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OPA2990: absolute maximum rating of the supply voltage

Part Number: OPA2990

I have a question about the absolute maximum rating of the supply voltage of the OPA2990IPWR.
It is stated that the minimum supply voltage is 0 [V] in the data sheet.
However, when I measured the voltage before the power was turned on or after the power was turned off (V + ≒ 0 [V] & V- ≒ 0 [V]), Vs = (V +)-(V-) =-6.8 [mV].
Ideally, both V + and V- are at the GND level, but it is presumed that this result is caused by external noise.
Is this usage OK? Or will this op amp break?

  • Hi Mr. Yamamoto,

    -6.8mV doesn't look dangerous, but you should check wether the supply voltage pin is becoming more negative than -6.8mV during power-up and power-down. This would be dangerous.

    Seeing a negative supply voltage is a bit weird and can mean that some current is drawn from the supply voltage even with zero supply voltage. This can be seen sometimes when a bipolar supply voltage is used and an OPAmp is supplied by both supply voltages and the supply voltages don't go down synchronously during power-down, for instance because from one of the supply voltages a larger current is drawn or because one of the circuits driving the supply voltage regulators is weaker than the other.

    A dummy resistor from the supply voltage to signal ground can help, unless the current is high.

    But in case I would recommend to add a Schottky diode latch-up protection to the supply voltage output. See my links given in this thread:


  • Hello Yamamoto-san, 

    I agree with Kai's comments but would also like to point out that going beyond the absolute max ratings of the device will damage the device in unpredictable ways. I recommend fixing your V- pin to be within the recommend operating range and replacing the potentially damaged device currently on your board. 

    All the best,