CN111654184A - Communication voltage conversion circuit, communication device and communication voltage identification method - Google Patents

Communication voltage conversion circuit, communication device and communication voltage identification method Download PDF

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Publication number
CN111654184A
CN111654184A CN202010564609.7A CN202010564609A CN111654184A CN 111654184 A CN111654184 A CN 111654184A CN 202010564609 A CN202010564609 A CN 202010564609A CN 111654184 A CN111654184 A CN 111654184A
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China
Prior art keywords
voltage
communication unit
circuit
communication
signal
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Chinese (zh)
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刘国涛
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Shenzhen Shuliantianxia Intelligent Technology Co Ltd
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Shenzhen Shuliantianxia Intelligent Technology Co Ltd
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Priority to CN202010564609.7A priority Critical patent/CN111654184A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
    • H03K19/02—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits using specified components
    • H03K19/08—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits using specified components using semiconductor devices
    • H03K19/082—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits using specified components using semiconductor devices using bipolar transistors

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Computing Systems (AREA)
  • General Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Dc Digital Transmission (AREA)

Abstract

The embodiment of the invention relates to the technical field of wireless communication, and discloses a communication voltage conversion circuit, a communication device and a communication voltage identification method, wherein the circuit comprises a received signal conversion circuit; the received signal conversion circuit includes: the input end of the first switch circuit is connected with the first control end of the first communication unit, the control end of the first switch circuit is connected with the first power supply, and the output end of the first switch circuit is connected with the first end of the first pull-up circuit; the input end of the second switch circuit is connected with the first control end, the control end is connected with the second power supply, and the output end is connected with the first end of the first pull-up circuit; the input end of the third switch circuit is connected with the first power supply, the control end of the third switch circuit is connected with the signal sending end of the first communication unit, and the output end of the third switch circuit is connected with the signal receiving end of the second communication unit; the second end of the first pull-up circuit is connected with the signal receiving end of the second communication unit. Through the mode, the embodiment of the invention realizes communication voltage conversion.

Description

Communication voltage conversion circuit, communication device and communication voltage identification method
Technical Field
The embodiment of the invention relates to the technical field of wireless communication, in particular to a communication voltage conversion circuit, a communication device and a communication voltage identification method.
Background
With the rapid development of the internet of things, the intellectualization of household electrical appliances becomes the trend of future development of household electrical appliances, and various wireless communication technologies are widely applied to the development and design of household electrical appliances. Household electrical appliances main control unit MCU, what some products adopted is 8 MCU, what some products adopted is 32 MCU, and 8 MCU's power supply is 5V supply voltage, serial communication level is also 5V, 32 MCU's power supply is 3.3V supply voltage, serial communication level also is 3.3V naturally, wireless communication MCU is 32 bits and is 3.3V power supply, serial communication level also is 3.3V naturally.
Before the wireless communication MCU communicates with the MCU of the household appliance controller, the working voltage condition of the MCU of the household appliance controller needs to be known in advance, and then a communication circuit conversion circuit is designed according to the specific working voltage. That is, when the household electrical appliances with different working voltages communicate, the communication voltage converting circuit needs to be specially designed for the voltage of the household electrical appliances, so that the design cost of the communication voltage converting circuit is high.
Disclosure of Invention
In view of the foregoing problems, embodiments of the present invention provide a communication voltage converting circuit, a communication device, and a method for identifying a communication voltage, which are used to solve the problem of high design cost of an MCU communication circuit in the prior art.
According to an aspect of an embodiment of the present invention, there is provided a communication voltage converting circuit including a received signal converting circuit; the receiving signal conversion circuit is used for converting the voltage signal sent by the first communication unit into the communication voltage of the second communication unit; the received signal conversion circuit includes: the first pull-up circuit comprises a first switch circuit, a second switch circuit, a third switch circuit and a first pull-up circuit;
the input end of the first switch circuit is connected with the first control end of the first communication unit, the control end of the first switch circuit is connected with a first power supply, and the output end of the first switch circuit is connected with the first end of the first pull-up circuit; the first voltage of the first power supply is the same as the communication voltage of the first communication unit; the first switching circuit is switched on or switched off according to a first control signal sent by a first control end of the first communication unit; when the first switch circuit is conducted, the voltage of the output end of the first switch circuit is the first voltage;
the input end of the second switch circuit is connected with the first control end of the first communication unit, the control end of the second switch circuit is connected with a second power supply, and the output end of the second switch circuit is connected with the first end of the first pull-up circuit; the second voltage of the second power supply is the same as the communication voltage of the second communication unit, and the second switch circuit is switched on or switched off according to the first control signal; when the second switch circuit is conducted, the voltage of the output end of the second switch circuit is the second voltage;
the input end of the third switch circuit is connected with the first power supply, the control end of the third switch circuit is connected with the signal sending end of the first communication unit, and the output end of the third switch circuit is connected with the signal receiving end of the second communication unit; the third switch circuit is switched on or switched off according to a voltage signal sent by a signal sending end of the first communication unit; when the third switch circuit is turned on, the output end of the third switch circuit outputs a voltage signal sent by the signal sending end of the first communication unit;
a first end of the first pull-up circuit is connected with an output end of the first switch circuit and an output end of the second switch circuit respectively, and a second end of the first pull-up circuit is connected with a signal receiving end of the second communication unit;
when the communication voltage of the first communication unit is different from the communication voltage of the second communication unit, the first control signal is at a high level, the first switch circuit is turned off, the second switch circuit is turned on, and the voltage of the first end of the first pull-up circuit is the second voltage; when the signal sending end of the first communication unit sends a high-voltage signal to the second communication unit, the third switch circuit is turned off, and the voltage signal received by the second communication unit is the second voltage; when the signal sending end of the first communication unit sends a low-voltage signal to the second communication unit, the third switch circuit is turned on, and the voltage signal received by the second communication unit is low-voltage.
In an alternative form, the first switching circuit includes: the first PNP type triode is connected with the first voltage-dividing resistor;
the first voltage-dividing resistor and the second voltage-dividing resistor are connected in series between a first control end of the first communication unit and the first power supply, the other end of the first voltage-dividing resistor is connected with the first control end of the first communication unit, and the other end of the second voltage-dividing resistor is connected with the first power supply;
a base electrode of the first PNP type triode is connected to a common end of the first voltage-dividing resistor and the second voltage-dividing resistor, an emitter electrode of the first PNP type triode is connected to the first power supply, a base electrode of the first PNP type triode is connected to a common end of the first voltage-dividing resistor and the second voltage-dividing resistor, and a collector electrode of the first PNP type triode is connected to a first end of the first pull-up circuit;
when the first control signal is at a high level, the first PNP type triode is turned off; when the first control signal is at a low level, the second voltage-dividing resistor and the first voltage-dividing resistor divide the first voltage to turn on the first PNP transistor, and the voltage of the collector of the first PNP transistor is the first voltage.
