Switch driving device, battery management system, battery pack and electric device

Abstract

A switch driving device comprises a DC-DC conversion circuit, an integrated circuit, a driving circuit and a gallium nitride switch, and the driving circuit is electrically connected with the integrated circuit, the gallium nitride switch and the DC-DC conversion circuit. The driving circuit comprises a first switch and a second switch, the first switch and the second switch are connected in series between the DC-DC conversion circuit and the ground, the DC-DC conversion circuit is electrically connected with the control end of the gallium nitride switch through the first switch, and the control end of the gallium nitride switch is electrically connected with the ground through the second switch; the drive circuit is configured to be at least one of the following: in response to the integrated circuit transmitting a first control signal to the drive circuit, the first switch is turned on, the second switch is turned off, and the second switch is turned off first and then the first switch is turned on; in response to the integrated circuit transmitting a second control signal to the driving circuit, the first switch is turned off, the second switch is turned on, and the first switch is turned off first and then the second switch is turned on.

Description

Technical Field

[0001] The present application relates to the field of battery management technology, and in particular to a switch drive device, a battery management system, a battery pack and an electrical device. Background Art

[0002] In order to control the charging and discharging of the battery module, switches are usually set on the discharge path and the charging path, and the drive circuit is set to control the state of the switch. For example, when discharging or charging is required, the drive circuit controls the corresponding switch to close. For another example, when discharging or charging is not required, the drive circuit controls the corresponding switch to open. Summary of the invention

[0003] The embodiments of the present application provide a switch driving device, a battery management system, a battery pack and an electrical device, which can save costs.

[0004] In a first aspect, an embodiment of the present application provides a switch driving device, including a DC-DC conversion circuit, an integrated circuit, a driving circuit and a gallium nitride switch, wherein the driving circuit is electrically connected to the integrated circuit, the gallium nitride switch and the DC-DC conversion circuit, respectively; the driving circuit includes a first switch and a second switch, the first switch and the second switch are connected in series between the DC-DC conversion circuit and the ground, the DC-DC conversion circuit is electrically connected to a control end of the gallium nitride switch through the first switch, and the control end of the gallium nitride switch is electrically connected to the ground through the second switch; the driving circuit is constructed as at least one of the following: in response to the integrated circuit transmitting a first control signal to the driving circuit, the first switch is turned on, the second switch is turned off, and the second switch is turned off first and then the first switch is turned on; in response to the integrated circuit transmitting a second control signal to the driving circuit, the first switch is turned off, the second switch is turned on, and the first switch is turned off first and then the second switch is turned on.

[0005] According to the switch driving device provided in the embodiment of the present application, the gallium nitride switch can save costs compared with the silicon-based switch; in addition, by providing a driving circuit, an integrated circuit and a DC-DC conversion circuit, the gallium nitride switch can be controlled to be turned on or off, so that normal charging and discharging control can be performed; and the first switch and the second switch in the driving circuit are turned on and off in a certain order, which can prevent the voltage output by the DC-DC conversion circuit from being directly pulled to the ground, thereby preventing excessive current from damaging the device.

[0006] In a second aspect, based on the same inventive concept, an embodiment of the present application further provides a battery management system, comprising a switch driving device as described in the first aspect or any one embodiment of the first aspect.

[0007] In the third aspect, based on the same inventive concept, the embodiment of the present application also provides a battery pack, including a battery module, and a battery management system as described in the embodiment of the second aspect.

[0008] In a fourth aspect, based on the same inventive concept, an embodiment of the present application further provides an electrical device, comprising a battery pack as described in the embodiment of the third aspect.

[0009] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Other features, objects and advantages of the present application will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features and the accompanying drawings are not drawn to scale.

[0011] Figure 1 A schematic diagram showing a structure of an electric device provided in an embodiment of the present application is shown;

[0012] Figure 2 A schematic diagram showing the structure of a battery pack provided in an embodiment of the present application is shown;

[0013] Figure 3 A schematic diagram of the structure of a battery management system provided in an embodiment of the present application is shown;

[0014] Figure 4 A schematic diagram showing a circuit structure of a switch driving device provided in an embodiment of the present application is shown;

[0015] Figure 5 A schematic diagram showing a circuit structure of a DC-DC conversion circuit in a switch driving device provided in an embodiment of the present application is shown;

[0016] Figure 6 Another circuit structure schematic diagram of the switch driving device provided in an embodiment of the present application is shown;

[0017] Figure 7 A schematic diagram showing another circuit structure of the switch driving device provided in an embodiment of the present application is shown;

[0018] Figure 8 A schematic diagram showing a circuit structure of a driving circuit in a switch driving device provided in an embodiment of the present application is shown;

[0019] Fig. 9 Another circuit structure schematic diagram of a drive circuit in a switch drive device provided in an embodiment of the present application is shown;

[0020] Fig.10Another circuit structure schematic diagram of a drive circuit in a switch drive device provided in an embodiment of the present application is shown;

[0021] Fig.11 Another circuit structure schematic diagram of a drive circuit in a switch drive device provided in an embodiment of the present application is shown;

[0022] Fig.12 A schematic diagram showing another circuit structure of the switch driving device provided in an embodiment of the present application is shown;

[0023] Fig.13 A schematic diagram showing another circuit structure of the switch driving device provided in an embodiment of the present application is shown;

[0024] Fig.14 A circuit structure schematic diagram of a protection circuit in a switch driving device provided in an embodiment of the present application is shown;

[0025] Fig.15 Another circuit structure schematic diagram of a protection circuit in a switch driving device provided in an embodiment of the present application is shown;

[0026] Fig.16 A schematic diagram showing a circuit structure of a control circuit in a switch driving device provided in an embodiment of the present application is shown;

[0027] Fig.17 Another circuit structure schematic diagram of a control circuit in a switch driving device provided in an embodiment of the present application is shown;

[0028] Fig.18 A schematic diagram showing another circuit structure of the switch driving device provided in an embodiment of the present application is shown;

[0029] Fig.19 A schematic diagram showing another circuit structure of the switch driving device provided in an embodiment of the present application is shown;

[0030] Fig. 20 A schematic diagram of another circuit structure of the switch driving device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0031] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only constructed to explain the present application and are not constructed to limit the present application.

[0032] In the present application, when an element is stated to be “connected” or “electrically connected” to another element, it may be directly connected to the other element or one or more intervening elements may be present therebetween.

[0033] The implementation methods and specific features in the implementation methods provided in the embodiments of the present application can be combined with each other if there is no contradiction.

[0034] In order to control the charging and discharging of the battery module, switches can be set on the discharge path and the charging path, and the state of the switch controlled by the drive circuit can be set. For example, when the battery module needs to be discharged or charged, the drive circuit controls the corresponding switch to be closed. For another example, when it does not need to be discharged or charged, the drive circuit controls the corresponding switch to be opened.

[0035] In the related art, silicon-based (Si) metal-oxide-semiconductor field-effect transistors (MOSFETs) are usually used as charge and discharge switches. However, Si-MOS transistors have parasitic diodes and must be used in pairs to control the charge and discharge currents, resulting in higher costs.

[0036] In response to the above technical problems, the present application provides a switch driving device, a battery management system, a battery pack and an electrical device that can save costs.

[0037] like Figure 1 As shown, the electric device 3000 in this embodiment includes a battery pack 1000 , and the electric device 3000 also includes a load 2000 . The battery pack 1000 is electrically connected to the load 2000 to provide electric energy for the load 2000 .

[0038] In one application scenario, the power-consuming device 3000 is electrically connected to a charging device (not shown in the figure), and the charging device charges the battery pack 1000 .

[0039] In the present application, the power-consuming device 3000 includes but is not limited to power tools, electric vehicles, drones, energy storage devices, smart doors, etc. In some specific implementations, the power tools include electric drills, electric saws, etc., the electric vehicles include electric cars, electric motorcycles, electric bicycles, etc., and the energy storage devices include household energy storage devices, industrial and commercial energy storage devices, uninterruptible power supplies, etc.

[0040] like Figure 2 As shown, the battery pack 1000 includes a battery management system 100 and a battery module 200. The battery management system 100 is electrically connected to the battery module 200. The battery module 200 includes a plurality of battery cells connected in series, in parallel or in mixed connection. Mixed connection means that the electrical connection between the battery cells includes series connection and parallel connection.

[0041] The battery management system 100 detects the parameters of the battery module 200, including voltage, current, temperature, etc., and controls the charging and discharging of the battery module 200. When the battery management system 100 detects that the battery module 200 has a fault such as overvoltage, undervoltage, overcurrent, or overtemperature, the charging and discharging switch in the battery management system 100 is disconnected, thereby cutting off the charging and discharging of the battery module.

