CN110416989A - Protective device and guard method applied to communication interface - Google Patents
Protective device and guard method applied to communication interface Download PDFInfo
- Publication number
- CN110416989A CN110416989A CN201910709930.7A CN201910709930A CN110416989A CN 110416989 A CN110416989 A CN 110416989A CN 201910709930 A CN201910709930 A CN 201910709930A CN 110416989 A CN110416989 A CN 110416989A
- Authority
- CN
- China
- Prior art keywords
- interface
- signal
- current
- protective device
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
- H02H9/025—Current limitation using field effect transistors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
- H02H9/042—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage comprising means to limit the absorbed power or indicate damaged over-voltage protection device
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
- H02H9/045—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage adapted to a particular application and not provided for elsewhere
- H02H9/047—Free-wheeling circuits
Abstract
The present invention relates to a kind of protective device and guard method applied to communication interface, which includes signal input interface, signal output interface and pressure limiting circuit；Signal input interface, pressure limiting circuit and signal output interface are sequentially connected；Signal input interface is used to external signal being transmitted to protective device；Pressure limiting circuit is used to generate the first secure communication signals after external signal is carried out pressure limiting；Signal output interface from protective device for exporting the first secure communication signals；Pressure limiting circuit includes Transient Suppression Diode, triode and ground resistance；The first end of Transient Suppression Diode is connect with signal input interface, the second end of Transient Suppression Diode and the base stage of triode are connected with the first end of ground resistance, the second end of ground resistance and the emitter of triode are grounded, and the collector of triode is connect with signal output interface.When guaranteeing that external signal is lasting high voltage signal, protective device, connected product and communication interface are not easy to be damaged.
Description
Technical field
The present invention relates to communication interfaces to protect field of circuit technology, and in particular to a kind of protection dress applied to communication interface
It sets and guard method.
Background technique
In production, test process, it will usually because specific reasons generate excessively high voltage signal, such as because produce
Interference, the crosstalk of line and equipment cause sign mutation, and then generate excessively high voltage signal, or because route misconnection generated
High voltage signal etc..And these excessively high voltage signals may be damaged connected product or communication interface.
The relevant technologies use the setting protection circuit in communication interface, specific to be inhibited using transient state in parallel in communication interface
Diode limits the voltage value of external signal.However, when external signal is lasting high voltage signal, the transient state of the parallel connection
Inhibit diode that will be damaged, and then connected product and communication interface are also damaged.
Summary of the invention
In view of this, a kind of protective device and guard method applied to communication interface is provided, to solve to work as external signal
When for lasting high voltage signal, protection circuit is connected product and communication interface is easy impaired problem.
The present invention adopts the following technical scheme:
The application first aspect provides a kind of protective device applied to communication interface, should be applied to the guarantor of communication interface
Protection unit includes signal input interface, signal output interface and pressure limiting circuit；The signal input interface, the pressure limiting circuit and
The signal output interface is sequentially connected；The signal input interface is used to external signal being transmitted to the protective device；Institute
Pressure limiting circuit is stated for generating the first secure communication signals after the external signal is carried out pressure limiting；The signal output interface is used
It is exported from the protective device in by first secure communication signals；The pressure limiting circuit include Transient Suppression Diode,
Triode and ground resistance；The first end of the Transient Suppression Diode is connect with the signal input interface, the transient state suppression
The second end of diode processed and the base stage of the triode are connected with the first end of the ground resistance respectively, the ground connection electricity
The emitter of the second end of resistance and the triode is grounded, and the collector and the signal output interface of the triode connect
It connects.
It further, should further include current-limiting circuit applied to the protective device of communication interface；The signal input interface, institute
It states current-limiting circuit and the pressure limiting circuit is sequentially connected.
Further, first current-limiting circuit includes the first current-limiting resistance and fuse；The fuse and described the
One current-limiting resistance is connected in series.
Further, the type of the fuse includes self-recovery fuse.
It further, should further include diode applied to the protective device of communication interface；The cathode of the diode and institute
Signal input interface connection, the plus earth of the diode are stated, the negative voltage for inputting a signal into interface carries out pressure release.
It further, should further include the second current-limiting circuit applied to the protective device of communication interface；The diode passes through
Second current-limiting circuit is connect with the signal input interface；Second current-limiting circuit is output to for limiting from the diode
The electric current and voltage of the signal input interface.
It further, should further include the second current-limiting resistance applied to the protective device of communication interface；The second current limliting electricity
The both ends of resistance are connect with the collector of the signal output interface and the triode respectively, for limiting the triode current collection
The input current of pole.
