A kind of isolating and protecting device of USB3.0 interface at full speed
Technical field
The present invention relates to circuit isolating and protecting device field, be specially a kind of isolating and protecting device of USB3.0 interface at full speed.
Background technology
Along with the requirement of industrial electrical equipment to data exchange velocity is more and more higher, increasing commercial unit also brings into use USB interface, also more and more higher to the reliability requirement of communication.But the ability of existing USB communicating circuit antagonism running environment interference, very easily be subject to the electrostatic in industrial environment and Electromagnetic Interference, and due to the complicacy of industrial environment, host side may be different with equipment end interface level, the equipment of both sides may be made after connection all cannot normally to work, and the interference of either side can be delivered to host/device end along USB interface, easily causes badly damaged to whole system.
At home and abroad widely used power supply and signal isolating and protecting device are mainly divided into three kinds at present: photoelectric-isolated, transformer isolation formula, Capacitor apart formula.
As Chinese patent 200510043916.6, a kind of photoelectric-isolated rs 232 serial interface signal spacer assembly is provided, this device uses optical coupling isolator to carry out signal transmission, although the buffer action of serving, but due to the restriction of photoelectric material character, transmission speed is very slow, can only be used for the transmission of serial ports class low speed signal, the isolation transmission of high speed signal cannot be realized, and cannot isolated from power be realized.
As Chinese patent 201320715627.6, a kind of Capacitor apart formula signal isolating device of RS232 interface is provided, the Capacitor apart of this device compares Phototube Coupling, although simplify circuit design, reduce cost, but transmission speed is slow, and RS232 low speed signal can only be used to transmit, communication efficiency is still very low, still cannot isolate transmit high-speed signals.And additive method of comparing, isolation voltage withstand voltagely to affect by electric capacity is maximum, can be lower.And still cannot insulating power supply.
As Chinese patent 200720305047.4, a kind of USB-TTL signal isolating device using transformer isolation is provided, this device employs transformer isolation, improve transmission speed to a certain extent, and can insulating power supply, but because apparatus design problem, still cannot reach the velocity standard of usb bus, be still rs 232 serial interface signal in essence.
At present, external You Jijia semiconductor company provides solution for the isolation of USB2.0 signal, but price is high, and conceptual design is complicated, and extremely difficulty is generalized to practical application.And, along with the proposition of USB3.0 standard, USB2.0 standard turn increases 4 unidirectional differential signal lines of high speed, and requirements at the higher level are proposed to the transfer rate of isolation signals, the solution of above company was all lost efficacy to USB3.0.
Current domestic and international widely used ESD electrostatic protection device; all containing larger diode PN junction stray capacitance; the transmission demand of high speed signal cannot be adapted to; even aim at the ESD electrostatic protection device of USB interface design; also inevitably the transmission speed of equipment is impacted, and the solution of this discrete device is large due to volume, there is extra PCB layout stray capacitance; designing wiring difficulty, no longer reliable.
Summary of the invention
Technical matters solved by the invention is to provide a kind of isolating and protecting device of USB3.0 interface at full speed; power supply and the signal that can not only realize Universal USB interface are truly isolated; and increased substantially the transfer rate of isolation signals; make it to reach USB3.0SuperSpeed level; and add antistatic protection; the electrostatic interference of either side can be prevented, make it there is practical value widely in actual applications.
Technical matters solved by the invention realizes by the following technical solutions: a kind of isolating and protecting device of USB3.0 interface at full speed, comprise: main frame portion, from machine portion, described main frame portion, high speed signal isolation module is provided with between machine portion, low speed differential data and power isolation module, electromagnetic shield module, described main frame portion, high speed unidirectional differential signal modulation /demodulation module is comprised in machine portion, ESD electrostatic defending module, described ESD electrostatic defending model calling is on USB3. port, ESD electrostatic defending module is electrically connected on high speed unidirectional differential signal modulation /demodulation module and low speed differential data and power isolation module, main frame portion, connected by high speed signal isolation module between the high speed in machine portion unidirectional differential signal modulation /demodulation module, main frame portion, be connected with power isolation module by low speed differential data between the ESD electrostatic defending module in machine portion, low speed differential data and power isolation module are connected with DC/DC Voltage stabilizing module, DC/DC Voltage stabilizing module is arranged on from machine portion, DC/DC Voltage stabilizing module is connected to the ESD electrostatic defending module from machine portion, described main frame portion, electromagnetic shield module is provided with outside machine portion.
Described high speed unidirectional differential signal modulation /demodulation module is by high frequency Full differential operational amplifier, to achieve in USB3.0 interface two pairs of fully differential signal pins to the modulation /demodulation of line transformer, and enhance the driving force of signal, make high speed signal can drive line transformer in high speed signal isolation module, or amplify the signal transmitted through line transformer.
