OK first a failure at Digikey. I went searching for difference amps, but they are listed in many different places. (So it's hard to look at them all at once. (See table 5.7 pg 353 in AoE3)) Most are listed as Differential amps w/o differential outputs. But the LT1191 is under programmable gain, and INA134 is under linear-amps-audio. (A section I'm going to have to troll a bit more... lotsa potential power op-amps, that I don't know about.)
Anyway, I need a few difference amps. The ina132 is a reasonable example,
I've been using an instrument amp, but it's overkill. I've never used a difference amp. First question, do you expect these to go away in the future? (say 10 years) Hmm that might be my only question. Would you use these instead of an opamp and 0.1% R's?
Thanks
George H.