The application second aspect provides a kind of guard method applied to communication interface, should be applied to the guarantor of communication interface
Maintaining method is applied to the protective device applied to communication interface that the application first aspect provides, should be applied to the guarantor of communication interface
Maintaining method includes: to receive external signal by the signal input interface；When the voltage value of the external signal is greater than default electricity
When pressing threshold value, the Transient Suppression Diode conducting, the collector and emitter conducting of the triode, so that the external letter
Number voltage drop as low as the predetermined voltage threshold below；The external signal after reducing voltage is the first secure communication letter
Number；First secure communication signals are exported from the protective device by the signal output interface.
The application third aspect provides a kind of guard method applied to communication interface, should be applied to the guarantor of communication interface
Maintaining method is applied to the protective device applied to communication interface that the application first aspect provides, should be applied to the guarantor of communication interface
Protection unit includes at least signal input interface, signal output interface, pressure limiting circuit and current-limiting circuit, should be applied to communication interface
Guard method includes: to receive external signal by the signal input interface；By first current-limiting circuit by the outside
The current value of signal is limited within the scope of predetermined current threshold, and the second secure communication signals are transmitted to the pressure limiting circuit,
The external signal after reducing electric current is the second secure communication signals；When the voltage value of second secure communication signals is greater than
When predetermined voltage threshold, the Transient Suppression Diode conducting, the collector and emitter conducting of the triode, so that described
The voltage drop of external signal as low as the predetermined voltage threshold below；The external signal after reducing electric current and voltage is third
Secure communication signals；The third secure communication signals are exported from the protective device by the signal output interface.
The application fourth aspect provides a kind of guard method applied to communication interface, should be applied to the guarantor of communication interface
Maintaining method is applied to the protective device applied to communication interface that the application first aspect provides, should be applied to the guarantor of communication interface
Protection unit includes at least signal input interface, signal output interface, pressure limiting circuit and diode, should be applied to the guarantor of communication interface
Maintaining method includes: to receive external signal by the signal input interface；When the voltage value of the external signal is greater than default electricity
When pressing threshold value, the Transient Suppression Diode conducting, the collector and emitter conducting of the triode, so that the external letter
Number voltage drop as low as the predetermined voltage threshold below；The external signal after reducing voltage is the first secure communication letter
Number；When the connected product of signal input interface connection generates negative voltage, the diode current flow, the negative voltage letter
Number ground is transmitted to by the diode；By the signal output interface by first secure communication signals from the guarantor
It is exported in protection unit.
The invention adopts the above technical scheme, and pressure limiting circuit includes Transient Suppression Diode, triode and ground resistance.When
When external signal is the high voltage signal for the clamp voltage that voltage value is greater than Transient Suppression Diode, Transient Suppression Diode is led
Logical, electric current flows through ground resistance, because the base stage of triode is connect with ground resistance, when ground resistance has electric current to flow through, and three poles
The base voltage of pipe increases, and then is switched between the collector and emitter of triode, and because the emitting stage of triode is grounded,
So the collector voltage of triode declines, the collector of triode and the input terminal potential of Transient Suppression Diode are equal, because
The input terminal voltage of this Transient Suppression Diode declines, when voltage drops to the clamp voltage of Transient Suppression Diode, transient state
Inhibit diode cut-off, while thus triode had both been realized because base voltage decline is also switched off by the voltage of external signal
The purpose being limited within the scope of safe voltage, but realize avoid Transient Suppression Diode for a long time receive high voltage signal and by
The purpose of damage, when ensure that external signal is lasting high voltage signal, protective device, connected product and communication interface are equal
It is not easy to be damaged.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with
It obtains other drawings based on these drawings.
Fig. 1 is the structural schematic diagram of the protective device provided in an embodiment of the present invention applied to communication interface.
Fig. 2 is the circuit diagram of the protective device provided in an embodiment of the present invention applied to communication interface.
Fig. 3 is the structural schematic diagram of another protective device for being applied to communication interface provided in an embodiment of the present invention.
Fig. 4 is the circuit diagram of another protective device for being applied to communication interface provided in an embodiment of the present invention.
Fig. 5 is the flow diagram of the guard method provided in an embodiment of the present invention applied to communication interface.
Fig. 6 is the flow diagram of another guard method for being applied to communication interface provided in an embodiment of the present invention.
Fig. 7 is the flow diagram of another guard method for being applied to communication interface provided in an embodiment of the present invention.
Specific embodiment
To make the object, technical solutions and advantages of the present invention clearer, technical solution of the present invention will be carried out below
Detailed description.Obviously, described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Base
Embodiment in the present invention, those of ordinary skill in the art are obtained all without making creative work
Other embodiment belongs to the range that the present invention is protected.
Fig. 1 is the structural schematic diagram of the protective device provided in an embodiment of the present invention applied to communication interface.With reference to Fig. 1,
The protective device for being applied to communication interface includes signal input interface 11, signal output interface 12 and pressure limiting circuit 13.
