Did anyone use "programmable" Difference Amplifier /op-Amp Subtractor IC ? (looks like PGA programmable gain amplifier)
There's no point in bumping a thread after less than six hours. You need to be more patient.
Are you talking about making a PGA, or buying a pre-made IC?
No, I haven't used a PGA before, but I did investigate using the PGA280, as part of a datalogger project, which didn't happen. The reason was because it works over a wide supply voltage range up to ±18V and the gain can be varied from
1⁄
8 to 128, allowing the voltage to scaled both up and down, to suit an ADC.
https://www.ti.com/lit/ds/symlink/pga280.pdf