CN205017345U - High -speed CAN communication circuit and electric automobile - Google Patents
High -speed CAN communication circuit and electric automobile Download PDFInfo
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- CN205017345U CN205017345U CN201520514484.1U CN201520514484U CN205017345U CN 205017345 U CN205017345 U CN 205017345U CN 201520514484 U CN201520514484 U CN 201520514484U CN 205017345 U CN205017345 U CN 205017345U
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Abstract
The utility model discloses a high -speed CAN communication circuit, the control source is connected with isolation power supply circuit and microprocessor, provides working power supply for high -speed CAN communication circuit, it keeps apart to keep apart the interfering signal of power supply circuit in to control power output's voltage to output isolation voltage is connected CAN communication circuit extremely, CAN communication circuit carries out filtering to the bus differential signal that inserts to to pass through CAN signal input to the connected buffer circuit that the post -filter obtained, the CAN signal that buffer circuit sent CAN communication circuit carries out the post -filter and sends to microprocessor to and carry out the post -filter to the CAN signal that microprocessor sent and send to CAN communication circuit, CAN communication circuit carries out filtering once more to the CAN signal through filtering that buffer circuit sent to will be through CAN signal transmission to the bus of filtering once more. The utility model discloses interference killing feature that can the high -speed CAN communication of effectual improvement.
Description
Technical field
The utility model relates to CAN communication technical field, particularly relates to a kind of high-speed CAN communicating circuit and electric automobile.
Background technology
Controller Area Network BUS (CAN, ControllerAreaNetwork) communication is widely used in automobile electronics, current most of key components and parts all adopts CAN communication technology, speed according to transmission is divided into high-speed CAN and low speed CAN, and the speed of high-speed CAN communication is at more than 500kbps.These systems directly related with running car such as the main connecting engine control unit of high-speed CAN bus, anti-blocking brake system control unit, air bag control unit, combination instrument.Comparatively large due to amount of transmitted information and for information transmission the speed of these systems has very high requirement, so need the needs that high-speed CAN bus is transmitted to meet its information.Because the signal transmission rate of CAN is very large to the safety effects of car load, in order to improve the fail safe of car load, how protecting CAN not disturb by extraneous factor as far as possible in high speed communication process is a problem demanding prompt solution.
Utility model content
The utility model provides a kind of high-speed CAN communicating circuit, effectively can improve the antijamming capability of high-speed CAN communication.
The utility model provides a kind of high-speed CAN communicating circuit, comprising: control power supply, insulating power supply circuit, CAN communication circuit, buffer circuit and microprocessor; Wherein:
Described control power supply is connected with described insulating power supply circuit and described microprocessor, for described high-speed CAN communicating circuit provides working power;
Interference signal in the voltage that described insulating power supply circuit exports described control power supply is isolated, and exports isolation voltage VCC_CAN to connected described CAN communication circuit;
The bus differential signal of described CAN communication circuit to access carries out filtering, and the CAN signal obtained afterwards is after filtering inputed to connected described buffer circuit;
Described buffer circuit is sent to described microprocessor after carrying out filtering to the CAN signal that described CAN communication circuit sends, and is sent to described CAN communication circuit after carrying out filtering to the CAN signal that described microprocessor sends;
Described CAN communication circuit carries out filtering again to the CAN signal after filtering that described buffer circuit sends, and the CAN signal through filtering is again sent to bus.
Preferably, described circuit also comprises: terminal resistance match circuit and isolation control circuit; Wherein:
The control signal that described isolation control circuit exports according to connected described microprocessor, controls connected described terminal resistance match circuit and exports the resistance mated with terminal.
Preferably, described insulating power supply circuit comprises: inductance L 3, electric capacity C13, electric capacity C10, insulating power supply chip PW1, electric capacity C14, electric capacity C11 and resistance R12; Wherein:
One end of described inductance L 3 is connected with described control power supply, and the other end is connected with the input pin of described insulating power supply chip PW1;
One end of described electric capacity C13 is connected with the input pin of described insulating power supply chip PW1, other end ground connection;
One end of described electric capacity C10 is connected with the input pin of described insulating power supply chip PW1, other end ground connection, the grounding leg ground connection of described insulating power supply chip PW1;
One end of described electric capacity C14 is connected with the output pin of described insulating power supply chip PW1, and the other end is connected with reference to lower margin with the output of described insulating power supply chip PW1;
One end of described electric capacity C11 is connected with the output pin of described insulating power supply chip PW1, and the other end is connected with reference to lower margin with the output of described insulating power supply chip PW1;
One end of described resistance R12 is connected with the output pin of described insulating power supply chip PW1, and the other end is connected with reference to lower margin with the output of described insulating power supply chip PW1;
The output pin of described insulating power supply chip PW1 exports described isolation voltage VCC_CAN, exports with reference to lower margin access isolation voltage earth terminal VSS_CAN.
Preferably, described insulating power supply chip PW1 is CF0505XT-1WR2.