In an alternative form, the second switching circuit includes: the first NPN type triode, the second PNP type triode and the first current limiting resistor are connected in series;
the third voltage dividing resistor and the fourth voltage dividing resistor are connected in series between the second power supply and the collector of the first NPN-type transistor, the other end of the third voltage dividing resistor is connected to the second power supply, and the other end of the fourth voltage dividing resistor is connected to the collector of the first NPN-type transistor;
a base electrode of the first NPN type triode is connected with a first control end of the first communication unit through the first current limiting resistor, a collector electrode of the first NPN type triode is connected with one end of the fourth voltage dividing resistor, and an emitter electrode of the first NPN type triode is grounded;
a base electrode of the second PNP type triode is connected with a common end of the third voltage dividing resistor and the fourth voltage dividing resistor, an emitting electrode of the second PNP type triode is connected with the second power supply, and a collecting electrode of the second PNP type triode is connected with a first end of the first pull-up circuit;
when the first control end of the first communication unit outputs a high level, the first NPN type triode is turned on, and a collector electrode of the first NPN type triode outputs a low level, so that the second PNP type triode is turned on, and the voltage of the collector electrode of the second PNP type triode is the second voltage; when the first control end of the first communication unit outputs a low level, the first NPN type triode and the second PNP type triode are both turned off.
In an alternative form, the third switching circuit includes: the second NPN type triode and the second current limiting resistor are connected; a base electrode of the second NPN type triode is connected with the first power supply through the second current-limiting resistor, an emitting electrode of the second NPN type triode is connected with a signal sending end of the first communication unit, and a collecting electrode of the second NPN type triode is connected with a signal receiving end of the second communication unit;
when the first control end of the first communication unit outputs a high level, the second NPN type triode is turned off; when the first control end of the first communication unit outputs a low level, the second NPN type triode is turned on, and a collector of the second NPN type triode outputs a low level.
In an optional manner, the circuit further includes a transmission signal conversion circuit, where the transmission signal conversion circuit is configured to convert a voltage signal transmitted by the second communication unit into a communication voltage of the first communication unit; the transmitting signal conversion circuit comprises a fourth switch circuit, a fifth switch circuit, a sixth switch circuit and a second pull-up circuit;
an input end of the fourth switch circuit is connected with the second control end of the first communication unit, a control end of the fourth switch circuit is connected with the first power supply, and an output end of the fourth switch circuit is connected with the first end of the second pull-up circuit; the fourth switching circuit is switched on or switched off according to a second control signal sent by a second control end of the first communication unit; when the fourth switching circuit is conducted, the voltage of the output end of the fourth switching circuit is the first voltage;
an input end of the fifth switch circuit is connected with the second control end of the first communication unit, a control end of the fifth switch circuit is connected with the first power supply, an output end of the fifth switch circuit is connected with the first end of the second pull-up circuit, and the fifth switch circuit is turned on or off according to the second control signal; when the fifth switch circuit is turned on, the voltage of the output end of the fifth switch circuit is the first voltage;
the input end of the sixth switching circuit is connected with a second power supply, the control end of the sixth switching circuit is connected with the signal sending end of the second communication unit, and the output end of the sixth switching circuit is connected with the signal receiving end of the first communication unit; the sixth switching circuit is switched on or off according to a voltage signal sent by the signal sending end of the second communication unit; when the sixth switching circuit is turned on, the output end of the sixth switching circuit outputs a voltage signal sent by the signal sending end of the second communication unit;
a first end of the second pull-up circuit is connected with an output end of the fourth switch circuit and an output end of the fifth switch circuit respectively, and a second end of the second pull-up circuit is connected with a signal receiving end of the first communication unit;
when the communication voltage of the first communication unit is different from the communication voltage of the second communication unit, the second control signal is at a high level, the fourth switch circuit is turned off, the fifth switch circuit is turned on, and the voltage of the first end of the second pull-up circuit is the first voltage; when the signal sending end of the second communication unit sends a high-voltage signal to the first communication unit, the sixth switching circuit is turned off, and the voltage signal received by the first communication unit is the first voltage; when the signal sending end of the second communication unit sends a low-voltage signal to the first communication unit, the sixth switch circuit is turned on, and the voltage signal received by the first communication unit is low-voltage.
In an optional manner, the circuit further includes a transmission signal conversion circuit, where the transmission signal conversion circuit is configured to convert a voltage signal transmitted by the second communication unit into a communication voltage of the first communication unit; the transmission signal conversion circuit includes: a fifth voltage-dividing resistor, a sixth voltage-dividing resistor, a third NPN type triode and a second current-limiting resistor;
the fifth voltage-dividing resistor and the sixth voltage-dividing resistor are connected in series between a signal sending end of the second communication unit and a collector of the third NPN type triode, the other end of the fifth voltage-dividing resistor is connected with the signal sending end of the second communication unit, the sixth voltage-dividing resistor is connected with the collector of the third NPN type triode, an emitter of the third NPN type triode is grounded, and a base of the third NPN type triode is connected with the second control port of the first communication unit through the second current-limiting resistor; the third NPN type triode is switched on or switched off according to a second control signal sent by a second control port of the first communication unit;
when the communication voltage of the first communication unit is lower than the communication voltage of the second communication unit, the second control signal is at a high level, the third NPN type triode is turned on, and the sixth voltage-dividing resistor and the fifth voltage-dividing resistor divide the voltage signal sent by the second communication unit to obtain the voltage signal of the first communication unit and send the voltage signal to the signal receiving end of the first communication unit;
when the communication voltage of the first communication unit is the same as that of the second communication unit, the second control signal is at a low level, the third NPN type triode is turned off, and the second communication unit sends a voltage signal to the first communication unit through the fifth voltage-dividing resistor.
In an optional manner, the transmission signal conversion circuit further includes a protection diode; the anode of the protection diode is connected with the common end of the fifth voltage-dividing resistor and the sixth voltage-dividing resistor, and the cathode of the protection diode is connected with the first power supply; when the voltage of the sixth divider resistor is greater than the first voltage, the protection diode is turned on, so that the voltage of the signal receiving end of the first communication unit is smaller than the sum of the first voltage and the voltage drop of the protection diode.
According to another aspect of the embodiments of the present invention, there is provided a communication apparatus, including: the communication device comprises a first communication unit and a communication voltage conversion circuit; the first communication unit comprises a first control end, a second control end, a signal sending end and a signal receiving end; the communication voltage conversion circuit is the communication voltage conversion circuit in any of the embodiments described above.
