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I stumbled upon the most uncommon thing. An 8-PIN DIP IC with part number (OP277PA.)

However, the datasheet is nowhere to be found and I've done my research.

Is it possible that it is an OPA277P, or is it its own thing?

Does anybody have a clever way to test if it is a low noise precision opamp?

enter image description here

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    \$\begingroup\$ Do you have a good-quality picture of the IC to share? \$\endgroup\$ – Ron Beyer Sep 2 at 14:55
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    \$\begingroup\$ Does it have a Ti or Burr Brown logo? \$\endgroup\$ – Colin Sep 2 at 14:55
  • \$\begingroup\$ @Colin Yes it is Burr Brown.. \$\endgroup\$ – forthelulx Sep 2 at 15:03
  • \$\begingroup\$ @RonBeyer I just added one \$\endgroup\$ – forthelulx Sep 2 at 15:03
  • \$\begingroup\$ Why was this question flagged as "too broad"? If anything, it is too narrow, not too broad. \$\endgroup\$ – dim Sep 3 at 7:54
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The OP277PA is an earlier version of the OPA277 precision opamp (Datasheet)

If you scroll down to the orderable information you will find this the orderable part number for the device in a plastic DIP package.

The final A refers to the die revision.

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  • \$\begingroup\$ If you look at the picture attached in the question you'll see that the IC is OP277PA and not OPA277PA. and that is the question are they equivalent? not the OPA277 and OPA277PA. \$\endgroup\$ – forthelulx Sep 2 at 15:10
  • \$\begingroup\$ @forthelulx Answer updated. The OP277 is long obsolete and was replaced (pin for pin compatibility, better specs) by the OPA277 series. \$\endgroup\$ – Peter Smith Sep 2 at 15:16
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The answer is found in the OPA277 datasheet.

Op-amps, particularly older designs, often are available in different grades.

In the case of OPA277, the "A" grade device has slightly specifications:

enter image description here

There are additional relaxed specifications for input current, CMRR, etc.

So the basic chip here is the OPA277. The "P" suffix indicates the DIP package. And the "A" suffix indicates the relaxed specifications.

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  • \$\begingroup\$ Thanks for your answer, but my confusion is not the grade.. but rather the IC part number OPA or OP... \$\endgroup\$ – forthelulx Sep 2 at 15:07
  • \$\begingroup\$ @forthelulx, looks like you might be looking at a counterfeit part. The only reference I find to the OP277 online is a couple of Ali Baba sellers claiming to have it available. \$\endgroup\$ – The Photon Sep 2 at 15:14
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The OP277 was a part made by Burr-Brown. BB were bought by Texas Instruments and the original part was discontinued and replaced by the TI OPA277 (even though the datasheet only states "Replaces OP-07, OP-77, and OP-177")

All the letters after the numbers refer to package types and performance grades.

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