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OPA2810: Can I supply OPA2810 and OPA356 with asymmetric power rail?

DeWei Lan
Prodigy 250 points
Part Number: OPA2810
Other Parts Discussed in Thread: OPA356

I have OPA2810 and OPA356.

I'd like to configure OPA356 as I-V converter(Photodiode)

and OPA2810 as second non invert or invert amplifier(integrator, G=10)

AFAIK, some OP-AMPs supplied with  asymmetric power rail, then would get a bias =  (V+ - V-)/2 + v-

For instance,

I supplied some OP-AMP with +4.5V and -2.5V, and input is 0V, configure this OP-AMP as follower buffer.

I would get output bias: (4.5 - (-2.5))/2 + (-2.5V) = 3.5V + (-2.5V) = 1V

Has OPA2810 and OPA356 a problem?

  • +1
    TI__Intellectual 1470 points

    Hi DeWei,

    Both OPA2810 and OPA356 can operate just fine with asymmetric power rail. But make sure the total supply (V+ - V-) should be within the recommended operating voltage range. [For OPA356 it should be within 2.5V to 5.5V and for OPA2810 it should be within 4.57V to 27V]

    In your case if you power say suppose OPA2810 with +4.5V and -2.5V in voltage follower buffer configuration, and set input to 0V, the output will also be 0V only and not 1V.

    Regards

    Anant

  • +1
    Prodigy 250 points

    Hi :

    Got it, thanks!

    I read OPA356 datasheet which mentioned Supply voltage of Absolute Maximum Ratings is 7.5V.

    Although beyond the recommended operating conditions, they are still at absolute maximum ratings.

    Is also well  when I supply OPA356 with +4.5V ~ -2.5V?

  • 0 in reply to DeWei Lan
    TI__Prodigy 525 points

    Hi DeWei,

    It is recommended to use the OPA356 with a supply voltage between 2.5 V and 5.5 V. The proposed usage with a total 7 V supply is beyond the recommended supply voltage rating and extended usage of the device at 7 V may cause permanent damage due to stress on internal components, and hence should be avoided.

    If operation with >5.5 V supply is needed, an alternate option is the OPA814 with 250 MHz GBW which works from 6 V to 12.6 V supply and could be used as a TIA here.

    Regards,

    Bharat Agrawal