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Photodiode design wizard: issues with op amp models

Question asked by imolina on Jul 3, 2016
Latest reply on Jul 7, 2016 by imolina

Hi,

 

I've being playing around with the photo-diode design wizard. I had to produce a commercial TIA-based design for which I tried several op amps: ADA4899-1, ADA4817, AD8045 and ADA4857.

The problem was that once I submitted the design results achieved by the design wizard to my e-mail and tried to reproduce the results obtained within the wizard, I never succeeded to get the same response from the PSPICE simulations.

It is clear that the op amp models embedded within the wizard are different from the ones submitted and from those you can download from the AD website.

I could see over the posts of the designers that for instance the ADA4899-1 provided erroneous noise values. I downloaded all updated models I came across over this forum, but the models are some times better (for the ADA4899-1) but really bad in other cases and anyway still not matching with what the wizard provides.

 

Please, could you provide coherent models for the devices mentioned above?. Of course first, I would need to know whether the models utilized by the wizard are correct or not. Second, I would need please to have reliable models for those devices, otherwise I will have to discard the AD op amps for my implementation, since I am loosing so much time now.

It is very disappointing that there are such discrepancies among the models.

 

Any hint?

 

Thanks in advance,

 

Best regards,

 

Ignacio

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