TXS0108E: Ramifications of operating VCCA=3.3V and VCCB=1.8V

Part Number: TXS0108E

According to the datasheet, VCCA shall be <= VCCB. However, a recently designed board contains VCCA=3.3V and VCCB=1.8V.

Q1. What are the ramifications of connecting VCCA and the A side bus to 3.3V signals, while connecting VCCB and the B side bus to 1.8V signals?

Q2. Is there a chance that the B side will experience voltage levels higher than 1.8V?

Q3. Besides reducing the VCCA and A side bus signals from 3.3V to 1.8V or lower, what other temporary board mods can you recommend to test the functionality of the level translators under proper operating conditions given that the existing 1.8V signals are not 3.3V tolerant?

Regards

  • Hello,
    I have notified the appropriate applications engineer who will be back with you soon.


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  • In reply to Emrys Maier:

    Hello,

    While the datasheet does not explicitly state what will happen with the device if VCCA > VCCB, the device will not operate properly.
    The device will not be able to bidirectionally translate as it is supposed to.

    It is recommended to redesign in order to have this device work properly.
    I would not recommend any temporary solutions, a complete fix is required.

    Best,
    Michael

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