The unidirectional differential signal isolation module of described high speed, by the magnetic coupling of two high-frequency transmission line transformers, to achieve in USB3.0 interface two to the unidirectional differential data line of high speed at main frame with from the high speed signal isolation transmission between machine.
The isolation that described low speed differential data and power isolation module use transformer magnetic coupling to achieve a pair low-speed bidirectional differential signal in USB3.0 interface is transmitted, and use transformer Magnetic isolation to achieve the isolated from power conversion of USB interface, and for providing working power from the unidirectional differential signal isolation module of pusher side high speed.
Described ESD electrostatic defending module is being connected from pusher side with data line and power lead; 6 HW High Way and 4 power leads of USB3.0 are connected by high-speed high-performance TVS array; clamper protection is carried out to line level; the impact preventing static discharge from bringing the work of USB3.0 equipment, guarantees that equipment does not cause serviceability to decline because of esd protection simultaneously.
Described DC/DC Voltage stabilizing module effectively can absorb due to voltage spikes, prevents the impact that commercial unit voltage fluctuation brings equipment work, for equipment work provides stable operating voltage.
Described electromagnetic shield module carries out electromagnetic signal shielding to above-mentioned module, prevent the interference being subject to from the external world with upper module, and the electromagnetic signal produced when avoiding work causes interference to other equipment.
Compared with public technology, there is following advantage in the present invention: 1, the present invention uses the full differential operational amplifier in hypervelocity broadband to carry out driving isolation transformer, achieve the modulation /demodulation to the unidirectional differential data signals of USB3.0 high speed, eliminate modulation /demodulation in signal isolation in the past and, to the restriction of speed, solve the problem that high speed signal in the past cannot be isolated.
2, the present invention uses the line transformer containing sendust core, realizes the electrical isolation of USB3.0 high-speed differential signal transmission, achieves the insulation blocking of USB3.0 signal at full speed.
3, the present invention uses isolation type bus transceiver to realize and transmits the isolation of low-speed bidirectional differential data signals in USB3.0 interface, and data can be automatically switched to send or accepting state, prevent the data on two-way difference signal wire from sending and influence each other with reception.
4, the present invention achieves complete high power power isolation by DC/DC power isolation module, further increases isolation performance.
5, the present invention uses high-performance TVS array to provide ESD electrostatic leakage to protect to usb signal line, to effectively prevent in working environment electrostatic to the damage of equipment.
Accompanying drawing explanation
Fig. 1 is system architecture schematic diagram of the present invention.
Fig. 2 is high speed of the present invention unidirectional differential signal modulation /demodulation module circuit diagram.
Fig. 3 is high speed signal isolation module circuit diagram of the present invention.
Fig. 4 is low speed differential data of the present invention and power isolation module circuit diagram.
Fig. 5 is ESD electrostatic defending module circuit diagram of the present invention.
Fig. 6 is DC/DC Voltage stabilizing module circuit diagram of the present invention.
Embodiment
Object is reached and effect is easy to understand in order to make technological means of the present invention, creation characteristic, workflow, using method, below in conjunction with the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
As shown in Figure 1, a kind of isolating and protecting device of USB3.0 interface at full speed, comprise: main frame portion, from machine portion, described main frame portion, high speed signal isolation module is provided with between machine portion, low speed differential data and power isolation module, electromagnetic shield module, described main frame portion, high speed unidirectional differential signal modulation /demodulation module is comprised in machine portion, ESD electrostatic defending module, described ESD electrostatic defending model calling is on USB3. port, ESD electrostatic defending module is electrically connected on high speed unidirectional differential signal modulation /demodulation module and low speed differential data and power isolation module, main frame portion, connected by high speed signal isolation module between the high speed in machine portion unidirectional differential signal modulation /demodulation module, main frame portion, be connected with power isolation module by low speed differential data between the ESD electrostatic defending module in machine portion, low speed differential data and power isolation module are connected with DC/DC Voltage stabilizing module, DC/DC Voltage stabilizing module is arranged on from machine portion, DC/DC Voltage stabilizing module is connected to the ESD electrostatic defending module from machine portion, described main frame portion, electromagnetic shield module is provided with outside machine portion.
Described high speed unidirectional differential signal modulation /demodulation module is by high frequency Full differential operational amplifier, to achieve in USB3.0 interface two pairs of fully differential signal pins to the modulation /demodulation of line transformer, and enhance the driving force of signal, make high speed signal can drive line transformer in high speed signal isolation module, or amplify the signal transmitted through line transformer.
The unidirectional differential signal isolation module of described high speed, by the magnetic coupling of two high-frequency transmission line transformers, to achieve in USB3.0 interface two to the unidirectional differential data line of high speed at main frame with from the high speed signal isolation transmission between machine.