[0042] like Figure 3 As shown, the battery management system 100 includes a switch driving device 10, and the switch driving device 10 controls the charging and discharging of the battery module.

[0043] like Figure 4 As shown, the switch driving device 10 includes a DC-DC conversion circuit 1 , an integrated circuit 2 , a driving circuit 3 and a gallium nitride switch 4 .

[0044] The driving circuit 3 is electrically connected to the integrated circuit 2 , the gallium nitride switch 4 and the DC-DC conversion circuit 1 respectively.

[0045] The driving circuit 3 includes a first switch Q1 and a second switch Q2. The first switch Q1 and the second switch Q2 are connected in series between the DC-DC conversion circuit 1 and the ground GND. The DC-DC conversion circuit 1 is electrically connected to the control end of the gallium nitride switch 4 through the first switch Q1, and the control end of the gallium nitride switch 4 is electrically connected to the ground GND through the second switch Q2.

[0046] The driving circuit 3 is configured as at least one of the following:

[0047] In response to the integrated circuit 2 transmitting the first control signal to the driving circuit 3, the first switch Q1 is turned on, the second switch Q2 is turned off, and the second switch Q2 is turned off first, and then the first switch Q1 is turned on;

[0048] In response to the integrated circuit 2 transmitting the second control signal to the driving circuit 3 , the first switch Q1 is turned off and the second switch Q2 is turned on, and the first switch Q1 is turned off first and then the second switch Q2 is turned on.

[0049] The gallium nitride switch 4 is a GaN MOS transistor, which is a metal oxide semiconductor field effect transistor (MOSFET) manufactured based on gallium nitride material. The main conductive structure of the gallium nitride switch is a two-dimensional gas (2DEG) layer. Unlike the inversion layer of the Si MOS transistor, the gallium nitride switch has no PN structure and no body diode. The gallium nitride switch can achieve bidirectional conduction. A gallium nitride switch can replace a pair of Si MOS transistors. The gallium nitride switch is small in size. The use of a gallium nitride switch can save circuit board space and reduce overall weight, thereby reducing costs and facilitating the layout and wiring of the circuit board. In addition, the gallium nitride switch has a high withstand voltage and a strong overcurrent capability. Compared with the Si MOS transistor, the gallium nitride switch has a lower on-resistance (Rds(on)) at the same voltage level, so the gallium nitride switch generates lower power consumption in the on state.

[0050] In one application scenario, the first end of the gallium nitride switch 4 is electrically connected to the first pole of the battery module 20, and the second end of the gallium nitride switch 4 is electrically connected to the load. The battery module 20 discharges to the load through the gallium nitride switch 4, and the gallium nitride switch 4 is a switch on the discharge path of the battery module 20.

[0051] In another application scenario, the first end of the GaN switch 4 is electrically connected to the first pole of the battery module 20, and the second end of the GaN switch 4 is electrically connected to the charging device. The charging device charges the battery module through the GaN switch 4, and the GaN switch 4 is a switch on the charging path of the battery module 20.

[0052] Exemplarily, the first electrode of the battery module 20 is the positive electrode of the battery module.

[0053] Exemplarily, the input end of the DC-DC conversion circuit 1 is electrically connected to the first pole of the battery module 200, and the DC-DC conversion circuit 1 boosts the voltage from the first pole of the battery module 200 and outputs it to the drive circuit 3. For example, Figure 4 In the figure, the voltage of the first electrode of the battery module 200 is marked as V_B+, the voltage output by the DC-DC conversion circuit 1 is marked as V_Boost, and V_Boost is greater than V_B+. For example, V_Boost is about 6.2V higher than V_B+.

[0054] Exemplarily, the integrated circuit 2 includes but is not limited to a microcontroller unit (MCU) and / or an analog front end (AFE). The integrated circuit 2 can transmit a control signal to the driving circuit 3 as required. For example, when the gallium nitride switch 4 needs to be turned on, the first control signal provided by the integrated circuit 2 is a high level; when the gallium nitride switch 4 needs to be turned off, the second control signal provided by the integrated circuit 2 is a low level.

[0055] The driving circuit 3 includes a first switch Q1 and a second switch Q2. By controlling the states of the first switch Q1 and the second switch Q2, the signal connected to the control end of the GaN switch 4 is changed, thereby driving the GaN switch 4 to be turned off or on.

[0056] It is understandable that the first switch Q1 is illustrated as a PNP transistor and the second switch Q2 is an NMOS transistor in the drawings of the present application. In other examples, the first switch Q1 is a PMOS transistor and / or the second switch Q2 is an NPN transistor.

[0057] Exemplarily, when the first switch Q1 is turned on and the second switch Q2 is turned off, the control end of the gallium nitride switch 4 is electrically connected to the DC-DC conversion circuit 1 through the first switch Q1, and the voltage V_Boost output by the DC-DC conversion circuit 1 is transmitted to the control end of the gallium nitride switch 4, thereby controlling the gallium nitride switch 4 to turn on, thereby charging or discharging the battery module. In addition, the second switch Q2 is turned off first, and then the first switch Q1 is turned on, to prevent the high voltage V_Boost output by the DC-DC conversion circuit 1 from being directly transmitted to the ground GND through the first switch Q1 and the second switch Q2, to avoid excessive current and damage to the device, and to avoid V_Boost from being unable to be transmitted to the control end of the gallium nitride switch 4, and unable to turn on the gallium nitride switch 4.

[0058] When the first switch Q1 is turned off and the second switch Q2 is turned on, the control end of the gallium nitride switch 4 is electrically connected to the ground GND through the second switch Q2, and the potential of the control end of the gallium nitride switch 4 is pulled down, thereby controlling the gallium nitride switch 4 to turn off, thereby stopping the battery module from charging or discharging. In addition, the first switch Q1 is turned off first, and then the second switch Q2 is turned on, to prevent the high voltage V_Boost output by the DC-DC conversion circuit 1 from being directly transmitted to the ground GND through the first switch Q1 and the second switch Q2, thereby avoiding excessive current and damaging the device.

[0059] According to the switch driving device provided in the embodiment of the present application, the gallium nitride switch can save costs compared with the silicon-based switch; in addition, by providing a driving circuit, an integrated circuit and a DC-DC conversion circuit, the gallium nitride switch can be controlled to be turned on or off, so that normal charging and discharging control can be performed; and the first switch and the second switch in the driving circuit are turned on and off in a certain order, which can prevent the voltage output by the DC-DC conversion circuit from being directly pulled to the ground, thereby preventing excessive current from damaging the device.

[0060] As an example, the structure of the DC-DC conversion circuit 1 includes but is not limited to Figure 5 As shown in the structure. Figure 5 As shown, the voltage V_B+ of the battery module 200 charges the capacitor C6 and the capacitor C7, and the upper voltage of the capacitor C6 is higher than the lower voltage of the capacitor C7 by V_B+. When the PWM signal is at a low level, the switch Q11 is turned off and the switch Q10 is turned on. At this time, the lower voltage of the capacitor C7 is 15V. Since the capacitor voltage cannot change suddenly, the upper voltage of the capacitor C6 is the sum of 15V and V_B+, that is, the voltage of the node N1 is the sum of 15V and V_B+ (ignoring the voltage drop of the diode D10), so as to achieve the purpose of boosting. When the PWM signal is at a high level, the voltage of the node N1 is maintained by the capacitor C8 and the capacitor C9, and will not change suddenly, and this cycle repeats. The voltage of the node N1 is stably higher than the voltage V_B+ by about 15V, and then the voltage regulator diode ZD2 is relied on to ensure that the voltage V_Boost output by the DC-DC conversion circuit is higher than the voltage V_B+.

[0061] For example, combined with reference Figure 4 and Figure 5 The voltage regulator diode ZD2 is a 6.2V voltage regulator tube, which can make the voltage V_Boost 6.2V higher than the voltage V_B+. After deducting the voltage drop of the back-end device, when the first switch Q1 of the driving circuit 3 is turned on and the second switch Q2 is turned off, the voltage transmitted to the control end of the gallium nitride switch 4 is approximately (5.5+V_B+)V, thereby controlling the gallium nitride switch 4 to turn on.

[0062] In some optional implementations, such as Figure 6 As shown, the driving circuit 3 includes a first switch unit 31 and a second switch unit 32 .

[0063] The first switch unit 31 is electrically connected to the integrated circuit 2 and the control end of the first switch Q1 respectively. The first switch unit 31 is constructed to control the first switch Q1 to be turned off or on in response to the integrated circuit 2 transmitting a control signal to the first switch unit 31 .

[0064] The second switch unit 32 is electrically connected to the integrated circuit 2 and the control end of the second switch Q2 respectively. The second switch unit 32 is constructed to control the second switch Q2 to be turned off or on in response to the integrated circuit 2 transmitting a control signal to the second switch unit 32 .