According to another aspect of the embodiments of the present invention, there is provided a method for identifying a communication voltage, applied to a first communication unit, the method including:
sending a first control signal with low level and a second control signal with low level to the receiving signal conversion circuit and the sending signal conversion circuit respectively, and sending test data to the second communication unit to obtain a test result;
if response data sent by the second communication unit are received, determining that the test result is that the communication voltage of the second communication unit is the same as the communication voltage of the first communication unit; otherwise, determining that the test result is that the communication voltage of the second communication unit is different from the communication voltage of the first communication unit;
respectively sending a first control signal and a second control signal to a receiving signal conversion circuit and a sending signal conversion circuit according to the test result;
the received signal conversion circuit is a received signal conversion circuit in the communication voltage conversion circuit of any of the above embodiments; the transmission signal conversion circuit is a transmission signal conversion circuit in the communication voltage conversion circuit of any of the above embodiments.
According to another aspect of the embodiments of the present invention, there is provided a communication unit including: the processor, the memory and the communication interface complete mutual communication through the communication bus;
the memory is used for storing at least one executable instruction, and the executable instruction enables the processor to execute the operation corresponding to the communication voltage identification method.
Through the embodiment of the invention, the second communication unit MCU-B can receive the voltage matched with the communication voltage no matter what the communication voltage of the second communication unit MCU-B is, compared with the prior art that a corresponding communication voltage conversion circuit is specially designed for the second communication unit MCU-B with different communication voltages, the embodiment of the invention can be suitable for the second communication unit MCU-B with any communication voltage, thereby saving the design cost of the communication voltage conversion circuit.
The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:
fig. 1 is a functional block diagram of a communication voltage converting circuit according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a communication voltage converting circuit according to an embodiment of the present invention;
fig. 3 is a functional block diagram of a communication voltage converting circuit according to another embodiment of the present invention;
fig. 4 is a schematic diagram of a communication voltage converting circuit according to another embodiment of the present invention;
fig. 5 is a schematic diagram of a communication voltage converting circuit according to another embodiment of the present invention;
fig. 6 is a schematic structural diagram of a communication device according to an embodiment of the present invention;
fig. 7 is a flowchart illustrating a method for identifying a communication voltage according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a communication unit according to an embodiment of the present invention.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.
The application scenario of the embodiment of the invention is voltage conversion in wireless communication. When the two communication units communicate, if the communication voltages are inconsistent, one of the communication units cannot identify the signal sent by the other communication unit, which results in communication failure. For example, the communication voltage of the first communication unit is 3.3V, the communication voltage of the second communication unit is 5V, and when the first communication unit sends a voltage signal to the second communication unit, the high level signal in the voltage signal is 3.3V, and the low level signal is 0V. The communication voltage of the second communication unit is 5V, that is, the second communication unit can identify the received voltage signal as a high level signal only when receiving the voltage of 5V, and the second communication voltage cannot be identified for the voltage signal of 3.3V. The embodiment of the invention carries out communication voltage conversion according to the communication voltages of the two communication units, so that the two communication units with any working voltage can identify the signal sent by the other communication unit when carrying out communication. The embodiment of the invention does not need to specially design the corresponding communication voltage conversion circuit according to the communication voltages of the two communication units, and the voltage conversion of the communication units with any working voltage can be realized through the embodiment of the invention, so that the design cost of the communication voltage conversion circuit is reduced.
Referring to fig. 1, fig. 1 is a functional block diagram of a communication voltage converting circuit according to an embodiment of the present invention. The communication voltage conversion circuit comprises a receiving signal conversion circuit 10, wherein the receiving signal conversion circuit 10 is used for converting a voltage signal sent by a first communication unit MCU-A into a communication voltage of a second communication unit MCU-B. The first communication unit MCU-A is an MCU of wireless communication equipment, for emutexample, an MCU of a GPRS module; the second communication unit MCU-B is an MCU of intelligent electrical equipment or intelligent electronic equipment. The received signal conversion circuit 10 includes: a first switch circuit 11, a second switch circuit 12, a third switch circuit 13, and a first pull-up circuit 14. The input end of the first switch circuit 11 is connected with a first control end GPIO1 of the first communication unit MCU-a, the control end of the first switch circuit 11 is connected with a first power supply VDD1, and the output end of the first switch circuit 11 is connected with a first end of the first pull-up circuit 14; the first voltage VD1 of the first power source VDD1 is the same as the communication voltage of the first communication unit MCU-a. The first switch circuit 11 is turned on or off according to a first control signal sent by a first control terminal GPIO1 of the first communication unit MCU-a; when the first switch circuit 11 is turned on, the voltage at the output terminal of the first switch circuit 11 is the first voltage VD 1.
The input end of the second switch circuit 12 is connected with a first control end GPIO1 of the first communication unit MCU-A, the control end of the second switch circuit 12 is connected with a second power supply VDD2, and the output end of the second switch circuit 12 is connected with a first end of the first pull-up circuit 14; the second voltage VD2 of the second power supply VDD2 is the same as the communication voltage of the second communication unit MCU-B, and the second switch circuit 12 is switched on or off according to the first control signal; when the second switch circuit 12 is turned on, the voltage at the output terminal of the second switch circuit 12 is the second voltage VD 2.
The input end of the third switch circuit 13 is connected with the first power supply VDD1, the control end of the third switch circuit 13 is connected with the signal transmitting end A-TXD of the first communication unit MCU-A, and the output end of the third switch circuit 13 is connected with the signal receiving end B-RXD of the second communication unit MCU-B; the third switch circuit 13 is turned on or off according to a voltage signal sent by the signal sending terminal of the first communication unit MCU-a. When the third switch circuit 13 is turned on, the output terminal of the third switch circuit 13 outputs the voltage signal sent by the signal sending terminal of the first communication unit MCU-a. That is, when the voltage signal sent by the signal sending end of the first communication unit MCU-a is VD1, the third switch circuit 13 outputs VD 1; when the voltage signal sent by the signal sending end of the first communication unit MCU-a is 0, the third switch circuit 13 outputs 0.
A first end of the first pull-up circuit 14 is connected to an output end of the first switch circuit 11 and an output end of the second switch circuit 12, respectively, and a second end of the first pull-up circuit 14 is connected to a signal receiving end B-RXD of the second communication unit MCU-B.
When the communication voltage of the first communication unit MCU-A is different from the communication voltage of the second communication unit MCU-B, the first control signal is at a high level, namely VD1, the first switch circuit 11 is turned off, the second switch circuit 12 is turned on, and the voltage of the first end of the first pull-up circuit 14 is a second voltage VD 2; when the signal transmitting end of the first communication unit MCU-A transmits a low voltage signal to the second communication unit MCU-B, the third switch circuit 13 is turned on, and the voltage signal received by the second communication unit MCU-B is a low voltage.
