DS90UB954-Q1: Question of recommended POC

Hello Harry,

Whether you choose to use all 3 inductors or remove one of the ferrite beads, as long as you are meeting our Channel Specs IL/RL limit lines, then the PoC network can be used. We expect that if you use all 3 ferrite beads, the inductor, and follow best-practice layout guidelines, then you can meet the full 4Gbps application of the SerDes link. You can choose to remove an inductor in this PoC network if you maybe operate at a lower link rate or have lower current/temperature requirements in the system.

But customers have to verify themselves on their own PCB if they can still meet IL/RL limits when they start removing inductors. Removing inductors in the PoC network will reduce the impedance through the PoC network and cause more loss on the high-speed channel.

If you want a general recommendation for the least amount of loss, we recommend keeping all ferrite beads and inductors.

Best,

Justin Phan