[0065] The control signal transmitted by the integrated circuit 2 to the first switch unit 31 includes a first control signal and a second control signal. Specifically, the first switch unit 31 is configured as follows: in response to the integrated circuit 2 transmitting the first control signal to the first switch unit 31, the first switch unit 31 controls the first switch Q1 to be turned on; in response to the integrated circuit 2 transmitting the second control signal to the first switch unit 31, the first switch unit 31 controls the first switch Q1 to be turned off.

[0066] The control signal transmitted by the integrated circuit 2 to the second switch unit 32 includes a first control signal and a second control signal. Specifically, the second switch unit 32 is configured as follows: in response to the integrated circuit 2 transmitting the first control signal to the second switch unit 32, the second switch unit 32 controls the second switch Q2 to be turned off; in response to the integrated circuit 2 transmitting the second control signal to the second switch unit 32, the second switch unit 32 controls the second switch Q2 to be turned on.

[0067] In this embodiment, by providing a first switch unit and a second switch unit, the first switch unit receives a control signal of the integrated circuit and controls the first switch to be turned off or on, and the second switch unit receives a control signal of the integrated circuit and controls the second switch to be turned off or on. Different switch units control the states of the first switch and the second switch, so that the first switch and the second switch can be turned on and off in a certain order.

[0068] As an example, Figure 6 As shown, the first switch unit 31 and the second switch unit 32 are both electrically connected to the first pin pin1 of the integrated circuit 2. In this example, the control signal received by the first switch unit 31 and the second switch unit 32 from the integrated circuit 2 is the same control signal. In addition, ignoring the signal delay caused by the connection line between the first switch unit 31 and the second switch unit 32 and the integrated circuit 2, the first switch unit 31 and the second switch unit 32 simultaneously receive the control signal provided by the integrated circuit 2. In this example, by designing the hardware circuit structure of the first switch unit 31 and the second switch unit 32, the first switch and the second switch are turned on and off in a certain order.

[0069] As another example, Figure 7As shown, the first switch unit 31 is electrically connected to the second pin pin2 of the integrated circuit 2, and the second switch unit 32 is electrically connected to the third pin pin3 of the integrated circuit 2. In this example, the integrated circuit 2 is constructed such that the moment when the second pin pin2 outputs the control signal is different from the moment when the third pin pin3 outputs the control signal. That is, the second pin pin2 and the third pin pin3 output the control signal at a certain interval, and the interval is preset according to actual needs.

[0070] As an example, the third pin pin3 of the integrated circuit 2 first transmits the first control signal to the second switch unit 32, and the second switch unit 32 controls the second switch Q2 to turn off. After a certain interval, the second pin pin2 of the integrated circuit 2 transmits the first control signal to the first switch unit 31, and the first switch unit 31 controls the first switch Q1 to turn on, thereby achieving the second switch Q2 being turned off first and then the first switch Q1 being turned on.

[0071] As another example, the second pin pin2 of the integrated circuit 2 first transmits the second control signal to the first switch unit 31, and the first switch unit 31 controls the first switch Q1 to turn off. After a certain interval, the third pin pin3 of the integrated circuit 2 transmits the second control signal to the second switch unit 32, and the second switch unit 32 controls the second switch Q2 to turn on, thereby achieving the first switch Q1 being turned off first and then the second switch Q2 being turned on.

[0072] In some optional implementations, such as Figure 8 As shown, the switch driving device 10 further includes a first power supply V1. For example, the output voltage of the first power supply V1 is 3.3V.

[0073] The first switch unit 31 includes a third switch Q3 , a first resistor R1 , and a second resistor R2 .

[0074] A first end of the third switch Q3 is electrically connected to the control end of the first switch Q1, a second end of the third switch Q3 is electrically connected to the ground GND, a first resistor R1 is electrically connected between the control end of the third switch Q3 and the ground GND, a second resistor R2 is electrically connected between the control end of the third switch Q3 and the integrated circuit 2, and the second resistor R2 is also connected in series with the first resistor R1 between the integrated circuit 2 and the ground GND.

[0075] The second switch unit 32 includes a fourth switch Q4 , a third resistor R3 , a fourth resistor R4 , and a fifth resistor R5 .

[0076] A first end of the fourth switch Q4 is electrically connected to the first power source V1 through the third resistor R3, and a first end of the fourth switch Q4 is electrically connected to the control end of the second switch Q2, a second end of the fourth switch Q4 is electrically connected to the ground GND, a fourth resistor R4 is electrically connected between the control end of the fourth switch Q4 and the ground GND, a fifth resistor R5 is electrically connected between the control end of the fourth switch Q4 and the integrated circuit 2, and the fifth resistor R5 is also connected in series with the fourth resistor R4 between the integrated circuit 2 and the ground GND.

[0077] For example, Figure 8 As shown, the second resistor R2 is electrically connected to the second pin pin2 of the integrated circuit 2 , and the fifth resistor R5 is electrically connected to the third pin pin3 of the integrated circuit 2 .

[0078] For example, the third pin pin3 of the integrated circuit 2 first outputs a high-level signal, which is transmitted to the control end of the fourth switch Q4 through the fifth resistor R5, the fourth switch Q4 is turned on, the potential of the control end of the second switch Q2 is pulled down by the ground GND, and the second switch Q2 is turned off. After a certain interval, the second pin pin2 of the integrated circuit 2 outputs a high-level signal again, which is transmitted to the control end of the third switch Q3 through the second resistor R2, the third switch Q3 is turned on, the potential of the control end of the first switch Q1 is pulled down by the ground GND, the first switch Q1 is turned on, and the voltage output by the DC-DC conversion circuit 1 is transmitted to the control end of the gallium nitride switch 4 through the first switch Q1, and the gallium nitride switch 4 is turned on. In this example, the third pin pin3 first outputs a high-level signal, and after a certain interval, the second pin pin2 outputs a high-level signal again, so that the second switch Q2 is turned off first, and then the first switch Q1 is turned on, and the first control signal output by the integrated circuit 2 is high.

[0079] In some embodiments, the third resistor R3 is used for current limiting.

[0080] It is understandable that the third switch Q3 and the fourth switch Q4 are illustrated as NMOS transistors in the drawings of the present application. In other examples, the third switch Q3 and / or the fourth switch Q4 are NPN transistors.

[0081] In some optional implementations, such as Fig. 9 As shown, the first switch unit 31 further includes a first capacitor C1 , and the first capacitor C1 is electrically connected between the control end of the third switch Q3 and the ground GND.

[0082] The second switch unit 32 further includes a second capacitor C2 , and the second capacitor C2 is electrically connected between the control terminal of the fourth switch Q4 and the ground GND.

[0083] The product of the resistance value of the second resistor R2 and the capacitance value of the first capacitor C1 is a first product, the product of the resistance value of the fifth resistor R5 and the capacitance value of the second capacitor C2 is a second product, and the first product is greater than the second product.

[0084] The second resistor R2 and the first capacitor C1 form a delay circuit for controlling the third switch Q3 to be turned on, and the fifth resistor R5 and the second capacitor C2 form a delay circuit for controlling the fourth switch Q4 to be turned on. The product of the resistance value and the capacitance value in the delay circuit is the time constant of the delay. The larger the time constant, the longer the delay; conversely, the smaller the time constant, the shorter the delay.

[0085] For example, Fig. 9 As shown, the second resistor R2 and the fifth resistor R5 are electrically connected to the first pin pin1 of the integrated circuit 2. The first pin pin1 of the integrated circuit 2 outputs a high level signal, and since the first product is greater than the second product, the fourth switch Q4 is turned on first, and then the third switch Q3 is turned on after a certain interval, so that the second switch Q2 is turned off first, and then the first switch Q1 is turned on.

[0086] In this embodiment, by setting the first capacitor and the second capacitor, and designing the product of the resistance value of the second resistor and the capacitance value of the first capacitor to be greater than the product of the resistance value of the fifth resistor and the capacitance value of the second capacitor, in this way, the second switch can be disconnected first and then the first switch is opened through hardware design. In this way, the integrated circuit only needs to send a first control signal, which can simplify the control program of the integrated circuit, save the pin resources of the integrated circuit, and the implementation method of the hardware design has higher reliability.

[0087] In some optional implementations, such as Fig.10 As shown, the first switch unit 31 further includes a sixth resistor R6, a first diode D1 and a second diode D2.

[0088] The second resistor R2 and the first diode D1 are connected in series between the control end of the third switch Q3 and the integrated circuit 2 , and the cathode of the first diode D1 is electrically connected to the control end of the third switch Q3 .

