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OPA1662 Output behavior at Power off

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Genius 4260 points

Other Parts Discussed in Thread: OPA1662

Hi,

I got some question from my customer about the OPA1662 output behavior when

both power rail voltage reached about +/-1V.

(Please see the attached waveform.)

What is the primary cause of this phenomenon?

and how can we prevent this?

Thanks

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  • 0
    TI__Guru 74831 points

    Go,

    The primary reason for the OPA1662 output behavior as shown below is the violation of the minimum supply voltage.

    The minimum datasheet (PDS) specified supply voltage for OPA1662 is +/-1.5V (or +3V on single supply) and thus lowering the supply rails to +/-1V (or +2V single supply) does NOT allow enough voltage headroom for proper biasing of the internal circuitry (transistors are turn-off or operate in a non-linear region) resulting in random states of internal nodes and subsequent unpredictability of the output voltage.

    The only way to prevent this from happening is to apply the minimum +/-1.5V supply voltage specified in PDS.