LSF0204: Problems with the communication 3,3V CMOS to 5V TTL

Hi A. Foster,

For a short answer, translating from 3.3V to 5V is no different than translating from 1.8V to 3.3V or 1V to 5V. The same principles apply, and the same considerations are required in each situation.

It will definitely help you to get a full understanding of how the LSF0204 works. We have a video series that makes quick work of this (total under 20 minutes) located here:  

We also have some application reports that go into detail on how to design with LSF translators.

• Biasing Requirements for TXS, TXB, and LSF Auto-Bidirectional Translators

• Voltage-Level Translation With the LSF Family (Rev. B)

Additionally, looking at the LSF's evaluation module could be helpful to answer some questions.

• LSF-EVM Hardware User's Guide