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TLV9030: Input pins (IN+, IN–) goes outside abs max but small current is it safe?

Arturo Bayangos
Prodigy 20 points
Part Number: TLV9030


Tool/software:

Hi,

For our application, the (IN-) goes to about -700mV to -800mV. However due to our circuit configuration, the current though the (IN-) should be less than 10mA.

So is it ok that we are exceeding -300mV as per abs max if the current though (IN-) is limited below 10mA?

Thanks,

Arturo

  • +1
    Guru 317550 points

    Yes, this will not damage the device.

    (When an input voltage is outside the recommended input voltage range, correct operation is not guaranteed.)

  • +1
    TI__Guru 61536 points

    Hi Arturo,

    While it may not cause damage, there is the possibility of a false output if you go that low.

    As TI, we cannot condone violating the -0.3v specification  - so I cannot say -0.8V is okay. And I am not comfortable with -0.8V, as you are getting into reversal territory.

    Proper operation is only warrantied to -0.2V.

    This is a confusing spec as violating either 10mA or -0.3V violates the Abs max...so technically you cannot violate the 10mA without first violating the -0.3V limit. To get to 10mA, you need to be at almost -850mV.

    TI recommends using external clamping or attenuating to not violate the -0.3V, and limiting the current to less than 1mA.

  • 0 in reply to Paul Grohe
    Prodigy 20 points

    Hi everyone,

    Thanks for the fast response!

    I will take your comment into consideration. Thanks very much!

  • 0 in reply to Paul Grohe
    Prodigy 20 points

    Hi Paul,

    Just to confirm my understanding:

    If the IN- absolute limit is violated (e.g., goes below -0.3V) but the current is limited (say less than to 1mA), the device won’t be damaged. However, correct operation is not guaranteed — for example, the output may go high when it should be low, and vice versa. Is that accurate?

    Also, if the IN- voltage exceeds the absolute limit for part of the signal (e.g., half a period), but then returns to the recommended operating range for the remainder, would we expect normal operation during the time it's within spec, despite the earlier violation?

    I say this because we don't care about correct output during the time when the IN- abs max is being violated (exceeding -0.3V).

    Thanks,
    Arturo

  • 0 in reply to Arturo Bayangos
    TI__Guru 61536 points

    Hello Arturo,

    Arturo Bayangos said:
    If the IN- absolute limit is violated (e.g., goes below -0.3V) but the current is limited (say less than to 1mA), the device won’t be damaged. However, correct operation is not guaranteed — for example, the output may go high when it should be low, and vice versa. Is that accurate?

    Correct. It will not be damaged but we cannot guarantee the output will be correct when below -0.3V.

    Arturo Bayangos said:
    Also, if the IN- voltage exceeds the absolute limit for part of the signal (e.g., half a period), but then returns to the recommended operating range for the remainder, would we expect normal operation during the time it's within spec, despite the earlier violation?

    Correct. Worst case there may be a small "recovery time" when coming back into the operating range, slightly increasing the prop delay by a few dozen ns.

    Arturo Bayangos said:
    I say this because we don't care about correct output during the time when the IN- abs max is being violated (exceeding -0.3V).

    TI cannot say it is okay to exceed -0.3V, so you will have to assume the slight design risk.