Customer wants to double check if below 2 use case are ok?
1) VCC = 1.8V, Input = 3.3V
2) VCC = 3.3V, Input = 1.8V
Yes the two use cases you describe above are within normal operating conditions of the device. For use case 1 (VCC = 1.8V, Input = 3.3V) the customer can expect to see the 3.3V input down translated to 1.8V. For use case 2 (VCC = 3.3V, Input = 1.8V) the customer can expect to see the 1.8V input up translated to 3.3V. The features section of the datasheet highlights these use cases as shown below.
For more information on use case 1 where Vcc < Vin, see the FAQ Can the input voltage (Vi) to my logic device be higher than the supply voltage (Vcc)?
Use case 2 can also be confirmed by viewing the VIH for a 3.3V supply in the electrical characteristics table in the datasheet:
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs and
embedded processors, along with software, tools and the industry’s largest sales/support staff.