When the communication voltage of the first communication unit MCU-A is the same as that of the second communication unit MCU-B, the first control signal is at a low level, namely 0, the first switch circuit 11 is switched on, the second switch circuit 12 is switched off, and the voltage of one end of the first pull-up circuit 14, which is connected with the output end of the first switch circuit 11, is the first voltage VD 1; when the signal sending end of the first communication unit MCU-A sends a high-voltage signal to the second communication unit MCU-B, the third switch circuit 13 is turned off, and the voltage signal received by the second communication unit MCU-B is the first voltage VD 1; when the signal transmitting end of the first communication unit MCU-A transmits a low voltage signal to the second communication unit MCU-B, the third switch circuit 13 is turned on, and the voltage signal received by the second communication unit MCU-B is a low voltage.
In some embodiments, referring to fig. 2, fig. 2 is a schematic diagram of a communication voltage converting circuit according to an embodiment of the invention. In fig. 2, the first switch circuit 11 includes: the circuit comprises a first voltage-dividing resistor R19, a second voltage-dividing resistor R12 and a first PNP type triode Q12. The first voltage-dividing resistor R19 and the second voltage-dividing resistor R12 are connected in series between the first control end of the first communication unit MCU-A and the first power supply VDD1, the other end of the first voltage-dividing resistor R19 is connected with the first control end of the first communication unit MCU-A, and the other end of the second voltage-dividing resistor R12 is connected with the first power supply VDD 1.
The base of the first PNP transistor Q12 is connected to the common terminal of the first divider resistor R19 and the second divider resistor R12, the emitter of the first PNP transistor Q12 is connected to the first power supply, the base of the first PNP transistor Q12 is connected to the common terminal of the first divider resistor R19 and the second divider resistor R12, and the collector of the first PNP transistor Q12 is connected to the first terminal of the first pull-up circuit 14.
When the first control signal is at a high level, i.e., VD1, the first PNP transistor Q12 is turned off; when the first control signal is at a low level, i.e. 0, the second voltage-dividing resistor R12 and the first voltage-dividing resistor R19 divide the first voltage VD1, so that the first PNP transistor Q12 is turned on, and the voltage at the collector of the first PNP transistor Q12 is the first voltage VD 1.
In some embodiments, with continued reference to fig. 2, the second switch circuit 12 includes: the circuit comprises a third voltage dividing resistor R11, a fourth voltage dividing resistor R10, a second PNP type triode Q11, a first NPN type triode Q14 and a first current limiting resistor R13. The third voltage dividing resistor R11 and the fourth voltage dividing resistor R10 are connected in series between the second power supply and the collector of the first NPN-type triode Q14, the other end of the third voltage dividing resistor R11 is connected with the second power supply, and the other end of the fourth voltage dividing resistor R10 is connected with the collector of the first NPN-type triode Q14; the base electrode of the second PNP transistor Q11 is connected to the common terminal of the third voltage dividing resistor R11 and the fourth voltage dividing resistor R10, the emitter electrode of the second PNP transistor Q11 is connected to the second power supply, and the collector electrode of the second PNP transistor is connected to the first terminal of the first pull-up circuit 14; the base of the first NPN type triode Q14 is connected to the first control end of the first communication unit through a first current limiting resistor, the collector of the first NPN type triode Q14 is connected to one end of the fourth voltage dividing resistor R10, and the emitter of the first NPN type triode Q14 is grounded.
When the first control end of the first communication unit outputs a high level, the first NPN type triode Q14 is turned on, and the collector electrode of the first NPN type triode Q14 outputs a low level, so that the second PNP type triode Q11 is turned on, and the voltage of the collector electrode of the second PNP type triode Q11 is a second voltage; when the first control terminal GPIO1 of the first communication unit MCU-a outputs a low level, both the first NPN transistor Q14 and the second PNP transistor Q11 are turned off.
In some embodiments, with continued reference to fig. 2, the third switch circuit includes: a second NPN transistor Q13 and a second current limiting resistor R15; the base electrode of the second NPN type triode Q13 is connected with the first power supply VDD1 through a second current limiting resistor R15, the emitter electrode of the second NPN type triode Q13 is connected with the signal sending end of the first communication unit MCU-A, and the collector electrode of the second NPN type triode Q13 is connected with the signal receiving end B-RXD of the second communication unit MCU-B.
When the first control terminal GPIO1 of the first communication unit MCU-A outputs a high level, the second NPN type triode Q13 is turned off; when the first control terminal GPIO1 of the first communication unit MCU-a outputs a low level, the second NPN transistor Q13 is turned on, and the collector of the second NPN transistor Q13 outputs a low level.
In some embodiments, with continued reference to fig. 2, the first pull-up circuit 14 includes a first pull-up resistor R14.
The operation of the circuit of fig. 2 is explained below.
When the communication voltage of the second communication unit MCU-B is different from the communication voltage of the first communication unit MCU-A, the GPIO1 at the first control end of the first communication unit MCU-A outputs a first control signal with high level, namely VD 1. The first PNP transistor Q12 is turned off, the first NPN transistor Q14 is turned on, the collector of the first NPN transistor Q14 outputs a low level, so that the second PNP transistor Q11 is turned on, and the potential of the first end of the first pull-up resistor R14 is the emitter potential VD2 of the second PNP transistor Q11. In this case, if the signal transmitting terminal a-tmutexd of the first communication unit MCU-a transmits a high level signal, i.e., VD1, the second NPN transistor Q13 is turned off, and the second terminal of the first pull-up resistor R14 has the same potential as the first terminal, i.e., VD2, so that the signal receiving terminal B-rmutexd of the second communication unit MCU-B receives the high level signal, i.e., VD 2. If the signal transmitting end A-TXD of the first communication unit MCU-A transmits a low level signal, the second NPN type triode Q13 is conducted, the potential of the second end of the first pull-up resistor R14 is low level, the first pull-up resistor R14 consumes the voltage VD2 of the first end, and therefore the signal receiving end B-RXD of the second communication unit MCU-B receives the low level signal.
