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ISO1211: isolated interface IC that can translate a digital signal from 12V to 5V

Part Number: ISO1211

Hi Team,

Our customer would like to use ISO1211 to translate a digital signal from 12V into a 5V (TTL) signal. The datasheet shows that INx and SENSEx pins can accept voltage from –60V to 60V. However, the datasheet also shows that the input voltage is between 24-60V. Our customer would like to know if the ISO1211 can accept 12V.

I have searched our isolated interface ICs and digital isolators but most devices can accept up to VCC+0.5V only. Can we use a voltage divider from 12V to 5V before connecting to INx and Sensex?



  • Hi Danilo:

    Thanks for posting your question on E2E and apologies for the confusion on the operational voltage range!

    ISO1211 is capable of operating down to 9VDC. You may use RTHR = 0 for the lowest threshold values. See below for the snippet from the datasheet page 12.

    Other input thresholds could be calculated using this spreadsheet.

    24V to 60V refers to the typical IEC 61131-2 supply voltage of 24V, not the minimum supply for the ISO1211. Negative voltage inputs are accepted with one of the circuit configurations shown in Figure 29 or Figure 30 of the datasheet. 

    Finally, you're correct - all of our digital isolators are 1.8V - 5V, so the correct device for your application is ISO1211.



  • Hi Dushmantha,

    Thank you very much for your clear explanation.