Single-wire communication circuit, battery pack and electronic equipment

Abstract

The single-wire communication circuit comprises a microcontroller, the microcontroller comprises a sending pin, the single-wire communication circuit further comprises a first switch unit and a power supply, the first switch unit is electrically connected with the sending pin and the power supply, and the first switch unit is configured to be electrically connected with a negative electrode output terminal of a battery pack; the power supply is configured to supply power to the first switch unit, the power supply is further configured to respond to the microcontroller to send a high level to the first switch unit, and the power supply provides the high level for the first communication wire harness; the first switching unit is configured to electrically connect the first communication harness to the negative output terminal in response to the microcontroller transmitting a low level to the first switching unit.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of single-line communication technology, and in particular to a single-line communication circuit, a battery pack, and an electronic device. Background Art

[0002] The battery pack is equipped with a communication harness, a connector and a battery management system. The battery management system includes a microcontroller and a communication circuit. The microcontroller communicates with external electronic devices through the communication circuit, communication harness and connector to realize data interaction between the battery pack and the electronic devices. Summary of the invention

[0003] In the related art, single-line communication is used between the battery pack and the electronic device. This communication solution can reduce the cost of the battery pack and the electronic device because the single-line communication usually only requires one communication harness, the connector matched with the communication harness has fewer signal terminals, and the communication circuit matched with the single-line communication is simpler.

[0004] When developing the technology and products of single-line communication, the inventors found that when the battery pack transmits digital signals to the electronic device, for example, the battery pack and the electronic device transmit high-level signals 1 and low-level signals 0 to each other, and the low-level signal 0 is generated by the pull-down circuit provided on the battery management system, and the high-level signal 0 is generated by the pull-up circuit provided on the electronic device. However, for different electronic devices, the design schemes and design parameters of the electronic devices of various manufacturers are not the same, resulting in the communication circuit in the battery pack needing to adapt to the needs of different manufacturers, which is not friendly to the pursuit of standardized design of the communication circuit in the battery pack.

[0005] Based on this, in the first aspect, an embodiment of the present application provides a single-line communication circuit, including a microcontroller, the microcontroller including a sending pin, and the single-line communication circuit also includes: a first switch unit and a power supply, the first switch unit is electrically connected to the sending pin and the power supply respectively, and the first switch unit is configured to be electrically connected to the negative output terminal of the battery pack. The power supply is configured to supply power to the first switch unit, and the power supply is also configured to provide a high level for the first communication harness in response to the microcontroller sending a high level to the first switch unit. The first switch unit is configured to electrically connect the first communication harness to the negative output terminal in response to the microcontroller sending a low level to the first switch unit.

[0006] When the battery pack transmits data to the electronic device, when the microcontroller sends a high level to the first communication harness, the power supply provides a high level to the first communication harness, and pulls up the electrical signal on the first communication harness to a high level. When the microcontroller sends a low level to the first communication harness, the first switch unit opens, electrically connects the first communication harness to the negative output terminal of the battery pack, and pulls down the electrical signal on the first communication harness to a low level.

[0007] The single-line communication in the battery management system has its own electrical signal pull-up and pull-down functions, so that the microcontroller transmits data in binary format to the electronic device through the single-line communication circuit.

[0008] In some embodiments, the microcontroller further includes a receiving pin, and the single-line communication circuit further includes a second switch unit, and the second switch unit is electrically connected to the receiving pin, the power supply, and the ground respectively. The power supply is configured to supply power to the second switch unit, and the power supply is also configured to provide a high level to the receiving pin in response to the electronic device sending a high level to the first communication wiring harness. The second switch unit is configured to electrically connect the receiving pin to the ground in response to the electronic device sending a low level to the first communication wiring harness.

[0009] When the electronic device transmits data to the battery pack, the electronic device sends a high level to the first communication harness, the power supply provides a high level to the receiving pin, the microcontroller receives the high level, the electronic device sends a low level to the first communication harness, the second switch unit is opened to electrically connect the receiving pin to the ground, the potential on the receiving pin is pulled down, and the microcontroller receives the low level.

[0010] The single-line communication in the battery management system has its own electrical signal pull-up and pull-down functions, so that the electronic device transmits data in binary format to the microcontroller through the single-line communication circuit.

[0011] Therefore, the single-line communication circuit can autonomously generate a high-level digital signal 1 and a low-level digital signal 0, thereby enabling the battery pack and the electronic device to transmit data to each other, so that the single-line communication circuit no longer needs to be adapted to electronic devices from different manufacturers, thereby expanding the application scope of the battery pack.

