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SN55LVCP22A-SP: Max Quiescent Current Draw

Rick Brown
Prodigy 30 points
Part Number: SN55LVCP22A-SP

Tool/software:

Hi,

Per Figure 6-2, for 25C, the supply current as a function of frequency is relatively flat, sitting around 60mA.
Per datasheet section 6.5, the quiescent current is 60mA (TYP) and 87 mA (MAX).  Typical values are noted at 25C and 3.3V.

1) What are the conditions for the stated MAX current draw?  Is is safe to assume this is a function of temperature?  (i.e. is MAX for 125C?)
2) Assuming that is temperature related, do you have any data for supply current vs temperature?  Is it linear with increasing temperature?

Thank you

  • 0
    TI__Genius 9616 points

    Hi Rick, 

    The min and max values on the Electrical Characteristics are over recommend operating conditions (section 6.3) as stated at the header of the table. That includes the temperature range of -55 to +125C. We unfortunately don't have a typical curve for supply current vs temperature. However, supply current will increase with temperature, so you can use the max current value (which is spec'd with margin) as the upper bound for your design. 

    Regards,

    Matt 

  • 0 in reply to Matt Smith
    Prodigy 30 points

    Matt,

    Thank you for the reply.

    For additional background, we are using the datasheet parameters for parts stress analysis.  As you indicated, we did start with the datasheet max current as the upper bound, however, after derating, we are exceeding our stress limit for power dissipation.

    Thermally, we are not operating our design at the 125C upper bound so we were assuming a lower supply current draw below the datasheet max would be reasonable.  For instance, could we assume a linear relationship and interpolate supply current for our assumed operating limit?  Would TI discourage that approach and/or can you offer any guidance?

    Thank you. 

  • 0 in reply to Rick Brown
    TI__Genius 9616 points

    Rick,

    You're welcome. The linear interpolation you mentioned is generally a decent rule of thumb, however, not always guaranteed. Some devices will have more of a logarithmic or exponential curve depending on their architecture. 

    Did I understand you correctly that you are operating our device below 125C ambient and you are seeing the supply current exceed 87 mA? What temperature are you operating at if not 125C? Any test conditions you can share will be helpful here. 

    Regards,

    Matt