• Resolved

TRS3253E: VL voltage level

Part Number: TRS3253E

Hi,

How should we decide the votlage level for VL?

Currently we need ROUT and DIN to be 1,8V, should we provide 1.8V to VL?

Will RIN and DOUT be 1.8V as well?

THanks!

Antony

  • Hi Antony,

    Yes, the VL pin is used to set the logic voltage levels for the ROUT and DIN. If you want these to use 1.8-V levels, you should set VL to 1.8 V.

    Regards,
    Max
  • In reply to Max Robertson:

    Hi Max,

    In addition to the questions above, customer want to support 3.3V @ RIN and DOUT, can we support such level.  How should we supply V+/V-/Vcc/VL?  Can we just put 0.1uF for C1/C2/C3/C4?

    Thanks!

    Antony

  • In reply to Antony Lin:

    Hi Antony,

    Just to confirm - do you want to support +/- 3.3-V signaling or 0-V-to-3.3-V signaling on the RS-232 lines? Neither of these would be typical for RS-232 - do you know why the customer wants this?

    Regards,
    Max
  • In reply to Max Robertson:

    Hi Max,

    It's 0V to 3.3V only.  Their customer just told them they need to support such voltage level and didn't reveal further information, so we don't have the reason yet.  Can we support this?

    Antony

  • In reply to Antony Lin:

    Hi Antony,

    It sounds like you need a level shifter, not an RS-232 transceiver. Those devices are used to translate between single-ended logic signals at different voltage levels (1.8 V, 3.3 V, 5 V, etc.). If you make a post on this forum, they should be able to help you look for a device that is suitable for this application:

    e2e.ti.com/.../

    If I missed something and an RS-232 transceiver is needed for some reason, though, please let me know.

    Max