Multi-part component simulation with LTSpice

What is the difference between the two opamps?

Do you see the power pins in the EAGLE schematic or are these hidden pins? Maybe that's the problem and you have to INVOKE the power gates into EAGLE schematic?....

Regards,

Richard

The two opamps are exactly the same. The power pins are only on the first part in the eagle schematic. I have tried to draw also power pins on the second opamp in the Eagle library editor, but these pins would be connected on the same power pads of the common package. Eagle does not allow this, since these package pads are already connected to the power pins from the first opamp (there would be more pins on the two opamps, than pads on the package).

What am I doing wrong?

Best regards,

Zoltan

Hi,

please use the INVOKE command in EAGLE and click onto the opamp with the missing pwr pins. Select the gate from the list and place it and connect the pins. Now it should work.

Regards,

Richard

Hi Richard,

thanks for the answer, but that does not help. First of all, I have no separete power gate in my component lib. If I would create one, it will be even worse, because Eagle would export it as a separate LTSpice component (.asy).

Please find my files attached.

adtest.lbr - the Eagle library containing the opamps (ADTEST).

ADTESTG$1.asy, ADTESTG$2.asy - the two LTSpice components generated by Eagle. If you compare the two files, you will see, that the G$2 does not have any connection the V+ and V-.

adtest2.asc - the LTSpice test schematic exported from Eagle. The output signal on both opamps should be the same, but it is not, because the second opamp has no power.

Could you please have a look at it?

Thanks,

Zoltan

Hi Zoltan,

the problem seems to be that LT Spice can't handle compnents that consist of more than one gate. So your opamp has to have both gates in one common symbol. If you 'ld change the library definition in EGALE it should work with LT Spice.

Regards,

Richard

Hi Richard,

I can change the library to contain only one gate, but then I also have to change the spice model description, to contain something like a "double opamp". I am not a spice expert, so could you please help with this change? Is it possible at all to have two opamps in one spice subcircuit?

Best regards,

Zoltan