Preferably, described buffer circuit comprises: resistance R1, electric capacity C1, resistance R2, electric capacity C2, electric capacity C5, inductance L 2, electric capacity C6 and isolating chip U2;
Described CAN communication circuit comprises: CAN communication chip U1, electric capacity C7, electric capacity C3, electric capacity C4, resistance R3, resistance R4 and electrostatic protection diode Z1, and described electrostatic protection diode is made up of the first diode and the second diode; Wherein:
The first end of described resistance R1 is connected with the pin OUTA of described isolating chip U2, second end of described resistance R1 is connected with one end of described microprocessor and described electric capacity C1, the other end ground connection of described electric capacity C1, described isolating chip U2 exports CAN signal to described microprocessor;
The first end of described resistance R2 is connected with described microprocessor, and second end of described resistance R2 is connected with the pin INB of described isolating chip U2 and one end of described electric capacity C2 respectively, the other end ground connection of described electric capacity C2;
The pin VCC1 of described isolating chip U2 accesses power supply, pin GND1 ground connection, and pin VCC2 accesses described isolation voltage VCC_CAN, and pin GND2 accesses described isolation voltage earth terminal VSS_CAN, and pin OUTB accesses described CAN communication circuit;
One end of described inductance L 2 is connected with the pin INA of described isolating chip U2, and the other end is connected with the pin RXD of described CAN communication chip U1;
One end of described electric capacity C5 is connected with the pin VCC1 of described isolating chip U2, other end ground connection;
One end of described electric capacity C6 is connected with the pin VCC2 of described isolating chip U2, and the other end accesses described isolation voltage earth terminal VSS_CAN;
The pin TXD of described CAN communication chip U1 is connected with the pin OUTB of described isolating chip U2, pin GND, pin S and pin NC access described isolation voltage earth terminal VSS_CAN respectively, pin VCC accesses described isolation voltage VCC_CAN, and pin RXD is connected with described inductance L 2;
One end of electric capacity C7 is connected with the pin VCC of described CAN communication chip U1, and the other end accesses described isolation voltage earth terminal VSS_CAN;
One end of electric capacity C4 is connected with the pin CANH of described CAN communication chip U1, the other end is connected with one end of electric capacity C3, the other end of electric capacity C3 is connected with the pin CANL of described CAN communication chip U1, and the tie point of electric capacity C3 and electric capacity C4 accesses described isolation voltage earth terminal VSS_CAN;
One end of described resistance R3 is connected with the pin CANH of described CAN communication chip U1, and the other end is connected with the negative electrode of the first diode in described electrostatic protection diode Z1;
One end of described resistance R4 is connected with the pin CANL of described CAN communication chip U1, and the other end is connected with the negative electrode of the second diode in described electrostatic protection diode Z1;
The anode of the first diode is connected with the anode of the second diode and accesses described isolation voltage earth terminal VSS_CAN afterwards;
The other end of described resistance R3, the other end of resistance R4 are used for bus differential signal described in input and output.
Preferably, described isolating chip U2 is ISO7421A-Q1; Described CAN communication chip U1 is TJA1057.
Preferably, described terminal resistance match circuit comprises: the first analog switch U3, the second analog switch U4, resistance R5, resistance R6 and electric capacity C12; Wherein:
The pin NO of described first analog switch U3 is connected with the pin CANL of described CAN communication chip U1, pin COM is connected with one end of resistance R5, pin GND accesses described isolation voltage earth terminal VSS_CAN, pin IN is connected with described isolation control circuit, and pin V accesses described isolation voltage VCC_CAN;
The pin NO of described second analog switch U4 is connected with the pin CANH of described CAN communication chip U1, pin COM is connected with one end of resistance R6, pin GND accesses described isolation voltage earth terminal VSS_CAN, pin IN is connected with described isolation control circuit, and pin V accesses described isolation voltage VCC_CAN;
The other end of described resistance R5 is connected with the other end of resistance R6;
One end of described electric capacity C12 is connected with the tie point of resistance R6 with described resistance R5, and the other end accesses described isolation voltage earth terminal VSS_CAN.
Preferably, described first analog switch U3 and the second analog switch U4 is SN74LVC1G66-Q1.
Preferably, described isolation control circuit comprises: resistance R7, resistance R8, optocoupler PC1, electric capacity C8, resistance R11, resistance R10, electric capacity C9, resistance R9 and switching tube Q1; Wherein:
The former limit anode access power supply of described optocoupler PC1; One end of resistance R7 is connected with described microprocessor, and the other end is connected with the former limit negative electrode of described optocoupler PC1; One end of described resistance R8 is connected with the former limit anode of described optocoupler PC1, and the other end is connected with the former limit negative electrode of described optocoupler PC1;
The secondary of described optocoupler PC1 exports collector electrode and accesses described isolation voltage VCC_CAN;
One end of described electric capacity C8 exports emitter-base bandgap grading with the secondary of described optocoupler PC1 and is connected, and the other end is connected with the base stage of described switching tube Q1; One end of described resistance R11 exports emitter-base bandgap grading with the secondary of described optocoupler PC1 and is connected, and the other end is connected with the base stage of described switching tube Q1;
One end of described resistance R10 is connected with the base stage of described switching tube Q1, and the other end is connected with the emitter of described switching tube Q1; One end of described electric capacity C9 is connected with the base stage of described switching tube Q1, and the other end is connected with the emitter of described switching tube Q1;
Described isolation voltage VCC_CAN is accessed in one end of described resistance R9, the other end is connected with the collector electrode of described switching tube Q1, the collector electrode of described switching tube Q1 is connected with described terminal resistance match circuit as the output of isolation control circuit, and emitter accesses described isolation voltage earth terminal VSS_CAN.
