Single-wire communication circuit and communication system

Abstract

The application discloses a single-wire communication circuit and a communication system. The single-wire communication circuit comprises a first switch branch, a second switch branch, a first pull-up branch and a second pull-up branch. The first switch branch is turned on in response to a first communication signal output by a signal output end, so as to generate a first level signal at a first node. The first switch branch is turned off in response to a second communication signal output by the signal output end, and the first node is pulled up by the first pull-up branch to generate a second level signal when the first switch branch is turned off. The second switch branch is turned on in response to a third communication signal output by a second electronic product, so as to generate the first level signal at a second node. The second switch branch is turned off in response to a fourth communication signal output by the second electronic product, and the second node is pulled up by the second pull-up branch to generate the second level signal when the second switch branch is turned off. In this way, the communication between two electronic products can be realized through a single wire, and the cost is low.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a single-wire communication circuit and communication system. Background Technology

[0002] When two electronic products, such as the Battery Management System (BMS) and the Electronic Control Unit (ECU) of an electric vehicle, need to communicate digitally to transmit communication data between them, this is usually achieved through RS485 communication or CAN communication.

[0003] However, both RS485 and CAN communication require at least two communication lines, and they also require dedicated isolators, transceivers, and isolated power supplies, resulting in higher costs. Utility Model Content

[0004] This application provides a single-wire communication circuit and communication system that enables communication between two electronic products via a single wire, and at a low cost.

[0005] In a first aspect, embodiments of this application provide a single-wire communication circuit for connecting a first electronic product and a second electronic product. The single-wire communication circuit includes: a first switch branch, a second switch branch, a first pull-up branch, and a second pull-up branch. A first terminal of the first switch branch is connected to the signal output terminal of the first electronic product. A second terminal of the first switch branch is connected to a first node via both the first terminal of the second switch branch and the first pull-up branch. The first node is used to connect to the second electronic product. A second terminal of the second switch branch is connected to a second node via the second pull-up branch. The second node is used to connect to the signal input terminal of the first electronic product. The first switch branch is configured to respond to the signal input terminal of the first electronic product. The first electronic product is turned on by a first communication signal output from its signal output terminal to generate a first level signal at a first node; the first switch branch is also configured to turn off in response to a second communication signal output from its signal output terminal, wherein when the first switch branch is turned off, the first node is pulled up by the first pull-up branch to generate a second level signal; the second switch branch is configured to turn on in response to a third communication signal output from the second electronic product to generate the first level signal at a second node; the second switch branch is also configured to turn off in response to a fourth communication signal output from the second electronic product, wherein when the second switch branch is turned off, the second node is pulled up by the second pull-up branch to generate the second level signal.

[0006] In one or more embodiments, the first switching branch includes a first resistor, a second resistor, and a first PNP transistor; the first resistor is connected between the signal output terminal of the first electronic product and the base of the first PNP transistor, the second resistor is connected between the emitter of the first PNP transistor and the first node, and the collector of the first PNP transistor is grounded; wherein, the first communication signal and the first level signal are both low-level signals, and the second communication signal and the second level signal are both high-level signals.

[0007] In one or more embodiments, the second switching branch includes a third resistor and a second PNP transistor; the third resistor is connected between the base of the second PNP transistor and the first node, the emitter of the second PNP transistor is connected to the second node, and the collector of the second PNP transistor is grounded; wherein, the third communication signal is a low-level signal, and the fourth communication signal is a high-level signal.

[0008] In one or more embodiments, the first switching branch includes a fourth resistor, a fifth resistor, and a first NPN transistor; the fourth resistor is connected to the signal output terminal of the first electronic product and the base of the first NPN transistor; the fifth resistor is connected between the base of the first NPN transistor and ground; the emitter of the first NPN transistor is grounded; and the collector of the first NPN transistor is connected to the first node; wherein, the second communication signal and the first level signal are both low-level signals, and the first communication signal and the second level signal are both high-level signals.