The isolation that described low speed differential data and power isolation module use transformer magnetic coupling to achieve a pair low-speed bidirectional differential signal in USB3.0 interface is transmitted, and use transformer Magnetic isolation to achieve the isolated from power conversion of USB interface, and for providing working power from the unidirectional differential signal isolation module of pusher side high speed.
Described ESD electrostatic defending module is being connected from pusher side with data line and power lead; 6 HW High Way and 4 power leads of USB3.0 are connected by high-speed high-performance TVS array; clamper protection is carried out to line level; the impact preventing static discharge from bringing the work of USB3.0 equipment, guarantees that equipment does not cause serviceability to decline because of esd protection simultaneously.
Described DC/DC Voltage stabilizing module effectively can absorb due to voltage spikes, prevents the impact that commercial unit voltage fluctuation brings equipment work, for equipment work provides stable operating voltage.
Described electromagnetic shield module carries out electromagnetic signal shielding to above-mentioned module, prevent the interference being subject to from the external world with upper module, and the electromagnetic signal produced when avoiding work causes interference to other equipment.
Preferably, described high speed unidirectional differential signal modulation /demodulation module, comprise the full differential operational amplifier in LTC6409 hypervelocity broadband of Linear company, its gain bandwidth product reaches 10GHz, and input and output are fully differential structure, the high speed differential data transmission requirement of unidirectional differential data passage 5Gbps in full speed USB3.0 interface can be met, exporting by amplifying differential signal, can be signal transformer and high-speed data-flow is provided.
Preferably, the unidirectional differential signal isolation module of described high speed, uses the high frequency magnetic coupling properties of two line transformers, realizes the electrical isolation of two pairs of high-speed differential signal transmission.Wherein, the magnetic material of line transformer adopts the KM77050 Sendust Cores of Mei Ci company, utilizes its high-frequency loss little, the characteristic that magnetic permeability is high, meets the transmission rate request of USB3.0 high-speed differential signal 5Gbps.Transformer coiling adopts the paste paint enameled wire two-wire of withstand voltage 3kv to walk abreast coiling, further reduces high-frequency loss, improves isolation performance.
Preferably, described low speed differential data and power isolation module use the LTM2884 chip of Linear company, the inner transmission using transformer to carry out digital signal and power supply, isolation signals transmission is carried out for the low-speed bidirectional differential data line of two in USB3.0 interface, and data can be automatically switched to according to data transmission scenarios to send or accepting state, prevent from influencing each other with reception with the data transmission on a pair differential signal line; The insulating power supply of built-in chip type can produce the isolation and amplifier of a 5.0V for the input of 4.5V ~ 5.5V, and the isolation voltage in 2.5kVrms can be provided to protect.
Preferably; described DC/DC Voltage stabilizing module uses the LTC3115 tetra-switch synchronous buck-step-up DC/DC converter of Linear company; in 2.7V to 40V voltage range, provide 5V2A to export; quiescent current only 30 μ A during operation; load regulation is only 0.1%; significantly solve the power supply ripple problem brought due to DC/DC isolated from power, and protection can be provided to the voltage fluctuation up to 40V.
Preferably; described ESD electrostatic defending module uses the SP3003-02UTG electrostatic protection TVS diode array of Littelfuse company; for 2 row differential data passages provide ± 12kV electrostatic protection; combine low clamp voltage and low electric capacity, while protection is provided, reduces the impact on normal transmission to greatest extent.
Principle of work of the present invention is: the electromagnetic shield module in device and ESD electrostatic defending module are passive module, no matter whether power on, and all can be this equipment and provide electromagnetic screen and electrostatic protection.After the USB interface of this device access host side, system electrification, first power unit in low speed differential data and power isolation module and DC/DC Voltage stabilizing module start working, for from pusher side USB interface, tcp data segment in low speed differential data and power isolation module, and provide stable insulating power supply from pusher side signal isolation modulation /demodulation module, after above-mentioned signal isolation transceiver module powers on, with regard to starting, isolation transmission is carried out to the data-signal of USB3.0 interface transmission, wherein 2 carry out differential amplification to the unidirectional differential signal of high speed through high speed unidirectional differential signal modulation /demodulation module, and carry out isolation transmission by line transformer, 1 pair of low-speed bidirectional differential signal is wherein transmitted by low speed differential data and the built-in isolating difference signal transceiver of power isolation module and signal transformer, under normal operation, the transmission delay of usb signal is in 1ns.
More than show and describe ultimate principle of the present invention, principal character and advantage of the present invention.The technician of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and instructions just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.Claimed scope of the present invention is defined by appending claims and equivalent thereof.