# LTspice Transient Simulation with external components

My problem is that I want to simulate a circuit with a transient analysis but as soon as I hit the simulate button, the simulation runs and runs and runs and won't terminate (although my stop-time is already at 0.1 s). Since I don't have much experience in SPICE, I think my problem lies in the embedding of external 2 op amps. Therefore I followed these steps (correct me, if I did something wrong here):

1. I searched for the .cir files of the mentioned op amps and saved the files in the same directory, my schematic is located.
2. I looked for the name after .SUBCKT in the .cir files and auto-generated a fitting symbol. After placing it in the circuit, I renamed the value and set the prefix to X.
3. I used .include <filename>.cir to include the .cir file

After that I built my circuit and hit the simulation button. Anyone knows where my problem might be?

edit: Here are my circuits. I embedded the two op amps (there isn't any mistake in the pin connection)

• Can you add a picture showing the circuit? – Warren Hill Aug 3 '16 at 13:11
• Depending on what you're simulating, 0.1s can be a long time. – W5VO Aug 3 '16 at 13:18
• I added two pictures. I hope they will help :) – Tobbe Aug 3 '16 at 14:15
• Are you sure you want to run your AD8221 without a power supply? – pipe Aug 3 '16 at 15:04
• I found my problem: It was the low performance of the main cpu... ~~ and I spent 2 hours on that problem – Tobbe Aug 3 '16 at 15:39