[0009] In one or more embodiments, the second switching branch includes a sixth resistor, a seventh resistor, and a second NPN transistor; the sixth resistor is connected between the base of the second NPN transistor and the first node, the seventh resistor is connected between the base of the second NPN transistor and ground, the emitter of the second NPN transistor is grounded, and the collector of the second NPN transistor is connected to the second node; wherein, the third communication signal is a high-level signal, and the fourth communication signal is a low-level signal.

[0010] In one or more embodiments, the first pull-up branch includes an eighth resistor; the eighth resistor is connected between the power supply and the first node.

[0011] In one or more embodiments, the first pull-up branch further includes a diode; the anode of the diode is connected to the power supply, and the cathode of the diode is connected to the eighth resistor.

[0012] In one or more embodiments, the second pull-up branch includes a ninth resistor; the ninth resistor is connected between the power supply and the second node.

[0013] Secondly, embodiments of this application provide a communication system, including a first electronic product, a second electronic product, and a single-wire communication circuit as described above, wherein the single-wire communication circuit is connected between the first electronic product and the second electronic product.

[0014] The beneficial effects of this application are as follows: The single-wire communication circuit of this application embodiment is used to connect a first electronic product and a second electronic product. The single-wire communication circuit includes a first switch branch, a second switch branch, a first pull-up branch, and a second pull-up branch. The first end of the first switch branch is connected to the signal output terminal of the first electronic product. The second end of the first switch branch is connected to the first end of the second switch branch and the first pull-up branch at a first node, which is used to connect to the second electronic product. The second end of the second switch branch is connected to the second pull-up branch at a second node, which is used to connect to the signal input terminal of the first electronic product. When the first electronic product outputs a signal and the second electronic product receives a signal, if the signal output terminal of the first electronic product outputs a first communication signal, the first switch branch is turned on, and the first node generates a first-level signal. If the signal output terminal of the first electronic product outputs a second communication signal, the first switch branch is turned off, and the first node is pulled up by the first pull-up branch to generate a second-level signal. When the second electronic product outputs a signal and the first electronic product receives the signal, if the second electronic product outputs a third communication signal, the second switch branch is turned on, and the second node generates a first-level signal; if the second electronic product outputs a fourth communication signal, the second switch branch is turned off, and the second node is pulled up by the second pull-up branch to generate a second-level signal. Through this process, communication between the first and second electronic products is achieved. Furthermore, the single-wire communication circuit is connected to the second electronic product via only a single wire, enabling communication between the two electronic products through a single wire. Moreover, this process is implemented through hardware circuitry, eliminating the need for isolators or other equipment, resulting in lower costs. Attached Figure Description

[0015] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0016] Figure 1 This is a schematic diagram of the composition of the communication system provided in the embodiments of this application; Figure 2 This is a schematic diagram of the composition block diagram of the single-wire communication circuit provided in the embodiments of this application; Figure 3This is a schematic diagram of the circuit structure of the single-wire communication circuit provided in the embodiments of this application. Figure 1 ; Figure 4 This is a schematic diagram of the circuit structure of the single-wire communication circuit provided in the embodiments of this application. Figure 2 ; Figure 5 This is a schematic diagram of the circuit structure of the single-wire communication circuit provided in the embodiments of this application. Figure 3 . Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0018] It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements between them.

[0019] Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0020] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the composition of a communication system provided in an embodiment of this application. Figure 1 As shown, the communication system 1000 includes a first electronic product 200, a second electronic product 300, and a single-wire communication circuit 100, which is connected between the first electronic product 200 and the second electronic product 300.

[0021] The second electronic product 300 is connected to the single-wire communication circuit 100 via a single wire, enabling single-wire communication between the first electronic product 200 and the second electronic product 300. The two communication devices in single-wire communication are connected by a single communication data line (i.e., the communication data line between the second electronic product 300 and the single-wire communication circuit 100). At any given time, data can only be transmitted unidirectionally between the two electronic products. For example, at one moment, the first electronic product 200 sends data, and the second electronic product 300 receives data; at another moment, the second electronic product 300 sends data, and the first electronic product 200 receives data.