A kind of electric automobile, comprises as the high-speed CAN communicating circuit in claim 1-9 as described in any one.
From such scheme, a kind of high-speed CAN communicating circuit that the utility model provides, the isolation to interference signal can be realized by insulating power supply circuit, by CAN communication circuit can achieve a butt joint into bus differential signal carry out filtering, can realize carrying out filtering to the CAN signal of microprocessor reception and the CAN signal of transmission by buffer circuit, thus effectively raise the antijamming capability of high-speed CAN communication.
Accompanying drawing explanation
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiments more of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
The structural representation of Fig. 1 a kind of high-speed CAN communicating circuit disclosed in the utility model embodiment;
The structural representation of Fig. 2 a kind of high-speed CAN communicating circuit disclosed in another embodiment of the utility model;
The circuit diagram of Fig. 3 insulating power supply circuit disclosed in the utility model;
The circuit diagram of Fig. 4 CAN communication buffer circuit disclosed in the utility model;
The circuit diagram of Fig. 5 terminal resistance match circuit disclosed in the utility model;
The circuit diagram of Fig. 6 isolation control circuit disclosed in the utility model.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
As shown in Figure 1, a kind of high-speed CAN communicating circuit disclosed in the utility model embodiment, comprising: control power supply 10, insulating power supply circuit 11, CAN communication circuit 12, buffer circuit 13 and microprocessor 14; Wherein:
Control power supply 10 to be connected with insulating power supply circuit 11 and microprocessor 14, for the microprocessor 14 in high-speed CAN communicating circuit, insulating power supply circuit 11, buffer circuit 13 and CAN communication circuit 12 provide working power;
Insulating power supply circuit 11 is connected with control power supply 10, isolates the interference signal controlled in the voltage of power supply 10 output, and exports isolation voltage VCC_CAN to connected CAN communication circuit 12; Wherein, the interference signal controlled in the voltage of power supply 10 output comprises ripple interference signal, pulse interference signal and voltage fluctuation interference signal.
The bus differential signal of CAN communication circuit 12 to the entire car controller of access carries out filtering, and the CAN signal obtained afterwards is after filtering inputed to connected buffer circuit 13; Microprocessor 14 is sent to after the CAN signal that buffer circuit 13 pairs of CAN communication circuit 12 send carries out filtering;
And the CAN signal that sends of the buffer circuit 13 pairs of microprocessors 14 carry out filtering after be sent to CAN communication circuit 12; The CAN signal after filtering that CAN communication circuit 12 pairs of buffer circuits 13 send carries out filtering again, and the CAN signal through filtering is again sent to bus.
High-speed CAN communicating circuit disclosed in the present embodiment, by the insulating power supply circuit in high-speed CAN communicating circuit, filtering is carried out to the interference signal controlling to carry in the voltage of power supply output, by CAN communication circuit, filtering is carried out to the bus differential signal of entire car controller, and the CAN signal that the CAN signal to be sent CAN communication circuit by buffer circuit and microprocessor are sent carries out filtering, and by CAN communication circuit, filtering is again carried out to the CAN signal after filtering that buffer circuit sends, effectively raise the antijamming capability of high-speed CAN communicating circuit, and then improve the fail safe of full-vehicle control.
Concrete, as shown in Figure 3, insulating power supply circuit comprises: inductance L 3, electric capacity C13, electric capacity C10, model are insulating power supply chip PW1, electric capacity C11, the electric capacity C14 and resistance R12 of the automotive grade of CF0505XT-1WR2; Wherein:
One end of inductance L 3 is connected with control power supply, and the other end and model are that the input pin VIN of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected;
One end and the model of electric capacity C13 are that the input pin VIN of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected, other end ground connection; One end and the model of electric capacity C10 are that the input pin VIN of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected, other end ground connection; Electric capacity C13 is used for voltage stabilizing, and electric capacity C10 is used for decoupling, the LC filter circuit of formation;
One end and the model of electric capacity C14 are that the output pin V0 of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected, and the other end and model are that the output of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected with reference to lower margin 0V; One end and the model of electric capacity C11 are that the output pin V0 of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected, and the other end and model are that the output of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected with reference to lower margin 0V; C14 carries out voltage stabilizing to insulating power supply circuit output end, carries out decoupling by electric capacity C11 to insulating power supply circuit output end;
One end and the model of resistance R12 are that the output pin V0 of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected, and the other end and model are that the output of the insulating power supply chip PW1 of CF0505XT-1WR2 is connected with reference to lower margin 0V;
Model is the grounding leg GND ground connection of the insulating power supply chip PW1 of CF0505XT-1WR2, output pin V0 exports isolation voltage VCC_CAN, export and access isolation voltage earth terminal VSS_CAN with reference to lower margin 0V, be connected with casing etc. with reference to lower margin 0V as exported, realize exporting with reference to lower margin 0V ground connection.
