TINA/Spice/TL081: offset pins are missing

Part Number: TL081

Tool/software: TINA-TI or Spice Models


I've found a serious problem. I've tried to used the TL081 Amplifier with offset, but the Spice was not well definied.  Please catch these:

You can clearly see that Offset N1 and Offset N2 are valid on pin1 and on pin5.

Has anybody suggestion (or step-by-step tutorial) how to make it correctly work in the simulation?

Thank's in advance,

  • The TL082 (w/o offset pins) and TL081 seem to share the same model, also without the offset pins. This model was done back in 1989, so we no longer have records about why it was done that way.
    The most likely reason is that modeling the real TL081 offset behavior wouldn't have been practical since it would depend on variations within the manufacturing and assembly process.
    As a workaround, you could adjust the model's output offset with an external DC voltage source at the inverting or noninverting pins, but it probably won't have the same behavior as the real TL081.