Hello, I downloaded the AD620 spice model and am trying to simulate something in LTspice just to make shure everything is ok, but I’m noticing some strange things.

The first is that when I measure the output when I my input singal is DC 9.99mV signal, I get some noise, although the amplitude of this noise is almost negligible. I'm not sure if this is normal. I did the same with the LT1167, and it didn’t show the noise.

Also, when I apply a sinusoidal signal, for example, 9.99 mV amplitude at 1 kHz, it seems to work fine, but if I increase the amplitude to 60 mV, the behavior becomes somewhat buggy. Can someone explain why this happens?

 

Hi Spo,
Try it with these test additions.
E

 

Hi Spo,
Try it with these test additions.

With the RG resistor connected, the circuit doesn't work, but once I disconnect it, the simulation appears to progress normally.




[UPDATE] Never mind, I just switched from NORMAL to ALTERNATE, and now it works.

 

Hi S,
Place this .cir file in the same folder as your asc file

Remove the .txt extension from the name, it was added so that I could upload the file.
E