Customer:
I’m looking for a high speed logic level shifter for 3.3V-5V bidirectional UART. I found your 333017 and 333029 units and I was wondering what the differences between the two were in terms of performance. For either, I would also like to verify that I need to provide 3.3V to VCCL and 5V to VCCH, and TX and RX to A1, A2, B1, B2 for the unit to function.
Originally submitted via email support on 18 November 2024. Migrated to the forum for community visibility.
Soldered Support:
The TXB0104 is a dedicated IC which does the logic level shifting. If your VCCL and VCCH are 3.3V and 5V, that would be the maximum data rate which is 100Mbps, which will be plenty for your UART needs as it doesn’t reach those speeds. This breakout should work without problem in any UART implementation. Check the datasheet on page 8: https://www.ti.com/lit/gpn/txb0104
The other converter, which is made using N type MOSFETs (check the schematic), will work reliably for speeds under 1Mbps so for most UART needs it should work perfectly fine. It is also bidirectional and has been used in the office for UART implementation.
Both will be good for your project, regarding UART speed and voltage levels.