[0022] Please refer to Figure 2 , Figure 2This is a schematic diagram of the block diagram of a single-wire communication circuit provided in an embodiment of this application. The single-wire communication circuit 100 is used to connect the first electronic product 200 and the second electronic product 300. Figure 2 As shown, the single-wire communication circuit 100 includes a first switch branch 10, a second switch branch 20, a first pull-up branch 30, and a second pull-up branch 40.

[0023] The first end of the first switch branch 10 is connected to the signal output terminal TX of the first electronic product 200. The second end of the first switch branch 10 is connected to the first end of the second switch branch 20 and the first pull-up branch 30 at the first node P1. The first node P1 is connected to the second electronic product 300. The second end of the second switch branch 20 is connected to the second pull-up branch 40 at the second node P2. The second node P2 is connected to the signal input terminal RX of the first electronic product 200.

[0024] Specifically, the first switch branch 10 is configured to be turned on in response to a first communication signal output from the signal output terminal TX of the first electronic product 200, to generate a first level signal at the first node P1. The first switch branch 10 is also configured to be turned off in response to a second communication signal output from the signal output terminal TX of the first electronic product 200, wherein when the first switch branch 10 is turned off, the first node P1 is pulled up by the first pull-up branch 30 to generate the second level signal. The second switch branch 20 is configured to be turned on in response to a third communication signal output from the second electronic product 300, to generate a first level signal at the second node P2. The second switch branch 20 is also configured to be turned off in response to a fourth communication signal output from the second electronic product 300, wherein when the second switch branch 20 is turned off, the second node P2 is pulled up by the second pull-up branch 40 to generate the second level signal. The first communication signal, the second communication signal, the third communication signal, the fourth communication signal, the first level signal, and the second level signal are all either high-level signals or low-level signals.

[0025] In practical applications, when the first electronic product 200 outputs a signal and the second electronic product 300 receives a signal, if the signal output terminal TX of the first electronic product 200 outputs a first communication signal, the first switch branch 10 is turned on, and the first node P1 generates a first-level signal; if the signal output terminal TX of the first electronic product 200 outputs a second communication signal, the first switch branch 10 is turned off, and the first node P1 is pulled up by the first pull-up branch 30 to generate a second-level signal. When the second electronic product 300 outputs a signal and the first electronic product 200 receives a signal, if the second electronic product 300 outputs a third communication signal, the second switch branch 20 is turned on, and the second node P2 generates a first-level signal; if the second electronic product 300 outputs a fourth communication signal, the second switch branch 20 is turned off, and the second node P2 is pulled up by the second pull-up branch 40 to generate a second-level signal. Through the above process, the communication process between the first electronic product 200 and the second electronic product 300 is realized. Furthermore, the single-wire communication circuit 100 and the second electronic product 300 are connected only through a single wire to realize communication between the two electronic products through a single wire. In addition, the above process is implemented through hardware circuits, without the need to set up isolators or other equipment, resulting in lower costs.

[0026] Please refer to Figure 3 , Figure 3 This application provides a circuit structure for a single-wire communication circuit. For example... Figure 3 As shown, the first switch branch 10 includes a first resistor R1, a second resistor R2, and a first PNP transistor PN1.

[0027] The first resistor R1 is connected between the signal output terminal TX of the first electronic product 200 and the base of the first PNP transistor PN1, and the second resistor R2 is connected between the emitter of the first PNP transistor PN1 and the first node P1. The collector of the first PNP transistor PN1 is grounded to GND. Both the first resistor R1 and the second resistor R2 are current-limiting resistors.

[0028] In some embodiments, the second switching branch 20 includes a third resistor R3 and a second PNP transistor PN2.

[0029] The third resistor R3 is connected between the base of the second PNP transistor PN2 and the first node P1. The emitter of the second PNP transistor PN2 is connected to the second node P2. The collector of the second PNP transistor PN2 is grounded to GND. The third resistor R3 is a current-limiting resistor.

