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SN74HC27: Input of overshoot and undershoot

ttd
Mastermind 8610 points
Part Number: SN74HC27

Dear Technical Support Team,

Is it possible to withstand overshoot and undershoot below?

These exceed absolute min and max(-0.5V and 7V), so I' d like to know reference value.

①overshoot ⇒　7.2V ( The time of exceeding over 7V is  about 0.5ns  )

②undershoot ⇒　-3.2V (The time of exceeding over -0.5 is about 2ns )

Best Regards,

ttd

  • 0
    TI__Guru* 97046 points
    Hi ttd,
    The device is not guaranteed to operate outside of the absolute maximum ratings. That being said, there is a caveat on the SN74HC27's datasheet (beneath the absolute maximum ratings table):

    "1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed."

    The input current rating is 20 mA. Note that there is no time limit here -- if you exceed 20mA, the device will likely be damaged, if not, the device will continue to operate normally.

    A series resistor can be used at the input to guarantee the current is limited to 20mA or less.