discharges, lowering the second voltage VOUT. When the divided voltage V4 is not greater than the second reference voltage Vref2, the second comparator CMP2 outputs a low level, which enters the first drive circuit 351341, turning off the second transistor NMOS3 and turning on the second transistor PMOS2. This charges the first capacitor C1, raising the second voltage VOUT, thereby lowering the first voltage and stabilizing it at the second voltage VOUT. Through this process, the step-down function of making the second voltage VOUT lower than the first voltage is achieved.

[0052] In this embodiment, switching voltage reduction can be achieved through the second transistor PMOS2, the second transistor NMOS3, the second comparator CMP2, the first driving circuit 351341, the second voltage divider circuit 352342, the first inductor L1, and the first capacitor C1. The structure is simple and the circuit complexity is reduced.

[0053] In one embodiment, the boost circuit 35 includes a second inductor L2, a third comparator CMP3, a third voltage divider circuit, a fourth transistor NMOS4, a second driving circuit, a first diode D1, and a first capacitor C1. The first terminal of the second inductor L2 is connected to the switching circuit 32, and the second terminal of the second inductor L2 is connected to the first terminal of the fourth transistor NMOS4 and the anode of the first diode D1. The second terminal of the fourth transistor NMOS4 is grounded. The cathode of the first diode D1 is connected to the first terminal of the first capacitor C1, and the second terminal of the first capacitor C1 is grounded. The first terminal of the third voltage divider circuit is connected to the cathode of the first diode D1 and the first terminal of the first capacitor C1. The second terminal of the third voltage divider circuit is grounded, and the third terminal of the third voltage divider circuit is connected to the non-inverting input terminal of the third comparator CMP3. The inverting input terminal of the third comparator CMP3 is connected to the third reference voltage terminal, and the output terminal of the third comparator CMP3 is connected to the second driving circuit. The second driving circuit is connected to the third terminal of the fourth transistor NMOS4.

[0054] The fourth transistor NMOS4 can be a MOSFET or a bipolar transistor. Preferably, the fourth transistor NMOS4 is a MOSFET to ensure a faster switching speed. For example, the fourth transistor NMOS4 is a PMOS transistor, with its first terminal being the source, its second terminal being the drain, and its third terminal being the gate.

[0055] As an example, the third voltage divider circuit includes a fifth resistor R5 and a sixth resistor R6. The fifth resistor R5 and the sixth resistor R6 are connected in series, and the connection node between the fifth resistor R5 and the sixth resistor R6 is connected to the non-inverting input of the third comparator CMP3.

[0056] As an example, when the load connection is under heavy load and high voltage, the fourth transistor NMOS4 turns on and off to charge and discharge the second inductor L2, thus completing the voltage boost function. The second voltage VOUT is divided by the fifth resistor R5 and the sixth resistor R6, forming a divided voltage V5 = VOUT * R6 / (R5 + R6) at the non-inverting input of the third comparator CMP3. The divided voltage V5 is compared with the third reference voltage Vref3 provided by the third reference voltage terminal. When the divided voltage V5 is greater than the third reference voltage Vref3, the third comparator CMP3 outputs a high level, which enters the second drive circuit, turns off the fourth transistor NMOS4, and discharges the first capacitor C1, thus reducing the second voltage VOUT. When the divided voltage V5 is not greater than the third reference voltage Vref3, the third comparator CMP3 outputs a low level, which enters the second drive circuit, turns on the fourth transistor NMOS4, and charges the first capacitor C1, thus increasing the second voltage VOUT. Through the above process, the voltage boost function of the second voltage VOUT being higher than the first voltage is achieved.

[0057] In this embodiment, boost voltage can be achieved through the second inductor L2, the third comparator CMP3, the third voltage divider circuit, the fourth transistor NMOS4, the second driving circuit, the first diode D1, and the first capacitor C1. The structure is simple and the circuit complexity is reduced.

[0058] Understandably, the linear buck circuit 33, the switching buck circuit 34, and the boost circuit 35 can share a first capacitor C1 to reduce costs.

[0059] In one embodiment, the secondary battery charging and discharging control circuit further includes a charging module 5; the charging module 5 is connected to an external power source and the secondary battery circuit 1, and is used to charge the secondary battery circuit 1 according to the charging voltage provided by the external power source.

[0060] The external power source can be the mains power grid or a USB charging device.

[0061] In this embodiment, the charging module 5 is connected to the external power supply and the secondary battery circuit 1, and is used to charge the secondary battery circuit 1 according to the charging voltage provided by the external power supply, so that the secondary battery can be reused.

