CN220711484U - Anti-interference single-wire bidirectional communication circuit - Google Patents
Anti-interference single-wire bidirectional communication circuit Download PDFInfo
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- CN220711484U CN220711484U CN202322423202.4U CN202322423202U CN220711484U CN 220711484 U CN220711484 U CN 220711484U CN 202322423202 U CN202322423202 U CN 202322423202U CN 220711484 U CN220711484 U CN 220711484U
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- 230000007175 bidirectional communication Effects 0.000 title claims abstract description 23
- 238000002955 isolation Methods 0.000 claims abstract description 20
- 230000006854 communication Effects 0.000 description 10
- 238000004891 communication Methods 0.000 description 10
- 230000005540 biological transmission Effects 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 208000033999 Device damage Diseases 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
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Abstract
The utility model discloses an anti-interference single-wire bidirectional communication circuit, which comprises: the port isolation protection circuit, the RXD switch control circuit and the TXD switch control circuit; the connection end of the port isolation protection circuit is electrically connected with an external port Comm and is electrically connected with a power supply VCC through a matching resistor, the other connection end of the port isolation protection circuit is electrically connected with the connection end of the RXD switch control circuit and the connection end of the TXD switch control circuit respectively, the other connection end of the RXD switch control circuit is electrically connected with a system signal receiving end RXD, and the other connection end of the TXD switch control circuit is electrically connected with a system signal transmitting end TXD. The utility model combines two signal interfaces of the system signal receiving end RXD and the system signal transmitting end TXD into an external signal interface, and realizes data receiving and transmitting in a half-duplex control mode, thereby saving one external signal port on the system and saving the structural space.
Description
Technical Field
The utility model particularly relates to an anti-interference single-wire bidirectional communication circuit.
Background
In a signal transmission system, a communication circuit is an important component, and can enable data transmission and signal control between two systems. The communication circuit generally comprises two signal wires for transmitting and receiving, but the signal wires for transmitting and receiving cannot be simultaneously placed on the communication circuit under the condition of limited system architecture or space, and then a single-wire bidirectional communication circuit is needed, namely, one signal wire is used for simultaneously realizing the functions of transmitting and receiving.
The traditional serial communication circuit adopts two independent signal interfaces to respectively transmit and receive, thereby realizing duplex or half duplex communication mode. The use of two independent signal interfaces occupies more communication interfaces and structural space, and cannot meet the requirements of normal information transmission and data exchange under the conditions of system architecture or space limitation.
Disclosure of Invention
In order to solve the technical problems, the utility model provides an anti-interference single-wire bidirectional communication circuit.
In order to achieve the above purpose, the technical scheme of the utility model is as follows:
the utility model discloses an anti-interference single-wire bidirectional communication circuit, which comprises: the port isolation protection circuit, the RXD switch control circuit and the TXD switch control circuit;
the connection end of the port isolation protection circuit is electrically connected with an external port Comm and is electrically connected with a power supply VCC through a matching resistor, the other connection end of the port isolation protection circuit is respectively electrically connected with the connection end of the RXD switch control circuit and the connection end of the TXD switch control circuit, the other connection end of the RXD switch control circuit is electrically connected with a system signal receiving end RXD, and the other connection end of the TXD switch control circuit is electrically connected with a system signal transmitting end TXD;
the port isolation protection circuit includes: the anode of the protection diode D1 is electrically connected with the external port Comm, and the cathode of the protection diode D1 is electrically connected with the RXD switch control circuit and the TXD switch control circuit respectively;
the RXD switch control circuit includes: the base electrode of the transistor Q3 is electrically connected with the cathode of the protection diode D1, the collector electrode of the transistor Q3 is electrically connected with the power supply VDD and the base electrode of the transistor Q4 respectively, the emitter electrode of the transistor Q4 is grounded, the base electrode of the transistor Q4 is electrically connected with the collector electrode of the transistor Q3, the collector electrode of the transistor Q4 is electrically connected with the power supply VDD and the system signal receiving end RXD respectively, and the emitter electrode of the transistor Q4 is grounded;
the TXD switch control circuit includes: and the collector of the transistor Q1 is electrically connected with the cathode of the protection diode D1, the base of the transistor Q1 is electrically connected with the power supply VDD and the collector of the transistor Q2 respectively, the emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is electrically connected with the base of the transistor Q1, the base of the transistor Q2 is electrically connected with the system signal transmitting end TXD, and the emitter of the transistor Q2 is grounded.
