CN202034207U

CN202034207U - Double-mouth gigabit network transformer with enhanced electromagnetic interference suppression capability

Info

Publication number: CN202034207U
Application number: CN2011200264590U
Authority: CN
Inventors: 杨先进; 张大伟
Original assignee: DONGGUAN MENTECH ELECTRONIC Co Ltd
Current assignee: Dongguan Mentech Optical and Magnetic Co Ltd
Priority date: 2011-01-24
Filing date: 2011-01-24
Publication date: 2011-11-09
Anticipated expiration: 2021-01-24

Abstract

The utility model discloses a double-mouth gigabit network transformer with an enhanced electromagnetic interference suppression capability, which comprises a CMC circuit topological structure consisting of a plurality of sets of common mode coils and is applied to network exchange equipment, wherein an integrated dual Port supports 10/100/1000 Base-T transmission rate, the electric property parameter and performance conform to the IEEE802.3ab international standards, and the electromagnetic suppression capability meets the EN55022Class B standard requirements.

Description

The twoport gigabit networking transformer that a kind of reinforced electric magnetic disturbance suppresses

Technical field

The utility model relates to network transformer, is specifically related to the twoport gigabit networking transformer that a kind of reinforced electric magnetic disturbance suppresses.

Background technology

The electromagnetic interference of existing twoport gigabit networking transformer suppresses ability, can not satisfy the demand that equipment increases.

The utility model content

The problem that the utility model need solve provides the twoport gigabit networking transformer that a kind of reinforced electric magnetic disturbance suppresses.

To achieve these goals, the utility model is designed a kind of gigabit networking transformer of ultra-thin encapsulating structure, and the twoport gigabit networking transformer that described reinforced electric magnetic disturbance suppresses is formed CMC line topological structure by some groups of co-mode coils.

The twoport gigabit networking transformer application that the magnetic disturbance of the utility model reinforced electric suppresses is in the network switching equipment, integrated dual Port, support the 10/100/1000Base-T transmission rate, electrical parameter and performance meet the IEEE802.3ab international standard, and electromagnetism inhibition ability meets EN55022Class B standard-required.The twoport gigabit networking transformer that the magnetic disturbance of the utility model reinforced electric suppresses is the completely new product that the applicant develops.The applicant in the industry cycle enjoys the reputation of perfect EMI rejection always, with Foxconn, close duty, in many collaborative projects of emerging, HW, the design centre has accumulated abundant EMI design concept and EMI improves experience.In the twoport gigabit networking transformer that the magnetic disturbance of the utility model reinforced electric suppresses, 3 line CMC+Transformer+3 line CMC line topological structural designs have been adopted, enjoy unique perfectly EMI and suppress effect, the EMI rejection of product obtains breakthrough raising.

Description of drawings:

Fig. 1 is the principle schematic of the twoport gigabit networking transformer of the utility model reinforced electric magnetic disturbance inhibition.

Embodiment

For the ease of those skilled in the art's understanding, structural principle of the present utility model is described in further detail below in conjunction with specific embodiment and accompanying drawing:

As shown in Figure 1, a kind of embodiment of twoport gigabit networking transformer of reinforced electric magnetic disturbance inhibition.The twoport gigabit networking transformer that described reinforced electric magnetic disturbance suppresses is formed CMC line topological structure by eight groups of co-mode coils.

The generation of common-mode signal clutter: because this transformer operating frequency is higher, the magnetic field that generates during work can not only be transmitted in magnetic core, will inevitably induce electromagnetic signal to the external world, can induce common-mode signal mutually between the magnetic core element on the mainboard like this, this is equivalent to interference signal, very unfavorable to transfer of data, the method that reduces common mode conduction noise be in holding wire or power line, connect common mode choke, shunt capacitor, ratio of components filter carry out filtering between ground and lead, elimination common mode conducted noise.

Co-mode coil CMC (Common Mode Choke) suppresses common-mode signal clutter operation principle: as its name suggests, common mode choke is to be used for suppressing common mode noise signal (useless signal, interference signal) element, it forms high impedance to common mode noise signal, and to the essentially no influence of difference mode signal (useful signal).Common mode choke work is similar with transformer, and it also is the coupling of using the different coils on the same magnetic core to produce magnetic.It and transformer difference are that it is not conversion and the isolation that is used as signal, say more definitely, and promptly it presents high impedance to the common-mode signal that adds thereon, allow difference mode signal to pass through in the clear.The choke that is added on input when common-mode voltage as shown in Figure 2, the reference level among the figure is arbitrarily.The electric current and the voltage that are added on each bar line are (it normally turn back on the reference level by parasitic capacitance) that equates.The turn ratio of two windings is 1: 1 on the same magnetic core, and in the ideal case, all magnetic fluxs all are (the same with ideal transformer) that intercouples.Two common mode currents in that same direction flows produce the identical magnetic flux of phase place.The influence that their produce just is equivalent to the induction reactance of connecting, and its size depends on the parameter (as magnetic core cross section and magnetic permeability etc.) of signal frequency and coil.The choke that is added on input when differential mode voltage as shown in Figure 3, total resultant current flows through load and returns by choke.Flowing through rightabout current flux in choke cancels out each other.Choke is actually " not recognizing " to difference mode signal.The perfect choke of narrating above has the frequency response of no limit for width, and common-mode signal is presented infinitely-great impedance, is zero to the difference mode signal impedance.Actual choke is the same with transformer to also have leakage inductance, distributed capacitance and core loss except that winding resistance is arranged.The effect that its produces is not equal to zero the impedance except difference mode signal is had, and its frequency response also is that limited, common code impedance also is limited.In general, the operating frequency of common mode choke and its common mode inductance are inversely proportional to.

The utility model also has following main electrical function: signal transmission, impedance matching, signal noise suppress, the high voltage isolation features

A, the signal transmission: support the 10/100/1000Base-T transmission rate, electrical parameter and performance meet IEEE 802.3and ANSIX3.263 international standard, and can be coupled to an other end of the connection netting twine of varying level by the conversion of electromagnetic field.

B, impedance matching: the impedance of coupling client mainboard 100Ohm, can effectively control ReturnLoss.

C, the common-mode signal clutter suppresses: the product magnet assembly has adopted 3 line CMC (CommonMode Choke)+Transformer+3 line CMC (Common Mode Choke) line topological structure, wherein adopt the three-wire type common mode choke coil, when producing opposite magnetic field during by co-mode coil in magnetic core, the differential mode signal cancels out each other, the magnetic field that produces equidirectional when common-mode signal during by coil in magnetic core is strengthened, it can make, and useful difference mode signal is almost loss-free to be passed through, and common mode interference signal is presented high impedance, make its a large amount of decay, thereby reach the purpose that suppresses common mode EMI, meet EN55022Class B standard-required.

D, high voltage is isolated: product magnet assembly design insulation voltage satisfies IEEE802.3.2002.PARA 40.6.1.1, ITEM a﹠amp; The b requirement; the varying level of isolating heterogeneous networks equipment room in the netting twine connection; make die terminals and external isolation; antijamming capability strengthens greatly; and chip increased very big protective effect (as thunderbolt); to prevent that different voltages from transmitting damage equipment by netting twine, can play certain lightning protection and shock resistance protective effect to customer equipment thus.

Claims

1. the twoport gigabit networking transformer that suppresses of a reinforced electric magnetic disturbance, it is characterized in that: the twoport gigabit networking transformer that described reinforced electric magnetic disturbance suppresses is formed CMC line topological structure by some groups of co-mode coils.