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Part Number: LM397 Other Parts Discussed in Thread: LM339
Hello team,
My customer uses our LM397, there is 29V of BAT_F, but sometimes the VS voltage change from 12V to 0, the voltage of pin4 is higher than pin5, it is risk? our part will be broken? thanks
The LM397 is the single version of the LM339/393 comparator series.
The LM339/393 series has the unique ability to tolerate input voltages above V+, even with no supply voltage. It does not contain the "upper" ESD diodes to clamp the inputs to V+.
The LM397 Abs Max ratings show a maximum input voltage of 30V, with no references to supply voltage -similar to the LM339/393. So even with V+ at 0V, the input can go up to 30V (from V-) without damage.
So most likely the LM397 is not damaged. Though we do not recommend doing this as part of normal operation. Current should be limited by a series resistor to 1mA or less, and an external clamp diode added between the inputs and V+.