[0012] In some embodiments of the present application, the first switch unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first switch, and a second switch. The first end of the first resistor is electrically connected to the sending pin, the second end of the first resistor is electrically connected to the first end of the first switch and the first end of the second resistor, the second end of the second resistor is electrically connected to the power supply and the second end of the first switch, the third end of the first switch is electrically connected to the first end of the third resistor, the second end of the third resistor is electrically connected to the first end of the fourth resistor and the first end of the second switch, the second end of the second switch and the second end of the fourth resistor are configured to be electrically connected to the negative output terminal, the third end of the second switch is electrically connected to the first end of the fifth resistor, the third end of the second switch is also configured to be electrically connected to the first communication harness, and the second end of the fifth resistor is electrically connected to the power supply.

[0013] In some embodiments of the present application, the first switch unit further includes a first capacitor, the first capacitor is connected in parallel with the third resistor, and the first capacitor and the third resistor are arranged between the third end of the first switch and the first end of the second switch.

[0014] The embodiment of the present application uses a first capacitor to adjust the conduction speed of the second switch, and after the first capacitor is fully charged, the current limiting effect of the third resistor ensures that the second switch will not be in deep saturation, thereby speeding up the conduction speed of the second switch without affecting the turn-off speed of the second switch.

[0015] In some embodiments of the present application, the second switch unit includes a third switch, a fourth switch, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor. The first end of the third switch is electrically connected to the second end of the fifth resistor, the first end of the third switch is also electrically connected to the first end of the sixth resistor, the second end of the sixth resistor is electrically connected to the power supply, the second end of the third switch, and the first end of the ninth resistor, respectively, the third end of the third switch is electrically connected to the first end of the seventh resistor, the second end of the seventh resistor is electrically connected to the first end of the eighth resistor and the first end of the fourth switch, respectively, the second end of the eighth resistor and the second end of the fourth switch are commonly grounded, and the third end of the fourth switch and the second end of the ninth resistor are electrically connected to the receiving pin.

[0016] In some embodiments of the present application, the first switch includes a PNP transistor or a P-type FET, the second switch includes an NPN transistor or an N-type FET, the third switch includes a PNP transistor or a P-type FET, and the fourth switch includes an NPN transistor or an N-type FET.

[0017] In some embodiments of the present application, the second switch unit further includes a second capacitor, the second capacitor is connected in parallel with the seventh resistor, and the second capacitor and the seventh resistor are arranged between the third end of the third switch and the first end of the fourth switch.

[0018] The embodiment of the present application uses a second capacitor to adjust the conduction speed of the fourth switch, and after the second capacitor is fully charged, the current limiting effect of the seventh resistor ensures that the fourth switch will not be in deep saturation, thereby speeding up the conduction speed of the fourth switch without affecting the turn-off speed of the fourth switch.

[0019] In some embodiments of the present application, the communication circuit also includes a diode, the diode and the fifth resistor are connected in series between the power supply and the third end of the second switch, the anode of the diode is electrically connected to the power supply, and the cathode of the diode is electrically connected to the third end of the second switch.

[0020] If the first communication harness is connected to high voltage, the diode cuts off the external high voltage input, reducing the influence of the high voltage on the second switch unit 40 .

[0021] In some embodiments of the present application, the communication circuit also includes a protection unit, the protection unit includes a positive temperature coefficient thermistor, the first end of the positive temperature coefficient thermistor is configured to be electrically connected to the first communication wiring harness, and the second end of the positive temperature coefficient thermistor is electrically connected to the first switch unit and the power supply, respectively; and / or, the protection unit includes a transient voltage suppression diode, the first end of the transient voltage suppression diode is configured to be electrically connected to the first communication wiring harness, and the second end of the transient voltage suppression diode is configured to be electrically connected to the negative output terminal.

[0022] In an embodiment of the present application, if the first communication wiring harness is connected to a high-voltage signal, the positive temperature coefficient thermistor will generate heat due to overcurrent, and its impedance will increase, thereby reducing the current flowing through the positive temperature coefficient thermistor and the second switch, thereby playing a current limiting role and reducing the risk of damage to the second switch due to overcurrent.