[0062] In one embodiment, the charging module 5 includes a fourth comparator CMP4, a fifth comparator CMP5, a fifth transistor PMOS5, a sixth transistor PMOS6, a seventh transistor PMOS7, and a fourth voltage divider circuit 51; the non-inverting input of the fourth comparator CMP4 is connected to the secondary battery circuit 1, and the inverting input of the fourth comparator CMP4 is connected to an external power supply; the output of the fourth comparator CMP4 is connected to the third terminal of the fifth transistor PMOS5, the first terminal of the fifth transistor PMOS5 is connected to the second terminal of the sixth transistor PMOS6 and the external power supply, and the second terminal of the fifth transistor PMOS5 is grounded; the sixth transistor PMOS5... The first terminal of MOS6 and the first terminal of the seventh transistor PMOS7 are connected together and connected to the first power supply terminal. The second terminal of the seventh transistor PMOS7 is connected to the secondary battery circuit 1. The first terminal of the fourth voltage divider circuit 51 is connected to the secondary battery circuit 1 and the second terminal of the seventh transistor PMOS7. The second terminal of the fourth voltage divider circuit 51 is grounded. The third terminal of the fourth voltage divider circuit 51 is connected to the non-inverting input terminal of the fifth comparator CMP5. The inverting input terminal of the fifth comparator CMP5 is connected to the fourth reference voltage terminal. The output terminal of the fifth comparator CMP5 is connected to the third terminal of the sixth transistor PMOS6 and the third terminal of the seventh transistor PMOS7.

[0063] In this configuration, the fifth transistor PMOS5, the sixth transistor PMOS6, and the seventh transistor PMOS7 can be either MOSFETs or bipolar transistors. Preferably, all three transistors are PMOS transistors to ensure a faster switching speed. Exemplarily, the first terminal of one of the transistors is the source, the second terminal is the drain, and the third terminal is the gate. This first power supply terminal provides a power supply voltage V1 to ensure the normal operation of the transistors.

[0064] As an example, the fourth voltage divider circuit 51 includes a seventh resistor R7 and an eighth resistor R8. The seventh resistor R7 and the eighth resistor R8 are connected in series, and the connection node between the seventh resistor R7 and the eighth resistor R8 is connected to the non-inverting input of the fifth comparator CMP5.

[0065] As an example, the drain of the fifth transistor PMOS5 is also grounded through a current-limiting resistor R9.

[0066] In this embodiment, the charging voltage VIN is compared with the first voltage VBAT by the fourth comparator CMP4. When the charging voltage VIN is higher than the first voltage VBAT, the fifth transistor PMOS5 is turned on to start charging the secondary battery circuit 1. The width-to-length ratio of the sixth transistor PMOS6 and the seventh transistor PMOS7 is in a preset ratio to control the charging current. The first voltage VBAT is divided by the seventh resistor R7 and the eighth resistor R8, and a divided voltage V2 = VBAT * R8 / (R7 + R8) is generated at the non-inverting input of the fifth comparator CMP5. By comparing this voltage with the fourth quasi-quasi-voltage provided by the fourth quasi-quasi-voltage terminal, the conduction state of the sixth transistor PMOS6 and the seventh transistor PMOS7 is controlled to control the charging current of different magnitudes in different voltage domains.

[0067] This embodiment provides a battery module, including the aforementioned secondary battery charging and discharging control circuit.

[0068] The above-described 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. A secondary battery charging and discharging control circuit, characterized in that, Includes a secondary battery circuit, a load detection circuit, and a discharge mode switching circuit; The secondary battery circuit is used to output the first voltage; The load detection circuit is used to connect to the load connection terminal and to detect the load signal; The discharge mode switching circuit is connected to the secondary battery circuit, the load detection circuit and the load connection terminal, and is used to switch different voltage adjustment modes to adjust the first voltage according to the load signal, and output the second voltage to the load connection terminal.

2. The secondary battery charging and discharging control circuit according to claim 1, characterized in that, The secondary battery charging and discharging control circuit also includes a mode selection switch. The mode selection switch is connected to the discharge mode switching circuit. When triggered, it outputs a mode selection signal to the discharge mode switching circuit, so that the discharge mode switching circuit switches to different voltage adjustment modes to adjust the first voltage and outputs a second voltage to the load connection terminal.

3. The secondary battery charging and discharging control circuit according to claim 1, characterized in that, The discharge mode switching circuit includes a signal processing circuit, a switching circuit, a linear buck circuit, a switching buck circuit, and a boost circuit. The signal processing circuit is connected to the load detection circuit and the switching circuit, and is used to output a mode switching signal to the switching circuit according to the load signal. The switching circuit is connected to the secondary battery circuit, the linear buck circuit, the switching buck circuit, and the boost circuit, and is used to select one of the linear buck circuit, the switching buck circuit, and the boost circuit to be connected to the secondary battery circuit according to the mode switching signal. The linear step-down circuit is connected to the load connection terminal and is used to linearly step down the first voltage when the secondary battery circuit is turned on, and output the second voltage to the load connection terminal. The switching step-down circuit is connected to the load connection terminal and is used to perform switching step-down processing on the first voltage when it is connected to the secondary battery circuit, and output the second voltage to the load connection terminal. The boost circuit is connected to the load connection terminal and is used to boost the first voltage when the secondary battery circuit is turned on, and output the second voltage to the load connection terminal.

