• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 20 subscribers
  • Views 355 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.

SN74LVC8T245 output capacitance

Madhuri Akkenepalli
Expert 1215 points
Other Parts Discussed in Thread: SN74LVC8T245, SN74LVC541A, SN74AVC8T245

There is an issue of data corruption in a project that my customer is working on, and a question came up as to whether the SN74LVC8T245 has too much capacitive loading (please see the attached drawing). 

I would like to understand the reason for the small output capacitive load (CL = 15pF) in the datasheet, and the implications on the rise and fall times, as well as potentially degraded signal quality that may result from the amount of capacitance at the output of the device in the application. 

Specifically the question is whether there is sufficient capacitive loading as indicated in the drawing to warrant concerns of data integrity between the SN74LVC8T245, and the SN74LVC541A.

Please check the attached drawing.

Thank you for your help.

5353.Visio-Ribbon Cable Signals Load.pdf

  • 0
    TI__Expert 6430 points

    Hi, Madhuri

    The SN74AVC8T245 switching characteristic parameters are measured at 15pF capacitor load. So in the measure circuit, the 15pF cap load is given (on the page 8 in SN74AVC8T245 datasheet).  For SN74AVC8T245, its output current can be up to 32mA (on the page 4 in SN74AVC8T245 datasheet). I am not clear whether the 32mA output current is enough in your application.

    For SN74LVS541A, the comments are as same as SN74AVC8T245’s.

    I hope it pass some helpful information to you.

    Thanks