CN207251583U - Number bus isolates telecommunication circuit - Google Patents
Number bus isolates telecommunication circuit Download PDFInfo
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- CN207251583U CN207251583U CN201721189981.4U CN201721189981U CN207251583U CN 207251583 U CN207251583 U CN 207251583U CN 201721189981 U CN201721189981 U CN 201721189981U CN 207251583 U CN207251583 U CN 207251583U
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Abstract
It the utility model is related to a kind of number bus isolation telecommunication circuit, it is characterized in that, including multichannel input/output circuitry, digital signal input end, digital signal output end, all the way digital signal input/output terminal, input circuit and output circuit all the way are included per road input/output circuitry.The utility model circuit is realized simple, reliable, not only it is applicable in the isolation and communication of the input/output signal to the number bus of wide-voltage range, it is also suitable the on-off model input/output circuitry of 24V in commercial Application, and the high-level threshold of 24V switching value voltages can arbitrarily be set as needed, can be achieved with by adjusting comparison reference voltage Vr values.
Description
Technical field
It the utility model is related to and a kind of be used for realization Bus isolation suitable for bus type digital temperature and humidity sensor
And the circuit of data communication.
Background technology
Present single line or the digital temperature and humidity sensor of two wires data/address bus formula are applied in many fields.Although with
It is more reliable by cable transmission measurement than traditional mode signal that digital signal by bus transfer obtains temperature, humidity measurements
And strong antijamming capability, but there is also signal acquiring system and Bus isolation difficult problem.
The input of general industry instrument digital signal is more typical with optocoupler isolation ratio, its typical application circuit is as shown in Figure 1, figure
Middle R1、R2For resistance, U1For optocoupler.When optocoupler input signal IN is high level, optocoupler is not turned on, and optocoupler output OUT is height
Level；When optocoupler input signal IN is low level, optocoupler conducting, optocoupler output OUT is low level.But during this circuit concrete application
There is specific requirement to the magnitude of voltage of optocoupler input signal IN, if VCCFor 5V power voltage supply systems, then the high level voltage of signal IN
3.3V is cannot be below, because optocoupler input conducting voltage is typically 1.15V, then 5-3.3-1.15=0.55 (V), if resistance R1For
510 Ω, flow through resistance R1Electric current be about 1m A, optocoupler is in the conduction state.In practical application, inside signal acquiring system
The high low value of signal level is certain, but the voltage range of external digital bus is very wide, from 2.7V~5.5V, as long as voltage is higher than 2.5V
High level is taken as, circuit application so as shown in Figure 1 is restricted.
The content of the invention
The utility model solve technical problem be：With same circuits realize wide-voltage range digital signal input and it is defeated
Go out.
In order to solve the above-mentioned technical problem, the technical solution of the utility model there is provided a kind of number bus isolation communication
Circuit, it is characterised in that including multichannel input/output circuitry, include digital signal input end, number per road input/output circuitry
Word signal output part, all the way digital signal input/output terminal, input circuit and output circuit all the way, wherein：
Digital signal output end connects digital signal input/output terminal via output circuit, and output circuit includes photoelectricity coupling
Close circuit one and open-drain comparator one, the input connection digital signal output end of photoelectric coupling circuit one, photoelectric coupling circuit one
Output connection open-drain comparator one in-phase input end, the inverting input input comparison voltage of open-drain comparator one, open-drain
The output terminal connection digital signal input/output terminal of comparator one, constant pressure source connect the defeated of open-drain comparator one via resistance one
Outlet；
Digital signal input/output terminal connects digital signal input end via input circuit, and input circuit includes photoelectricity coupling
Close circuit two and open-drain comparator two, the in-phase input end of digital signal input/output terminal connection open-drain comparator two, constant pressure source
The in-phase input end of open-drain comparator two is also connected via resistance one, the inverting input input of open-drain comparator two is more electric
Pressure, the input of the output terminal connection photoelectric coupling circuit two of open-drain comparator two, the output connection numeral of photoelectric coupling circuit two
Signal input part.
Preferably, constant pressure source connects the output terminal of the open-drain comparator two via resistance two.
The utility model circuit is realized simply, reliably, is not only applicable in the input/output to the number bus of wide-voltage range
The isolation and communication of signal, are also suitable the on-off model input/output circuitry of 24V in commercial Application, and 24V switching values electricity
The high-level threshold of pressure can arbitrarily be set as needed, can be achieved with by adjusting comparison reference voltage Vr values.
Brief description of the drawings
Fig. 1 is the circuit for transmitting digital signals of existing single line light-coupled isolation；
Fig. 2 is the single-wire data bus input/output circuitry disclosed in embodiment.
Embodiment
To become apparent the utility model, hereby with preferred embodiment, and attached drawing is coordinated to be described in detail below.
By taking single-wire data bus input/output circuitry as shown in Figure 2 as an example, to a kind of numeral provided by the utility model
Bus isolation telecommunication circuit is further detailed.
