Connection mode between the CHIP PHY and the network transformer

Connection mode between the CHIP PHY and the network transformer

1) Current-driven PHY,

The 2-wire common-mode inductor can be placed only on the RJ45 side of the cable.

The 3-wire common-mode inductor should be placed on the PHY side.

For 2-wire common-mode inductor + autotransformer, the autotransformer is placed on the RJ45 side

The center tap of the network transformer is connected to the VCC, which is the power supply voltage for the PHY

2) Voltage driven PHY,

2-wire common-mode inductors can be placed on the PHY side or cable side.

The 3-wire common-mode inductor should be placed on the PHY side.

In the case of 2-wire common-mode inductor + auto-transformer, the auto-transformer is placed in the center tap of the network transformer at the RJ45 side to connect the ground capacitor.