I’m laying out my custom carrier board at the moment, and am a little confused regarding the USB3.0 common mode chokes used in the Ixora carrier board. The choke used is the DLW21SN900SQ2L, which has the following equivalent circuit:
My interpretation of this image, is that pads 1 and 2 are connected, and pads 3 and 4 are connected. However, the schematic for the Ixora shows connections between pads 2 and 3, and between 1 and 4:
These connections are obviously reiterated in the Ixora layout:
The Ixora carrier board obviously works as intended, so I’m guessing I’ve just misunderstood the equivalent circuit?