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SN74LVC1G123 Pulse Time Tolerances

Simon Calcutt
Prodigy 20 points
Other Parts Discussed in Thread: SN74LVC1G123

I am working on a high volume design where I am using an SN74LVC1G123 and I am trying to check the tolerance on the monostable output pulse duration. I can easily determine the tolerance in output pulse duration due to the resistors and capacitors but I cannot find enough data in the datasheet or application notes to define the tolerance due to temperature variation and manufacturing tolerances in the monostable IC. Have I missed the data somewhere or is this data that you would be able to provide?

Thank you for your help.

Kind Regards,

Simon

  • 0
    TI__Intellectual 2050 points
    Hi Simon,

    Thank you for posting on E2E! I hope to help answer your question.

    You mentioned that you looked through application notes. Did you get a chance to look at the 'Designing with the SN74LVC1G123 Monostable Multivibrator' app note?

    URL here: www.ti.com/.../slva720.pdf

    I want to point you to section 4.1.1.1 Temperature Stability, starting on page 4. The section shows plots for pulse width over a large temperature range. Does this help?

    In the meantime I will continue to look into manufacturing tolerances for you.

    Couple questions:

    What temperature ranges are you designing for?
    What tolerance range are you aiming for?

    Regards,
    Joe
  • 0
    TI__Guru 56220 points
    Simon ,
    Please refer to the app note on LVC1G123 .www.ti.com/.../slva720.pdf
    which talks about temperature stability of the device in page 5.
    The datasheet have the switching char across -40 to 85c/125C on the output pulse width .
  • 0 in reply to ShreyasRao
    Prodigy 20 points

    Joe and Shreyas,

    Thank you for your replies. I am designing for an operating temperature range of +5oC to +42oC so the app note is useful in terms of understanding but it does not provide a data for the whole temperature range that I am designing to. I do not have tight timing tolerances requirements (+/-30% would be acceptable) but I need to check the tolerances so I can be confident that the timing operating will be robust in high volume manufacture.

    The datasheet values on the switching characteristics are useful but they only provide a maximum. I am looking for a minimum and maximum tolerance on the width of the timing pulse.

    The data I can find is also only for a limited set of R and C values. In my design I am using Rext=390k, Cext=0.1uF so I am looking for data that I can read across to these values.

    Kind Regards,

    Simon

  • 0 in reply to Simon Calcutt
    TI__Guru 56220 points
    You could refer to the logic faq on temp stability for sn74lvc1G123.

    The part has approx. <10% variation and typically <3% on pulse width, not including the passives :

    e2e.ti.com/.../3209.how-stable-is-the-output-pulse-length-over-temperature-changes