• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 16 subscribers
  • Views 809 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.

SN74CBTLV3126: the logic 1.8v can be used with 3.3v VDD? should be no

Frank Xiao
Genius 12055 points
Part Number: SN74CBTLV3126
Other Parts Discussed in Thread: TMUX1511

hi team,

my customer wants to use the SN74CBTLV3126, but we need to check somethings below.

in my opinion, the logic 1.8v cannot be used with 3.3v VDD(for VIH of 3.3v is 2v), the picture from the datasheet may have some issues. Could you please help double check?

 

BTW: Whether the customer use A channel output as B channel input? in my opinion, it should be ok.

Thanks.

  • 0
    TI__Genius 9132 points

    Hi Frank,

    The SN74CBTLV3126 does not support 1.8V logic signals. The VIH varies with Vcc as shown in the datasheet.

    I would recommend using the TMUX1511 which is p2p compatible with the SN74CBTLV3126.  The key differences are the TMUX1511 supports 1.8V logic signals and it has a wider supply voltage range which gives designers more flexibility to use different power rails and on different projects.

    The TMUX1511 device is good for digital signaling applications like SPI or JTAG bus isolation.

    All our switches are bi-directional; the channel inputs of a switch or mux are interchangeable with the outputs

    Regards,

    Saminah

  • 0 in reply to Saminah C
    TI__Genius 12055 points

    hi Saminah,

    The TMUX1511  can be used with 3.3V VDD and 1.8v logic pin， correct? Thanks.

  • 0 in reply to Frank Xiao
    TI__Genius 9132 points

    Hi Frank,

    Yes, that is correct.

    The TMUX1511 has 1.8-V logic compatible control inputs. Regardless of the VDD voltage, the control input thresholds remain fixed, allowing a 1.8-V processor GPIO to control the TMUX1511 without the need for an external translator. 

    For more information on 1.8 V logic implementations refer to Simplifying Design with 1.8 V logic Muxes and Switches.

    Regards,

    Saminah