LTSPice + OP90

[dpj]

Hi All,
Wanted to add OP90 Amplifier to LTSpice Simulation with the SPICE file at following location.

https://www.analog.com/en/all-opera...amplifiers-op-amps/op90/products/product.html

Can anyone help me to how can I do this?
I am using LTSpice Version 4.14Z

Regards

 

[Roff]

Hi All,
Wanted to add OP90 Amplifier to LTSpice Simulation with the SPICE file at following location.

https://www.analog.com/en/all-opera...amplifiers-op-amps/op90/products/product.html

Can anyone help me to how can I do this?
I am using LTSpice Version 4.14Z

Regards

Analog Devices has a spice model of OP-90. I downloaded it and tried it. It is so poorly behaved that I am not going to post it. Sorry.

 

[ronv]

Maybe Eric can help.
I don't see the null pins in the subcircuit file but get a pin mismatch error without it.

 

[Roff]

Maybe Eric can help.
I don't see the null pins in the subcircuit file but get a pin mismatch error without it.

I used a standard 5 pin op amp symbol, for that reason.

 

[ronv]

So what was wrong with it?

 

[Roff]

So what was wrong with it?

I set up a noninverting amplfier with ±15V supplies and symmetrical (±V) square wave inputs of various amplitudes. Depending on amplitude and gain, the output would sometimes "blow up" and soar exponentially to megavolts. Sometimes the output would set at ≈-19V, with tiny impulses on the output when the input transitioned.
I played with it some more just now. It works or blows up depending on input levels and. closed loop gain. In one case, it worked with ±200mV square wave in and Rf=500k, Rs=10k, but not with Rf=50k, Rs=1k.

Attached is a zip file that should allow you to see for yourself what I see. If you run it and get good results, or find out what I am doing wrong, or find a spice tweak that fixes it, let us know.

 

[ericgibbs]

hi,
The bandwidth of the OP90 is awful at only 20KHz, IMO its only use would be in DC amp applications.
OP, why did you choose this OPA.?

Tweaked the cshunt values a little, to make the sim run.

Any sine wave test frequency above 1KHz produces a triangular wave output.


E

 

[dpj]

Thanks for the work guys!!!
I think better to switch to SPICE with better component library!!!
Thanks a lot!!!