[0023] If there is electrostatic discharge or surge voltage on the first communication harness, the transient voltage suppression diode can absorb the static electricity or surge voltage in time, reducing the impact of the static electricity or surge voltage on the internal components of the circuit.

[0024] In a second aspect, an embodiment of the present application provides a battery pack, including a battery management system, a first connector and a first communication harness, the first communication harness electrically connects the battery management system to the first connector, the first connector includes a negative output terminal, the battery management system includes the single-line communication circuit as described above, and the first communication harness includes a single communication wire.

[0025] In a third aspect, an embodiment of the present application provides an electronic device, including a second connector, a second communication harness electrically connected to the second connector, and a battery pack as described above, wherein the first connector is electrically connected to the second connector, and the second communication harness includes a single communication wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0027] Figure 1 is a structural schematic diagram of one of the electronic devices provided in the embodiments of the present application;

[0028] Figure 2 It is a structural schematic diagram of one of the single-line communication circuits provided in an embodiment of the present application;

[0029] Figure 3 It is a structural schematic diagram of one of the single-line communication circuits provided in an embodiment of the present application;

[0030] Figure 4It is a circuit structure diagram of one of the single-line communication circuits provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

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

[0033] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0034] See also Figure 1 , Figure 1 Schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 1 As shown, the electronic device 100 includes a battery pack 1, a second connector 2, and a second communication harness. The battery pack 1 includes a battery management system (BMS) 11 and a battery module (not shown in the figure) electrically connected to the battery management system. The battery module includes a plurality of parallel, series or mixed cells for storing and providing electrical energy. The mixed connection includes series and parallel connection. The BMS is used to manage the charging and / or discharging of the battery module, and is also used to monitor, manage and protect the performance and safety of the battery module.

[0035] The battery pack 1 also includes a first connector 12 and a first communication harness, and the first communication harness electrically connects the battery management system 11 and the first connector 12. The second communication harness is electrically connected to the second connector 2, and the second connector 2 is electrically connected to the first connector 12. The battery management system 11 includes a single-line communication circuit 111, and the first communication harness electrically connects the single-line communication circuit 111 to the first connector 12. The battery management system 11 implements a communication function with the electronic device 100 through the single-line communication circuit 111, the first communication harness, the first connector 12, the second connector 2, and the second communication harness. As an example, the electronic device 100 is an electric vehicle, such as an electric bicycle, and the battery management system 11 communicates with the vehicle controller 3 of the electric bicycle through the single-line communication circuit 111, the first communication harness, the first connector 12, the second connector 2, and the second communication harness. The following embodiment describes the present application by taking the communication between the battery management system 11 and the vehicle controller 3 as an example.

[0036] In some embodiments, the first connector 12 and the second connector 2 are aviation plugs, and the connection method between the first connector 12 and the second connector 2 is threaded connection, bayonet connection or pin connection. The first connector 12 and the second connector 2 usually have terminals and pins, including power terminals and signal pins. The power terminals are used to transmit electrical energy, and the signal pins realize signal transmission. The first connector 12 includes a negative power terminal P-, that is, a negative output terminal P- of the battery pack 1, and the single-line communication circuit 111 is also electrically connected to the negative output terminal P-.

[0037] In some implementations, the first communication harness and the second communication harness each include a single communication wire, and accordingly, the communication between the battery management system 11 and the vehicle controller 3 is single-wire communication.

[0038] In some embodiments, the communication data between the battery management system 11 and the vehicle controller 3 is in binary format. Specifically, when the battery management system 11 sends a signal to the vehicle controller 3, if a high level is sent to the vehicle controller 3, the electrical signal on the first communication harness needs to be pulled up to a high level, and then the vehicle controller 3 receives the high-level digital signal "1". If a low level is sent to the vehicle controller 3, the electrical signal on the first communication harness needs to be pulled down to a low level, and then the vehicle controller 3 receives the low-level digital signal "0". Similarly, when the vehicle controller 3 sends a signal to the battery management system 11, if a high level is sent to the battery management system 11, the electrical signal on the first communication harness needs to be pulled up to a high level, and then the battery management system 11 receives the high-level digital signal "1". If a low level is sent to the battery management system 11, the electrical signal on the first communication harness needs to be pulled down to a low level, and then the battery management system 11 receives the low-level digital signal "0".