[0089] The sixth resistor R6 and the second diode D2 are connected in series between the control terminal of the third switch Q3 and the integrated circuit 2 , and the anode of the second diode D2 is electrically connected to the control terminal of the third switch Q3 .

[0090] The first diode D1 and the second resistor R2 are arranged in the first path, the second diode D2 and the sixth resistor R6 are arranged in the second path, and the first path is connected in parallel with the second path.

[0091] The second switch unit 32 further includes a seventh resistor R7, a third diode D3 and a fourth diode D4.

[0092] The fifth resistor R5 and the third diode D3 are connected in series between the control terminal of the fourth switch Q4 and the integrated circuit 2 , and the cathode of the third diode D3 is electrically connected to the control terminal of the fourth switch Q4 .

[0093] The seventh resistor R7 and the fourth diode D4 are connected in series between the control terminal of the fourth switch Q4 and the integrated circuit 2 , and the anode of the fourth diode D4 is electrically connected to the control terminal of the fourth switch Q4 .

[0094] The third diode D3 and the fifth resistor R5 are arranged in the third path, the fourth diode D4 and the seventh resistor R7 are arranged in the fourth path, and the third path is connected in parallel with the fourth path.

[0095] For example, Fig.10 As shown, the second resistor R2 and the sixth resistor R6 are electrically connected to the second pin pin2 of the integrated circuit 2 , and the fifth resistor R5 and the seventh resistor R7 are electrically connected to the third pin pin3 of the integrated circuit 2 .

[0096] The above about Figure 8 In the example, the third pin pin3 of the integrated circuit 2 first outputs a high level signal, and after a certain interval, the second pin pin2 outputs a high level signal again, so that the second switch Q2 is turned off first, and then the first switch Q1 is turned on. Fig.10 The implementation method of first turning off the second switch Q2 and then turning on the first switch Q1 is the same as this, and will not be repeated here.

[0097] Please refer to Fig.10 , the second pin pin2 of the integrated circuit 2 first outputs a low-level signal, the control terminal voltage of the third switch Q3 is discharged through the sixth resistor R6 and the second diode D2, the third switch Q3 is turned off, and then the first switch Q1 is turned off. After a certain interval, the third pin pin3 of the integrated circuit 2 outputs a low-level signal again, the control terminal voltage of the fourth switch Q4 is discharged through the seventh resistor R7 and the fourth diode D4, the fourth switch Q4 is turned off, the control terminal potential of the second switch Q2 is pulled up by the first power supply V1, the second switch Q2 is turned on, the control terminal potential of the gallium nitride switch 4 is pulled down by the ground GND, and the gallium nitride switch 4 is turned off. In this example, the second pin pin2 first outputs a low-level signal, and after a certain delay, the third pin pin3 outputs a low-level signal again, so that the first switch Q1 is turned off first, and then the second switch Q2 is turned on.

[0098] It can be understood that the first path where the first diode D1 and the second resistor R2 are located can be used as a charging path for the third switch Q3, and the second path where the second diode D2 and the sixth resistor R6 are located can be used as a discharging path for the third switch Q3. The diodes arranged on the two paths make the charging path and the discharging path of the third switch Q3 independent of each other, which makes it easy to control the opening and closing sequence of the third switch Q3.

[0099] Similarly, the third path where the third diode D3 and the fifth resistor R5 are located can be used as a charging path for the fourth switch Q4, and the fourth path where the fourth diode D4 and the seventh resistor R7 are located can be used as a discharging path for the fourth switch Q4. The diodes arranged on the two paths make the charging path and the discharging path of the fourth switch Q4 independent of each other, which makes it easy to control the opening and closing sequence of the fourth switch Q4.

[0100] For example, Fig.10 or Fig.11 As shown, the resistance value of the sixth resistor R6 can be smaller than the resistance value of the first resistor R1, so that the control terminal voltage of the third switch Q3 can be discharged quickly. The resistance value of the seventh resistor R7 can be smaller than the resistance value of the fourth resistor R4, so that the control terminal voltage of the fourth switch Q4 can be discharged quickly.

[0101] In some optional implementations, the resistance value of the sixth resistor R6 is smaller than the resistance value of the seventh resistor R7.

[0102] For example, Fig.11 As shown, the second resistor R2, the sixth resistor R6, the fifth resistor R5 and the seventh resistor R7 are electrically connected to the first pin pin1 of the integrated circuit 2. The first pin pin1 of the integrated circuit 2 outputs a low level signal. Since the resistance value of the sixth resistor R6 is less than the resistance value of the seventh resistor R7, the third switch Q3 is turned off first, and then the fourth switch Q4 is turned off after a certain interval, so that the first switch Q1 is turned off first, and then the second switch Q2 is turned on. It can be understood that the second control signal output by the integrated circuit 2 is a low level.

[0103] In this embodiment, by setting the resistance value of the sixth resistor to be smaller than the resistance value of the seventh resistor, the first switch can be turned off first and then the second switch can be turned on through hardware design. In this way, the integrated circuit only needs to send a second control signal, which can simplify the control program of the integrated circuit and the reliability of the hardware design implementation method is higher.

[0104] In some optional implementations, such as Fig.10 or Fig.11 As shown, the switch driving device further includes an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10.

[0105] A first end of the eighth resistor R8 is electrically connected to the DC-DC conversion circuit 1, a second end of the eighth resistor R8 is electrically connected to a first end of a ninth resistor R9 and a first end of the first switch Q1, respectively, a second end of the ninth resistor R9 is electrically connected to a control end of the first switch Q1, and a second end of the first switch Q1 is electrically connected to a control end of the gallium nitride switch 4.

[0106] The tenth resistor R10 is electrically connected between the control end of the second switch Q2 and the first end of the second switch Q2 . The first end of the second switch Q2 is electrically connected to the ground GND. The second end of the second switch Q2 is electrically connected to the control end of the GaN switch 4 .

[0107] In this example, the eighth resistor R8 is used for current limiting. The ninth resistor R9 is used as a bias resistor of the first switch Q1, so that the first switch Q1 is turned off by default. The tenth resistor R10 is used as a bias resistor of the second switch Q2, so that the second switch Q2 is turned off by default.

[0108] In some optional implementations, such as Fig.10 or Fig.11 As shown, the switch driving device also includes: an eleventh resistor R11, electrically connected between the first switch unit 31 and the control end of the first switch Q1; a twelfth resistor R12, electrically connected between the second switch unit 32 and the control end of the second switch Q2; a thirteenth resistor R13, electrically connected between the second switch Q2 and the control end of the gallium nitride switch 4.

[0109] In this embodiment, the eleventh resistor R11, the twelfth resistor R12 and the thirteenth resistor R13 are all used for current limiting to prevent excessive current on the paths where these resistors are located, thereby preventing damage to the device.

[0110] In some optional implementations, such as Fig.10 or Fig.11 As shown, the switch driving device also includes: a fourteenth resistor R14, electrically connected between the second end of the first switch Q1 and the control end of the gallium nitride switch 4; and / or, a fifteenth resistor R15, wherein the first end of the fifteenth resistor R15 is electrically connected to the first switch Q1 and the second switch Q2 respectively, and the second end of the fifteenth resistor R15 is electrically connected to the control end of the gallium nitride switch 4.

[0111] In this embodiment, the fourteenth resistor R14 and / or the fifteenth resistor R15 are used for current limiting to prevent excessive current on the paths where these resistors are located, thereby preventing damage to the device.

[0112] In some optional implementations, such as Fig.10 or Fig.11As shown, the switch driving device also includes a positive temperature coefficient thermistor RT. The positive temperature coefficient thermistor RT is electrically connected between the DC-DC conversion circuit 1 and the first switch Q1. The resistance value of the positive temperature coefficient thermistor RT increases when the temperature is high, which can make the current on the path relatively small to protect the components in the circuit. The resistance value of the positive temperature coefficient thermistor RT is small when the temperature is low, so that the circuit can work normally.

[0113] In some optional implementations, such as Fig.12 As shown, the switch driving device 10 further includes a protection circuit 5 , which is electrically connected to the integrated circuit 2 and the control end of the gallium nitride switch 4 .

[0114] The protection circuit 5 is constructed to be electrically connected to the first pole of the battery module 200 and transmit a third control signal to the protection circuit 5 in response to the integrated circuit 2. The protection circuit 5 electrically connects the first pole of the battery module 200 to the control end of the gallium nitride switch 4.

[0115] Exemplarily, the protection circuit 5 and the driving circuit 3 are electrically connected to different pins of the integrated circuit 2. For example, the protection circuit 5 is electrically connected to the fourth pin pin4 of the integrated circuit 2.