When the communication voltage of the second communication unit MCU-B is the same as that of the first communication unit MCU-A, the first control terminal GPIO1 of the first communication unit MCU-A outputs a first control signal with low level. The first PNP type triode Q12 is conducted, the first NPN type triode Q14 is turned off, the base electrode of the second PNP type triode Q11 has no current, the second PNP type triode Q11 is turned off, and the potential of the first end of the first pull-up resistor R14 is the potential VD1 of the emitting electrode of the first PNP type triode Q12. In this case, if the signal transmitting terminal a-tmutexd of the first communication unit MCU-a transmits a high level signal, i.e., VD1, the second NPN transistor Q13 is turned off, and the second terminal of the first pull-up resistor R14 has the same potential as the first terminal, i.e., VD1, so that the signal receiving terminal B-rmutexd of the second communication unit MCU-B receives the high level signal, i.e., VD 1. If the signal transmitting end A-TXD of the first communication unit MCU-A transmits a low level signal, the second NPN type triode Q13 is conducted, the potential of the second end of the first pull-up resistor R14 is low level, the first pull-up resistor R14 consumes the voltage VD1 of the first end, and therefore the signal receiving end B-RXD of the second communication unit MCU-B receives the low level signal.
Before the first communication unit MCU-a sends the first control signal, the communication level of the second communication unit MCU-B is automatically identified, and the specific identification method is described in the following embodiments, please refer to the detailed description of the following embodiments, which is not described herein.
Through the embodiment of the invention, the second communication unit MCU-B can receive the voltage matched with the communication voltage no matter what the communication voltage of the second communication unit MCU-B is, compared with the prior art that a corresponding communication voltage conversion circuit is specially designed for the second communication unit MCU-B with different communication voltages, the embodiment of the invention can be suitable for the second communication unit MCU-B with any communication voltage, thereby saving the design cost of the communication voltage conversion circuit.
Fig. 3 shows a functional block diagram of a communication voltage converting circuit according to another embodiment of the present invention, and as shown in fig. 3, the communication voltage converting circuit according to the embodiment of the present invention further includes a transmission signal converting circuit 20. The transmission signal conversion circuit 20 is used for converting the voltage signal transmitted by the second communication unit MCU-B into the communication voltage of the first communication unit MCU-A; the transmission signal conversion circuit 20 includes a fourth switch circuit 21, a fifth switch circuit 22, a sixth switch circuit 23, and a second pull-up circuit 24. The input end of the fourth switch circuit 21 is connected with the second control end GPIO2 of the first communication unit MCU-A, the control end of the fourth switch circuit 21 is connected with the first power supply VDD1, and the output end of the fourth switch circuit 21 is connected with the first end of the second pull-up circuit 24; the fourth switch circuit 21 is turned on or off according to a second control signal sent by a second control terminal GPIO2 of the first communication unit MCU-a; when the fourth switch circuit 21 is turned on, the voltage at the output terminal of the fourth switch circuit 21 is the first voltage VD 1.
The input end of the fifth switch circuit 22 is connected with the second control end GPIO2 of the first communication unit MCU-a, the control end of the fifth switch circuit 22 is connected with the first power supply VDD1, the output end of the fifth switch circuit 22 is connected with the first end of the second pull-up circuit 24, and the fifth switch circuit 22 is turned on or off according to the second control signal; when the fifth switch circuit 22 is turned on, the voltage at the output terminal of the fifth switch circuit 22 is the first voltage VD 1.
The input end of the simutexth switch circuit 23 is connected with the second power supply VDD2, the control end of the simutexth switch circuit 23 is connected with the signal transmitting end B-TXD of the second communication unit MCU-B, and the output end of the simutexth switch circuit 23 is connected with the signal receiving end A-RXD of the first communication unit MCU-A; the sixth switching circuit 23 is turned on or off according to a voltage signal sent by the signal sending end of the second communication unit MCU-B; when the sixth switch circuit 23 is turned on, the output terminal of the sixth switch circuit 23 outputs the voltage signal sent by the signal sending terminal of the second communication unit MCU-B.
A first end of the second pull-up circuit 24 is respectively connected with an output end of the fourth switch circuit 21 and an output end of the fifth switch circuit 22, and a second end of the second pull-up circuit 24 is connected with a signal receiving end A-RXD of the first communication unit MCU-A;
when the communication voltage of the first communication unit MCU-A is different from the communication voltage of the second communication unit MCU-B, the second control signal is at a high level, the fourth switch circuit 21 is turned off, the fifth switch circuit 22 is turned on, and the voltage of the first end of the second pull-up circuit 24 is the first voltage; when the signal transmitting end B-TXD of the second communication unit MCU-B transmits a high-voltage signal to the first communication unit MCU-A, the simutexth switch circuit 23 is switched off, and the voltage signal received by the first communication unit 21 is the first voltage VD 1; when the signal transmitting terminal B-TXD of the second communication unit MCU-B transmits a low voltage signal to the first communication unit MCU-A, the simutexth switch circuit 23 is turned on, and the voltage signal received by the first communication unit 21 is a low voltage.
In the embodiment of the invention, when the communication voltage of the first communication unit MCU-a is different from the communication voltage of the second communication unit MCU-B, the first control signal and the second control signal are both at high level, and when the communication voltage of the first communication unit MCU-a is the same as the communication voltage of the second communication unit MCU-B, the first control signal and the second control signal are both at low level, so the first control terminal GPIO1 and the second control terminal GPIO2 of the first communication unit MCU-a may be the same terminal. In this way, the receiving signal conversion circuit 10 and the transmitting signal conversion circuit 20 can be simultaneously controlled only by sending one control signal, so that the control cost and the port development cost of the first communication unit MCU-a are reduced.
Fig. 3 shows a communication voltage conversion circuit in which a transmission signal conversion circuit 20 corresponds to a reception signal conversion circuit 10, and the implementation of each specific circuit in the transmission signal conversion circuit 20 corresponds to the implementation of each specific circuit in the reception signal conversion circuit 10. That is, the fourth switch circuit 21 in the transmission signal conversion circuit 20 may be implemented as the first switch circuit 11 in the reception signal conversion circuit 10 in fig. 2; the fifth switch circuit 22 in the transmission signal conversion circuit 20 may be implemented as the second switch circuit 12 in the reception signal conversion circuit 10 in fig. 2; the sixth switching circuit 23 in the transmission signal converting circuit 20 may be implemented as the third switching circuit 13 in the reception signal converting circuit 10 in fig. 2. In this implementation manner, a schematic diagram of the corresponding communication voltage conversion circuit is shown in fig. 4, and working processes of the fourth switch circuit 21, the fifth switch circuit 22, the sixth switch circuit 23, and the second pull-up circuit 24 in fig. 4 are the same as working processes of the first switch circuit 11, the second switch circuit 12, the third switch circuit 13, and the first pull-up circuit 14, please refer to the relevant description corresponding to fig. 2, which is not repeated herein.