[0039] By pulling up or pulling down the electrical signal on the first communication harness, the communication between the battery management system 11 and the vehicle controller 3 is realized. The single-line communication circuit 111 in the related art has only the pull-down capability but no pull-up capability. The pull-up circuit realizing the pull-up function is generally provided in the electronic device, which results in the single-line communication circuit 111 provided in the BMS needing to match the parameters with the external pull-up circuit. For example, in the face of different pull-up circuits, the parameters of the electronic components in the single-line communication circuit 111 need to be modified, resulting in limited adaptability of the communication circuit, complex design, and not conducive to the standardization of the communication circuit.

[0040] Based on the above reasons, the embodiment of the present application provides a single-line communication circuit, which has its own up and down and pull-down functions, is more adaptable, has a simple circuit structure, low device cost, is conducive to PCB layout, and reduces the layout area of ​​PCB.

[0041] like Figure 2As shown, the single-line communication circuit includes a microcontroller 20, a first switch unit 10 and a power supply 30. The microcontroller 20 includes a sending pin. The first switch unit 10 is electrically connected to the sending pin and the power supply 30, respectively. The first switch unit 10 is also electrically connected to the negative output terminal P- of the battery pack 1 and the first communication harness, and the power supply 30 supplies power to the first switch unit 10.

[0042] In some embodiments, the power supply 30 is an independent power supply, or the voltage of the battery pack 1 is converted by a voltage conversion circuit to obtain the voltage of the power supply 30 . The voltage of the power supply 30 is set as needed, for example, it is 5V, or 3.3V.

[0043] In some implementations, the first switch unit 10 includes a switch, and the first switch unit 10 is turned on and off by controlling the switch to be turned on and off. For example, the switch includes a bipolar transistor, a field effect transistor, and a combination of a bipolar transistor and a field effect transistor.

[0044] In some embodiments, the microcontroller 20 includes a microcontroller unit (MCU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a single-chip microcomputer, an ARM (Acorn RISC Machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components.

[0045] The first switch unit 10 is turned on or off by a level signal output by a sending pin of the microcontroller 20 , and the level signal includes a high level and a low level.

[0046] When the microcontroller 20 transmits or sends data to the vehicle controller 3, the microcontroller 20 sends a high level or a low level to the vehicle controller 3 to achieve communication. In some embodiments, the microcontroller 20 sends a high level through the sending pin, the first switch unit 10 is in the off state, the power supply 30 provides a high level for the first communication harness, pulls up the electrical signal on the first communication harness, and the vehicle controller 3 receives the high level. In some other embodiments, the microcontroller 20 sends a low level through the sending pin, the first switch unit 10 is in the open (conducting) state, so as to electrically connect the negative output terminal P- with the first communication harness, pull down the electrical signal on the first communication harness, and the vehicle controller 3 receives the low level.

[0047] Therefore, the single-wire communication circuit has its own pull-up and pull-down functions, so that the microcontroller 20 sends a signal to the first communication harness, enabling the microcontroller to communicate with the electronic device through the first communication harness. The single-wire communication circuit does not need to match external parameters, has stronger adaptability, and has a simple circuit structure and lower cost.

[0048] It should be noted that Figure 2 The microcontroller 20 and the vehicle controller 3 are used as an example for explanation. In other embodiments, the microcontroller 20 also communicates with other devices in the electronic device 100. The communication process between the microcontroller 20 and other devices in the electronic device 100 is similar to the above embodiment and will not be repeated here.

[0049] In some embodiments, the electronic device 100 also sends a signal to the battery management system 11 , and the microcontroller 20 receives the signal to achieve communication between the electronic device 100 and the battery management system 11 .

[0050] Specifically, Figure 3 As shown, the microcontroller 20 also includes a receiving pin, and the single-line communication circuit also includes a second switch unit 40, which is electrically connected to the receiving pin, the power supply 30 and the ground GND, respectively, wherein the power supply 30 supplies power to the second switch unit 40 to make it in a normal working state, such as on or off.

[0051] The second switch unit 40 includes a transistor or a relay to realize the on and off of the second switch unit 40. For example, the transistor includes a bipolar transistor, a field effect transistor, or a combination of a bipolar transistor and a field effect transistor.

[0052] If the electronic device 100 needs to communicate with the microcontroller 20, the electronic device 100 sends high and low levels to the microcontroller 20 to achieve communication. Specifically, when the electronic device 100 sends a high level to the first communication harness, the second switch unit 40 is in an off state, the power supply 30 provides a high level to the receiving pin, pulls up the potential at the receiving pin, and the microcontroller 20 receives the high level. When the electronic device 100 sends a low level to the first communication harness, the second switch unit 40 is in an open (conducting) state to electrically connect the receiving pin to the ground GND, pull down the potential at the receiving pin, and the microcontroller 20 receives the low level.

