VCA810: Gain Accuracy

Morning Tadahiko-san

TINA models are typical performance, never worst case

Michael-san,

I think that above TINA-TI result is worse than specification.

What do you think?

Kuramochi

can you attach a TINA file, 

Please find "sbom869.tsc" from my 1st post.

Ok Tadahiko-san, 

It looks like the model is producing a gain of 0.79dB instead of 0dB at Vg = -1V midrange. So that is not the typical +/-0.4dB gain error in the data sheet, but within the worst case 25C of +/-2.2dB. I tested 0V and -2V and in each case just a little less than the +/-40dB gain expected - I think it is working, the absolute can acccuracy for this part is not that good - if you need better, look at the VCA821

Also you need to move the source to be in series with the 20ohm if you want bias current cancellation, 

VCA810 gain test.TSC

I mind not just accuracy but temperature gain drift.

The models generally do not model temp drift effects, this one might do something as it is transistor based, but it was likely not tested. 

Michael-san,

Thank you for your comment.

I wait TIer's response.

Best Regards,

Kuramochi

Could TI'ers respond anything?

Best Regards,

Kuramochi