On the basis of the technical scheme, the following improvement can be made:
preferably, the port isolation protection circuit further comprises: at least one protection resistor is connected in series with the protection diode D1.
Preferably, the transistor Q4 is electrically connected to the power supply VDD through at least one pull-up resistor.
Preferably, the transistor Q2 is electrically connected to the power supply VDD through at least one pull-up resistor.
Preferably, the base of the transistor Q3 is electrically connected to the cathode of the protection diode D1 via at least one current limiting resistor.
Preferably, the base of the transistor Q4 is electrically connected to the collector of the transistor Q3 and the power supply VDD through at least one current limiting resistor, respectively.
Preferably, the base of the transistor Q2 is electrically connected to the system signal transmitter TXD through at least one current limiting resistor.
Preferably, the bases of the transistors Q1, Q2, Q3, and Q4 are grounded through at least one pull-down resistor, respectively.
The utility model discloses an anti-interference single-wire bidirectional communication circuit which has the following beneficial effects:
first, combine two signal interfaces of system signal receiving end RXD and system signal transmitting end TXD into an external signal interface, and realize receiving and transmitting data through half duplex control mode, save an external signal port on the system, save the structural space.
And secondly, the circuit is applied to a serial port communication circuit instead of an original double-wire control mode, and has the characteristics of bidirectional communication capacity for data receiving and transmitting, low circuit construction cost and strong anti-interference capacity.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a circuit diagram of an anti-interference single-wire bidirectional communication circuit according to an embodiment of the present utility model.
Detailed Description
Preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.
The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
The expression "comprising" an element is an "open" expression which merely means that the corresponding component is present and should not be interpreted as excluding additional components.
To achieve the object of the present utility model, in some embodiments of the anti-interference single-wire bidirectional communication circuit, as shown in fig. 1, the anti-interference single-wire bidirectional communication circuit includes: the port isolation protection circuit, the RXD switch control circuit and the TXD switch control circuit.
The connection end of the port isolation protection circuit is electrically connected with an external port Comm, and is electrically connected with a power supply VCC through a matching resistor R11, the other connection end of the port isolation protection circuit is respectively electrically connected with the connection end of the RXD switch control circuit and the connection end of the TXD switch control circuit, the other connection end of the RXD switch control circuit is electrically connected with a system signal receiving end RXD, and the other connection end of the TXD switch control circuit is electrically connected with a system signal transmitting end TXD.
The port isolation protection circuit includes: the protection diode D1 and the protection resistor R1 are connected in series, the anode of the protection diode D1 is electrically connected with the external port Comm through the protection resistor R1, and the cathode of the protection diode D1 is electrically connected with the RXD switch control circuit and the TXD switch control circuit respectively.
The RXD switch control circuit includes: a transistor Q3 and a transistor Q4.
The base electrode of the transistor Q3 is electrically connected with the cathode of the protection diode D1 through a current limiting resistor R6, and the base electrode of the transistor Q is grounded through a pull-down resistor R7; the collector of the transistor Q3 is electrically connected with the power supply VDD, and the collector of the transistor Q3 is also electrically connected with the base of the transistor Q4 through a current limiting resistor R8; the emitter of transistor Q3 is grounded.
The base electrode of the transistor Q4 is electrically connected with the collector electrode of the transistor Q3 through a current limiting resistor R8, and the base electrode of the transistor Q is grounded through a pull-down resistor R9; the collector of the transistor Q4 is electrically connected with a power supply VDD through a pull-up resistor R10, and the collector of the transistor Q is also electrically connected with a system signal receiving end RXD; the emitter of transistor Q4 is grounded.
The TXD switch control circuit includes: a transistor Q1 and a transistor Q2.
The collector of the transistor Q1 is electrically connected with the cathode of the protection diode D1; the base electrode of the transistor Q1 is grounded through a pull-down resistor R2 and is electrically connected with a power supply VDD through a pull-up resistor R3, and the base electrode of the transistor Q1 is also electrically connected with the collector electrode of the transistor Q2; the emitter of the transistor Q1 is grounded.
The collector of the transistor Q2 is electrically connected with the base of the transistor Q1 and is electrically connected with the power supply VDD through a pull-up resistor R3; the base electrode of the transistor Q2 is electrically connected with the system signal transmitting end TXD through a current limiting resistor R5, and the base electrode of the transistor Q is grounded through a pull-down resistor R4; the emitter of the transistor Q2 is grounded.
