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I have acquired some mcp-6002 op-amps in a SOIC package instead of the DIP I normally use. I have solder these to a SOIC to DIP "converter" so to fit on the breadboard. If I connect them as I do with the DIP (as simple buffers for testing) they don't seem to work, I tested 4 of these and all of them behave similarly, the upper part of the wave is non-existent and I get a small part from the bottom of the signal. Now I tried to put a voltage divider with half-the supply (because they are single supply) feeding the inverting input and the wave appears but the upper part of the signal is kind of low-pass filtered. So the question is, have I damaged these during soldering to the convertors or they behave differently?

enter image description here

correction: "applied"

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  • \$\begingroup\$ Have you tried rotating the adapter board? maybe you soldered the ic on the wrong way. \$\endgroup\$
    – Linkyyy
    Jan 11, 2019 at 12:06
  • \$\begingroup\$ @ Linkyyy Yes I tested the connections several times. They should be identical isn't this right? \$\endgroup\$
    – John Am
    Jan 11, 2019 at 12:07
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    \$\begingroup\$ If the part number is the same, then they should work the same, regardless of package (ignoring minor things like tiny differences in inductance and capacitance that shouldn't be a problem in what you are doing.) The pinout is often the same on DIP and SOIC, but not always. The datasheet for the MCP6002 says DIP and SOIC have the same pinout. \$\endgroup\$
    – JRE
    Jan 11, 2019 at 12:16
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    \$\begingroup\$ @ SamGibson ebay, china. Yes perhaps there is also the possibility to be bad IC's. It has never occured to me again, though. \$\endgroup\$
    – John Am
    Jan 11, 2019 at 12:27
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    \$\begingroup\$ @JohnAm - Agreed, that seems a likely conclusion. However if they are not the marked part number, then they could be almost anything else :-( Unless you de-encapsulate the die and hope to spot something on it (under the microscope) that leads you to a specific part number, then I don't know how you could get confident about what you really have :-( Even if you do find a part number on the die, those devices you have could be rejects of that part number, and so not meet the datasheet specifications. In short, as far as I can see, all bets are off :-( \$\endgroup\$
    – SamGibson ♦
    Jan 11, 2019 at 12:46

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Unfortunately this won't be the first time of ICs marked X not behaving as component X should do, having come from Ebay / AliExpress etc.

Since you have some known-good DIP versions of this device, and (excluding gross soldering mistakes) the SOIC version of this device should behave the same, I would be concerned that you don't have genuine, working ICs of the marked part number. We had another example of this situation with EEPROMs sold through AliExpress, in a question a few days ago. Sorry...

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