[0116] Exemplarily, the first end of the gallium nitride switch 4 is electrically connected to the first electrode of the battery module 200, and the second end of the gallium nitride switch 4 is electrically connected to the load, and the gallium nitride switch 4 is a switch on the discharge path of the battery module 200. For example, the battery module 200 is used in an electric vehicle, and when the battery module 200 is in the discharge mode, the electric vehicle runs downhill. In this case, the motor in the electric vehicle reverses and generates a feedback voltage. At this time, the feedback voltage is prevented from charging the battery module 200, so that the battery module 200 enters the feedback protection mode.

[0117] In this embodiment, a protection circuit is provided, and the protection circuit responds to the third control signal of the integrated circuit to electrically connect the first pole of the battery module to the control end of the gallium nitride switch. The voltages of the control end of the gallium nitride switch and the first end of the gallium nitride switch are equal to the first pole voltage of the battery module, so that the gallium nitride switch enters the diode mode, and the battery module performs a small current freewheeling discharge through the gallium nitride switch in the diode mode, so that feedback protection can be performed in the discharge mode.

[0118] In some optional implementations, such as Fig.13 As shown, the switch driving device 10 further includes a control circuit 6 , and the control circuit 6 is electrically connected to the integrated circuit 2 and the driving circuit 3 .

[0119] The control circuit 6 is configured to control the drive circuit 3 to disconnect the electrical connection with the gallium nitride switch 4 before the protection circuit 2 electrically connects the first electrode of the battery module 200 to the control end of the gallium nitride switch 4 .

[0120] The control end of the GaN switch 4 is not only electrically connected to the drive circuit 3, but also electrically connected to the protection circuit 5. Both the drive circuit 3 and the protection circuit 5 can transmit signals to the control end of the GaN switch 4. When charging or discharging control is required, the drive circuit 3 is electrically connected to the control end of the GaN switch 4. When feedback protection is required, the protection circuit 5 is electrically connected to the control end of the GaN switch 4.

[0121] In this embodiment, a control circuit is further provided. When the protection circuit performs feedback protection, the control circuit controls the driving circuit to disconnect the electrical connection with the gallium nitride switch, thereby ensuring the effectiveness of the feedback protection.

[0122] In some optional implementations, such as Fig.14 As shown, the protection circuit 5 includes a third switch unit 53, a fourth switch unit 54, a fifth switch Q5, a sixteenth resistor R16 and a seventeenth resistor R17.

[0123] The first end of the third switch unit 53 is electrically connected to the first end of the fourth switch unit 53 , the second end of the third switch unit 53 is configured to be electrically connected to the first pole of the battery module 200 , and the second end of the fourth switch unit 54 is electrically connected to the control end of the gallium nitride switch 4 .

[0124] A first end of the fifth switch Q5 is electrically connected to the ground GND, and a second end of the fifth switch Q5 is electrically connected to a third end of the third switch unit 53 and a third end of the fourth switch unit 54 , respectively.

[0125] The sixteenth resistor R16 is electrically connected between the control end of the fifth switch Q5 and the first end of the fifth switch Q5, the seventeenth resistor R17 is electrically connected between the integrated circuit 2 and the control end of the fifth switch Q5, and the sixteenth resistor R16 and the seventeenth resistor R17 are connected in series between the integrated circuit 2 and the ground GND.

[0126] The third switch unit 53 is configured to prevent the output voltage of the DC-DC conversion circuit 1 from flowing to the first electrode of the battery module 200 in response to the gallium nitride switch 4 being in the open state.

[0127] The fourth switch unit 54 is configured to prevent the voltage of the battery module 200 from flowing to the control terminal of the gallium nitride switch 4 in response to the gallium nitride switch 4 being in the off state.

[0128] The third terminal of the third switch unit 53 is its control terminal, and the third terminal of the fourth switch unit 54 is its control terminal.

[0129] In this embodiment, when the gallium nitride switch 4 is in the on state, the control end of the gallium nitride switch 4 is connected to the output voltage of the DC-DC conversion circuit 1, and the third switch unit 53 prevents the output voltage of the DC-DC conversion circuit 1 from flowing to the first pole of the battery module 200. When the gallium nitride switch 4 is in the off state, the control end of the gallium nitride switch 4 is electrically connected to the ground GND, and the fourth switch unit 54 prevents the voltage of the battery module 200 from flowing to the control end of the gallium nitride switch 4 to avoid affecting the off state of the gallium nitride switch 4. In this embodiment, the third switch unit 53 and the fourth switch unit 54 can play a role of bidirectional cutoff.

[0130] In addition, the sixteenth resistor R16 is used as a bias resistor of the fifth switch Q5, so that the fifth switch Q5 is in an off state by default, and the seventeenth resistor R17 is used for current limiting.

[0131] It is understandable that the fifth switch Q5 is illustrated as an NMOS transistor in the drawings of the present application. In other examples, the fifth switch Q5 is an NPN transistor.

[0132] In some optional implementations, such as Fig.15 As shown, the third switch unit includes a sixth switch Q6, the fourth switch unit includes a seventh switch Q7, and the third switch unit and the fourth switch unit both include an eighteenth resistor R18 and a nineteenth resistor R19.

[0133] The first end of the sixth switch Q6 is electrically connected to the first end of the seventh switch Q7, the second end of the sixth switch Q6 is electrically connected to the first electrode of the battery module 200, and the second end of the seventh switch Q7 is electrically connected to the control end of the gallium nitride switch 4. One end of the eighteenth resistor R18 is electrically connected to the first end of the sixth switch Q6 and the first end of the seventh switch Q7, respectively, and the other end of the eighteenth resistor R18 is electrically connected to the control end of the sixth switch Q6 and the control end of the seventh switch Q7, respectively. One end of the nineteenth resistor R19 is electrically connected to the control end of the sixth switch Q6 and the control end of the seventh switch Q7, respectively, and the other end of the nineteenth resistor R19 is electrically connected to the second end of the fifth switch Q5.

[0134] In the case where feedback protection is required, the third control signal provided by the integrated circuit 2 to the protection circuit 5 is a high level, and the high level is transmitted to the control end of the fifth switch Q5 through the seventeenth resistor R17, the fifth switch Q5 is turned on, the potentials of the control ends of the sixth switch Q6 and the seventh switch Q7 are pulled down by the ground GND, the sixth switch Q6 and the seventh switch Q7 are turned on, and the first electrode of the battery module 200 is electrically connected to the control end of the gallium nitride switch 4 through the sixth switch Q6 and the seventh switch Q7, the potentials of the control end and the first end of the gallium nitride switch 4 are equal, so that the gallium nitride switch 4 enters the diode mode, thereby performing feedback protection.

[0135] Exemplarily, the sixth switch Q6 and the seventh switch Q7 are PMOS transistors, and both the sixth switch Q6 and the seventh switch Q7 include body diodes, and the cathodes of the body diodes of the two are connected. When the gallium nitride switch 4 is in the on state, the body diode of the sixth switch Q7 prevents the voltage at the control end of the gallium nitride switch 4 from flowing to the first pole of the battery module 200, that is, prevents the voltage output by the DC-DC conversion circuit from flowing to the positive pole of the battery module 200. When the gallium nitride switch 4 is in the off state, the body diode of the seventh switch Q7 prevents the voltage at the first pole of the battery module 200 from flowing to the control end of the gallium nitride switch 4.

[0136] The eighteenth resistor R18 is used as a bias resistor for the sixth switch Q6 and the seventh switch Q7, so that the sixth switch Q6 and the seventh switch Q7 are in an off state by default. The nineteenth resistor R19 is used for current limiting.

[0137] In some optional implementations, such as Fig.15 As shown, the protection circuit 5 further includes a twentieth resistor R20, a fifth diode D5 and a sixth diode D6.

[0138] The fifth diode D5 and the seventeenth resistor R17 are connected in series between the integrated circuit 2 and the fifth switch Q5 . The cathode of the fifth diode D5 is electrically connected to the control terminal of the fifth switch Q5 .

[0139] The sixth diode D6 and the twentieth resistor R20 are connected in series between the integrated circuit 2 and the fifth switch Q5 . The anode of the sixth diode D6 is electrically connected to the control terminal of the fifth switch Q5 .

[0140] The fifth diode D5 and the seventeenth resistor R17 are arranged in the fifth path, the sixth diode D6 and the twentieth resistor R20 are arranged in the sixth path, and the fifth path and the sixth path are connected in parallel.

[0141] When feedback protection is not required, the third control signal provided by the integrated circuit 2 to the protection circuit 5 is at a low level, the control terminal voltage of the fifth switch Q5 is discharged through the sixth diode D6 and the twentieth resistor R20, the fifth switch Q5 is turned off, and then the sixth switch Q6 and the seventh switch Q7 are turned off.