The port isolation protection circuit includes: the protection diode D1 and the protection resistor R1 isolate the system circuit from an external circuit through the protection diode D1, so that the device damage caused by inconsistent communication signal levels on the system circuit and the external circuit is prevented.
The RXD switch control circuit includes: the transistor Q3 and the transistor Q4 are switching control triodes of the system signal receiving end RXD, and meanwhile, the signal isolation function is also realized.
The TXD switch control circuit includes: the transistor Q1 and the transistor Q2 are switching control transistors of the system signal transmitting terminal TXD, and also play a role in signal isolation.
The resistor R5, the resistor R6 and the resistor R8 are current limiting resistors of the base electrodes of the transistor Q2, the transistor Q3 and the transistor Q4 respectively; the resistor R2, the resistor R4, the resistor R7 and the resistor R9 are respectively pull-down resistors of the bases of the transistor Q1, the transistor Q2, the transistor Q3 and the transistor Q4; the resistor R3 is a pull-up resistor of the collector of the transistor Q2 and is also a base signal control resistor of the transistor Q1; resistor R10 is the pull-up resistor of the collector of transistor Q4 and the system signal receiving end RXD; the resistor R11 is a pull-up resistor of the external port Comm and is also a matching resistor of the system end and the external end.
The working flow of the anti-interference single-wire bidirectional communication circuit is described below.
(1) When receiving data, the method comprises the following steps:
when the external port Comm inputs a high level, the base of the transistor Q3 is high, the transistor Q3 is in an on state, the collector of the transistor Q3 is low, the base of the transistor Q4 is also low, the transistor Q4 is in an off state, the collector of the transistor Q4 is pulled up to be high through the resistor R10, and the system signal receiving terminal RXD receives a high level signal.
When the external port Comm inputs a low level, the base of the transistor Q3 is pulled down to a low level through the resistor R7, the transistor Q3 is turned off, the collector of the transistor Q3 is high level, the base of the transistor Q4 is also high level, the transistor Q4 is turned on, the collector of the transistor Q4 is low level, and the system signal receiving terminal RXD receives a low level signal.
(2) When transmitting data, the method comprises the following steps:
when the system signal transmitting terminal TXD outputs a high level, the base of the transistor Q2 is high, the transistor Q2 is in an on state, the collector of the transistor Q2 is low, the base of the transistor Q1 is also low, the transistor Q1 is in an off state, meanwhile, due to the presence of the protection diode D1, the system terminal does not output a level signal, the external port Comm is pulled up to a high level through the resistor R11, the external terminal receives a high level signal, the collector of the transistor Q1 and the base of the transistor Q3 are pulled up to a high level through unidirectional conductivity of the protection diode D1, and the system signal receiving terminal RXD also receives a high level signal synchronously.
When the system signal transmitting terminal TXD outputs a low level, the base of the transistor Q2 is low, the transistor Q2 is in an off state, the collector of the transistor Q2 is pulled up to be high through the resistor R3, meanwhile, the base of the transistor Q1 is also high, the transistor Q1 is in an on state, the collectors of the transistor Q1 and the base of the transistor Q3 are low, meanwhile, the external port Comm is pulled down to be low through the protection diode D1, the external port receives a low level signal, and the system signal receiving terminal RXD also receives a low level signal synchronously; the system side synchronously receives the transmission data of the system signal transmitting end TXD through the system signal receiving end RXD and also plays a role in detecting whether the transmission data is normal or not, and if the transmission data is detected to be abnormal, a retransmission mechanism can be started to ensure that the data is completely transmitted.
Because no actual signal is output when the system end sends a high-level signal, the external end is required to receive the high level through the internal resistance R11 pull-up resistor, otherwise, complete signal receiving cannot be realized, the design also enables the system end and the external end to have matching properties, if the system end communicates with the non-matching external end, the non-matching external end cannot receive complete data, and communication data confidentiality is realized.
In the above embodiment, the transistors Q1, Q2, Q3 and Q4 are NPN transistors, but it should be noted that the transistors Q1, Q2, Q3 and Q4 may be N-channel field effect transistors or other transistors having the same function.
The protection diode D1 may be, but is not limited to, a schottky diode.
The utility model discloses an anti-interference single-wire bidirectional communication circuit which has the following beneficial effects:
first, combine two signal interfaces of system signal receiving end RXD and system signal transmitting end TXD into an external signal interface, and realize receiving and transmitting data through half duplex control mode, save an external signal port on the system, save the structural space.
