Summary:
All of our Industrial Ethernet PHYs support Transformer-less Operation via Capacitive Coupling except for the DP83867.
The DP83867 does not support Transformer-less Operation.
List of Industrial Ethernet PHYs that support Transformer-less Operation:
- DP83869
- DP83848
- DP83822
- DP83826
- DP83825
Context:
Our Physical Layer Ethernet PHYs typically have the same functional topology.
Figure 1 - DP83869 Typical Copper Application
The Block labeled "Magnetics" is what this FAQ will be discussing.
A typical application will use a Transformer, mainly to keep the network cable DC isolated (the Cable connector from Figure 1).
Figure 2 - Typical 10/100 Mbps Twisted Pair Interface
However a transformer is not the only solution to isolate DC Voltage. Isolation that transformers provide can be realized using non-polarized capacitors.
Figure 3 - Transformer-less Configuration
Further Details can be found in the following Application Note:
DP83848 Transformer-less Operation
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Regards,
Alvaro Reyes