Signal input interface 11, pressure limiting circuit 13 and signal output interface 12 are sequentially connected；Signal input interface 11 is used for
External signal is transmitted to the protective device；Pressure limiting circuit 13 is used to generate the first peace after the external signal to be carried out to pressure limiting
Full communication signal；Signal output interface 12 from the protective device for exporting first secure communication signals.
Wherein, pressure limiting circuit 13 includes Transient Suppression Diode, triode and ground resistance；The Transient Suppression Diode
First end connect with signal input interface 11 and signal output interface 12, the second end of the Transient Suppression Diode and described
The base stage of triode is connected with the first end of the ground resistance respectively, the second end of the ground resistance and the triode
Emitter be grounded, the collector of the triode is connect with the signal output interface.
Specifically, signal input interface 11 can be connect by I/O interface with connected product, signal output interface 12
It can be connect by I/O interface with detection device, being connected the external signal of product first, by I/O interface to be transmitted to signal defeated
The external signal is transmitted to pressure limiting circuit 13 by incoming interface 11, signal input interface 11, and then pressure limiting circuit 13 is by external signal
Voltage value be limited within the scope of predetermined voltage threshold, and the first secure communication signals by voltage value within preset range
Be transmitted to signal output interface 12, finally, signal output interface 12 by I/O interface by the first secure communication signals from the guarantor
It is exported in protection unit, wherein when the external signal that voltage value is higher than predetermined voltage threshold passes through pressure limiting circuit 13, pressure limiting circuit 13
The voltage value of the external signal is limited within the scope of predetermined voltage threshold, and the external signal after reduction voltage is known as first
Secure communication signals, predetermined voltage threshold be user according to circuit safety need to set can be by being applied to communication interface
The maximum voltage of protective device.
It is applied to the protection of communication interface to this below with reference to the protective device circuit diagram for being applied to communication interface
The working principle of device and the specific structure of each section are described in detail.
Fig. 2 is the circuit diagram of the protective device provided in an embodiment of the present invention applied to communication interface.Such as Fig. 2 institute
Show, pressure limiting circuit 13 specifically includes: Transient Suppression Diode (i.e. figure label be D1 component), triode (i.e. figure acceptance of the bid
Number component for being Q2) and ground resistance (i.e. figure label be R3 component).
Wherein, the first end of Transient Suppression Diode is connect with signal input interface 11 and signal output interface 12, transient state
The base stage of the second end and triode that inhibit diode is connected with the first end of ground resistance respectively, the second end of ground resistance
It is grounded with the emitter of triode, the collector of triode is connect with signal output interface 12.
Specifically, Transient Suppression Diode can be two-way Transient Suppression Diode, when two-way Transient Suppression Diode
Voltage positive pressure voltage between first end and ground, and voltage value be higher than two-way Transient Suppression Diode clamp voltage when, it is two-way
Transient Suppression Diode can just be connected, and otherwise, two-way Transient Suppression Diode will be in off state.When two-way transient state inhibits two
When pole pipe is connected, the electric current flowed out from two-way Transient Suppression Diode second end flows to the base stage and ground resistance of triode respectively
First end, the voltage value of transistor base increases, and the first end of the collector of triode and two-way Transient Suppression Diode
Connection, therefore the collector junction reverse bias of triode, are on shape between the collector of triode and the emitter of triode
State, but the emitter of triode is grounded, therefore, and after triode ON, the collector voltage decline of triode namely two-way transient state
Inhibit the voltage decline of the first end of diode, it is two-way when voltage value is less than the clamp voltage of two-way Transient Suppression Diode
Transient Suppression Diode is in off state, the voltage decline of transistor base, and triode is also at off state.
The invention adopts the above technical scheme, and pressure limiting circuit includes Transient Suppression Diode, triode and ground resistance.When
When external signal is the high voltage signal for the clamp voltage that voltage value is greater than Transient Suppression Diode, Transient Suppression Diode is led
Logical, electric current flows through ground resistance, because the base stage of triode is connect with ground resistance, when ground resistance has electric current to flow through, and three poles
The base voltage of pipe increases, and then is switched between the collector and emitter of triode, and because the emitting stage of triode is grounded,
So the collector voltage of triode declines, the collector of triode and the input terminal potential of Transient Suppression Diode are equal, because
The input terminal voltage of this Transient Suppression Diode declines, when voltage drops to the clamp voltage of Transient Suppression Diode, transient state
Inhibit diode cut-off, while thus triode had both been realized because base voltage decline is also switched off by the voltage of external signal
The purpose being limited within the scope of safe voltage, but realize avoid Transient Suppression Diode for a long time receive high voltage signal and by
The purpose of damage, when ensure that external signal is lasting high voltage signal, protective device, connected product and communication interface are equal
It is not easy to be damaged.
