ADG441 Input analog signal exceed Vdd~Vss


Hello ADI team.

My customer is considering to use ADG441 and trying to input analog voltage exceed the analog signal range. If it is not exceed ABSOLUTE MAXIMUM RATINGS, is ADG441 not broken? (Of course, it is disobey the datasheet specification, so it goes out of specification range.)

Is my recognition is true?

Warm Regards.

  • 0
    •  Analog Employees 
    on May 12, 2016 3:14 PM

    Hi Ishino,

    The ADG441 is only specified for signals from Vss to Vdd.  If the input signal goes below Vss or above Vdd you are in an over voltage situation and you will forward bias the internal ESD protection diodes and if the current gets high you will damage them.

    There are some things you can do to avoid damaging the part if the input signal goes outside Vss/Vdd.  Here is a link to a technical article showing what happens to a switch in an overvoltage situation (Figure 1) and what you can do (Figure 3) plus some fault protected switch alternatives (Table 1, 2). The ADG5412F would be a good replacement here that will turn off in over voltage situations.

    Here is another related technical article on the same topic.  See figure 8 and 9.

    Note the AMR rating says the input signal rating is Vss - 2V to Vdd + 2V or 30mA whichever comes first, this is a once off stress situation and is not a recommended use case.

    I hope this helps.

    Regards,

    Eric.