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ADS114S08: Absolute Maximum Rating

Lillian Liu(SH)
Expert 4620 points

Part Number: ADS114S08

Hi team,

I would like to consult the Absolute Maximum Ratings section of the ADS114S08IPBSR manual about the impact on the device if the input signal exceeds the marked value. Difference evaluation of signals of different amplitudes and durations outside the Absolute Maximum Ratings.
For example, the signal rail of ADS114S08 adopts ±2.5V power supply. In theory, the signal cannot be greater than ±2.8V. If the overvoltage signal input with ±5V lasting 1ns and lasting 1ms will cause damage to the device, is there any way to evaluate the difference? 
Thanks
Lillian
  • 0
    TI__Guru** 113765 points

    Hi Lillian,

    Customers like to ask this question a lot in terms of how close to the danger point can you get without damage.  I like to think of this question in a similar situation by lighting a candle and asking how close to the flame can I move my hand and how long can can I hold it there without getting burned.  The obvious answer is to say "don't hold your hand over the flame and you won't get burned".  For the IC, don't exceed the absolute maximum ratings and you won't damage the part.

    But there is a difference in the ideal situation and the real world system.  There are often transients that can exceed the ideal input voltages.  The short answer to your question is any excursion of the absolute maximum ratings can damage the device.  Some of the damage may not become evident for a long time and sometimes it becomes evident right away.

    For the analog inputs, there are two ratings.  One is a voltage rating and the other is the current rating.  The voltage rating relates to the supply and this rating is the point in which current will begin to conduct through the ESD structure.  If this happens, then to prevent catastrophic damage you need to limit the current to a maximum of 10mA.

    In many cases the current can be limited by using the input filter resistance.  So the voltage drop across the filter resistor must limit the current to the point where the current through the device pin is 10mA or less.

    Even by limiting the current does not mean that the device will work normally as you are forcing current into the device outside the designed operating parameters of the device.  In other words, there are diodes internal to the device that may conduct other than the ESD protection that may cause error within the device.

    Best regards,

    Bob  B