Further, protective device further includes current-limiting circuit.
Fig. 3 is the structural schematic diagram of another protective device for being applied to communication interface provided in an embodiment of the present invention.Ginseng
Fig. 3 is examined, which includes signal input interface 11, signal output interface 12, pressure limiting circuit
13 and first current-limiting circuit 31, wherein signal input interface 11, the first current-limiting circuit 31 and pressure limiting circuit 13 are sequentially connected.
Specifically, the first current-limiting circuit 31 is big for limiting the electric current for being input to protective device from signal input interface 11
It is small, and the second secure communication signals are transmitted to pressure limiting circuit 13, it is logical that the external signal after reduction electric current is known as the second safety
Believe signal, wherein predetermined current threshold is the maximum current that can flow through the first current-limiting circuit 31.Therefore, it is logical to avoid high current
Overprotection device protects connected product, protective device and communication interface.
Further, the first current-limiting circuit 31 includes the first current-limiting resistance and fuse；The fuse and described first
Current-limiting resistance is connected in series.
Detailed, the both ends that can be fuse connect respectively at the first end of signal input interface 11 and the first current-limiting resistance
It connects, the second end of the first current-limiting resistance is connect with the input terminal of pressure limiting circuit 13, reduces pressure limiting electricity by the first current-limiting resistance
The input voltage on road 13, and when the current value of external signal is greater than the blowout current of fuse, fuse itself fusing, into
And cut off electric current.The first current-limiting circuit composed structure is simple, and the scope of application is wider, can be applied in most current-limiting apparatus.
Further, the type of fuse includes self-recovery fuse.
Detailed, self-recovery fuse can be the just warm thermistor (PPTC) of polymeric or ceramic base temperature-sensitive electricity
It hinders (CPTC), when the electric current for flowing through self-recovery fuse is excessive, such as the high current that generates when line short or overload, from extensive
Double insurance silk becomes high-impedance state, reduces the electric current in circuit, so that circuit is protected, when the electric current for flowing through self-recovery fuse
When reverting to electric current when circuit works normally, self-recovery fuse becomes low resistive state, relative to common fuse in electricity
Itself fusing is understood when flowing through big, needs manually to re-replace fuse, be become using self-recovery fuse, may be implemented without people
The purpose of work replacement fuse.
Further, protective device further includes diode；The cathode of the diode is connect with signal input interface 11, institute
The plus earth for stating diode, the negative voltage for inputting a signal into interface 11 carry out pressure release.
Specifically, test be connected product during, there may be backward voltages in circuit, such as from connected production
Product interface introduces high-pressure electrostatic, AC influence signal etc. there may be backward voltage, and backward voltage passes through signal input interface
11 are transmitted in protective device, may be damaged the circuit and communication interface of protective device, therefore, in 11 He of signal input interface
A diode is connected between ground, the cathode of the diode is connect with signal input interface 11, the plus earth of the diode,
It is released by the negative voltage that the diode can quickly be input a signal at interface 11, protects protective device and connected product
Deng.
It further, further include the second current-limiting circuit applied to the protective device of communication interface；The diode passes through the
Two current-limiting circuits are connect with signal input interface 11；Second current-limiting circuit is output to signal for limiting from the diode
The electric current and voltage of input interface 11.
It is detailed, when the backward voltage between signal input interface 11 and ground is excessive, it will have high current logical from ground
It crosses diode and signal input interface 11 flows to and is connected product, and then signal input interface 11 may be damaged and be connected and produced
Therefore product access the second current-limiting circuit between the output end and signal input interface 11 of diode to limit from two pole
Pipe is output to the electric current of signal input interface 11, and when including current-limiting resistance in the second current-limiting circuit, which may be used also
The voltage of signal input interface 11 is output to limit limitation from the diode.In addition, in order to simplify circuit, the second current limliting electricity
Road and the first current-limiting circuit can be same current-limiting circuit.It avoids protective device and connected product generates super-high-current, protect
Connected product and protective device are protected.
It further, should further include the second current-limiting resistance applied to the protective device of communication interface；The second current limliting electricity
The both ends of resistance are connect with the collector of signal output interface 12 and triode respectively, for limiting the input electricity of transistor collector
Stream, prevents the input current of transistor collector excessive and burns out triode by high current, to protect triode.
