I would like to add an offset to a signal to send it on a differential ADC. But i want to be able to control the value of this offset with a PWM. My sensor has a bandwidth of [1-100Hz] and i only have a 0-5V supply.
It works well with offset of 2.5V / 2V / 1V but for 0.512V i have an offset of 4V instead at output. And i don't understand why.
The OP-Amp use is a TL072, maybe it's a limit of that Op-Amp?
If you guys have an idea about how i can fix that or which Op-Amp should i use or an another way to doing that i'll like to hear that !
Schematic V2 :