In some embodiments, the communication voltage of the second communication unit MCU-B is higher than that of the first communication unit MCU-A, and the communication voltages of different first communication units MCU-A are the same. In these embodiments, a schematic diagram of the communication voltage converting circuit is shown in fig. 5. In fig. 5, the transmission signal conversion circuit 20 includes: a fifth voltage-dividing resistor R16, a sixth voltage-dividing resistor R17, a third NPN type triode Q15 and a second current-limiting resistor R18. The fifth voltage-dividing resistor R16 and the simutexth voltage-dividing resistor R17 are connected in series between a signal transmitting end B-TXD of the second communication unit MCU-B and a collector of a third NPN type triode Q15, the other end of the fifth voltage-dividing resistor R16 is connected with the signal transmitting end B-TXD of the second communication unit MCU-B, the simutexth voltage-dividing resistor R17 is connected with a collector of a third NPN type triode Q15, an emitter of the third NPN type triode Q15 is grounded, and a base of the third NPN type triode Q15 is connected with a second control port GPIO2 of the first communication unit MCU-A through the second current-limiting resistor R18; and the third NPN type triode Q15 is turned on or off according to a second control signal sent by the second control port GPIO2 of the first communication unit MCU-a.
When the communication voltage of the first communication unit MCU-A is smaller than that of the second communication unit MCU-B, the second control signal is at a high level, the third NPN type triode Q15 is conducted, and the simutemutemutexth voltage-dividing resistor R17 and the fifth voltage-dividing resistor R16 divide the voltage signal sent by the second communication unit MCU-B to obtain the voltage signal of the first communication unit MCU-A and send the voltage signal to the signal receiving end A-RXD of the first communication unit MCU-A.
When the communication voltage of the first communication unit MCU-A is the same as that of the second communication unit MCU-B, the second control signal is at a low level, the third NPN type triode Q15 is turned off, and the second communication unit MCU-B sends a voltage signal to the first communication unit MCU-A through the fifth voltage-dividing resistor R16.
Compared with the transmission signal conversion circuit 20 in fig. 4, the transmission signal conversion circuit 20 provided by the embodiment of the present invention reduces the number of components and reduces the design cost of the transmission signal conversion circuit 20.
In some embodiments, with continued reference to fig. 5, the transmission signal conversion circuit 20 further includes a protection diode D11; the anode of the protection diode D11 is connected with the common end of the fifth voltage-dividing resistor R16 and the sixth voltage-dividing resistor R17, and the cathode of the protection diode D11 is connected with the first power supply VDD 1; when the voltage of the simutexth voltage-dividing resistor R17 is greater than the first voltage VD1, the protection diode D11 is turned on, and the voltage of the signal receiving terminal a-rmutexd of the first communication unit MCU-a is less than the sum of the first voltage VD1 and the voltage drop of the protection diode D11. For emutemutexample, the voltage drop of the protection diode is 0.5V, and the voltage of the signal receiving end a-rmutemutexd of the first communication unit MCU-a can be limited within VD1+0.5V by arranging the protection diode, so as to prevent the first communication unit MCU-a from being damaged.
Fig. 6 is a schematic structural diagram of a communication device according to an embodiment of the present invention, and as shown in fig. 6, the communication device includes: a first communication unit MCU-A and a communication voltage conversion circuit 100. The first communication unit MCU-A comprises a first control end GPIO1, a second control end GPIO2, a signal transmitting end A-TXD and a signal receiving end A-RXD. The first control terminal GPIO1 and the second control terminal GPIO2 may be the same terminal or different terminals, which is not limited in the embodiments of the present invention. The first control terminal GPIO1 and the second control terminal GPIO2 transmit first control signals and second control signals to the communication voltage conversion circuit 100. The voltage converting circuit 100 in the embodiment of the present invention is the communication voltage converting circuit in any one of the above embodiments, and please refer to the detailed description of the above embodiments for the connection manner between the first control terminal GPIO1 and the second control terminal GPIO2 and the communication voltage converting circuit 100.
The communication device in the embodiment of the present invention may be implemented as any communication device, for example, a GPRS module. When the communication device is a GPRS module, the GPRS module comprises a GPRS module and a communication voltage conversion circuit, and the first communication unit is an MCU of the GPRS module.
The communication device provided by the embodiment of the invention can realize communication with the second communication unit MCU-B with any voltage, and the development cost of the communication device is reduced.
Fig. 7 shows a communication voltage identification method according to an embodiment of the present invention, applied to a first communication unit, the method including the following steps:
step 701: and respectively sending a first control signal with low level and a second control signal with low level to the receiving signal conversion circuit and the sending signal conversion circuit, and sending test data to the second communication unit to obtain a test result.
In this step, the received signal conversion circuit and the transmitted signal conversion circuit are the received signal conversion circuit and the transmitted signal conversion circuit in any of the above-described communication voltage conversion circuit embodiments.
Step 702: it is determined whether the response data sent by the second communication unit is received, if yes, step 703 is performed, and if no, step 704 is performed.
In this step, the second communication unit returns the response data to the first communication unit only when receiving the test data sent by the first communication unit. When the low level is sent to the receiving signal conversion circuit, the first switch circuit in the receiving signal conversion circuit is turned on, the second switch circuit is turned off, and the test data sent to the second communication unit is not subjected to voltage conversion. Similarly, when transmitting a low level to the transmission signal conversion circuit, the transmission signal conversion circuit does not perform level conversion. If the response data of the second communication unit is received, it indicates that the second communication unit receives the test data sent by the first communication unit without voltage conversion, that is, the communication level of the second communication unit is the same as the communication level of the first communication unit. Otherwise, the communication level of the second communication unit is different from the communication level of the first communication unit.
Step 703: and determining that the communication voltage of the second communication unit is the same as the communication voltage of the first communication unit according to the test result.
In this step, if the response data sent by the second communication unit is received, it is determined that the communication voltage of the second communication unit is the same as the communication voltage of the first communication unit.
Step 704: and determining that the test result is that the communication voltage of the second communication unit is different from the communication voltage of the first communication unit.
In this step, if the response data sent by the second communication unit is not received, it is determined that the communication voltage of the second communication unit is different from the communication voltage of the first communication unit.
Step 705: and respectively sending a first control signal and a second control signal to the receiving signal conversion circuit and the sending signal conversion circuit according to the test result.
In this step, after the communication voltage of the second communication unit is determined, the first control signal and the second control signal are transmitted. If the communication voltage of the second communication unit is different from the communication voltage of the first communication unit, the first control signal and the second control signal are both high level; and if the communication voltage of the second communication unit is the same as that of the first communication unit, the first control signal and the second control signal are both in low level.
The embodiment of the invention can test whether the communication voltage of the second communication unit is consistent with the communication voltage of the first communication unit, and is convenient for sending different first control signals and second control signals according to the test result so as to realize reliable communication of the first communication unit and the second communication unit.