Insulating power supply circuit disclosed in the utility model, the insulating power supply chip PW1 being CF0505XT-1WR2 by model can realize the electrical isolation to the voltage+5V and isolation voltage VCC-CAN controlling power supply output, simultaneously to be that the insulating power supply chip PW1 of CF0505XT-1WR2 can also realize the direct voltage of 3500V withstand voltage for model, and isolation electric machine controller internal circuit and strongly disturbing external circuit.By the LC filter that inductance L 3, electric capacity C13 and electric capacity C10 are formed, effectively filtering the ripple interference signal in the voltage of power supply output can be controlled.The output of power supply smoothly can be controlled by electric capacity.Resistance R12 is dummy load, can play the effect of Differential Output voltage.
Concrete, as shown in Figure 4, CAN communication buffer circuit disclosed in the utility model, comprising: buffer circuit and CAN communication circuit; Wherein:
Buffer circuit comprises: resistance R1, electric capacity C1, resistance R2, electric capacity C2, electric capacity C5, inductance L 2, electric capacity C6 and model are the isolating chip U2 of ISO7421A-Q1; Wherein:
First end and the model of resistance R1 are that the pin OUTA of the isolating chip U2 of ISO7421A-Q1 is connected, second end of described resistance R1 is connected with one end of described microprocessor and electric capacity C1, the other end ground connection of electric capacity C1, model is that the isolating chip U2 of ISO7421A-Q1 exports CAN signal to described microprocessor by pin OUTA;
The first end of resistance R2 is connected with microprocessor, second end of resistance R2 is that the pin INB of ISO7421A-Q1 isolating chip U2 and one end of electric capacity C2 are connected respectively with model, the other end of electric capacity C2 and ground connection, CAN signal is inputed to the isolating chip U2 of ISO7421A-Q1 by microprocessor by pin INB;
Model is that the pin VCC1 of the isolating chip U2 of ISO7421A-Q1 accesses power supply, pin GND1 ground connection, and pin VCC2 accesses isolation voltage VCC_CAN, and pin GND2 accesses isolation voltage earth terminal VSS_CAN, and pin OUTB accesses CAN communication circuit;
One end and the model of inductance L 2 are that the pin INA of the isolating chip U2 of ISO7421A-Q1 is connected, and the other end is connected with CAN communication circuit;
One end and the model of electric capacity C5 are that the pin VCC1 of the isolating chip U2 of ISO7421A-Q1 is connected, other end ground connection; One end and the model of electric capacity C6 are that the pin VCC2 of the isolating chip U2 of ISO7421A-Q1 is connected, other end access isolation voltage earth terminal VSS_CAN.
CAN communication circuit comprises: model is CAN communication chip U1, the electric capacity C7 of TJA1057, electric capacity C3, electric capacity C4, resistance R3, resistance R4 and electrostatic protection diode Z1, and described electrostatic protection diode Z1 is made up of the first diode and the second diode; Wherein:
Model is that the pin OUTB that pin TXD and the model of the CAN communication chip U1 of TJA1057 is the isolating chip U2 of ISO7421A-Q1 is connected, pin GND, pin S and pin NC access isolation voltage earth terminal VSS_CAN respectively, pin VCC accesses isolation voltage VCC_CAN, and pin RXD is connected with inductance L 2;
One end and the model of electric capacity C7 are that the pin VCC of the CAN communication chip U1 of TJA1057 is connected, other end access isolation voltage earth terminal VSS_CAN;
One end of electric capacity C4 is connected with the pin CANH of the CAN communication chip U1 of model TJA1057, the other end is connected with one end of electric capacity C3, the other end and the model of electric capacity C3 are that the pin CANL of the CAN communication chip U1 of TJA1057 is connected, the tie point access isolation voltage earth terminal VSS_CAN of electric capacity C3 and electric capacity C4;
One end and the model of resistance R3 are that the pin CANH of the CAN communication chip U1 of TJA1057 is connected, and the other end is connected with the negative electrode of the first diode in electrostatic protection diode Z1;
One end and the model of resistance R4 are that the pin CANL of the CAN communication chip U1 of TJA1057 is connected, and the other end is connected with the negative electrode of the second diode in electrostatic protection diode Z1;
The anode of the first diode is connected with the anode of the second diode and accesses described isolation voltage earth terminal VSS_CAN afterwards;
The other end of resistance R3, the other end of resistance R4 are used for input and output bus differential signal.
CAN communication buffer circuit disclosed in the utility model, CANH and CANL is vehicle local CAN differential bus, by the electrostatic protection diode Z1 of access, can realize the electrostatic protection to bus.CAN common-mode filter is formed by resistance R3, resistance R4 and electric capacity C3, electric capacity C4, the filter of the CAN signal CAN-RX that microprocessor receives is formed by resistance R1 and electric capacity C1, the filter of the CAN signal CAN-TX that microprocessor sends is formed by resistance R2 and electric capacity C2, by inductance L 2 filtering high-frequency interferencing signal, enhance the antijamming capability of system.By adopting CAN communication chip TJA1057, the common mode inductance that cost is higher can be saved, the basis ensureing CAN communication circuit reliability effectively provides cost savings.In communication isolation, adopt the isolating chip ISO7421A-Q1 of automotive grade, isolation and the life requirements of high-speed CAN communication can be met.Electric capacity C5, electric capacity C6 and electric capacity C7 are decoupling capacitance, can the ripple that brings of elimination isolating chip ISO7421A-Q1 and CAN communication chip TJA1057 power supply or interference.
