M52235 ePHY Electrical Specifications

[Jaux]

Can anybody point me to this document?

I need to spec the magnetics for a new development - at the moment I am going with the configuration per the M52235EVB schematics, but I would like peruse the actual spec for the ePHY.

Thanks, J

[vier_kuifjes]

I recently designed a 52235 board. I wanted a small, simple design and used a RJ-45 connector with built-in magnetics. I used a Stewart SI-50158-F jack for this purpose, which was easily available from Farnell. It worked fine from the first power up of the board!

[jab]

I can't seem to find the H2019NL magnetics chip that's used on the MCF32235EVB. I'm going to try a RJ45 with magnetics jack from Halo (HFJ11-2450E-L11RL). It has a turn ratio of 1:1 and has the 75ohm resistors and 1000pF capacitor needed for the termination of the spare lines built in.

Of course i'm still going to terminate the lines with 49.9ohm 1% resistors as shown in the EVB schematic.

Wish me well . 

[scifi]

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jab wrote:

I can't seem to find the H2019NL magnetics chip that's used on the MCF32235EVB. I'm going to try a RJ45 with magnetics jack from Halo (HFJ11-2450E-L11RL). It has a turn ratio of 1:1 and has the 75ohm resistors and 1000pF capacitor needed for the termination of the spare lines built in.

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The H2019NL is for Power Over Ethernet. You probably don't need that. The suitable low-cost part from Pulse Engineering is H1102. Of course, an RJ45 jack with everything built-in is nice to use. I wouldn't anticipate any problems with it.

[DrSeuss]

Sorry, but I do not understand. What specification are you referring to? The internal ePHY is 802.3 compliant. Magnetics that support this standard should work. As freescale does no manufacturer magnetics we do not include them in the specification.

All ePHY specification are in the device data sheet.

[Jaux]

Dr S,

Referring to the various devices from for example Halo and Pulse, I see all the different flavours are IEEE 802.3 complient, but depending on the electrical specs of the ePhy certain turns ratios must be selected ( 1:1, 2:1, 1:1.41 Tx to Rx 1:1), ( line impeadance matching - Halo fastjacks is supplied with 75 ohm resistors where the EVB has 49.9 ohm resistors) etc etc.

According to our local Halo supplier the magnetics must match certain spesifics of the ePhy, hence my question.

I humbly appologize if this is a stupid question, but the reason I ask is because I don't know.

Your help is appreciated.

J

[bhirisys]

The reference manual:
http://www.freescale.com/files/32bit/doc/ref_manual/MCF52235RM.pdf
states on page 331:
" 1:1 common transformer "

M52233DEMO board appears to use Pulse H1102 magnetics.

The 75 ohm resistors are usually on the spare lines, or transformer centre tap.
Data lines are terminated with a total of 100 ohm (49.9 + 49.9).
See the M52233DEMO schematic:
http://www.freescale.com/files/32bit/hardware_tools/schematics/M52233DEMO_SCH.pdf