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TXB0102: Whether there is an internal pullup resistor

Rannie Zhou
Intellectual 2900 points
Part Number: TXB0102
Other Parts Discussed in Thread: TXU0102

Tool/software:

Hi team,

Could you please help to recommend a device without internal pull-up resistor?

Other requirements:

  • No requirement on data rate
  • the direction is from A->B (fixed or bi-directional), 1.8V->3.3V
  • 2 wires (GPIO)

I noticed the TXB0102 in our portfolio can met the requirement, could you please help to double confirm whether there is no internal pullup resistor?

BRs,

Rannie

  • 0
    Guru 298810 points

    The 4 kΩ resistor works as a pull-down or pull-up resistor, depending on the state of the pin on the other side.

    You want the TXU0102.

  • 0 in reply to Clemens Ladisch
    TI__Intellectual 2900 points

    Thanks for your reply.

    I'm curious why the 4kOhm is PL/PH resistor? My understanding is like below:

  • 0 in reply to Rannie Zhou
    Guru 298810 points

    You have marked the one-shot, which is activated only for a short time for signal edges.

    The buffer with the 4 kΩ series resistor is always active, on both sides. This is the output, but with a very low drive strength. The resistor allows an external device to override the voltage at the pin (this allows bidirectional signals).

  • 0 in reply to Clemens Ladisch
    TI__Mastermind 31126 points

    Hi Rannie,

    Clemens is correct here. The 4k series resistor is implemented here by design and is considered to be "weak" such that it allows for inputs at either A/B side to change direction. 

    TXU0x02 follows the requirements given so far as fixed direction translators for GPIO signals without internal pullup resistors. 

    Regards,

    Jack