In sum, high-speed CAN communicating circuit disclosed in the utility model, the isolation to interference signal can be realized by other insulating power supply circuit of use automotive grade, by use automotive grade other CAN communication circuit can achieve a butt joint into bus differential signal carry out filtering, can realize carrying out filtering to the CAN signal of microprocessor reception and the CAN signal of transmission by buffer circuit, thus effectively raise the antijamming capability of high-speed CAN communication; Simultaneously, use other insulating power supply circuit of automotive grade, other CAN communication circuit of automotive grade and buffer circuit, the requirement of dynamical system parts about ISO26262 automotive safety of automobile rank high safety grade can be met completely, and effectively reduce the cost of product development.
As shown in Figure 2, the utility model also discloses a kind of high-speed CAN communicating circuit on the basis of above-described embodiment, comprising: control power supply 20, insulating power supply circuit 21, CAN communication circuit 22, buffer circuit 23, microprocessor 24, terminal resistance match circuit 25 and isolation control circuit 26; Wherein:
Control power supply 20 to be connected with insulating power supply circuit 21 and microprocessor 24, for the microprocessor 24 in high-speed CAN communicating circuit, insulating power supply circuit 21, buffer circuit 23 and CAN communication circuit 22 provide working power;
Insulating power supply circuit 21 is connected with control power supply 20, the interference signal controlled in the voltage of power supply 20 output is isolated, and export isolation voltage to connected CAN communication circuit 22, wherein, the interference signal controlled in the voltage of power supply 10 output comprises ripple interference signal, pulse interference signal and voltage fluctuation interference signal.
The bus differential signal of CAN communication circuit 22 to the entire car controller of access carries out filtering, and the CAN signal obtained afterwards is after filtering inputed to connected buffer circuit 23;
Be sent to microprocessor 24 after the CAN signal that buffer circuit 23 pairs of CAN communication circuit 22 send carries out filtering, and be sent to CAN communication circuit 22 after filtering is carried out to the CAN signal that microprocessor 24 sends;
The CAN signal after filtering that CAN communication circuit 22 pairs of buffer circuits 23 send carries out filtering again, and the CAN signal through filtering is again sent to bus;
The control signal that isolation control circuit 26 exports according to connected microprocessor 24, controls connected terminal resistance match circuit 25 and exports the resistance mated with terminal.
The present embodiment adds terminal resistance match circuit and isolation control circuit on the basis of above-described embodiment, while the antijamming capability realizing the communication of raising high-speed CAN, can also realize effective matched termination resistance.
The present embodiment the implementation realizing the antijamming capability improving high-speed CAN communication with on the principle of an embodiment identical, do not repeat them here.Highlight the coupling of terminal resistance below.
Concrete, as shown in Figure 5, terminal resistance match circuit disclosed in the utility model, comprising: the first analog switch U3, the second analog switch U4, resistance R5, resistance R6 and electric capacity C12; Wherein:
Model in pin NO and Fig. 4 of first analog switch U3 is that the pin CANL of the CAN communication chip U1 of TJA1057 is connected, pin COM is connected with one end of resistance R5, pin GND accesses isolation voltage earth terminal VSS_CAN, pin IN is connected with isolation control circuit, and pin V accesses isolation voltage VCC_CAN;
Model in pin NO and Fig. 4 of second analog switch U4 is that the pin CANH of the CAN communication chip U1 of TJA1057 is connected, pin COM is connected with one end of resistance R6, pin GND accesses isolation voltage earth terminal VSS_CAN, pin IN is connected with isolation control circuit, and isolation voltage VCC_CAN is stated in pin V access;
The other end of resistance R5 is connected with the other end of resistance R6;
One end of electric capacity C12 is connected with the tie point of resistance R6 with resistance R5, other end access isolation voltage earth terminal VSS_CAN.
Wherein, the first analog switch U3 and the second analog switch U4 is SN74LVC1G66-Q1.For matched termination resistance after resistance R5 and resistance R6 connects, by controlling the break-make of the first analog switch U3 and the second analog switch U4, realize the access state to resistance R5 and resistance R6 in terminal resistance match circuit, the resistance of output and terminal are matched.
