- on Miscellaneous Electronics
- Published in issue 12/2000 on page 0
Instrumentation Amplifier withImproved CMRR
This circuit is a relatively simple instrumentation amplifier that can be powered from a single 5-V supply. The output voltage is given by the formula: ... For the optimum CMRR, the ratio of R1 to R2 should be the same as that of R3 to R4. If we let R1 = R4 and R2 = R3, the formula becomes: ... Thanks to the 2.5-V reference voltage provided by IC1, this circuit can work with a single supply voltage.