Input VCC range is from 3.0 to 4.4V, but why does it recommend 3.8V in the design guideline?
it’s not a common power rail value as most of the mini PCI-E slot only support 3.3V.
If we only use data no voice, would it be OK with 3.3V power supply like MC7750?
I believe it is a document issue and you are using the outdated one.
Please refer to latest PTS for MC7354 (rev.4) and which indicated 3.3v as typical (min 3.0, max 3.6)
And for sure, MC7354 definitely works with 3.3V, the standard.
Hope it helps.