OPA391: Direct Replacement

Aaron Bosscher

Part Number: OPA391

Tool/software:

Hi all,

I am working on a design that I've recently added a negative supply rail to the OPA391 (now operating at +/- 3V instead of 3V). The OPA391 datasheet states the maximum operating voltage at 6V and suggested as 5.5V. What I have been looking for is a direct replacement to the OPA391DCKT with a larger supply voltage range.

I am open to moving away from the OPA series, but I need an ultra-high precision op-amp that will not distort my signal which ranges from (10mVpp - 3Vpp).

Thanks!

5 months ago

+1 Clemens Ladisch 5 months ago

Guru 288050 points

No, the maximum operating voltage is not 6 V. Footnote 1 in section 5.1 says:

Absolute Maximum Ratings do not imply functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions. If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not be fully functional.

Here is a search for opamps that support at least 12 V and have an offset error of at most 10 µV: ti.com/amplifier-circuit/op-amps/precision/products.html#480=1&1261max=12;180&2max=0.002;0.01 But there is no high-voltage opamp in the SC70 package.

+1 Art Kay 5 months ago

TI__Mastermind 22797 points

Aaron,

I agree with Clemens. You always want to keep your supply voltage within the recommended operating range. That is where the specification table is valid. I also agree with his parametric search link. Thanks Clemens!

Best regards, Art

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OPA391: Direct Replacement