Fig. 4 is the circuit theory for the protective device that the another kind that further embodiment of this invention provides is applied to communication interface
Figure.It should include fuse (i.e. figure label be F1 component), first applied to protective device of communication interface with reference to Fig. 4
Current-limiting resistance (i.e. figure label be R1 component), diode (i.e. figure label be D2 component), transient state inhibit two poles
Pipe (i.e. figure label be D1 component), ground resistance (i.e. figure label be R3 component), triode (i.e. figure label
For the component of Q2), the second current-limiting resistance (i.e. figure label be R2 component), signal input interface 11 and signal output connects
Mouth 12.
Wherein, the both ends of fuse are separately connected the first end of signal input interface 11 and the first current-limiting resistance, the first limit
The second end of leakage resistance connects the collector and second of the output end of diode, the first end of Transient Suppression Diode, triode
The emitter of the first end of current-limiting resistance, the input terminal of diode, the second end of ground resistance and triode is grounded, transient state suppression
The second end of diode processed is connected with the base stage of triode, and the second end of the second current-limiting resistance is connect with signal output interface 12.
This is applied to the working principle of the protective device of communication interface are as follows: external signal is entered by signal input interface 11
After protective device, first by fuse and the first current-limiting resistance, fuse and the first current-limiting resistance can be with limiting protectors
The size of middle electric current, and the first current-limiting resistance can according to external signal generate the first secure communication signals, and by this first
Secure communication signals are transmitted to the first end of Transient Suppression Diode, if the voltage of first secure communication signals is positive electricity
Pressure, and voltage value be greater than Transient Suppression Diode clamp voltage when, Transient Suppression Diode conducting, draw high the base stage of triode
Voltage, triode ON, and then the collector voltage of triode is reduced, realize the voltage value for reducing the first secure communication signals
Purpose, if the voltage of the first secure communication signals is forward voltage, and voltage value is less than the clamp voltage of Transient Suppression Diode
When, the first secure communication signals will be exported directly from protective device by the second current-limiting resistance and signal output interface 12.This
Outside, at signal input interface 11 be negative voltage over the ground when, which can quickly be released by diode.
Fig. 5 is the flow diagram of the guard method provided in an embodiment of the present invention applied to communication interface, this is applied to
The guard method of communication interface can be realized by the protective device applied to communication interface of the application.With reference to Fig. 5, this is applied to
The guard method of communication interface includes the following steps:
S501, external signal is received by signal input interface 11.
Detailed, signal input interface 11 can be directly connected to the communication interface of connected product, can also with connected
The communication interface of product of practicing midwifery is connected by switching device, the external signal sent for receiving connected product, the external signal
It may include the information such as the electric property for being connected product.
S502, when the voltage value of the external signal be greater than predetermined voltage threshold when, Transient Suppression Diode conducting, three poles
The collector and emitter of pipe is connected so that the voltage drop of the external signal as low as the predetermined voltage threshold below；It reduces
The external signal after voltage is the first secure communication signals.
Specifically, if the external signal is directly transmitted to interface switching device, such as when the voltage of external signal is excessive
Asynchronous transmission standard interface (RS-232) turns life span (Time To Live, TTL) electric level interface, may be damaged interface and turns
Changing device or connected product, it is therefore desirable to the voltage for the external signal that limitation is input in detection device.External signal transmission
When to signal input interface 11, external signal is sent to the first end of Transient Suppression Diode by signal input interface 11, works as wink
State inhibit diode first end and ground between be positive voltage, and voltage value be greater than Transient Suppression Diode clamp voltage when,
Transient Suppression Diode conducting, and then triode ON, triode ON, obtain Transient Suppression Diode under first end voltage
Drop, when below the clamp voltage for dropping to Transient Suppression Diode, Transient Suppression Diode cut-off, triode is also switched off.By
This realizes the voltage value for reducing external signal, is limited in the voltage value of external signal within the scope of predetermined voltage threshold, will
The external signal after reducing voltage is known as the first secure communication signals.
S503, first secure communication signals are exported from the protective device by signal output interface 12.
Specifically, signal output interface 12 can be directly connected to detection device, conversion equipment and detection can also be passed through
Device connection, conversion equipment can be interface conversion circuit etc., and detection device can be computer.For example, working as signal output interface
After 12 connect with conversion equipment, secure communication No. the first can be transmitted to conversion equipment by signal output interface 12.
Fig. 6 is the flow diagram of another guard method for being applied to communication interface provided in an embodiment of the present invention, should
Guard method applied to communication interface can be realized by the protective device applied to communication interface of the application, should be applied to logical
The protective device for believing interface includes signal input interface 11, signal output interface 12, pressure limiting circuit 13 and current-limiting circuit.With reference to figure
6, it should include the following steps: applied to the guard method of communication interface
S601, external signal is received by signal input interface 11.