[0030] In some embodiments, the first pull-up branch 30 includes an eighth resistor R8.

[0031] The eighth resistor, R8, is connected between the power supply VCC and the first node P1. The eighth resistor, R8, is a pull-up resistor.

[0032] In some embodiments, the second pull-up branch 40 includes a ninth resistor R9.

[0033] The ninth resistor, R9, is connected between the power supply VCC and the second node P2. The ninth resistor, R9, is a pull-up resistor.

[0034] The following are Figure 3 The principle of the circuit structure shown will be explained. When the signal output terminal TX of the first electronic product 200 outputs a first communication signal (a low-level signal in this embodiment), the first PNP transistor PN1 is turned on, and the first node P1 is grounded to GND through the second resistor R2 and the first PNP transistor PN1. This is equivalent to the first node P1 being pulled down, i.e., a first-level signal (a low-level signal in this embodiment) is generated on the first node P1. When the signal output terminal TX of the first electronic product 200 outputs a second communication signal (a high-level signal in this embodiment), the first PNP transistor PN1 is turned off, and the first node P1 is connected to the power supply VCC through the eighth resistor R8. This is equivalent to the first node P1 being pulled up, i.e., a second-level signal (a high-level signal in this embodiment) is generated on the first node P1. In summary, this achieves the following: the first electronic product 200 outputs a low-level signal, and the second electronic product 300 receives a low-level signal; the first electronic product 200 outputs a high-level signal, and the second electronic product 300 receives a high-level signal.

[0035] When the second electronic product 300 outputs a third communication signal (a low-level signal in this embodiment), the second PNP transistor PN2 is turned on, and the second node P2 is grounded to GND through the second PNP transistor PN2. This is equivalent to the second node P2 being pulled down, generating a first-level signal (a low-level signal in this embodiment) on the second node P2. The signal input terminal RX of the first electronic product 200 receives the first-level signal. When the second electronic product 300 outputs a fourth communication signal (a high-level signal in this embodiment), the second PNP transistor PN2 is turned off, and the second node P2 is connected to the power supply VCC through the ninth resistor R9. The second node P2 is pulled up, generating a second-level signal (a high-level signal in this embodiment) on the second node P2. The signal input terminal RX of the first electronic product 200 receives the second-level signal. In summary, this achieves the following: when the second electronic product 300 outputs a low-level signal, the first electronic product 200 receives a low-level signal; when the second electronic product 300 outputs a high-level signal, the first electronic product 200 receives a high-level signal.

[0036] Through the above process, the communication process between the first electronic product 200 and the second electronic product 300 is realized. Furthermore, the single-wire communication circuit 100 and the second electronic product 200 are connected only through a single wire to realize communication between the two electronic products through a single wire. In addition, the above process is implemented through hardware circuits, without the need to set up isolators or other equipment, resulting in lower costs.

[0037] In some embodiments, such as Figure 4 As shown, the first pull-up branch 30 also includes a diode D1.

[0038] In this configuration, the anode of diode D1 is connected to the power supply VCC, and the cathode of diode D1 is connected to the eighth resistor R8. Diode D1 is used to prevent the current flowing through the first node P1 from flowing back into the power supply VCC, thus protecting the power supply VCC.

[0039] Please refer to Figure 5 , Figure 5 This application provides another circuit structure for a single-wire communication circuit. The specific implementation process of the first pull-up branch 30 and the second pull-up branch 40 is as follows: Figure 3 and Figure 4 Similarly, here it is with Figure 4 For example, the specific implementation process can be found in the documentation for [specific example]. Figure 3 and Figure 4 The explanation will not be repeated here.

[0040] like Figure 5 As shown, the first switch branch 10 includes a fourth resistor R4, a fifth resistor R5, and a first NPN transistor NP1.

