Road by implement be every family is necessary article, its advocate board contained the module such as USB, LAN, SDRAM, 2.4G, WIFI, involve among these module the dot has RF, USB Differential, ESD, WIFI, 50 ohmic impedance, 90 ohmic impedance to wait a moment, today with respect to the road by implement the place that layout wiring needs to notice is done discuss simply.

 

Net mouth transformer

In aether network equipment, when passing PHY join RJ45, intermediate metropolis adds transformer of a network. Some accept take a percentage of a deal among its power source, and some ground connection, power source is worth different, 3.3V, 2.5V, 1.8V has. Can bring about very big electric current to flow to the device with small electromotive force from the equipment with high electromotive force so. Keep apart transformer to solve above problem Transformer() this parts of an apparatus with respect to emerge as the times require, the wave of coil coupling filter that the signal needing branch that it sends PHY uses wrong standard coupling in order to enhance signal, and pass the changeover coupling of electromagnetism field arrive of join reticle additional one aspect of the matter. Such not only make go up without physics between reticle and PHY join and change transmitted signal, cut off the dc heft in signal, still can be in the equipment of different 0V n deferent data.

 

1.Main job principle:

 

V model signal passes the signal flow direction when keeping apart transformer:

 

 

In all modular signal flows to through keeping apart the signal when transformer:

 

 

When in all when modular signal course keeps apart transformer, as a result of coil the voltage polarity of two end is identical, won’t form electric current. Reason won’t will in all modular signal is delivered to secondary coil. But the coupling capacitance Cww between line garden is in all of modular signal deliver provided access:

 

 

Keep apart transformer in all modular signal is restrained

 

To prevent advocate on class coil in all modular signal is delivered to secondary coil, in advocate central take a percentage of a deal is added to be in class coil in all the release of modular signal provides access, (take a percentage of a deal of major moment center adds filtrate circuitry and cannot or very well benefit in all the model disturbs signal, because this a lot of engineers can choose to take in all the segregation transformer of modular inductance, perhaps divide signal to walk along the obligate on the line in net mouth difference in all the position of modular inductance) :

 

 

Conclusion: Transformer of the segregation in aether net design is satisfying a function (the signal that need branch is transmitted) below premise, can fight faze to arriving since back end circuit not only safety action, still can or benefit in all modular radiate noise. Because this segregation transformer is the mark of aether net mouth,deserve to design.

 

2.Action:

 

Enhance signal, make its transmit a distance farther;

 

Make chip end and exterior segregation, interference rejection ability increases greatly, and added very big protection effect to chip (like be struck by lightning) ;

 

Should receive different n (if some PHY chip are 2.5V, some PHY chip are 3.3V) when net mouth, won’t cause an effect to each other equipment.

 

In all the model is restrained;

 

3.PCB sets timing note:

 

Network transformer lower part is all layer hollow.

 

Network transformer lower part prohibits crossing the line that has nothing to do with network transformer.

 

Net mouth GND, spread copper alone, as removed as GND copper skin (be more than 80mil) .

 

Hollow lower part is all layer copper skin

 

Net mouth (RJ45) separate store copper
 

 

Spread cupreous span
 

 

Aerial

Aerial layout

 

 

Divide spur track distribution, walk along a line to must be linear (π filter wave)

 

The layer that layout of aerial parts of an apparatus is in, need hollow copper skin, all round (> 10mil) bag ground (ground of best and stereo bag) . If multilayer board, need hollow and the layer that aerial is in and the layer with its photograph adjacent. (secondary floor is referenced) to control impedance, increase ply of impedance calculative medium.

 

The place that aerial is in, prohibit other the line that has nothing to do with aerial signal is crossed.

 

Aerial takes line line wide (10mil~20mil) .

 

Aerial takes a line with circular arc.

 

Capacitance of aerial filter wave stands by aerial interface to put.

 

 

Secondary floor is referenced, hollow carries layer and layer of photograph adjacent GND2 on the head, three-layer does referenced layer.

 

 

Layout of antenna of π filter wave, take the air line, curve transfers, hollow, bag ground.

 

 

Clock

1.Brilliant brace up layout takes a line

Stand by chip to put, make chip stabilizes the job;

 

π put, take kind of line that need branch and add thick;

 

The bag is located in manage

 

 

Clock line (- CLK) the processing that include the land.

 

Watch for convenient everybody, made a piece of thinking guide graph, if pursue:

 

Thinking guides graph