The auto-direction sensing feature eliminates the need for a direction-control pin and its associated firmware overhead, which simplifies the BOM and frees a GPIO on the host controller.
Dual-supply rails — sizing the domains
The translator powers up from whichever rail rises first, and the output on the other side stays in high-impedance until its own supply is present. For a 1.8 V core logic to 3.3 V peripheral bridge, VCCA gets the 1.8 V rail and VCCB the 3.3 V rail. The 100 Mbps data rate is specified with a 15 pF load — enough margin for a short PCB trace to one or two loads, but you lose speed if the trace runs long or fans out to multiple receivers without buffering.
Package and footprint — 14-VQFN with exposed pad
The TXB0104RGYRG4 comes in a 14-VFQFN exposed-pad package, supplier device package 14-VQFN (3.5x3.5). Surface-mount assembly only.
Temperature grade — industrial, not extended
If your application sees sustained junction temperatures above 85°C — under-hood automotive, downhole, or near a hot power stage — this part is not the right choice; look at the TXB0104-Q1 variant or a translator with a 125°C rating.