(VCA - VGA) Design of an amplifier controlled by a ramp
For those who are interrested by the answer. I used a multiplier as a VGA. In order to create this function I used :


2x Log amplifier
1x sum amplifier
1x Exp amplifier


If I want multiply a signal V1 with a signal V2 =>

exp(log(V1)+log(V2)) = V1 * V2

The following figure is the result :