Concrete, as shown in Figure 6, isolation control circuit disclosed in the utility model, comprising: resistance R7, resistance R8, optocoupler PC1, electric capacity C8, resistance R11, resistance R10, electric capacity C9, resistance R9 and switching tube Q1; Wherein:
The former limit anode access power supply of optocoupler PC1;
One end of resistance R7 is connected with microprocessor, and the other end is connected with the former limit negative electrode of optocoupler PC1;
One end of resistance R8 is connected with the former limit anode of optocoupler PC1, and the other end is connected with the former limit negative electrode of optocoupler PC1;
The secondary of optocoupler PC1 exports collector electrode and accesses described isolation voltage VCC_CAN;
One end of electric capacity C8 exports emitter-base bandgap grading with the secondary of optocoupler PC1 and is connected, and the other end is connected with the base stage of switching tube Q1;
One end of resistance R11 exports emitter-base bandgap grading with the secondary of optocoupler PC1 and is connected, and the other end is connected with the base stage of switching tube Q1;
One end of resistance R10 is connected with the base stage of switching tube Q1, and the other end is connected with the emitter of switching tube Q1;
One end of electric capacity C9 is connected with the base stage of switching tube Q1, and the other end is connected with the emitter of described switching tube Q1;
One end access isolation voltage VCC_CAN of resistance R9, the other end is connected with the collector electrode of switching tube Q1;
The collector electrode of switching tube Q1 is connected with terminal resistance match circuit as the output of isolation control circuit, emitter access isolation voltage earth terminal VSS_CAN.
Due to multiple terminal equipment can be accessed in the CAN network of automotive control system, such as: entire car controller, battery management system, electric machine controller, engine management system etc.In order to make each terminal equipment all can work normally, access terminal resistors match circuit usually in high-speed CAN communicating circuit, mates needing the terminal equipment of resistors match.
Concrete, the control of terminal resistance is realized by the first analog switch U3 and the second analog switch U4, the TERMINATO-O signal that the control signal of analog switch exports from microprocessor, the TERMINATO-O signal that microprocessor exports is determined by the terminal equipment accessed in CAN network.When the TERMINATO-O signal that microprocessor exports is low level, optocoupler PC1 conducting, switching tube Q1 conducting, the SWITCH signal that isolation control circuit exports is low level, first analog switch U3 and second analog switch U4 all not conductings, now terminal resistance R5 and R6 not access differential bus; Otherwise when the TERMINATO-O signal that microprocessor exports is high level, the SWITCH signal that isolation control circuit exports is high level, the first analog switch U3 and the equal conducting of the second analog switch U4, terminal resistance access differential bus.Meanwhile, owing to mostly there is common mode disturbances in CAN network, therefore need to adopt the common mode disturbances in the first analog switch U3 and the second analog switch U4 filtering CAN network simultaneously.Electric capacity C8 in isolation control circuit and electric capacity C9 is filter capacitor, can realize filtering.Resistance R9 pull-up provides biased to SWITCH signal.
In sum, the utility model is by automotive grade analog switch SN74LVC1G66-Q1, and as switching device, not only small volume, and turning on and off by analog switch SN74LVC1G66-Q1, can very convenient effective matched termination resistance.
The invention also discloses a kind of electric automobile, comprise the high-speed CAN communicating circuit as described in above-described embodiment, the transmission of electric automobile whole control information can be completed by high-speed CAN communicating circuit, improve the fail safe of full-vehicle control.
If the function described in the present embodiment method using the form of SFU software functional unit realize and as independently production marketing or use time, can be stored in a computing equipment read/write memory medium.Based on such understanding, the part of the part that the utility model embodiment contributes to prior art or this technical scheme can embody with the form of software product, this software product is stored in a storage medium, comprising some instructions in order to make a computing equipment (can be personal computer, server, mobile computing device or the network equipment etc.) perform all or part of step of method described in each embodiment of the utility model.And aforesaid storage medium comprises: USB flash disk, portable hard drive, read-only memory (ROM, Read-OnlyMemory), random access memory (RAM, RandomAccessMemory), magnetic disc or CD etc. various can be program code stored medium.
In this specification, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiment, between each embodiment same or similar part mutually see.
To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the utility model.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein when not departing from spirit or scope of the present utility model, can realize in other embodiments.Therefore, the utility model can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.
Claims (10)
1. a high-speed CAN communicating circuit, is characterized in that, comprising: control power supply, insulating power supply circuit, CAN communication circuit, buffer circuit and microprocessor; Wherein:
Described control power supply is connected with described insulating power supply circuit and described microprocessor, for described high-speed CAN communicating circuit provides working power;
Interference signal in the voltage that described insulating power supply circuit exports described control power supply is isolated, and exports isolation voltage VCC_CAN to connected described CAN communication circuit;
The bus differential signal of described CAN communication circuit to access carries out filtering, and the CAN signal obtained afterwards is after filtering inputed to connected described buffer circuit;
Described buffer circuit is sent to described microprocessor after carrying out filtering to the CAN signal that described CAN communication circuit sends, and is sent to described CAN communication circuit after carrying out filtering to the CAN signal that described microprocessor sends;
Described CAN communication circuit carries out filtering again to the CAN signal after filtering that described buffer circuit sends, and the CAN signal through filtering is again sent to bus.
2. circuit according to claim 1, is characterized in that, also comprises: terminal resistance match circuit and isolation control circuit; Wherein:
The control signal that described isolation control circuit exports according to connected described microprocessor, controls connected described terminal resistance match circuit and exports the resistance mated with terminal.
