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How to use Ethernet PHY-PHY interconnect on same PCB?
That said, see TI document SLLA310 for more info on various non-standard methods of ethernet interconnects. Re: Ethernet PHY — PHY interconnect on same PCB. In a similar situation I left the PHYs out and connected RMI (I) master to RMI (I) slave. If the PHYs must be used then you can probably connect the RX and TX pairs with a capacitor.
Can a PHY be used with more than one transformer?
If you use a phy that’s mangetic-only you can do away with a single transformer per pair. Find the simplest magnetics you can, with simple 1:1 center tapped transformers and no internal termination, and terminate each side of the transformer as you would on the chip side, and you should be good to go.
How many pairs of PHY do I need for 1000BASE-KX?
Also 1000Base-KX only need 2 pairs (Full-Duplex) but the operating frequency is around 1Ghz which involves signal integrity issues where 1000Base-T and 100Base-T (X) stays at 125MHz. What you really need is a different variety of PHY, so called “backplane phy”. Those are specifically designed to work with capacitive coupling over PCB traces.
What happens if PHY line is not inverted?
So it doesn’t matter if the line is inverted or not as the transitions carry the information, not the levels. Now, it’s possible that some PHY chips will not be able to drive something that’s not a transformer, so you may have a problem there depending on how it’s connected.
Can a PHY be used without a transformer?
This application report describes an application using Texas Instruments Ethernet PHY products without a transformer. This document also gives instructions for configuring the TLK110 in this mode, and the resulting behavior and performance of the PHY. A transformerless operation mode has great benefit in the following scenarios: 1.
Why do we need Transformers in Ethernet PHY?
Transformers also protect silicon from line disturbances that might otherwise kill silicon so be aware of this. They also isolate galvanically the two systems and stop earth loops passing currents that can cause poor data quality.
When to wake up tlk110 Ethernet PHY transformerless operation?
Typical 10/100 Mbps Twisted-PairInterface In default configuration, the chip wakes up when auto-negotiationis enabled with 10 Mbps and 100 Mbps. The auto-MDIXis also enabled in order to select which pair to use for RX and which pair to use for TX, allowing either straight-throughor crossover cables to be used.