Fig. 8 is a schematic structural diagram of a communication unit according to an embodiment of the present invention. As shown in fig. 8, the communication unit includes: a processor (processor)402, a Communications Interface 404, a memory 406, and a Communications bus 408.
Wherein: the processor 402, communication interface 404, and memory 406 communicate with each other via a communication bus 408. A communication interface 404 for communicating with network elements of other devices, such as clients or other servers. The processor 402 is configured to execute the program 410, and may specifically execute the relevant steps in the above embodiment of the identification method for communication voltage.
In particular, program 410 may include program code comprising computer-executable instructions.
The processor 402 may be a central processing unit CPU, or an application specific Integrated circuit asic, or one or more Integrated circuits configured to implement an embodiment of the present invention. The communication unit comprises one or more processors, which can be the same type of processor, such as one or more CPUs; or may be different types of processors such as one or more CPUs and one or more ASICs.
And a memory 406 for storing a program 410. Memory 406 may comprise high-speed RAM memory, and may also include non-volatile memory (non-volatile memory), such as at least one disk memory.
The program 410 may be specifically called by the processor 402 to make the communication unit execute steps 701 to 705 in fig. 7.
It is to be noted that technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which embodiments of the present invention belong, unless otherwise specified.
In the description of the present embodiments, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships that are based on the orientations and positional relationships shown in the drawings, and are used only for convenience in describing the embodiments of the present invention and for simplicity in description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the embodiments of the present invention.
Furthermore, the technical terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the description of the novel embodiments of the present invention, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. Specific meanings of the above terms in the embodiments of the present invention can be understood by those of ordinary skill in the art according to specific situations.
In describing the novel embodiments of this embodiment, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (10)

1. A communication voltage conversion circuit is characterized by comprising a receiving signal conversion circuit; the receiving signal conversion circuit is used for converting the voltage signal sent by the first communication unit into the communication voltage of the second communication unit; the received signal conversion circuit includes: the first pull-up circuit comprises a first switch circuit, a second switch circuit, a third switch circuit and a first pull-up circuit;
the input end of the first switch circuit is connected with the first control end of the first communication unit, the control end of the first switch circuit is connected with a first power supply, and the output end of the first switch circuit is connected with the first end of the first pull-up circuit; the first voltage of the first power supply is the same as the communication voltage of the first communication unit; the first switching circuit is switched on or switched off according to a first control signal sent by a first control end of the first communication unit; when the first switch circuit is conducted, the voltage of the output end of the first switch circuit is the first voltage;
the input end of the second switch circuit is connected with the first control end of the first communication unit, the control end of the second switch circuit is connected with a second power supply, and the output end of the second switch circuit is connected with the first end of the first pull-up circuit; the second voltage of the second power supply is the same as the communication voltage of the second communication unit, and the second switch circuit is switched on or switched off according to the first control signal; when the second switch circuit is conducted, the voltage of the output end of the second switch circuit is the second voltage;
the input end of the third switch circuit is connected with the first power supply, the control end of the third switch circuit is connected with the signal sending end of the first communication unit, and the output end of the third switch circuit is connected with the signal receiving end of the second communication unit; the third switch circuit is switched on or switched off according to a voltage signal sent by a signal sending end of the first communication unit; when the third switch circuit is turned on, the output end of the third switch circuit outputs a voltage signal sent by the signal sending end of the first communication unit;
a first end of the first pull-up circuit is connected with an output end of the first switch circuit and an output end of the second switch circuit respectively, and a second end of the first pull-up circuit is connected with a signal receiving end of the second communication unit;
when the communication voltage of the first communication unit is different from the communication voltage of the second communication unit, the first control signal is at a high level, the first switch circuit is turned off, the second switch circuit is turned on, and the voltage of the first end of the first pull-up circuit is the second voltage; when the signal sending end of the first communication unit sends a high-voltage signal to the second communication unit, the third switch circuit is turned off, and the voltage signal received by the second communication unit is the second voltage; when the signal sending end of the first communication unit sends a low-voltage signal to the second communication unit, the third switch circuit is turned on, and the voltage signal received by the second communication unit is low-voltage.
2. The circuit of claim 1, wherein the first switching circuit comprises: the first PNP type triode is connected with the first voltage-dividing resistor;
the first voltage-dividing resistor and the second voltage-dividing resistor are connected in series between a first control end of the first communication unit and the first power supply, the other end of the first voltage-dividing resistor is connected with the first control end of the first communication unit, and the other end of the second voltage-dividing resistor is connected with the first power supply;
a base electrode of the first PNP type triode is connected to a common end of the first voltage-dividing resistor and the second voltage-dividing resistor, an emitter electrode of the first PNP type triode is connected to the first power supply, a base electrode of the first PNP type triode is connected to a common end of the first voltage-dividing resistor and the second voltage-dividing resistor, and a collector electrode of the first PNP type triode is connected to a first end of the first pull-up circuit;
when the first control signal is at a high level, the first PNP type triode is turned off; when the first control signal is at a low level, the second voltage-dividing resistor and the first voltage-dividing resistor divide the first voltage to turn on the first PNP transistor, and the voltage of the collector of the first PNP transistor is the first voltage.
3. The circuit of claim 1, wherein the second switching circuit comprises: the first NPN type triode, the second PNP type triode and the first current limiting resistor are connected in series;
the third voltage dividing resistor and the fourth voltage dividing resistor are connected in series between the second power supply and the collector of the first NPN-type transistor, the other end of the third voltage dividing resistor is connected to the second power supply, and the other end of the fourth voltage dividing resistor is connected to the collector of the first NPN-type transistor;
a base electrode of the first NPN type triode is connected with a first control end of the first communication unit through the first current limiting resistor, a collector electrode of the first NPN type triode is connected with one end of the fourth voltage dividing resistor, and an emitter electrode of the first NPN type triode is grounded;
a base electrode of the second PNP type triode is connected with a common end of the third voltage dividing resistor and the fourth voltage dividing resistor, an emitting electrode of the second PNP type triode is connected with the second power supply, and a collecting electrode of the second PNP type triode is connected with a first end of the first pull-up circuit;
when the first control end of the first communication unit outputs a high level, the first NPN type triode is turned on, and a collector electrode of the first NPN type triode outputs a low level, so that the second PNP type triode is turned on, and the voltage of the collector electrode of the second PNP type triode is the second voltage; when the first control end of the first communication unit outputs a low level, the first NPN type triode and the second PNP type triode are both turned off.