3. circuit according to claim 2, is characterized in that, described insulating power supply circuit comprises: inductance L 3, electric capacity C13, electric capacity C10, insulating power supply chip PW1, electric capacity C14, electric capacity C11 and resistance R12; Wherein:
One end of described inductance L 3 is connected with described control power supply, and the other end is connected with the input pin of described insulating power supply chip PW1;
One end of described electric capacity C13 is connected with the input pin of described insulating power supply chip PW1, other end ground connection; One end of described electric capacity C10 is connected with the input pin of described insulating power supply chip PW1, other end ground connection, the grounding leg ground connection of described insulating power supply chip PW1;
One end of described electric capacity C14 is connected with the output pin of described insulating power supply chip PW1, and the other end is connected with reference to lower margin with the output of described insulating power supply chip PW1; One end of described electric capacity C11 is connected with the output pin of described insulating power supply chip PW1, and the other end is connected with reference to lower margin with the output of described insulating power supply chip PW1;
One end of described resistance R12 is connected with the output pin of described insulating power supply chip PW1, and the other end is connected with reference to lower margin with the output of described insulating power supply chip PW1;
The output pin of described insulating power supply chip PW1 exports described isolation voltage VCC_CAN, exports with reference to lower margin access isolation voltage earth terminal VSS_CAN.
4. circuit according to claim 3, is characterized in that, described insulating power supply chip PW1 is CF0505XT-1WR2.
5. circuit according to claim 3, is characterized in that, described buffer circuit comprises: resistance R1, electric capacity C1, resistance R2, electric capacity C2, electric capacity C5, inductance L 2, electric capacity C6 and isolating chip U2;
Described CAN communication circuit comprises: CAN communication chip U1, electric capacity C7, electric capacity C3, electric capacity C4, resistance R3, resistance R4 and electrostatic protection diode Z1, and described electrostatic protection diode Z1 is made up of the first diode and the second diode; Wherein:
The first end of described resistance R1 is connected with the pin OUTA of described isolating chip U2, second end of described resistance R1 is connected with one end of described microprocessor and described electric capacity C1, the other end ground connection of described electric capacity C1, described isolating chip U2 exports CAN signal to described microprocessor;
The first end of described resistance R2 is connected with described microprocessor, and second end of described resistance R2 is connected with the pin INB of described isolating chip U2 and one end of described electric capacity C2 respectively, the other end ground connection of described electric capacity C2;
The pin VCC1 of described isolating chip U2 accesses power supply, pin GND1 ground connection, and pin VCC2 accesses described isolation voltage VCC_CAN, and pin GND2 accesses described isolation voltage earth terminal VSS_CAN, and pin OUTB accesses described CAN communication circuit;
One end of described inductance L 2 is connected with the pin INA of described isolating chip U2, and the other end is connected with the pin RXD of described CAN communication chip U1;
One end of described electric capacity C5 is connected with the pin VCC1 of described isolating chip U2, other end ground connection;
One end of described electric capacity C6 is connected with the pin VCC2 of described isolating chip U2, and the other end accesses described isolation voltage earth terminal VSS_CAN;
The pin TXD of described CAN communication chip U1 is connected with the pin OUTB of described isolating chip U2, pin GND, pin S and pin NC access described isolation voltage earth terminal VSS_CAN respectively, pin VCC accesses described isolation voltage VCC_CAN, and pin RXD is connected with described inductance L 2;
One end of electric capacity C7 is connected with the pin VCC of described CAN communication chip U1, and the other end accesses described isolation voltage earth terminal VSS_CAN;
One end of electric capacity C4 is connected with the pin CANH of described CAN communication chip U1, the other end is connected with one end of electric capacity C3, the other end of electric capacity C3 is connected with the pin CANL of described CAN communication chip U1, and the tie point of electric capacity C3 and electric capacity C4 accesses described isolation voltage earth terminal VSS_CAN;
One end of described resistance R3 is connected with the pin CANH of described CAN communication chip U1, and the other end is connected with the negative electrode of the first diode in described electrostatic protection diode Z1;
One end of described resistance R4 is connected with the pin CANL of described CAN communication chip U1, and the other end is connected with the negative electrode of the second diode in described electrostatic protection diode Z1;
The anode of the first diode is connected with the anode of the second diode and accesses described isolation voltage earth terminal VSS_CAN afterwards;
The other end of described resistance R3, the other end of resistance R4 are used for bus differential signal described in input and output.
6. circuit according to claim 5, is characterized in that, described isolating chip U2 is ISO7421A-Q1; Described CAN communication chip U1 is TJA1057.
7. circuit according to claim 5, is characterized in that, described terminal resistance match circuit comprises: the first analog switch U3, the second analog switch U4, resistance R5, resistance R6 and electric capacity C12; Wherein:
The pin NO of described first analog switch U3 is connected with the pin CANL of described CAN communication chip U1, pin COM is connected with one end of resistance R5, pin GND accesses described isolation voltage earth terminal VSS_CAN, pin IN is connected with described isolation control circuit, and pin V accesses described isolation voltage VCC_CAN;
The pin NO of described second analog switch U4 is connected with the pin CANH of described CAN communication chip U1, pin COM is connected with one end of resistance R6, pin GND accesses described isolation voltage earth terminal VSS_CAN, pin IN is connected with described isolation control circuit, and pin V accesses described isolation voltage VCC_CAN;
The other end of described resistance R5 is connected with the other end of resistance R6;
One end of described electric capacity C12 is connected with the tie point of resistance R6 with described resistance R5, and the other end accesses described isolation voltage earth terminal VSS_CAN.
