Electrical aspects common for both solutions
30/108
We strongly recommend to adhere to the following rules:
1. Take EMC aspects into account.
2. To do so, keep the length for the signal lines below 30 mm
3. Also make sure that the complete design fulfills the requirements of
specification IEEE 802.3.
4. On the host system, use magnetics.
5. Connect the housing of the RJ45 connector to earth ground directly for
improving noise immunity.
Note:
The resistor R11 connected to the PHY_EXTRES pin of netX 90
must have a resistivity of 6.49 kΩ ± 1%. If you would use a resistor
of 6.2 or 6.8 kΩ as substitute instead, you will operate the Ethernet
interface outside of its specifications!
In order to avoid this, the netRAPID already integrates this 6.49 kΩ
± 1% precision resistor on-board. So you do not need to take care
of this resistor in your design.
Note:
You should also take into account the design rules and
recommendations given in netX 90 Design-in Guide, section 6.2.5
“Ethernet interface”, p.65-66.
If the integrated Ethernet PHYs of the netX 90 are not used in the design,
the signal pins (i.e. PHY0/1_RXP/RXN, PHY0/1_TXP/TXN) should simply
be left open. However, all power supply pins must be connected. Example
schematics for cases of unused PHYs can be found within netX 90 Design-
in Guide..
Note:
For more information on the Real-time Ethernet SYNC-Signals, see
Meaning of the SYNC signals for various real-time Ethernet
protocols for netX 90.
netRAPID 90 | Design guide
DOC190601DG01EN | Revision 1 (Draft 10) | English | 2019-09 | Preliminary | Public
© Hilscher 2019