[0142] Exemplarily, the resistance value of the twentieth resistor R20 is smaller than the resistance value of the sixteenth resistor R16, so that the voltage at the control terminal of the fifth switch Q5 can be discharged quickly.

[0143] It is understandable that the fifth path where the fifth diode D5 and the seventeenth resistor R17 are located can be used as a charging path for the fifth switch Q5, and the sixth diode D6 and the twentieth resistor R20 are provided on the sixth path can be used as a discharging path for the fifth switch Q5. The diodes provided on the two paths make the charging path and the discharging path of the fifth switch Q5 independent of each other, which facilitates controlling the opening and closing sequence of the fifth switch Q5.

[0144] In some optional implementations, such as Fig.15 As shown, the protection circuit 5 further includes a twenty-first resistor R21, which is connected between the seventh switch Q7 and the control end of the gallium nitride switch 4; and / or, the protection circuit 5 further includes a first filtering unit 51, which is configured to be electrically connected between the first pole of the battery module 200 and the ground GND; and / or, a third capacitor C3, a first end of the third capacitor C3 is electrically connected to the second end of the fifth switch Q5, and a second end of the third capacitor C3 is electrically connected to the control end of the sixth switch Q6 and the control end of the seventh switch Q7 respectively; and / or, the protection circuit 5 further includes a Zener diode ZD1, a first end of the Zener diode ZD1 is electrically connected to the first end of the sixth switch Q6 and the first end of the seventh switch Q7 respectively, and a second end of the Zener diode ZD1 is electrically connected to the control end of the sixth switch Q6 and the control end of the seventh switch Q7.

[0145] The twenty-first resistor R21 can be used for current limiting.

[0146] The first filtering unit 51 is used for filtering. Exemplarily, the first filtering unit 51 includes at least one capacitor. For example, Fig.15 As shown, the first filtering unit 51 includes a capacitor C51 and a capacitor C52 connected in series.

[0147] The third capacitor C3 is used to enable the sixth switch Q6 and the seventh switch Q7 to be quickly turned on when the fifth switch Q5 is turned on.

[0148] The Zener diode ZD1 is used for voltage stabilization.

[0149] In some optional implementations, such as Fig.16 As shown, the control circuit 6 includes an eighth switch Q8, a twenty-second resistor R22, and a twenty-third resistor R23.

[0150] A first end of the eighth switch Q8 is electrically connected to the ground GND, and a second end of the eighth switch Q8 is electrically connected to the driving circuit 3 .

[0151] The twenty-second resistor R22 is electrically connected between the control terminal of the eighth switch Q8 and the ground GND.

[0152] The twenty-third resistor R23 is electrically connected between the control terminal of the eighth switch Q8 and the integrated circuit 2 . The twenty-third resistor R23 and the twenty-second resistor R22 are also connected in series between the integrated circuit 2 and the ground GND.

[0153] Exemplarily, the second end of the eighth switch Q8 is electrically connected to the control end of the third switch Q3 and the control end of the second switch Q2 in the driving circuit 3 .

[0154] Exemplarily, when feedback protection is required, the integrated circuit 2 provides a high level to the control circuit 6, and the high level is transmitted to the control end of the eighth switch Q8 through the twenty-third resistor R23. The eighth switch Q8 is turned on, so that the control end of the third switch Q3 and the control end of the second switch Q2 are electrically connected to the ground GND, the third switch Q3 and the second switch Q2 are turned off, and the first switch Q1 is turned off, thereby disconnecting the electrical connection between the control end of the gallium nitride switch 4 and the DC-DC conversion circuit 1, and disconnecting the electrical connection between the control end of the gallium nitride switch 4 and the ground GND.

[0155] The twenty-second resistor R22 serves as a bias resistor of the eighth switch Q8 , so that the eighth switch Q8 is in an off state by default.

[0156] The twenty-third resistor R23 is used for current limiting.

[0157] It is understandable that the eighth switch Q8 is illustrated as an NMOS transistor in the drawings of the present application, and in other examples, the eighth switch Q8 is an NPN transistor. Fig.16 Only some components in the driving circuit 3 are shown.

[0158] In some optional implementations, such as Fig.13 As shown, the protection circuit 5 is electrically connected to the fourth pin pin4 of the integrated circuit 2 , and the control circuit 6 is electrically connected to the fifth pin pin5 of the integrated circuit 2 .

[0159] Exemplarily, when feedback protection is required, the fifth pin pin5 of the integrated circuit 2 first transmits a control signal (e.g., a high level) to the control circuit 6, and the control circuit 6 responds to the control signal to control the drive circuit 3 to disconnect the electrical connection with the gallium nitride switch 4. After a certain period of time, the fourth pin pin4 of the integrated circuit 2 transmits a third control signal (e.g., a high level signal) to the protection circuit 5, and the protection circuit 5 responds to the third control signal to electrically connect the first electrode of the battery module to the control end of the gallium nitride switch 4, so that the gallium nitride switch 4 enters the diode mode to achieve feedback protection.

[0160] In some other optional implementations, please refer to Fig.15 and Fig.17The protection circuit 5 includes a fourth capacitor C4, the fourth capacitor C4 is electrically connected between the control terminal of the fifth switch Q5 and the ground GND, and the fourth capacitor C4 and the seventeenth resistor R17 are electrically connected between the integrated circuit 2 and the ground GND.

[0161] The control circuit 6 includes a fifth capacitor C5 , which is electrically connected between the control terminal of the eighth switch Q8 and the ground GND. The fifth capacitor C5 and the twenty-third resistor R23 are electrically connected between the integrated circuit 2 and the ground GND.

[0162] The product of the resistance value of the seventeenth resistor R17 and the capacitance value of the fourth capacitor C4 is the third product, the product of the resistance value of the twenty-third resistor R23 and the capacitance value of the fifth capacitor C5 is the fourth product, and the third product is greater than the fourth product.

[0163] The seventeenth resistor R17 and the fourth capacitor C4 form a delay circuit for controlling the fifth switch Q5 to be turned on, and the twenty-third resistor R23 and the fifth capacitor C5 form a delay circuit for controlling the eighth switch Q8 to be turned on. The product of the resistance value and the capacitance value in the delay circuit is the time constant of the delay. The larger the time constant, the longer the delay; conversely, the smaller the time constant, the shorter the delay.

[0164] like Fig.18 As shown, the protection circuit 5 and the control circuit 6 are both electrically connected to the sixth pin pin6 of the integrated circuit 2. Fig.19 As shown, the seventeenth resistor R17 and the twenty-third resistor R23 are both electrically connected to the sixth pin pin6 of the integrated circuit 2. In the case of needing feedback protection, the sixth pin pin6 of the integrated circuit 2 outputs a high level signal, and since the third product is greater than the fourth product, the eighth switch Q8 is first turned on, and after a certain interval, the fifth switch Q5 is then turned on, so that the control circuit 6 first disconnects the electrical connection between the drive circuit 3 and the gallium nitride switch 4, and the protection circuit 5 then electrically connects the first electrode of the battery module to the control end of the gallium nitride switch 4, so that the gallium nitride switch enters the diode mode for feedback protection.

[0165] In this embodiment, by setting the fourth capacitor and the fifth capacitor, and designing the product of the resistance value of the seventeenth resistor and the capacitance value of the fourth capacitor to be greater than the product of the resistance value of the twenty-third resistor and the capacitance value of the fifth capacitor, in this way, the control circuit first disconnects the electrical connection between the drive circuit and the gallium nitride switch through hardware design, and the protection circuit then electrically connects the first electrode of the battery module to the control end of the gallium nitride switch to achieve feedback protection. In this way, the integrated circuit only needs to send a control signal to the protection circuit and the control circuit, which can simplify the control program of the integrated circuit, save the pin resources of the integrated circuit, and the implementation method of the hardware design has higher reliability.

[0166] In some optional implementations, such as Fig.17 or Fig.19 As shown, the control circuit 6 further includes a twenty-fourth resistor R24, a seventh diode D7 and an eighth diode D8.

[0167] The seventh diode D7 and the twenty-third resistor R23 are connected in series between the integrated circuit 2 and the control end of the eighth switch Q8 . The cathode of the seventh diode D7 is electrically connected to the control end of the eighth switch Q8 .

[0168] The eighth diode D8 and the twenty-fourth resistor R24 ​​are connected in series between the integrated circuit 2 and the eighth switch Q8 . The anode of the eighth diode D8 is electrically connected to the control terminal of the eighth switch Q8 .

[0169] The seventh diode D7 and the twenty-third resistor R23 are disposed in the seventh path, the eighth diode D8 and the twenty-fourth resistor R24 ​​are disposed in the eighth path, and the seventh path is connected in parallel with the eighth path.