8. circuit according to claim 7, is characterized in that, described first analog switch U3 and the second analog switch U4 is SN74LVC1G66-Q1.
9. circuit according to claim 7, is characterized in that, described isolation control circuit comprises: resistance R7, resistance R8, optocoupler PC1, electric capacity C8, resistance R11, resistance R10, electric capacity C9, resistance R9 and switching tube Q1; Wherein:
The former limit anode access power supply of described optocoupler PC1; One end of resistance R7 is connected with described microprocessor, and the other end is connected with the former limit negative electrode of described optocoupler PC1; One end of described resistance R8 is connected with the former limit anode of described optocoupler PC1, and the other end is connected with the former limit negative electrode of described optocoupler PC1;
The secondary of described optocoupler PC1 exports collector electrode and accesses described isolation voltage VCC_CAN;
One end of described electric capacity C8 exports emitter-base bandgap grading with the secondary of described optocoupler PC1 and is connected, and the other end is connected with the base stage of described switching tube Q1; One end of described resistance R11 exports emitter-base bandgap grading with the secondary of described optocoupler PC1 and is connected, and the other end is connected with the base stage of described switching tube Q1;
One end of described resistance R10 is connected with the base stage of described switching tube Q1, and the other end is connected with the emitter of described switching tube Q1; One end of described electric capacity C9 is connected with the base stage of described switching tube Q1, and the other end is connected with the emitter of described switching tube Q1;
Described isolation voltage VCC_CAN is accessed in one end of described resistance R9, the other end is connected with the collector electrode of described switching tube Q1, the collector electrode of described switching tube Q1 is connected with described terminal resistance match circuit as the output of isolation control circuit, and emitter accesses described isolation voltage earth terminal VSS_CAN.
10. an electric automobile, is characterized in that, comprises as the high-speed CAN communicating circuit in claim 1-9 as described in any one.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520514484.1U CN205017345U (en) | 2015-07-15 | 2015-07-15 | High -speed CAN communication circuit and electric automobile |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520514484.1U CN205017345U (en) | 2015-07-15 | 2015-07-15 | High -speed CAN communication circuit and electric automobile |
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| CN205017345U true CN205017345U (en) | 2016-02-03 |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106067904A (en) * | 2016-08-22 | 2016-11-02 | 中国重汽集团济南动力有限公司 | A kind of vehicle CAN communication channel switching circuit |
| CN106877942A (en) * | 2017-02-24 | 2017-06-20 | 深圳市沃特玛电池有限公司 | CAN electromagnetic interference suppression circuits |
| CN108375943A (en) * | 2018-05-16 | 2018-08-07 | 苏州麦垛信息科技有限公司 | A kind of SCM Based editable vending machine wiring board |
| CN108470012A (en) * | 2018-07-25 | 2018-08-31 | 常州昊云工控科技有限公司 | Bus filter device, system on chip and electrostatic protection method are extended out for electrostatic protection |
| CN111294263A (en) * | 2018-12-10 | 2020-06-16 | 比亚迪股份有限公司 | CAN bus circuit |
| CN111614530A (en) * | 2019-02-25 | 2020-09-01 | 南宁学院 | CAN data acquisition circuit of WIFI communication |
| CN113169921A (en) * | 2020-08-26 | 2021-07-23 | 深圳欣锐科技股份有限公司 | Isolation circuit and device for controller area network communication |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106067904A (en) * | 2016-08-22 | 2016-11-02 | 中国重汽集团济南动力有限公司 | A kind of vehicle CAN communication channel switching circuit |
| CN106877942A (en) * | 2017-02-24 | 2017-06-20 | 深圳市沃特玛电池有限公司 | CAN electromagnetic interference suppression circuits |
| EP3401152A1 (en) * | 2017-02-24 | 2018-11-14 | Optimum Battery Co., Ltd. | Electric vehicle and electromagnetic interference suppression circuit thereof |
| CN108375943A (en) * | 2018-05-16 | 2018-08-07 | 苏州麦垛信息科技有限公司 | A kind of SCM Based editable vending machine wiring board |
| CN108470012A (en) * | 2018-07-25 | 2018-08-31 | 常州昊云工控科技有限公司 | Bus filter device, system on chip and electrostatic protection method are extended out for electrostatic protection |
| CN111294263A (en) * | 2018-12-10 | 2020-06-16 | 比亚迪股份有限公司 | CAN bus circuit |
| CN111614530A (en) * | 2019-02-25 | 2020-09-01 | 南宁学院 | CAN data acquisition circuit of WIFI communication |
| CN113169921A (en) * | 2020-08-26 | 2021-07-23 | 深圳欣锐科技股份有限公司 | Isolation circuit and device for controller area network communication |
| CN113169921B (en) * | 2020-08-26 | 2023-05-09 | 深圳欣锐科技股份有限公司 | Isolation circuit and device for controller area network communication |
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