[0053] Therefore, the single-line communication circuit has its own pull-up and pull-down functions, so that when the electronic device 100 sends a signal to the microcontroller 20, the receiving pin of the microcontroller 20 is pulled up or pulled down, and the microcontroller 20 receives the signal sent by the electronic device 100, thereby realizing the function of the electronic device 100 communicating with the microcontroller 20 through the first communication harness. The pull-up and pull-down functions of the single-line communication circuit do not need to match external parameters, and are more adaptable. The circuit structure is simple, the device cost is low, it is conducive to PCB layout, and reduces the layout area of ​​the PCB.

[0054] See also Figure 4 , Figure 4 Schematic diagram of a circuit structure of a single-line communication circuit provided in an embodiment of the present application. Figure 4As shown, the first switch unit 10 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first switch and a second switch.

[0055] In some embodiments, Figure 4 Taking the example that the first switch is a transistor Q1 and the second switch is a transistor Q2, the first switch is a PNP transistor Q1, the second switch is an NPN transistor Q2, the base of the transistor Q1 is the first end of the first switch, the emitter of the transistor Q1 is the second end of the first switch, the collector of the transistor Q1 is the third end of the first switch, the base of the transistor Q2 is the first end of the second switch, the emitter of the transistor Q2 is the second end of the second switch, and the collector of the transistor Q2 is the third end of the second switch.

[0056] The first end of the first resistor R1 is electrically connected to the sending pin M_TX, the second end of the first resistor R1 is electrically connected to the base of the transistor Q1 and the first end of the second resistor R2, the second end of the second resistor R2 is electrically connected to the power supply VCC and the emitter of the transistor Q1, the collector of the transistor Q1 is electrically connected to the first end of the third resistor R3, the second end of the third resistor R3 is electrically connected to the first end of the fourth resistor R4 and the base of the transistor Q2, the emitter of the transistor Q2 and the second end of the fourth resistor R4 are electrically connected to the negative output terminal P-, the collector of the transistor Q2 is electrically connected to the first end of the fifth resistor R5, the collector of the transistor Q2 is also electrically connected to the first communication wiring harness 1-Wi re, and the second end of the fifth resistor R5 is electrically connected to the power supply VCC.

[0057] In other embodiments, the first switch and the second switch are MOS tubes or IGBT switch tubes, for example, the first switch is a PNP type FET, and the second switch is an NPN type FET. Accordingly, the gate, source, and drain of the PNP type FET correspond to the first end, the second end, and the third end of the first switch, respectively, and the gate, source, and drain of the PNP type FET correspond to the first end, the second end, and the third end of the second switch, respectively.

[0058] The principle of the battery management system 11 sending or transmitting data to the vehicle controller 3 is as follows:

[0059] The microcontroller 20 sends a high-level signal, the voltage difference between the base and the emitter of the transistor Q1 is zero or close to zero, the transistor Q1 is turned off, the base and the emitter of the transistor Q2 are pulled down by the negative output terminal P- of the battery pack 1, the transistor Q2 is turned off, and the power supply VCC pulls up the electrical signal on the first communication wiring harness 1-Wi re through the fifth resistor R5, and the electronic device 100 receives a high level.

[0060] The microcontroller 20 sends a low-level signal, and the voltage drop of the power supply VCC on the second resistor R2 is the voltage difference between the base and the emitter of the transistor Q1, so the transistor Q1 is turned on, and the power supply VCC forms a loop through the emitter and collector of the transistor Q1, the third resistor R3, the fourth resistor R4 and the negative output terminal P- of the battery pack 1, forming a voltage drop on the fourth resistor R4. The voltage drop on the fourth resistor R4 is the voltage difference between the base and the emitter of the transistor Q2, and the transistor Q2 is turned on. The electrical signal on the first communication wiring harness 1-Wi re is pulled down by the negative output terminal P- of the battery pack 1, and the electronic device 100 receives a low level.

[0061] When the microcontroller 20 is in a dormant state, the microcontroller 20 outputs a high level through the sending pin M_TX to turn off the transistor Q1 and the transistor Q2. The single-line communication circuit has no leakage channel, thereby reducing power consumption.