S602, the current value of the external signal is limited in by predetermined current threshold range by the first current-limiting circuit 31
It is interior, and the second secure communication signals are transmitted to pressure limiting circuit 13, the external signal after reducing electric current is that the second safety is logical
Believe signal.
Detailed, predetermined current threshold is that can pass through the maximum current value of current-limiting circuit.It is defeated that external signal is transmitted to signal
When incoming interface 11, which is sent to current-limiting circuit by signal input interface 11, after current-limiting circuit receives external signal,
The current value of external signal is reduced, and sends the second secure communication signals to pressure limiting circuit 13, wherein by the institute after reduction electric current
It states external signal and is known as the second secure communication signals.
S603, when the voltage value of second secure communication signals be greater than predetermined voltage threshold when, Transient Suppression Diode
Conducting, the collector and emitter conducting of triode, so that the voltage drop of the external signal is as low as the predetermined voltage threshold
Below；The external signal after reducing electric current and voltage is third secure communication signals.
S604, the third secure communication signals are exported from the protective device by signal output interface 12.
Fig. 7 is the flow diagram of another guard method for being applied to communication interface provided in an embodiment of the present invention, should
Guard method applied to communication interface can be realized by the protective device applied to communication interface of the application, should be applied to logical
The protective device for believing interface includes signal input interface 11, signal output interface 12, pressure limiting circuit 13 and diode.With reference to Fig. 7,
The guard method for being applied to communication interface includes the following steps:
S701, external signal is received by signal input interface 11.
S702, when the voltage value of the external signal be greater than predetermined voltage threshold when, Transient Suppression Diode conducting, three poles
The collector and emitter of pipe is connected so that the voltage drop of the external signal as low as the predetermined voltage threshold below；It reduces
The external signal after voltage is the first secure communication signals.
S703, when signal input interface 11 connect product interface generate negative voltage when, diode current flow, the negative voltage
Signal is transmitted to ground by diode.
Specifically, can connect a diode between signal input interface 11 and ground, at signal input interface 11
When in the presence of negative voltage over the ground, pressure release is carried out by diode.It should be noted that may be used also between signal input interface 11 and ground
To connect other electric elements in addition to diode, for example, being also connected between signal input interface 11 and ground in addition to diode
Limited leakage resistance and fuse, when there is negative voltage over the ground at signal input interface 11, the negative voltage is through current-limiting resistance, insurance
Silk and diode are transmitted to ground.
S704, first secure communication signals are exported from the protective device by signal output interface 12.
The guard method applied to communication interface of the application can be filled by the protection applied to communication interface of the application
Realization is set, has corresponding beneficial effect.
It is understood that same or similar part can mutually refer in the various embodiments described above, in some embodiments
Unspecified content may refer to the same or similar content in other embodiments.
It should be noted that in the description of the present invention, term " first ", " second " etc. are used for description purposes only, without
It can be interpreted as indication or suggestion relative importance.In addition, in the description of the present invention, unless otherwise indicated, the meaning of " multiple "
Refer at least two.
Any process described otherwise above or method description are construed as in flow chart or herein, and expression includes
It is one or more for realizing specific logical function or process the step of executable instruction code module, segment or portion
Point, and the range of the preferred embodiment of the present invention includes other realization, wherein can not press shown or discussed suitable
Sequence, including according to related function by it is basic simultaneously in the way of or in the opposite order, Lai Zhihang function, this should be of the invention
Embodiment person of ordinary skill in the field understood.
It should be appreciated that each section of the invention can be realized with hardware, software, firmware or their combination.Above-mentioned
In embodiment, software that multiple steps or method can be executed in memory and by suitable instruction execution system with storage
Or firmware is realized.It, and in another embodiment, can be under well known in the art for example, if realized with hardware
Any one of column technology or their combination are realized: having a logic gates for realizing logic function to data-signal
Discrete logic, with suitable combinational logic gate circuit specific integrated circuit, programmable gate array (PGA), scene
Programmable gate array (FPGA) etc..
Those skilled in the art are understood that realize all or part of step that above-described embodiment method carries
It suddenly is that relevant hardware can be instructed to complete by program, the program can store in a kind of computer-readable storage medium
In matter, which when being executed, includes the steps that one or a combination set of embodiment of the method.
It, can also be in addition, each functional unit in each embodiment of the present invention can integrate in a processing module
It is that each unit physically exists alone, can also be integrated in two or more units in a module.Above-mentioned integrated mould
Block both can take the form of hardware realization, can also be realized in the form of software function module.The integrated module is such as
Fruit is realized and when sold or used as an independent product in the form of software function module, also can store in a computer
In read/write memory medium.
Storage medium mentioned above can be read-only memory, disk or CD etc..