And secondly, the circuit is applied to a serial port communication circuit instead of an original double-wire control mode, and has the characteristics of bidirectional communication capacity for data receiving and transmitting, low circuit construction cost and strong anti-interference capacity.
While the basic principles and main features of the present utility model and advantages of the present utility model have been shown and described, it will be understood by those skilled in the art that the present utility model is not limited by the foregoing embodiments, which are described in the foregoing specification merely illustrate the principles of the present utility model, and various changes and modifications may be made therein without departing from the spirit and scope of the utility model, which is defined in the appended claims and their equivalents.
Claims (8)
1. The anti-interference single-wire bidirectional communication circuit is characterized by comprising: the port isolation protection circuit, the RXD switch control circuit and the TXD switch control circuit;
the connection end of the port isolation protection circuit is electrically connected with an external port Comm and is electrically connected with a power supply VCC through a matching resistor, the other connection end of the port isolation protection circuit is respectively electrically connected with the connection end of the RXD switch control circuit and the connection end of the TXD switch control circuit, the other connection end of the RXD switch control circuit is electrically connected with a system signal receiving end RXD, and the other connection end of the TXD switch control circuit is electrically connected with a system signal transmitting end TXD;
the port isolation protection circuit includes: the anode of the protection diode D1 is electrically connected with the external port Comm, and the cathode of the protection diode D1 is electrically connected with the RXD switch control circuit and the TXD switch control circuit respectively;
the RXD switch control circuit includes: the base electrode of the transistor Q3 is electrically connected with the cathode of the protection diode D1, the collector electrode of the transistor Q3 is electrically connected with the power supply VDD and the base electrode of the transistor Q4 respectively, the emitter electrode of the transistor Q4 is grounded, the base electrode of the transistor Q4 is electrically connected with the collector electrode of the transistor Q3, the collector electrode of the transistor Q4 is electrically connected with the power supply VDD and the system signal receiving end RXD respectively, and the emitter electrode of the transistor Q4 is grounded;
the TXD switch control circuit includes: and the collector of the transistor Q1 is electrically connected with the cathode of the protection diode D1, the base of the transistor Q1 is electrically connected with the power supply VDD and the collector of the transistor Q2 respectively, the emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is electrically connected with the base of the transistor Q1, the base of the transistor Q2 is electrically connected with the system signal transmitting end TXD, and the emitter of the transistor Q2 is grounded.
2. The anti-interference single wire bi-directional communication circuit of claim 1, wherein said port isolation protection circuit further comprises: at least one protection resistor connected in series with the protection diode D1.
3. The anti-interference single wire bi-directional communication circuit according to claim 1, wherein the transistor Q4 is electrically connected to the power supply VDD through at least one pull-up resistor.
4. The anti-interference single wire bi-directional communication circuit according to claim 1, wherein the transistor Q2 is electrically connected to the power supply VDD through at least one pull-up resistor.
5. The anti-interference single wire bi-directional communication circuit according to claim 1, wherein the base of the transistor Q3 is electrically connected to the cathode of the protection diode D1 through at least one current limiting resistor.
6. The anti-interference single-wire bidirectional communication circuit according to claim 1, wherein the base electrode of the transistor Q4 is electrically connected to the collector electrode of the transistor Q3 and the power supply VDD through at least one current limiting resistor, respectively.
7. The anti-interference single wire bi-directional communication circuit according to claim 1, wherein the base of the transistor Q2 is electrically connected to the system signal transmitting terminal TXD through at least one current limiting resistor.
8. The anti-interference single wire bidirectional communication circuit according to claim 1, wherein the bases of the transistors Q1, Q2, Q3 and Q4 are respectively grounded through at least one pull-down resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322423202.4U CN220711484U (en) | 2023-09-07 | 2023-09-07 | Anti-interference single-wire bidirectional communication circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322423202.4U CN220711484U (en) | 2023-09-07 | 2023-09-07 | Anti-interference single-wire bidirectional communication circuit |
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| Publication Number | Publication Date |
|---|---|
| CN220711484U true CN220711484U (en) | 2024-04-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202322423202.4U Active CN220711484U (en) | 2023-09-07 | 2023-09-07 | Anti-interference single-wire bidirectional communication circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN220711484U (en) |
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- 2023-09-07 CN CN202322423202.4U patent/CN220711484U/en active Active
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