OPA820: Pspice model issue

Riccardo Villani

Part Number: OPA820
Other Parts Discussed in Thread: TINA-TI

Hi Team,

I downloaded the OPA820 spice model, in order to use it with LTSPICE.

Working within the datasheet conditions: GAIN=+2, Vout=2Vpp, Supply +/-5V, I have a distorted signal at 10MHz.

Do you know if the pspice model is correct?

Let me know if you want to take this offline.

Best Regards

Riccardo

over 5 years ago

0 Hasan Babiker31 over 5 years ago

TI__Genius 15565 points

Hello Riccardo,

Can you provide images of your circuit and the distorted output that you are reading?

Best,

Hasan Babiker

0 Riccardo Villani over 5 years ago in reply to Hasan Babiker31

TI__Intellectual 1185 points

The first image (no distortion) is @1MHz, while the second image (distortion) is @10MHz.

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Riccardo,

TINA-TI shows the same:

Seems to be related to a limited slew rate:

riccardo_opa820.TSC

Yes, the OPAmp seems to be slower in the simulation than specified in the datasheet.

Kai

0 Michael Steffes over 5 years ago in reply to kai klaas69

Guru 48395 points

Looks right Kai, the model does show about 100V/usec negative going slew rate - This old model by Rea Schmid might have been in error, but the online reference design shows the same thing,

I did use the OPA820 as a vehicle to show how to map LSBW to SR, I did not try the TINA model at that time so I missed this. the 2nd half of this article where I came up with a new mapping methodology for non - slew enhanced VFA like this one.

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OPA820: Pspice model issue