In the description of this specification, reference term " one embodiment ", " some embodiments ", " example ", " specifically show
The description of example " or " some examples " etc. means specific features, structure, material or spy described in conjunction with this embodiment or example
Point is included at least one embodiment or example of the invention.In the present specification, schematic expression of the above terms are not
Centainly refer to identical embodiment or example.Moreover, particular features, structures, materials, or characteristics described can be any
One or more embodiment or examples in can be combined in any suitable manner.
Although the embodiments of the present invention has been shown and described above, it is to be understood that above-described embodiment is example
Property, it is not considered as limiting the invention, those skilled in the art within the scope of the invention can be to above-mentioned
Embodiment is changed, modifies, replacement and variant.
Claims (10)
1. a kind of protective device applied to communication interface, which is characterized in that including signal input interface, signal output interface and
Pressure limiting circuit；
The signal input interface, the pressure limiting circuit and the signal output interface are sequentially connected；
The signal input interface is used to external signal being transmitted to the protective device；
The pressure limiting circuit is used to generate the first secure communication signals after the external signal is carried out pressure limiting；
The signal output interface from the protective device for exporting first secure communication signals；
The pressure limiting circuit includes Transient Suppression Diode, triode and ground resistance；The first of the Transient Suppression Diode
End connect with the signal input interface, the base stage of the second end of the Transient Suppression Diode and the triode respectively with institute
The first end for stating ground resistance is connected, and the emitter of the second end of the ground resistance and the triode is grounded, described
The collector of triode is connect with the signal output interface.
2. protective device according to claim 1, which is characterized in that further include the first current-limiting circuit；
The signal input interface, first current-limiting circuit and the pressure limiting circuit are sequentially connected.
3. protective device according to claim 2, which is characterized in that first current-limiting circuit includes the first current-limiting resistance
And fuse；
The fuse is connected in series with first current-limiting resistance.
4. protective device according to claim 3, which is characterized in that the type of the fuse includes self- recoverage insurance
Silk.
5. protective device according to claim 1, which is characterized in that further include diode；
The cathode of the diode is connect with the signal input interface, the plus earth of the diode, for signal is defeated
The negative voltage of incoming interface carries out pressure release.
6. protective device according to claim 5, which is characterized in that further include the second current-limiting circuit；The diode is logical
The second current-limiting circuit is crossed to connect with the signal input interface；Second current-limiting circuit is exported for limiting from the diode
To the electric current and voltage of the signal input interface.
7. protective device according to claim 1, which is characterized in that further include the second current-limiting resistance；
The both ends of second current-limiting resistance are connect with the collector of the signal output interface and the triode respectively.
8. a kind of guard method applied to communication interface, applied to the guarantor as described in claim 1 for being applied to communication interface
Protection unit characterized by comprising
External signal is received by the signal input interface；
When the voltage value of the external signal is greater than predetermined voltage threshold, the Transient Suppression Diode conducting, three pole
The collector and emitter of pipe is connected so that the voltage drop of the external signal as low as the predetermined voltage threshold below；It reduces
The external signal after voltage is the first secure communication signals；
First secure communication signals are exported from the protective device by the signal output interface.
9. a kind of guard method applied to communication interface is applied to be applied to lead to as claim 2,3,4 is described in any item
Believe the protective device of interface characterized by comprising
External signal is received by the signal input interface；
The current value of the external signal is limited within the scope of predetermined current threshold by first current-limiting circuit, and by
Two secure communication signals are transmitted to the pressure limiting circuit, and the external signal after reducing electric current is the second secure communication signals；
When the voltage value of second secure communication signals is greater than predetermined voltage threshold, the Transient Suppression Diode conducting,
The collector and emitter of the triode is connected so that the voltage drop of the external signal as low as the predetermined voltage threshold with
Under；The external signal after reducing electric current and voltage is third secure communication signals；
The third secure communication signals are exported from the protective device by the signal output interface.