[0170] The seventh path where the seventh diode D7 and the twenty-third resistor R23 are located serves as a charging path for the eighth switch Q8, and the eighth path where the eighth diode D8 and the twenty-fourth resistor R24 ​​are located serves as a discharging path for the eighth switch Q8. The diodes arranged on the two paths make the charging path and the discharging path of the eighth switch Q8 independent of each other, which facilitates controlling the opening and closing sequence of the eighth switch Q8.

[0171] Exemplarily, the resistance value of the twenty-fourth resistor R24 ​​may be smaller than the resistance value of the twenty-second resistor R22 , so that the voltage at the control terminal of the eighth switch Q8 can be discharged quickly.

[0172] In some optional implementations, such as Fig.17 or Fig.19 As shown, the control circuit 6 also includes a ninth switch Q9, a first end of the ninth switch Q9 is electrically connected to the first end of the eighth switch Q8, a second end of the ninth switch Q9 is electrically connected to the second end of the eighth switch Q8, and a control end of the ninth switch Q9 is electrically connected to the control end of the eighth switch Q8.

[0173] In this embodiment, the ninth switch Q9 and the eighth switch Q8 are arranged in parallel, thereby achieving redundant protection and improving the reliability of the circuit.

[0174] In some optional implementations, such as Fig. 20 As shown, the integrated circuit 2 includes an analog front-end chip (ActiveFront End, AFE) and a microcontroller unit (Microcontroller Unit, MCU), the analog front-end chip AFE is electrically connected to the driving circuit 3, and the microcontroller unit MCU is electrically connected to the protection circuit 5 and the control circuit 6.

[0175] Exemplarily, the analog front-end chip AFE is used to collect information such as voltage, current, temperature, etc. of the battery module, and the analog front-end chip AFE is communicated with the microcontroller unit MCU.

[0176] Exemplarily, the switch in the driving circuit 3 is a MOS transistor, and a voltage of 10V to 12V needs to be connected to turn on the MOS transistor. The analog front-end chip AFE has a boost circuit, a voltage stabilizing circuit, etc. inside, and the analog front-end chip AFE outputs a voltage of 10V to 12V. The analog front-end chip AFE directly controls the driving circuit 3, and there is no need to set up an additional boost circuit, etc., which can simplify the circuit.

[0177] Exemplarily, the first switch unit and the second switch power supply in the driving circuit 3 are both electrically connected to the first pin of the analog front-end chip AFE. Alternatively, the first switch unit in the driving circuit 3 is electrically connected to the second pin of the analog front-end chip AFE, and the second switch unit in the driving circuit 3 is electrically connected to the third pin of the analog front-end chip AFE.

[0178] Exemplarily, the protection circuit 5 and the control circuit 6 are both electrically connected to the sixth pin of the micro control unit MCU. Alternatively, the protection circuit 5 is electrically connected to the fourth pin of the micro control unit MCU, and the control circuit 6 is electrically connected to the fifth pin of the micro control unit MCU.

[0179] It should be noted that in the embodiments shown in the above figures, the resistor is represented by a single resistor, and the capacitor is represented by a single capacitor. In other embodiments, the resistor may be an integration of series, parallel or mixed resistors, and the capacitor may be an integration of series, parallel or mixed capacitors. The specific parameters of each device can be set according to actual needs, and this application does not limit this.

[0180] According to the embodiments described above in the present application, these embodiments do not describe all the details in detail, nor do they limit the present application to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and the modifications based on the present application. The present application is limited only by the claims and their full scope and equivalents.

Claims

1. A switch driving device, characterized in that: It includes a DC-DC conversion circuit, an integrated circuit, a drive circuit and a gallium nitride switch, wherein the drive circuit is electrically connected to the integrated circuit, the gallium nitride switch and the DC-DC conversion circuit respectively; The driving circuit includes a first switch and a second switch, the first switch and the second switch are connected in series between the DC-DC conversion circuit and the ground, the DC-DC conversion circuit is electrically connected to the control end of the gallium nitride switch through the first switch, and the control end of the gallium nitride switch is electrically connected to the ground through the second switch; The driving circuit is configured as at least one of the following: In response to the integrated circuit transmitting a first control signal to the driving circuit, the first switch is turned on and the second switch is turned off, and the second switch is turned off first and then the first switch is turned on; In response to the integrated circuit transmitting a second control signal to the driving circuit, the first switch is turned off and the second switch is turned on, and the first switch is turned off first and then the second switch is turned on.

2. The switch driving device according to claim 1, characterized in that: The driving circuit includes a first switch unit and a second switch unit; The first switch unit is electrically connected to the integrated circuit and the control end of the first switch respectively, and the first switch unit is configured to: in response to the integrated circuit transmitting a control signal to the first switch unit, the first switch unit controls the first switch to be turned off or on; The second switch unit is electrically connected to the integrated circuit and the control end of the second switch respectively, and the second switch unit is configured to control the second switch to be turned off or on in response to the integrated circuit transmitting a control signal to the second switch unit.

3. The switch driving device according to claim 2, characterized in that: Also included is a first power source; The first switch unit includes a third switch, a first resistor and a second resistor; The first end of the third switch is electrically connected to the control end of the first switch, the second end of the third switch is electrically connected to the ground, the first resistor is electrically connected between the control end of the third switch and the ground, the second resistor is electrically connected between the control end of the third switch and the integrated circuit, and the second resistor is also connected in series with the first resistor between the integrated circuit and the ground; The second switch unit includes a fourth switch, a third resistor, a fourth resistor and a fifth resistor; The first end of the fourth switch is electrically connected to the first power supply through the third resistor, and the first end of the fourth switch is electrically connected to the control end of the second switch, the second end of the fourth switch is electrically connected to the ground, the fourth resistor is electrically connected between the control end of the fourth switch and the ground, the fifth resistor is electrically connected between the control end of the fourth switch and the integrated circuit, and the fifth resistor is also connected in series with the fourth resistor between the integrated circuit and the ground.

4. The switch driving device according to claim 3, characterized in that: The first switch unit further includes a first capacitor, the first capacitor is electrically connected between the control end of the third switch and the ground, and the first capacitor is also connected in series with the second resistor between the integrated circuit and the ground; The second switch unit further includes a second capacitor, the second capacitor is electrically connected between the control end of the fourth switch and the ground, and the second capacitor and the fifth resistor are connected in series between the integrated circuit and the ground; The product of the resistance value of the second resistor and the capacitance value of the first capacitor is a first product, the product of the resistance value of the fifth resistor and the capacitance value of the second capacitor is a second product, and the first product is greater than the second product.

5. The switch driving device according to claim 3 or 4, characterized in that: The first switch unit further includes a sixth resistor, a first diode and a second diode; The second resistor and the first diode are connected in series between the control end of the third switch and the integrated circuit, and the cathode of the first diode is electrically connected to the control end of the third switch; The sixth resistor and the second diode are connected in series between the control end of the third switch and the integrated circuit, and the anode of the second diode is electrically connected to the control end of the third switch; Wherein, the first diode and the second resistor are arranged in a first path, the second diode and the sixth resistor are arranged in a second path, and the first path is connected in parallel with the second path; The second switch unit further includes a seventh resistor, a third diode and a fourth diode; The fifth resistor and the third diode are connected in series between the control terminal of the fourth switch and the integrated circuit, and the cathode of the third diode is electrically connected to the control terminal of the fourth switch; The seventh resistor and the fourth diode are connected in series between the control end of the fourth switch and the integrated circuit, and the anode of the fourth diode is electrically connected to the control end of the fourth switch; The third diode and the fifth resistor are arranged in a third path, the fourth diode and the seventh resistor are arranged in a fourth path, and the third path is connected in parallel with the fourth path.

6. The switch driving device according to claim 5, characterized in that: The resistance value of the sixth resistor is smaller than the resistance value of the seventh resistor.

7. The switch driving device according to any one of claims 1 to 6, characterized in that: The switch driving device further includes an eighth resistor, a ninth resistor, and a tenth resistor; The first end of the eighth resistor is electrically connected to the DC-DC conversion circuit, the second end of the eighth resistor is electrically connected to the first end of the ninth resistor and the first end of the first switch respectively, the second end of the ninth resistor is electrically connected to the control end of the first switch, and the second end of the first switch is electrically connected to the control end of the gallium nitride switch; The tenth resistor is electrically connected between the control end of the second switch and the first end of the second switch, the first end of the second switch is electrically connected to the ground, and the second end of the second switch is electrically connected to the control end of the gallium nitride switch.