[0062] In some embodiments, please refer to Figure 4 The first switch unit 10 further includes a first capacitor C1, the first capacitor C1 is connected in parallel with the third resistor R3, and the first capacitor C1 and the third resistor R3 are arranged between the collector of the transistor Q1 and the base of the transistor Q2.

[0063] The first capacitor C1 is used to provide a fast conduction path for transistors Q1 and Q2. When the microcontroller 20 sends a low level, the power supply VCC forms a first conduction path through the emitter and collector of the transistor Q1, the first capacitor C1, the fourth resistor R4 and the negative output terminal P- of the battery pack 1, using the principle that the voltage across the capacitor cannot change suddenly, so that the transistors Q1 and Q2 are turned on faster. After the first capacitor C1 is fully charged, the first conduction path is disconnected, and the power supply VCC forms a loop through the emitter and collector of the transistor Q1, the third resistor R3, the fourth resistor R4 and the negative output terminal P- of the battery pack 1 to ensure that the current is stable and the transistor Q2 remains in a stable conduction state.

[0064] The first capacitor C1 is used to adjust the conduction speed of the transistor Q2. After the first capacitor C1 is fully charged, the current limiting function of the third resistor R3 ensures that the transistor Q2 will not be in deep saturation, thereby speeding up the conduction speed of the transistor Q2 without affecting the turn-off speed of the transistor Q2.

[0065] In some implementations, please refer to Figure 4 The second switch unit 40 includes a third switch, a fourth switch, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9. Figure 4Taking the example that the third switch is a PNP transistor Q3 and the fourth switch is an NPN transistor Q4, the base of the transistor Q3 is the first end of the third switch, the emitter of the transistor Q3 is the second end of the third switch, the collector of the transistor Q3 is the third end of the third switch, the base of the transistor Q4 is the first end of the fourth switch, the emitter of the transistor Q4 is the second end of the fourth switch, and the collector of the transistor Q4 is the third end of the fourth switch.

[0066] The base of the transistor Q3 is electrically connected to the second end of the fifth resistor R5, and the base of the transistor Q3 is also electrically connected to the first end of the sixth resistor R6. The second end of the sixth resistor R6 is electrically connected to the power supply VCC, the emitter of the transistor Q3 and the first end of the ninth resistor R9 respectively. The collector of the transistor Q3 is electrically connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is electrically connected to the first end of the eighth resistor R8 and the base of the transistor Q4 respectively. The second end of the eighth resistor R8 and the emitter of the transistor Q4 are commonly grounded GND, and the collector of the transistor Q4 and the second end of the ninth resistor R9 are both electrically connected to the receiving pin M_RX.

[0067] In other embodiments, the third switch and the fourth switch are one of MOS tubes or IGBT switch tubes, etc., which are not limited here. For example, if the third switch is a PNP type FET, the gate of the PNP type FET is the first end of the third switch, the source of the PNP type FET is the second end of the third switch, and the drain of the PNP type FET is the third end of the third switch. The fourth switch is an NPN type FET, the gate of the NPN type FET is the first end of the fourth switch, the source of the NPN type FET is the second end of the fourth switch, and the drain of the NPN type FET is the third end of the fourth switch.

[0068] The principle of the vehicle controller 3 in the electronic device 100 sending or transmitting data to the battery management system 11 is as follows:

[0069] The vehicle controller 3 sends a high level through the first communication harness, the voltage difference between the base and emitter of the transistor Q3 is zero or close to zero, the transistor Q3 is turned off, the base and emitter of the transistor Q4 are both pulled down by the ground GND, the transistor Q4 is turned off, and the power supply VCC pulls up the electrical signal on the receiving pin M_RX through the ninth resistor R9, and the microcontroller 20 receives the high level.

[0070] The vehicle controller 3 sends a low level through the first communication harness, and the voltage drop of the power supply VCC on the sixth resistor R6 is the voltage difference between the base and the emitter of the transistor Q3. The transistor Q3 is turned on, and the power supply VCC forms a loop through the emitter and collector of the transistor Q3, the seventh resistor R7, the eighth resistor R8 and the ground GND. A voltage drop is formed on the eighth resistor R8, and the voltage drop on the eighth resistor R8 is the voltage difference between the base and the emitter of the transistor Q4. The transistor Q4 is turned on, and the electrical signal on the receiving pin M_RX is pulled low by the ground GND, and the microcontroller 20 receives a low level.