[0041] The fourth resistor R4 is connected to the signal output terminal TX of the first electronic product 200 and the base of the first NPN transistor NP1. The fifth resistor R5 is connected between the base of the first NPN transistor NP1 and ground GND. The emitter of the first NPN transistor NP1 is grounded to GND, and the collector of the first NPN transistor NP1 is connected to the first node P1. The fourth resistor R4 is used for current limiting. At the same time, the fourth resistor R4 and the fifth resistor R5 are used to divide the voltage of the signal output terminal TX of the first electronic product 200. When the voltage across the fifth resistor R5 is greater than the minimum forward voltage drop between the base and emitter of the first NPN transistor NP1, the first NPN transistor NP1 conducts.

[0042] In some embodiments, the second switching branch 20 includes a sixth resistor R6, a seventh resistor R7, and a second NPN transistor NP2.

[0043] In this circuit, the sixth resistor R6 is connected between the base of the second NPN transistor NP2 and the first node P1, and the seventh resistor R7 is connected between the base of the second NPN transistor NP2 and ground GND. The emitter of the second NPN transistor NP2 is grounded to GND, and the collector of the second NPN transistor NP2 is connected to the second node P2. The sixth resistor R6 is used for current limiting. Simultaneously, the sixth resistor R6 and the seventh resistor R7 are used to divide the voltage of the signal output by the second electronic product 300. Specifically, when the voltage across the seventh resistor R7 is greater than the minimum forward voltage drop between the base and emitter of the second NPN transistor NP2, the second NPN transistor NP2 conducts.

[0044] The following are Figure 3 The principle of the circuit structure shown will be explained. When the signal output terminal TX of the first electronic product 200 outputs a first communication signal (a high-level signal in this embodiment), the first PNP transistor PN1 is turned on, and the first node P1 is grounded to GND through the first NPN transistor NP1. This is equivalent to the first node P1 being pulled down, i.e., a first-level signal (a low-level signal in this embodiment) is generated on the first node P1. When the signal output terminal TX of the first electronic product 200 outputs a second communication signal (a low-level signal in this embodiment), the first PNP transistor PN1 is turned off, and the first node P1 is connected to the power supply VCC through the eighth resistor R8. The first node P1 is pulled up, i.e., a second-level signal (a high-level signal in this embodiment) is generated on the first node P1. In summary, this achieves the following: the first electronic product 200 outputs a high-level signal, and the second electronic product 300 receives a low-level signal; the first electronic product 200 outputs a low-level signal, and the second electronic product 300 receives a high-level signal.

[0045] When the second electronic product 300 outputs a third communication signal (a high-level signal in this embodiment), the second PNP transistor PN2 is turned on, and the second node P2 is grounded to GND through the second NPN transistor NP2. This is equivalent to the second node P2 being pulled down, generating a first-level signal (a low-level signal in this embodiment) on the second node P2. The signal input terminal RX of the first electronic product 200 receives the first-level signal. When the second electronic product 300 outputs a fourth communication signal (a low-level signal in this embodiment), the second PNP transistor PN2 is turned off, and the second node P2 is connected to the power supply VCC through the ninth resistor R9. The second node P2 is pulled up, generating a second-level signal (a high-level signal in this embodiment) on the second node P2. The signal input terminal RX of the first electronic product 200 receives the second-level signal. In summary, this achieves the following: the second electronic product 300 outputs a high-level signal, and the first electronic product 200 receives a low-level signal; the second electronic product 300 outputs a low-level signal, and the first electronic product 200 receives a high-level signal.

[0046] Through the above process, the communication process between the first electronic product 200 and the second electronic product 300 is realized. Furthermore, the single-wire communication circuit 100 and the second electronic product 200 are connected only through a single wire to realize communication between the two electronic products through a single wire. In addition, the above process is implemented through hardware circuits, without the need to set up isolators or other equipment, resulting in lower costs.

[0047] It should be noted that when the second electronic product 300 sends a signal and the first electronic product 200 receives the signal, the signal output terminal TX of the first electronic product 200 outputs a low-level signal to control the first NPN transistor NP1 to remain off, thereby not affecting the signal on the first node P1. Similarly, when the first electronic product 200 and the second electronic product 300 are not communicating, the signal output terminal TX of the first electronic product 200 also outputs a low-level signal to control the first NPN transistor NP1 to remain off, thereby not affecting the signal on the first node P1.