8. The switch driving device according to any one of claims 2 to 7, characterized in that: The switch driving device further comprises: an eleventh resistor, electrically connected between the first switch unit and the control end of the first switch; a twelfth resistor, electrically connected between the second switch unit and the control end of the second switch; The thirteenth resistor is electrically connected between the second switch and the control end of the gallium nitride switch.

9. The switch driving device according to any one of claims 1 to 8, characterized in that: Also includes: a fourteenth resistor, electrically connected between the first switch and the control end of the gallium nitride switch; And / or, a fifteenth resistor, wherein a first end of the fifteenth resistor is electrically connected to the first switch and the second switch respectively, and a second end of the fifteenth resistor is electrically connected to a control end of the gallium nitride switch.

10. The switch driving device according to any one of claims 1 to 9, characterized in that: Also included are positive temperature coefficient thermistors; The positive temperature coefficient thermistor is electrically connected between the DC-DC conversion circuit and the first switch.

11. The switch driving device according to any one of claims 4 to 10, characterized in that: The first switch unit and the second switch unit are both electrically connected to a first pin of the integrated circuit.

12. The switch driving device according to any one of claims 2 to 10, characterized in that: The first switch unit is electrically connected to the second pin of the integrated circuit, and the second switch unit is electrically connected to the third pin of the integrated circuit.

13. The switch driving device according to any one of claims 1 to 12, characterized in that: It also includes a protection circuit, which is electrically connected to the integrated circuit and the control end of the gallium nitride switch respectively; The protection circuit is constructed to be electrically connected to the first pole of the battery module and transmit a third control signal to the protection circuit in response to the integrated circuit. The protection circuit electrically connects the first pole of the battery module to the control end of the gallium nitride switch.

14. The switch driving device according to claim 13, characterized in that: Also includes a control circuit, the control circuit is electrically connected to the integrated circuit and the drive circuit; The control circuit is configured to control the drive circuit to disconnect the electrical connection with the gallium nitride switch before the protection circuit electrically connects the first electrode of the battery module to the control end of the gallium nitride switch.

15. The switch driving device according to claim 13 or 14, characterized in that: The protection circuit includes a third switch unit, a fourth switch unit, a fifth switch, a sixteenth resistor and a seventeenth resistor; The first end of the third switch unit is electrically connected to the first end of the fourth switch unit, the second end of the third switch unit is configured to be electrically connected to the first pole of the battery module, and the second end of the fourth switch unit is electrically connected to the control end of the gallium nitride switch; A first end of the fifth switch is electrically connected to the ground, and a second end of the fifth switch is electrically connected to a third end of the third switch unit and a third end of the fourth switch unit respectively; The sixteenth resistor is electrically connected between the control terminal of the fifth switch and the first terminal of the fifth switch, the seventeenth resistor is electrically connected between the integrated circuit and the control terminal of the fifth switch, and the sixteenth resistor and the seventeenth resistor are connected in series between the integrated circuit and the ground; The third switch unit is configured to prevent the output voltage of the DC-DC conversion circuit from being transmitted to the first pole of the battery module in response to the gallium nitride switch being in an open state; The fourth switch unit is configured to prevent the voltage of the battery module from being transmitted to the control terminal of the gallium nitride switch in response to the gallium nitride switch being in an off state.

16. The switch driving device according to claim 15, characterized in that: The third switch unit includes a sixth switch, the fourth switch unit includes a seventh switch, and the third switch unit and the fourth switch unit both include an eighteenth resistor and a nineteenth resistor; The first end of the sixth switch is electrically connected to the first end of the seventh switch, the second end of the sixth switch is configured to be electrically connected to the first electrode of the battery module, and the second end of the seventh switch is electrically connected to the control end of the gallium nitride switch; One end of the eighteenth resistor is electrically connected to the first end of the sixth switch and the first end of the seventh switch respectively, and the other end of the eighteenth resistor is electrically connected to the control end of the sixth switch and the control end of the seventh switch respectively; One end of the nineteenth resistor is electrically connected to the control end of the sixth switch and the control end of the seventh switch respectively, and the other end of the nineteenth resistor is electrically connected to the second end of the fifth switch.

17. The switch driving device according to claim 16, characterized in that: The protection circuit also includes a twentieth resistor, a fifth diode and a sixth diode; The fifth diode and the seventeenth resistor are connected in series between the integrated circuit and the fifth switch, and the cathode of the fifth diode is electrically connected to the control terminal of the fifth switch; The sixth diode and the twentieth resistor are connected in series between the integrated circuit and the fifth switch, and the anode of the sixth diode is electrically connected to the control terminal of the fifth switch; The fifth diode and the seventeenth resistor are arranged in a fifth path, the sixth diode and the twentieth resistor are arranged in a sixth path, and the fifth path is connected in parallel with the sixth path.

18. The switch driving device according to claim 16 or 17, characterized in that: The protection circuit further includes a twenty-first resistor, and the twenty-first resistor is connected between the seventh switch and the control end of the gallium nitride switch; And / or, the protection circuit further includes a first filter unit, wherein the first filter unit is configured to be electrically connected between a first pole of the battery module and the ground; and / or, a third capacitor, wherein a first end of the third capacitor is electrically connected to a second end of the fifth switch, and a second end of the third capacitor is electrically connected to a control end of the sixth switch and a control end of the seventh switch, respectively; And / or, the protection circuit also includes a Zener diode, a first end of the Zener diode is electrically connected to the first end of the sixth switch and the first end of the seventh switch respectively, and a second end of the Zener diode is electrically connected to the control end of the sixth switch and the control end of the seventh switch.

19. The switch driving device according to any one of claims 13 to 18, characterized in that: The first electrode of the battery module is the positive electrode of the battery module.

20. The switch driving device according to any one of claims 15 to 19, characterized in that: The control circuit includes an eighth switch, a twenty-second resistor, and a twenty-third resistor; A first end of the eighth switch is electrically connected to the ground, and a second end of the eighth switch is electrically connected to the driving circuit; The twenty-second resistor is electrically connected between the control terminal of the eighth switch and the ground; The twenty-third resistor is electrically connected between the control end of the eighth switch and the integrated circuit, and the twenty-third resistor is also connected in series with the twenty-second resistor between the integrated circuit and the ground.

21. The switch driving device according to any one of claims 15 to 20, characterized in that: The protection circuit is electrically connected to the fourth pin of the integrated circuit, and the control circuit is electrically connected to the fifth pin of the integrated circuit.

22. The switch driving device according to claim 20, characterized in that: The protection circuit includes a fourth capacitor, the fourth capacitor is electrically connected between the control terminal of the fifth switch and the ground, and the fourth capacitor and the seventeenth resistor are electrically connected between the integrated circuit and the ground; The control circuit includes a fifth capacitor, the fifth capacitor is electrically connected between the control terminal of the eighth switch and the ground, and the fifth capacitor and the twenty-third resistor are electrically connected between the integrated circuit and the ground; Among them, the product of the resistance value of the seventeenth resistor and the capacitance value of the fourth capacitor is a third product, the product of the resistance value of the twenty-third resistor and the capacitance value of the fifth capacitor is a fourth product, and the third product is greater than the fourth product.

23. The switch driving device according to claim 22, characterized in that: The protection circuit and the control circuit are both electrically connected to the sixth pin of the integrated circuit.

24. The switch driving device according to any one of claims 20 to 23, characterized in that: The control circuit also includes a twenty-fourth resistor, a seventh diode and an eighth diode; The seventh diode and the twenty-third resistor are connected in series between the integrated circuit and the control end of the eighth switch, and the cathode of the seventh diode is electrically connected to the control end of the eighth switch; The eighth diode and the twenty-fourth resistor are connected in series between the integrated circuit and the control end of the eighth switch, and the anode of the eighth diode is electrically connected to the control end of the eighth switch; The seventh diode and the twenty-third resistor are arranged in a seventh path, the eighth diode and the twenty-fourth resistor are arranged in an eighth path, and the seventh path is connected in parallel with the eighth path.

25. The switch driving device according to any one of claims 20 to 24, characterized in that: The control circuit further includes a ninth switch; The first end of the ninth switch is electrically connected to the first end of the eighth switch, the second end of the ninth switch is electrically connected to the second end of the eighth switch, and the control end of the ninth switch is electrically connected to the control end of the eighth switch.

26. The switch driving device according to any one of claims 14 to 25, characterized in that: The integrated circuit comprises an analog front-end chip and a micro control unit. The analog front-end chip is electrically connected to the driving circuit, and the micro control unit is electrically connected to the protection circuit and the control circuit.

27. A battery management system, characterized in that: Comprising a switch driving device as claimed in any one of claims 1-26.

28. A battery pack, characterized in that: The invention comprises a battery module and a battery management system as claimed in claim 27.

29. An electrical device, characterized in that: Comprising a battery pack as claimed in claim 28.

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