4. The secondary battery charging and discharging control circuit according to claim 3, characterized in that, The switching circuit includes a first switch, a second switch, and a third switch; The first terminal of the first switch is connected to the secondary battery circuit, the second terminal of the first switch is connected to the linear step-down circuit, and the third terminal of the first switch is connected to the signal processing circuit. The first terminal of the second switch is connected to the secondary battery circuit, the second terminal of the second switch is connected to the linear step-down circuit, and the third terminal of the second switch is connected to the signal processing circuit. The first terminal of the third switch is connected to the secondary battery circuit, the second terminal of the third switch is connected to the linear step-down circuit, and the third terminal of the third switch is connected to the signal processing circuit.

5. The secondary battery charging and discharging control circuit according to claim 3, characterized in that, The linear buck circuit includes a first transistor, a first comparator, a first voltage divider circuit, and a first capacitor; The first terminal of the first transistor is connected to the switching circuit, the second terminal of the first transistor is connected to the first terminal of the first capacitor, and the second terminal of the first capacitor is grounded. The first terminal of the first voltage divider circuit is connected to the second terminal of the first transistor and the first terminal of the first capacitor. The second terminal of the first voltage divider circuit is grounded. The third terminal of the first voltage divider circuit is connected to the non-inverting input terminal of the first comparator. The inverting input terminal of the first comparator is connected to the first reference voltage terminal, and the output terminal of the first comparator is connected to the third terminal of the first transistor.

6. The secondary battery charging and discharging control circuit according to claim 3, characterized in that, The switching buck circuit includes a second transistor, a third transistor, a second comparator, a first driver circuit, a second voltage divider circuit, a first inductor, and a first capacitor. The first terminal of the second transistor is connected to the switching circuit, the second terminal of the second transistor is connected to the second terminal of the third transistor, and the first terminal of the third transistor is grounded. The first terminal of the first inductor is connected to the second terminal of the second transistor and the second terminal of the third transistor. The second terminal of the first inductor is connected to the first terminal of the first capacitor. The second terminal of the first capacitor is grounded. The first terminal of the second voltage divider circuit is connected to the second terminal of the first inductor and the first terminal of the first capacitor. The second terminal of the second voltage divider circuit is grounded. The third terminal of the second voltage divider circuit is connected to the non-inverting input terminal of the second comparator. The inverting input of the second comparator is connected to the second reference voltage terminal, and the output of the second comparator is connected to the first driving circuit. The first driving circuit is connected to the third terminal of the second transistor and the third terminal of the third transistor.

7. The secondary battery charging and discharging control circuit according to claim 3, characterized in that, The boost circuit includes a second inductor, a third comparator, a third voltage divider circuit, a fourth transistor, a second driving circuit, a first diode, and a first capacitor; The first end of the second inductor is connected to the switching circuit, the second end of the second inductor is connected to the first end of the fourth transistor and the anode of the first diode, the second end of the fourth transistor is grounded, the cathode of the first diode is connected to the first end of the first capacitor, and the second end of the first capacitor is grounded. The first terminal of the third voltage divider circuit is connected to the cathode of the first diode and the first terminal of the first capacitor; the second terminal of the third voltage divider circuit is grounded; and the third terminal of the third voltage divider circuit is connected to the non-inverting input terminal of the third comparator. The inverting input terminal of the third comparator is connected to the third reference voltage terminal, and the output terminal of the third comparator is connected to the second driving circuit. The second driving circuit is connected to the third terminal of the fourth transistor.

8. The secondary battery charging and discharging control circuit according to claim 1, characterized in that, The secondary battery charge / discharge control circuit also includes a charging module. The charging module is connected to an external power source and the secondary battery circuit, and is used to charge the secondary battery circuit according to the charging voltage provided by the external power source.

9. The secondary battery charging and discharging control circuit according to claim 8, characterized in that, The charging module includes a fourth comparator, a fifth comparator, a fifth transistor, a sixth transistor, a seventh transistor, and a fourth voltage divider circuit; The non-inverting input of the fourth comparator is connected to the secondary battery circuit, and the inverting input of the fourth comparator is connected to the external power supply. The output terminal of the fourth comparator is connected to the third terminal of the fifth transistor, the first terminal of the fifth transistor is connected to the second terminal of the sixth transistor and the external power supply, and the second terminal of the fifth transistor is grounded. The first terminal of the sixth transistor and the first terminal of the seventh transistor are connected together and connected to the first power supply terminal, and the second terminal of the seventh transistor is connected to the secondary battery circuit; The first terminal of the fourth voltage divider circuit is connected to the second terminal of the secondary battery circuit and the seventh transistor, the second terminal of the fourth voltage divider circuit is grounded, and the third terminal of the fourth voltage divider circuit is connected to the non-inverting input terminal of the fifth comparator. The inverting input of the fifth comparator is connected to the fourth reference voltage terminal, and the output of the fifth comparator is connected to the third terminal of the sixth transistor and the third terminal of the seventh transistor.

10. A battery module, characterized in that, Includes the secondary battery charge / discharge control circuit as described in any one of claims 1 to 9.

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