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Original question:

TXS0108E: TXS0108E

TXS0108E: TXS0108E

Lev Gelerman
Prodigy 20 points
Part Number: TXS0108E
Other Parts Discussed in Thread: TXU0304, TCA9800, LSF0102, TXS0102, SN74LXC8T245, SN74AXC4T774

Hi,

According to our measurements the B port rise up when voltage on VCCB is turn on.

The OE in this case connected to GND.

According to datasheet, when OE input is low, all aoutputs should be placed in high impedance state.

  • 0
    TI__Mastermind 19961 points

    Hey Lev,

    I am seeing yellow waveform as B port and the green as the VCCB power supply- please correct me if I am wrong. What is the status of A port and VCCA power supply at this time? Is OE pin held low and measured 0V throughout entire duration of test? 

    Note that the TXS0108E does not have IOFF feature-if any power supplies are powered down and at 0V, the I/Os will not be guaranteed to go into a high-impedance state. 

    Regards,

    Jack 

  • 0 in reply to Jack Guan
    Prodigy 20 points

    Hi Jack,

    Regard to wavefortms you are understood right.

    We are using the translator as buffer, i.e. from same voltage on both sides (VCCA and VCCB).

    On A side when OE pin held low, the voltage is 0V.

    Attched pictures of schematics.

    Thanks,

    Lev

  • 0 in reply to Lev Gelerman
    TI__Mastermind 19961 points

    Hey Lev,

    The TXS0108E will not be able to buffer your GPIO signals. I would suggest taking a look at the AXC8T245/LXC8T245 that are direction controlled translators instead that will provide ~10mA of drive strength @1.8V. These translators also support IOFF feature, in which the I/Os will not be able to influence one another when either power supplies are powered off and at 0V. 

    Regards,

    Jack 

  • 0 in reply to Jack Guan
    Prodigy 20 points

    Hi,

    In some cases we are using translators for synchronous interfaces like SPI/I2C and also we need translator for GPIO that IO is configurable for (IN/OUT).

    Could you please recommend us device for this usage.

    Thanks,

    Lev

  • 0 in reply to Lev Gelerman
    Guru 256820 points

    For SPI, use the TXU0304.
    For I²C, use the TXS0102 or LSF0102 or TCA9800.
    For GPIOs with changing directions, use direction-controlled translators like the SN74LXC8T245 or SN74AXC4T774 (there are others with different numbers of channels).

  • 0 in reply to Clemens Ladisch
    TI__Mastermind 19961 points

    Hi Lev,

    In addition to Clemens' recommendations, please visit this reference page for further suggestions based on the interface of your signals.

    Regards,

    Jack