[FAQ] DP83867E: How do I choose magnetics for my industrial PHY?

There are 5 key parameters to look out for when selecting magnetics:

1. Magnetic type (specifically for integrated RJ-45/Magnetic component)
   
   1. Can the recommended MDI configuration still be met with this component?
2. Turns ratio
   1. Ideally 2%, but 3% is tolerable
3. Inductance
   1. High inductance is preferred. Usual numbers seen is around 350uH
4. Insertion loss
   1. As close to 0dB as possible compared to specified value for each range stated in datasheet
      1. If specification gives -1dB as typical, finding a component with -1dB, -0.9dB,... is recommended
5. Return loss
   1. At or smaller magnitude than specified in datasheet
      1. If specification gives -16dB as typical, finding a component with -16dB, -17dB,... is recommended

While this can give a helpful indication of compatible magnetics, it is strongly recommended that customers validate the magnetic in their design with their PHY.