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SN74CB3Q16811: SN74CB3Q16811DGVR Minimum supply voltage

Part Number: SN74CB3Q16811

Can SN74CB3Q16811DGVR be powered from single supply of 1.8V? I would like to use this device for 24-bit databus operating at 1.8V signal level. The databus clock is 180MHz. Is this device is a right choice? could you recommend appropriate device?

  • Hi Sam,

    The SN74CB3Q16811 supports a recommended operating supply from 2.3V to 3.6V, this is shown in the datasheet under the recommended operating conditions table.

    If you would like to use this device you would need to power it from higher than 1.8V supply. However, you can power the device with 3.3V supply and still pass 1.8V signals.

    You can also use the TI selection table and filter by minimum supply voltage, there is a newer part in the TMUX1511 than can operate at 1.8V on the supply. This is a 4channel device so you would need to use six of them for your 24bit databus.

    Regards,

    Dakotah

  • In reply to Dakotah:

    Hi Dakotah,
    Thank you.

    Just one thing to clarify with you. If SN74CB3Q16811 is power from 3.3V, only control signals have to be 3.3V to meet VIH and VIL threshold specifications, but not switch signals, am I correct? and 180MHz signal would not be a problem I guess, ?

    Regards,
    Sam
  • In reply to Sam Sangani:

    Hi Sam,

    If you power the device off of 3.3V, you input and output signals can range from 0V to 5V. Your control signals would have to operate between the levels specified in the recommended operating conditions image above. With a 3.3V supply your VIH would have to be between 2V to 5.5V. If you operate between 2.3V to 2.7V on the supply the VIH can operate down to 1.7V.

    Regarding the 180MHz signal - the bandwidth of the device is not specifically called out in the datasheet. However, the device does have low Rona and low capacitance, and it mentions high bandwidth on the first page of the datasheet. You can refer to this App Note  which shows a bandwidth plot of other CB3Q devices.

    Regards,

    Dakotah

  • In reply to Dakotah:

    Dakotah,

    Thank you. It seems like I can use SN74CB3Q16811 in my application. I will still confirm with you by sending signal block diagram to you just for final go.

    Regards,
    Sam
  • In reply to Sam Sangani:

    SN74CB3Q16811_questions.pptxDakotah,

    Please find top level block of my application for your final review.

    Regards,

    Sam

  • In reply to Sam Sangani:

    Hi Sam,

    The voltages in your diagram fall within the recommended operating conditions so you can use the specs in the datasheet for performance.

    Regarding the BIASV level, you can set that to the voltage equal to the receiver input threshold to reduce and glitches if your are planning to use the device in live-insertion applications.

    Regards,

    Dakotah