The AD8506/AD8508 are dual and quad micropower amplifiers featuring rail-to-rail input and output swings while operating from a 1.8 V to 5 V single or from 0.9 V to 2.5 V dual power supply. Using a novel circuit technology, these low cost amplifiers offer zero crossover distortion (excellent PSRR and CMRR performance) and very low bias current, while operating with a supply current of less than 20 A per amplifier. This amplifier family offers the lowest noise in its power class. This combination of features makes the AD8506/AD8508 amplifiers ideal choices for battery-powered applications because they minimize errors due to power supply voltage variations over the lifetime of the battery and maintain high CMRR even for a rail-to-rail input op amp.