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TXB0108: VCCA=1.2V

Part Number: TXB0108
Other Parts Discussed in Thread: SN74AVC4T245, PCA9306, TCA9800, LSF0102, TXS0108E, LSF0108

Tool/software:

Dear TI support Team,

Can you guarantee operation at VCCA=1.2V  and to what degree of error(±%) is acceptable?

Best Regards,

ttd

  • Hi TTD,

    The device is rated to 1.2V minimum, and its operating ch. is specified per datasheet. If operating lower then this value, its performance will no longer abide by datasheet specs and the device is no longer guaranteed to be functional. 

    Can you provide more details on its use case? Is the auto-directionality required? There are other 8-ch translators such as the AXC8T245 that support lower then 1.2V that can also be used if signal drivers are push-pull based. 

    Regards,

    Jack

  • Hi Jack,

    Thank you for your response, I will consider using the SN74AVC4T245 with a slightly higher voltage on the IO pin for the current situation.


    Also, for TXB, I2C is bidirectional, so auto-directionality is required. If there is a level shifter for I2C that has more margin than TXB when using 1.2V with auto-directionality, could you please introduce it?

    Best Reagrds,

    ttd

  • I²C uses open-drain signals and does not work with a translator with push/pull outputs like the TXB or SN74xxxT. For I²C, you must use the PCA9306/LSF0102 or TCA9800.

  • PCA9306 is 1.2V(min), so it seems to be no margin.

    What's the difference between TXS0108E and LSF0108  or TCA9800 ?

    If thre is a pincompatible package with TXB0108PWR, it is the best for me.

  • Ths LSF is a passive switch and requires external pull-up resistors. The TXS has internal pull-up resistors and edge accelerators. The TCA980x is a buffer (and requires no pull-ups on the B side). Only the TXS is pin compatible (but it has different electrical characteristics).

  • Hi TTD,

    Please let us know if you have any additional questions.

    Thanks,

    Jack