This document describes the features and characteristics of the AD8551/AD8552/AD8554 series of ultra-low drift, single-supply, rail-to-rail input/output operational amplifiers. These features include low offset voltage, drift, input/output swing, single-supply operation, high gain, CMRR, PSRR, ultra-low input bias current, and low supply current. They are suitable for applications such as temperature sensors, pressure sensors, precision current sensing, strain gage amplifiers, medical instrumentation, and thermocouple amplifiers.