10. a kind of guard method applied to communication interface, applied to the guarantor as claimed in claim 5 for being applied to communication interface
Protection unit characterized by comprising
External signal is received by the signal input interface；
When the voltage value of the external signal is greater than predetermined voltage threshold, the Transient Suppression Diode conducting, three pole
The collector and emitter of pipe is connected so that the voltage drop of the external signal as low as the predetermined voltage threshold below；It reduces
The external signal after voltage is the first secure communication signals；
When the product interface of signal input interface connection generates negative voltage, the diode current flow, the negative voltage letter
Number ground is transmitted to by the diode；
First secure communication signals are exported from the protective device by the signal output interface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910709930.7A CN110416989A (en) | 2019-07-31 | 2019-07-31 | Protective device and guard method applied to communication interface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910709930.7A CN110416989A (en) | 2019-07-31 | 2019-07-31 | Protective device and guard method applied to communication interface |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110416989A true CN110416989A (en) | 2019-11-05 |
Family
ID=68365403
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910709930.7A Pending CN110416989A (en) | 2019-07-31 | 2019-07-31 | Protective device and guard method applied to communication interface |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110416989A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113692099A (en) * | 2021-07-15 | 2021-11-23 | 中国电子科技集团公司第二十九研究所 | General IO protection tool |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101425463A (en) * | 2007-10-30 | 2009-05-06 | 上海韦尔半导体股份有限公司 | TVS diode device construction with low voltage/low leakage current and production method thereof |
| CN203377583U (en) * | 2013-08-15 | 2014-01-01 | 济南飞越机电科技有限公司 | Holder RS485 communication interface protection circuit |
| CN203774782U (en) * | 2013-12-31 | 2014-08-13 | 上海旋思科技有限公司 | Lightening protection device for communication port |
| CN206471337U (en) * | 2017-01-25 | 2017-09-05 | 杭州士兰集成电路有限公司 | One-way low-capacitance TVS device |
| CN207166116U (en) * | 2017-08-07 | 2018-03-30 | 东莞博力威电池有限公司 | Port multi-level protection circuit |
| CN209168077U (en) * | 2018-09-29 | 2019-07-26 | 赣州市德普特科技有限公司 | A kind of touch screen electrostatic surge absorbing circuit, touch screen and electronic equipment |
-
2019
- 2019-07-31 CN CN201910709930.7A patent/CN110416989A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101425463A (en) * | 2007-10-30 | 2009-05-06 | 上海韦尔半导体股份有限公司 | TVS diode device construction with low voltage/low leakage current and production method thereof |
| CN203377583U (en) * | 2013-08-15 | 2014-01-01 | 济南飞越机电科技有限公司 | Holder RS485 communication interface protection circuit |
| CN203774782U (en) * | 2013-12-31 | 2014-08-13 | 上海旋思科技有限公司 | Lightening protection device for communication port |
| CN206471337U (en) * | 2017-01-25 | 2017-09-05 | 杭州士兰集成电路有限公司 | One-way low-capacitance TVS device |
| CN207166116U (en) * | 2017-08-07 | 2018-03-30 | 东莞博力威电池有限公司 | Port multi-level protection circuit |
| CN209168077U (en) * | 2018-09-29 | 2019-07-26 | 赣州市德普特科技有限公司 | A kind of touch screen electrostatic surge absorbing circuit, touch screen and electronic equipment |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113692099A (en) * | 2021-07-15 | 2021-11-23 | 中国电子科技集团公司第二十九研究所 | General IO protection tool |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102185698B (en) | Ethernet power supply port protective circuit and ethernet power supply equipment | |
| CN104269835A (en) | Protection device, electronic equipment and power supply | |
| CN108352704B (en) | A kind of electrostatic discharge protective circuit | |
| CN209462021U (en) | A kind of reverse connection preventing over-pressure safety device, earphone and USB charging unit | |
| CN110416989A (en) | Protective device and guard method applied to communication interface | |
| CN100454708C (en) | Magnetic disc array system and electric source protector | |
| CN201868837U (en) | USB (universal serial bus) circuit | |
| JP2014147264A (en) | Surge protection circuit and communication device | |
| CN106952585A (en) | Led display screen system | |
| CN201699405U (en) | Transient strong electromagnetic pulse protection circuit of display interface of computer | |
| CN104597823B (en) | Avionics data bus system and its protection circuit | |
| CN103944140A (en) | Alternating current input over-voltage protection circuit | |
| CN206237118U (en) | With accurate overcurrent-overvoltage and under-voltage protection circuit | |
| CN104535887A (en) | Switch output circuit breaking diagnostic system and switch output module | |
| CN204391699U (en) | A kind of current foldback circuit based on triode | |
| CN208656504U (en) | Detection circuit, control system and electrical equipment | |
| CN108288846A (en) | A kind of optocoupler input protection circuit and its guard method | |
| CN103116122A (en) | Power unit detection circuit, series circuit and bypass detection system | |
| CN108733122B (en) | Digital output circuit and industrial control equipment | |
| CN110365322A (en) | A kind of digital output card | |
| CN206908279U (en) | A kind of lithium battery group overtemperature and overcurrent double protecting device | |
| CN110323728A (en) | Current foldback circuit, analog data acquisition module card, nuclear power plant instrument control device | |
| CN109617036A (en) | A kind of differential interface protection circuit communicated suitable for RS422 or RS485 | |
| CN211880078U (en) | Short-circuit protection circuit, power adapter and electronic equipment | |
| CN209250234U (en) | Protect circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20191105 |
|
| RJ01 | Rejection of invention patent application after publication |