Ask the Applications Engineer 39—Zero-Drift Operational Amplifiers

Zero-drift amplifiers dynamically correct their offset and reshape their noise density. Two commonly used types—auto-zero and choppers—achieve nanovolt-level offsets and extremely low drift. 1/f noise is seen as a dc error, so it is removed as well. In addition, zero-drift amplifiers have higher open-loop gain, power-supply rejection, and common-mode rejection than standard amplifiers.