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I measured the turn-on and turn-off behavior of an LM741 and found a weird phenomenon I cannot explain myself. I built an inverting amplifier with an amplification of 10.

Why is there such a weird kink just before the output crosses 0V? CH2: output; CH1: input (CH2: output; CH1: input) CH2: output; CH1: input (CH2: output; CH1: input)

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  • \$\begingroup\$ Welcome to EE.SE. A schematic would be very helpful. The 741 was on the market in the 1980's and has poor performance compared to what we have today. \$\endgroup\$
    – user105652
    Apr 22, 2018 at 2:46
  • \$\begingroup\$ pdf1.alldatasheet.com/datasheet-pdf/view/53589/FAIRCHILD/… That's the datasheet I used. It also includes the internal schematics.My circuit itself is a simple inverted amplifier with 560 Ohms and 5.6 kilo Ohms. \$\endgroup\$
    – Xenox
    Apr 22, 2018 at 2:51
  • \$\begingroup\$ Does this help youtube.com/watch?v=VgodYtiD_F0 ? \$\endgroup\$ Apr 22, 2018 at 3:08
  • \$\begingroup\$ @Sredni Vashtar That's exactly what I was looking for! Didn't know this is called "crossover distortion" so I couldn't find anything useful. Thanks a lot! \$\endgroup\$
    – Xenox
    Apr 22, 2018 at 3:22
  • \$\begingroup\$ Just look at the graphs in the data sheet. \$\endgroup\$
    – Andy aka
    Apr 22, 2018 at 8:14

1 Answer 1

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You are observing the slew-rate limited output of the amplifier to a step input (~0.5V/us output slew).

You shouldn't expect it to behave linearly under those conditions.

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