4. The circuit of claim 1, wherein the third switching circuit comprises: the second NPN type triode and the second current limiting resistor are connected; a base electrode of the second NPN type triode is connected with the first power supply through the second current-limiting resistor, an emitting electrode of the second NPN type triode is connected with a signal sending end of the first communication unit, and a collecting electrode of the second NPN type triode is connected with a signal receiving end of the second communication unit;
when the first control end of the first communication unit outputs a high level, the second NPN type triode is turned off; when the first control end of the first communication unit outputs a low level, the second NPN type triode is turned on, and a collector of the second NPN type triode outputs a low level.
5. The circuit of claim 1, further comprising a transmission signal conversion circuit for converting the voltage signal transmitted by the second communication unit into the communication voltage of the first communication unit; the transmitting signal conversion circuit comprises a fourth switch circuit, a fifth switch circuit, a sixth switch circuit and a second pull-up circuit;
an input end of the fourth switch circuit is connected with the second control end of the first communication unit, a control end of the fourth switch circuit is connected with the first power supply, and an output end of the fourth switch circuit is connected with the first end of the second pull-up circuit; the fourth switching circuit is switched on or switched off according to a second control signal sent by a second control end of the first communication unit; when the fourth switching circuit is conducted, the voltage of the output end of the fourth switching circuit is the first voltage;
an input end of the fifth switch circuit is connected with the second control end of the first communication unit, a control end of the fifth switch circuit is connected with the first power supply, an output end of the fifth switch circuit is connected with the first end of the second pull-up circuit, and the fifth switch circuit is turned on or off according to the second control signal; when the fifth switch circuit is turned on, the voltage of the output end of the fifth switch circuit is the first voltage;
the input end of the sixth switching circuit is connected with a second power supply, the control end of the sixth switching circuit is connected with the signal sending end of the second communication unit, and the output end of the sixth switching circuit is connected with the signal receiving end of the first communication unit; the sixth switching circuit is switched on or off according to a voltage signal sent by the signal sending end of the second communication unit; when the sixth switching circuit is turned on, the output end of the sixth switching circuit outputs a voltage signal sent by the signal sending end of the second communication unit;
a first end of the second pull-up circuit is connected with an output end of the fourth switch circuit and an output end of the fifth switch circuit respectively, and a second end of the second pull-up circuit is connected with a signal receiving end of the first communication unit;
when the communication voltage of the first communication unit is different from the communication voltage of the second communication unit, the second control signal is at a high level, the fourth switch circuit is turned off, the fifth switch circuit is turned on, and the voltage of the first end of the second pull-up circuit is the first voltage; when the signal sending end of the second communication unit sends a high-voltage signal to the first communication unit, the sixth switching circuit is turned off, and the voltage signal received by the first communication unit is the first voltage; when the signal sending end of the second communication unit sends a low-voltage signal to the first communication unit, the sixth switch circuit is turned on, and the voltage signal received by the first communication unit is low-voltage.
6. The circuit of claim 1, further comprising a transmission signal conversion circuit for converting the voltage signal transmitted by the second communication unit into the communication voltage of the first communication unit; the transmission signal conversion circuit includes: a fifth voltage-dividing resistor, a sixth voltage-dividing resistor, a third NPN type triode and a second current-limiting resistor;
the fifth voltage-dividing resistor and the sixth voltage-dividing resistor are connected in series between a signal sending end of the second communication unit and a collector of the third NPN type triode, the other end of the fifth voltage-dividing resistor is connected with the signal sending end of the second communication unit, the sixth voltage-dividing resistor is connected with the collector of the third NPN type triode, an emitter of the third NPN type triode is grounded, and a base of the third NPN type triode is connected with the second control port of the first communication unit through the second current-limiting resistor; the third NPN type triode is switched on or switched off according to a second control signal sent by a second control port of the first communication unit;
when the communication voltage of the first communication unit is lower than the communication voltage of the second communication unit, the second control signal is at a high level, the third NPN type triode is turned on, and the sixth voltage-dividing resistor and the fifth voltage-dividing resistor divide the voltage signal sent by the second communication unit to obtain the voltage signal of the first communication unit and send the voltage signal to the signal receiving end of the first communication unit;
when the communication voltage of the first communication unit is the same as that of the second communication unit, the second control signal is at a low level, the third NPN type triode is turned off, and the second communication unit sends a voltage signal to the first communication unit through the fifth voltage-dividing resistor.
7. The circuit of claim 6, wherein the transmit signal conversion circuit further comprises a protection diode; the anode of the protection diode is connected with the common end of the fifth voltage-dividing resistor and the sixth voltage-dividing resistor, and the cathode of the protection diode is connected with the first power supply; when the voltage of the sixth divider resistor is greater than the first voltage, the protection diode is turned on, so that the voltage of the signal receiving end of the first communication unit is smaller than the sum of the first voltage and the voltage drop of the protection diode.
8. A communication device, comprising: the communication device comprises a first communication unit and a communication voltage conversion circuit; the first communication unit comprises a first control end, a second control end, a signal sending end and a signal receiving end; the communication voltage conversion circuit according to any one of claims 1 to 7.
9. A method for identifying a communication voltage is applied to a first communication unit, and is characterized by comprising the following steps:
sending a first control signal with low level and a second control signal with low level to the receiving signal conversion circuit and the sending signal conversion circuit respectively, and sending test data to the second communication unit to obtain a test result;
if response data sent by the second communication unit are received, determining that the test result is that the communication voltage of the second communication unit is the same as the communication voltage of the first communication unit; otherwise, determining that the test result is that the communication voltage of the second communication unit is different from the communication voltage of the first communication unit;
respectively sending a first control signal and a second control signal to a receiving signal conversion circuit and a sending signal conversion circuit according to the test result;
the received signal conversion circuit is the received signal conversion circuit in the communication voltage conversion circuit according to any one of claims 1 to 6; the transmission signal conversion circuit is the transmission signal conversion circuit in the communication voltage conversion circuit according to claim 5 or 6.
10. A communication unit, comprising: the processor, the memory and the communication interface complete mutual communication through the communication bus;
the memory is used for storing at least one executable instruction, and the executable instruction causes the processor to execute the operation corresponding to the identification method of the communication voltage according to claim 9.
CN202010564609.7A 2020-06-19 2020-06-19 Communication voltage conversion circuit, communication device and communication voltage identification method Pending CN111654184A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010564609.7A CN111654184A (en) 2020-06-19 2020-06-19 Communication voltage conversion circuit, communication device and communication voltage identification method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010564609.7A CN111654184A (en) 2020-06-19 2020-06-19 Communication voltage conversion circuit, communication device and communication voltage identification method

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CN111654184A true CN111654184A (en) 2020-09-11

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Family Applications (1)

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Country Link
CN (1) CN111654184A (en)

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