I am looking for a simple small footprint and low cost op amp for a load cell Wheatstone bridge. I am already using the INA213 on this design and wondered about using the INA211. It is only speced for current sense and makes no mention of being usable in low current applications. However because it is differential and gives an output referenced to ground removing the bridges bias it seems ideal.

Details:
My supply voltage is 3.0
Load cell output full spec is 1.5 +/- 0.5 mv/V so scale is 3 - 6 mV (Circuit saturation at the peak is ok, do not need to have the full range)
12 bit A/D input range is 0 - 3.0 V
Total load cell system sensing accuracy of 0.2%. Unit will be paired with a load cell and calibrated to remove offset and adjust gain during manufacturing.

What am I missing?

Thanks

 

I would be concerned that the high output impedance of a bridge would impact gain accuracy. In general, the load on the bridge.

 

They're all the same family, low drift and offset using a Vref pin, just select the resistors for gain setting, max i/p off set +/-150uV.

http://www.ti.com/product/INA213

 

From your post, the wheatsone bridge output impeadence would be 'in series' with R3 & R4 which would change the gain of the amplifier. I did not do the math to see if the effect is linear.