• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 20 subscribers
  • Views 431 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TXB0102 Pull up resistor on input

Adam Torma
Mastermind 45595 points


There are warnings about using pull-up or pull-down resistors on this part, but we are not using its auto-directional capabilities. All of the pull-up or pull-down resistors connected to it are on what our design considers the input side. Since I don’t know how the auto-direction function works I’m wondering how this part will behave with pull up or pull-down resistors on the “input” side. Is my only concern to satisfy the 2mA drive current required stated in the data sheet?

Thanks,

Adam

  • 0
    TI__Expert 4705 points

    Hi, Adam

    yes, the minimum pullup or pull down resistor requirement is based on the bi-directional signal translation, and mainly for the output voltage level concern.

    if you use it as the fix direction one is input, and the other site is output. in this way, puting smaller pull up or pull down resistor at the input side is OK.

    except the current drive capability, the other concern is if you want to have the default high or low when no input or power ramp up by adding the pullup or pull down resistor. better to choose smaller resistor value to get it. better to be less than 10K.

    I am just curious about your design, since it is not auto-directional requriement, why don't you chose the SN74AVC2T(2)45 or SN74LVC2T(2)45, they don't have the current driver capability requirement, and no limitation for the pullup or pull down resistor. just a recommedation.

     

    BR
    Junjie