Single-wire data bus input/output circuitry as shown in Figure 2, mainly by optocoupler U1、U2, open-drain output compares
Device U3A、U3B, resistance R1~R6, constant pressure source VCC、VDDComposition.Open-drain output comparator and general comparator difference are
The high level voltage value of comparator output has external circuit decision, so unrelated with comparator itself operating voltage.Optocoupler U1With
Open-drain output comparator U3AForm digital signal output circuit；Optocoupler U2With open-drain output comparator U3BForm digital signal input
Circuit.D1OUTFor output digit signals, D1INTo input digital signal, DB1For input/output digital signal, VrFor comparator ratio
It can be set as needed compared with reference voltage, 1.5V is designed as in this circuit.
The operation principle of Fig. 2 circuits is：
1. circuit makees digital signal output
(1) signal D10UTFor high level when, optocoupler U1It is not turned on, optocoupler output is high level, i.e. IN+For high level, so
No matter in 5V supply voltage systems, or 3.3V supply voltage systems, IN+ voltages V is all higher thanr, comparator U3AExport as high electricity
It is flat, and high level voltage value is by the resistance R that comes up3On voltage VDDDetermine；
And high level voltage value is by pull-up resistor R3On voltage VDDDetermine；
(2) signal D1OUTFor low level when, optocoupler U1Conducting, optocoupler output is low level, i.e. IN+For low level, IN+Electricity
Force down in Vr, comparator U3AExport as low level.
2. circuit makees digital signal input
(1) signal D10UTPut high level, release bus signals DB1, i.e. DB1For high level state, this principle is by above electric
Make to illustrate during digital signal output in road；
(2) input signal DB1For high level when, due to DB1Voltage is higher than Vr, comparator U3BHigh level is exported, i.e. OUT is
High level, optocoupler U2It is not turned on, optocoupler output is high level, i.e. signal D1INFor high level；
(3) when DB1 bus signals are low level, due to DB1Voltage is less than Vr, comparator U3BLow level is exported, i.e. OUT is
Low level, optocoupler U2Conducting, optocoupler output is low level, i.e. signal D1INFor low level.
The utility model is low to the number bus voltage range requirement for needing to isolate, communicate, and circuit is versatile, and 3.3V is supplied
Electric system and 5V electric power systems are all suitable for, or even the 24V voltage signal systems of industrial standard are all suitable for.The voltage threshold of high level
Can be arbitrarily devised given as requested.
Claims (2)
1. a kind of number bus isolates telecommunication circuit, it is characterised in that including multichannel input/output circuitry, per road input/output
Circuit includes digital signal input end, digital signal output end, all the way digital signal input/output terminal, input circuit and all the way
Output circuit, wherein：
Digital signal output end connects digital signal input/output terminal via output circuit, and output circuit includes photoelectric coupling electricity
Road one and open-drain comparator one, photoelectric coupling circuit one input connection digital signal output end, photoelectric coupling circuit one it is defeated
Go out to connect the in-phase input end of open-drain comparator one, the inverting input input comparison voltage of open-drain comparator one, open-drain compares
The output terminal connection digital signal input/output terminal of device one, constant pressure source connect the output terminal of open-drain comparator one via resistance one；
Digital signal input/output terminal connects digital signal input end via input circuit, and input circuit includes photoelectric coupling electricity
Road two and open-drain comparator two, the in-phase input end of digital signal input/output terminal connection open-drain comparator two, constant pressure source via
Resistance one also connects the in-phase input end of open-drain comparator two, and the inverting input input comparison voltage of open-drain comparator two, is opened
The input of the output terminal connection photoelectric coupling circuit two of comparator two is leaked, the output connection digital signal of photoelectric coupling circuit two is defeated
Enter end.
2. a kind of number bus isolation telecommunication circuit as claimed in claim 1, it is characterised in that constant pressure source connects via resistance two
Connect the output terminal of the open-drain comparator two.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721189981.4U CN207251583U (en) | 2017-09-15 | 2017-09-15 | Number bus isolates telecommunication circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721189981.4U CN207251583U (en) | 2017-09-15 | 2017-09-15 | Number bus isolates telecommunication circuit |
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| Publication Number | Publication Date |
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| CN207251583U true CN207251583U (en) | 2018-04-17 |
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| CN201721189981.4U Active CN207251583U (en) | 2017-09-15 | 2017-09-15 | Number bus isolates telecommunication circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107682003A (en) * | 2017-09-15 | 2018-02-09 | 上海微程电气设备有限公司 | A kind of number bus isolates telecommunication circuit |
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2017
- 2017-09-15 CN CN201721189981.4U patent/CN207251583U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107682003A (en) * | 2017-09-15 | 2018-02-09 | 上海微程电气设备有限公司 | A kind of number bus isolates telecommunication circuit |
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