TUSB8041: Ferrite Bead Selection for 3.3V and 1.1V Rails on TUSB8041 EVM

Tool/software:

Hi,

I’m working on a custom board based on the TUSB8041, and I noticed that on the TUSB8041RGC EVM (Rev D), ferrite beads are placed on both the 3.3V and 1.1V power rails.

Specifically:

• For the 3.3V rail, the BOM lists BLM18PG221SN1D, which has 220 Ω impedance at 100 MHz.

• For the 1.1V rail, the schematic shows a ferrite bead, but the BOM uses a 0 Ω resistor instead.

Could you please help me with the following:

1. Is BLM18PG221SN1D a recommended choice for 3.3V power filtering in this design?

2. For the 1.1V rail, which typically supplies high-speed core logic or PLL circuits, can you recommend a suitable ferrite bead part number?

3. Was the 0 Ω on the 1.1V rail used just for flexibility in testing, or is there a reason not to use a ferrite there?

Thanks in advance for your guidance.

Best regards,