[0048] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0049] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A single-wire communication circuit, characterized by For connecting a first electronic product and a second electronic product, the single-wire communication circuit includes: First switch branch, second switch branch, first pull-up branch and second pull-up branch; The first end of the first switch branch is used to connect to the signal output terminal of the first electronic product. The second end of the first switch branch is connected to the first end of the second switch branch and the first pull-up branch at the first node. The first node is used to connect to the second electronic product. The second end of the second switch branch is connected to the second pull-up branch at the second node. The second node is used to connect to the signal input terminal of the first electronic product. The first switch branch is configured to be turned on in response to a first communication signal output from the signal output terminal of the first electronic product, so as to generate a first level signal at the first node; The first switch branch is also configured to be turned off in response to a second communication signal output from the signal output terminal of the first electronic product, wherein when the first switch branch is turned off, the first node is pulled up by the first pull-up branch to generate a second level signal; The second switch branch is configured to be turned on in response to a third communication signal output by the second electronic product in order to generate the first level signal at the second node; The second switch branch is also configured to turn off in response to a fourth communication signal output by the second electronic product, wherein when the second switch branch is turned off, the second node is pulled up by the second pull-up branch to generate the second level signal.

2. The single-wire communication circuit according to claim 1, characterized in that The first switching branch includes a first resistor, a second resistor, and a first PNP transistor; The first resistor is connected between the signal output terminal of the first electronic product and the base of the first PNP transistor, the second resistor is connected between the emitter of the first PNP transistor and the first node, and the collector of the first PNP transistor is grounded. Wherein, the first communication signal and the first level signal are both low-level signals, and the second communication signal and the second level signal are both high-level signals.

3. Single-wire communication circuit according to claim 1 or 2, characterized in that The second switching branch includes a third resistor and a second PNP transistor; The third resistor is connected between the base of the second PNP transistor and the first node, the emitter of the second PNP transistor is connected to the second node, and the collector of the second PNP transistor is grounded. The third communication signal is a low-level signal, and the fourth communication signal is a high-level signal.

4. The single-wire communication circuit of claim 1, wherein, The first switching branch includes a fourth resistor, a fifth resistor, and a first NPN transistor; The fourth resistor is connected to the signal output terminal of the first electronic product and the base of the first NPN transistor. The fifth resistor is connected between the base of the first NPN transistor and ground. The emitter of the first NPN transistor is grounded. The collector of the first NPN transistor is connected to the first node. Wherein, both the second communication signal and the first level signal are low-level signals, and both the first communication signal and the second level signal are high-level signals.

5. Single-wire communication circuit according to claim 1 or 4, characterized in that The second switching branch includes a sixth resistor, a seventh resistor, and a second NPN transistor; The sixth resistor is connected between the base of the second NPN transistor and the first node, the seventh resistor is connected between the base of the second NPN transistor and ground, the emitter of the second NPN transistor is grounded, and the collector of the second NPN transistor is connected to the second node; The third communication signal is a high-level signal, and the fourth communication signal is a low-level signal.

6. The single-wire communication circuit of claim 1, wherein, The first pull-up branch includes an eighth resistor; The eighth resistor is connected between the power supply and the first node.

7. The single-wire communication circuit of claim 6, wherein, The first pull-up branch also includes a diode; The anode of the diode is connected to the power supply, and the cathode of the diode is connected to the eighth resistor.

8. The single-wire communication circuit of claim 1, wherein, The second pull-up branch includes a ninth resistor; The ninth resistor is connected between the power supply and the second node.

9. A communication system, characterized by It includes a first electronic product, a second electronic product, and a single-wire communication circuit as described in any one of claims 1-8, wherein the single-wire communication circuit is connected between the first electronic product and the second electronic product.

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