Hello,
(1)
Could you please kindly let me know the optimization method of THD for OPA2209 ?
If there is any application note, please let me know.
(2)
Please see the attached file page 1 as the schematics.
In the schematics , Rf is fixed and Rs value change by SW for changing gain.
Could you please kindly let me know good value of Rf in the schematics?
Page 2, measument result of THD.
If Gain is 1, THD is better when Rf value is small.
If Gain is 11, THD is better when Rf value is large.
So, I can't understand how to select of Rf.