[0071] The vehicle controller 3 sends a high level through the first communication harness, the transistor Q3 is turned off, the transistor Q4 is turned off, the power supply VCC pulls up the electrical signal on the receiving pin M_RX, and the microcontroller 20 receives the high level. When the electronic device 100 sends a low level, the transistor Q3 is turned on, the transistor Q4 is turned on, the potential at the receiving pin M_RX is pulled down, and the microcontroller 20 receives the low level.

[0072] In some embodiments, please refer to Figure 4 The second switch unit 40 further includes a second capacitor C2. The second capacitor C2 is connected in parallel with the seventh resistor R7, and the second capacitor C2 and the seventh resistor R7 are arranged between the collector of the transistor Q3 and the base of the transistor Q4.

[0073] The second capacitor C2 is used to provide a fast conduction channel for the transistor Q3 and the transistor Q4. When the electronic device 100 sends a low level, the power supply VCC forms a second conduction path through the emitter and collector of the transistor Q3, the second capacitor C2, the eighth resistor R8 and the ground GND, and a voltage drop is formed on the eighth resistor R8. The voltage drop on the eighth resistor R8 rises faster, and the transistor Q4 is turned on faster. After the second capacitor C2 is fully charged, the second conduction path is disconnected, and the power supply VCC forms a loop through the emitter and collector of the transistor Q3, the seventh resistor R7, the eighth resistor R8 and the ground GND to ensure that the current is stable and the transistor Q4 remains in a stable conduction state.

[0074] The second capacitor C2 is used to adjust the conduction speed of the transistor Q4. After the second capacitor C2 is fully charged, the current limiting function of the seventh resistor R7 ensures that the transistor Q4 will not be in deep saturation, thereby accelerating the conduction speed of the transistor Q4 without affecting the turn-off speed of the transistor Q4.

[0075] In some embodiments, please refer to Figure 4 The single-line communication circuit also includes a diode D2, the diode D2 and the fifth resistor R5 are connected in series between the power supply VCC and the collector of the transistor Q2, the anode of the diode D2 is electrically connected to the power supply VCC, and the cathode of the diode D2 is electrically connected to the collector of the transistor Q2.

[0076] If the first communication harness is improperly connected to the high-voltage port, a high-voltage electrical signal is connected to the first communication harness, and the diode D2 is used to prevent the external high voltage from being input into the second switch unit 40, thereby reducing the impact of the high voltage on the transistors Q3 and Q4, and providing high-voltage protection for the transistors Q3 and Q4.

[0077] In some embodiments, please refer to Figure 4 The single-line communication circuit further includes a protection unit 50, which includes a positive temperature coefficient thermistor RT1, a first end of which is electrically connected to the first communication harness, and a second end of which is electrically connected to the first switch unit 10 and the power supply VCC. Specifically, the second end of the positive temperature coefficient thermistor RT1 is electrically connected to the collector of the transistor Q2, and is also electrically connected to the power supply VCC via the fifth resistor R5.

[0078] When the microcontroller 20 outputs a low level, the transistor Q1 is turned on and the transistor Q2 is turned on. If the first communication harness is connected to a high-voltage signal, the positive temperature coefficient thermistor RT1 is heated due to overcurrent, and its impedance increases, thereby reducing the current flowing through the positive temperature coefficient thermistor RT1 and the transistor Q2, thereby playing a current limiting role and reducing the risk of damage to the transistor Q2 due to overcurrent.

[0079] In some embodiments, the protection unit 50 includes a transient voltage suppression diode D1 , a first end of the transient voltage suppression diode D1 is electrically connected to the first communication harness, and a second end of the transient voltage suppression diode D1 is electrically connected to the negative output terminal P-.

[0080] When static electricity or surge voltage occurs on the first communication wiring harness 1-Wi re, the transient voltage suppression diode D2 absorbs the static electricity or surge voltage in time, reducing the influence of the static electricity or surge voltage on the internal components of the circuit.

[0081] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0082] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single-line communication circuit, comprising a microcontroller, wherein the microcontroller comprises a sending pin, characterized in that: The single-line communication circuit also includes: A first switch unit and a power supply, wherein the first switch unit is electrically connected to the sending pin and the power supply respectively, and the first switch unit is configured to be electrically connected to the negative output terminal of the battery pack; The power supply is configured to supply power to the first switch unit, and the power supply is further configured to provide a high level for the first communication harness in response to the microcontroller sending a high level to the first switch unit; The first switch unit is configured to electrically connect the first communication harness to the negative output terminal in response to the microcontroller sending a low level to the first switch unit.

