• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 20 subscribers
  • Views 868 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.

TXB0104-Q1: TXB0104-Q1 P2P but single direction part

Red Yen
Expert 4360 points
Part Number: TXB0104-Q1
Other Parts Discussed in Thread: TXS0104E-Q1, SN74LVC2T45-Q1

Hi Support team 

We have some question about the level shift IC(TXB0104-Q1).

 

The RS232 signal is workable on PCB board (Fig.1 & Fig.2).
But after we plug in RJ45 connector (no deviced connected),
there're lots of high frequency noises occur on RS232 signal (Fig.3 & Fig.4 & Fig.5)  .

We tried some trouble shooting then found out RS232 signal back to workable after bypass level shift IC.
Since this level shift IC is bidirection type so the inteference may come from output terminal, we would like to found single direction level shift IC to instead.
Do you have any suggestion about the pin to pin level shift IC with single direction?

 

  • 0
    Guru 316690 points
    The capcitances of the connector and the wire are obviously too large for the TXB.

    In the TSSOP package, the TXS0104E-Q1 has the same pinout. The TXS might work with a larger capacitive load, but only at low speeds.

    There is no other P2P device, especially not with these alternating TXD/RXD lines. You'd have to redesign the board to use something like 2× SN74LVC2T45-Q1, or build an adapter board.
  • 0 in reply to Clemens Ladisch
    TI__Guru 62050 points
    Thanks Clemens for your support.
    Red,
    Please consider using 2 of SN74LVC2T45-Q1 for each of RX and TX lines respectively.