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LMV339: Tolerances on 5V supply

Antonio Faggio
Expert 7190 points
Part Number: LMV339

Hi All,

I have a question regarding  the power supply of the LMV339 comparator to be used on a new customer project.

The questions are:
• Is it good to power the LMV339 at + 5V?
• if so what margin do we have?
• why in the absolute maximum ratings Vcc max = 5.5V and in the recommended operating conditions Vcc max = 5.5V? Why do the two data coincide?


In summary, I would need a response for the correctness of powering the integrated at + 5V and understanding what the tolerances can be met on the value of the power supply.

Many Thanks,

Antonio

  • 0
    Guru 140200 points

    Ciao Antonio,

    +5V supply voltage for the LMV339 is ok. Most voltage regulators like LM7805, e.g., generate the +5V with a tolerance of less than +/-5% which results in a range between 4.75V...5.25V.

    I wouldn't choose a supply voltage for the LMV339 which is higher than 5.25V.

    Kai

  • 0 in reply to kai klaas69
    TI__Mastermind 24260 points

    Antonio

    I realize that it seems odd for abs max and recommended levels to be the same but this is not totally uncommon on some of the older products.  Looking at plots, the LMV339 will operate like a comparator up to 5.5V.  When TI specifies a recommended range, that means the device will behave as a comparator over that entire range.  There is even a bias current plot showing performance up to 5.5V.  I would expect quiescent current to rise in a linear fashion beyond 5V but the device is not expected to have any dramatic changes in performance in the 5V to 5.5V range.

    The parameters in the EC table are specified at specific voltages of 2.7V and 5V.  This means that we warrant these specs at these specific voltages.  However, it is not expected that performance changes dramatically when the supply voltage is not exactly these voltages.

    I hope this helps.  If needed, we can take this offline and discuss further.

    Chuck

  • 0 in reply to Chuck Sins
    TI__Expert 7190 points

    Hi Chuck, All,

    Thanks for reply.

    I understand that if I power it at 5V5 the performance does not change, but my doubt is the reliability of the component.

    Are we sure there is no drastic reduction in life time?

    The datasheet says:

    “(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.” (pag.4/40)

    Many Thanks,

     

    Antonio

  • 0 in reply to Antonio Faggio
    Guru 140200 points

    Hi Antonio,

    that's why I recommended a maximum supply voltage of 5.25V. This would give you a certain reserve against ripple, noise and transients appearing at the output of +5V regulator.

    Kai.

  • 0 in reply to kai klaas69
    TI__Mastermind 24260 points

    Antonio

    Kai's suggestion is valid in order to remain within the recommended voltage range of 5.5V.  Unfortunately this is an older device and there is not much information for me to share that goes beyond what is stated in the datasheet.  While it seems unusual to operate up to the abs max voltage value, this device is not expected to have any diminished long term performance if operated up to 5.5V.  I am going to reach out offline to discuss some new options to consider that are in development.

    Since there is nothing additional that can be shared in regard to this post, I will close it out.

    Chuck