2. The single-line communication circuit according to claim 1, characterized in that: The microcontroller also includes a receiving pin; The single-line communication circuit further includes a second switch unit, which is electrically connected to the receiving pin, the power supply and the ground respectively; The power supply is configured to supply power to the second switch unit, and the power supply is further configured to provide a high level to the receiving pin in response to the electronic device sending a high level to the first communication harness; The second switch unit is configured to electrically connect the receiving pin to the ground in response to the electronic device sending a low level to the first communication harness.

3. The single-line communication circuit according to claim 1 or 2, characterized in that: The first switch unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first switch and a second switch; The first end of the first resistor is electrically connected to the sending pin, the second end of the first resistor is electrically connected to the first end of the first switch and the first end of the second resistor, the second end of the second resistor is electrically connected to the power supply and the second end of the first switch, the third end of the first switch is electrically connected to the first end of the third resistor, the second end of the third resistor is electrically connected to the first end of the fourth resistor and the first end of the second switch, the second end of the second switch and the second end of the fourth resistor are configured to be electrically connected to the negative output terminal, the third end of the second switch is electrically connected to the first end of the fifth resistor, the third end of the second switch is also configured to be electrically connected to the first communication harness, and the second end of the fifth resistor is electrically connected to the power supply.

4. The single-line communication circuit according to claim 3, characterized in that: The first switch unit further includes a first capacitor; The first capacitor and the third resistor are connected in parallel, and the first capacitor and the third resistor are arranged between the third end of the first switch and the first end of the second switch.

5. The single-line communication circuit according to claim 3 or 4, characterized in that: The second switch unit includes a third switch, a fourth switch, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor; The first end of the third switch is electrically connected to the second end of the fifth resistor, the first end of the third switch is also electrically connected to the first end of the sixth resistor, the second end of the sixth resistor is electrically connected to the power supply, the second end of the third switch and the first end of the ninth resistor respectively, the third end of the third switch is electrically connected to the first end of the seventh resistor, the second end of the seventh resistor is electrically connected to the first end of the eighth resistor and the first end of the fourth switch respectively, the second end of the eighth resistor and the second end of the fourth switch are commonly grounded, and the third end of the fourth switch and the second end of the ninth resistor are electrically connected to the receiving pin.

6. The single-wire communication circuit according to claim 5, characterized in that: The first switch includes a PNP transistor or a P-type FET, and the second switch includes an NPN transistor or an N-type FET; The third switch includes a PNP transistor or a P-type FET, and the fourth switch includes an NPN transistor or an N-type FET.

7. The single-line communication circuit according to claim 5 or 6, characterized in that: The second switch unit further includes a second capacitor; The second capacitor and the seventh resistor are connected in parallel, and the second capacitor and the seventh resistor are arranged between the third end of the third switch and the first end of the fourth switch.

8. The single-line communication circuit according to any one of claims 3 to 7, characterized in that: The communication circuit also includes a diode; The diode and the fifth resistor are connected in series between the power supply and the third end of the second switch, the anode of the diode is electrically connected to the power supply, and the cathode of the diode is electrically connected to the third end of the second switch.

9. The single-line communication circuit according to any one of claims 1 to 8, characterized in that: The communication circuit also includes a protection unit; The protection unit comprises a positive temperature coefficient thermistor, a first end of the positive temperature coefficient thermistor is configured to be electrically connected to the first communication harness, and a second end of the positive temperature coefficient thermistor is electrically connected to the first switch unit and the power supply respectively; and / or, The protection unit includes a transient voltage suppression diode, a first end of the transient voltage suppression diode is configured to be electrically connected to the first communication wiring harness, and a second end of the transient voltage suppression diode is configured to be electrically connected to the negative output terminal.

10. A battery pack, comprising a battery management system, a first connector and a first communication harness, wherein the first communication harness electrically connects the battery management system to the first connector, and the first connector comprises a negative output terminal; characterized in that: The battery management system comprises a single-wire communication circuit as claimed in any one of claims 1 to 9; The first communication harness includes a single communication conductor.

11. An electronic device, characterized in that: comprising a second connector, a second communication harness electrically connected to the second connector, and a battery pack as claimed in claim 10; The first connector is electrically connected to the second connector, and the second communication harness includes a single communication conductor.

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