FAQ: Logic and Voltage Translation > Auto-Bidirectional Level-Shifters >> Current FAQ
The most common reason is due to impedance mismatches.
TXB0304 specifies a stronger output impedance than TXB0104, as highlighted below:
This implies TXB0104's output impedance is matched closer to the typical 50 ohms transmission line.
When using TXB0304, appropriate impedance matching is recommended.
See [FAQ] Can I estimate appropriate dampening resistor value for level-shifter outputs?