Other Parts Discussed in Thread: TINA-TI
Hello ,
I am designing A DAC analog stage using the OPA1602. The IV stage was changed so from my DAC I get a 2.0Vrms. Of course on summing I want to have the same 2.0Vrms output single ended.
Referring to fig 37 from datasheet , I understand that to have unity gain I have to change the R330 to 680. Of course the capacitor C2700pf will change (decrease) and keep the same cutoff frequency
What I don't understand is the R 620 function (see below one function) and how to calculate in function of my feedback capacitor.
One more doubt , you have a 8200pF capacitor across the phases , thats usually for differential noise reduction . Would 2 capacitors in series (mid point going to ground) not be better ? It will take care of both CM and DM noise,, I also understand that last R (620 in your case) is to decouple opamp inputs from that cap.. Still I think that 620R can be lowered to around 100R but I dont know if you have a specific formula to calculate it
