The LMV321, NCV321, LMV358/LMV358I and LMV324 are CMOS single, dual, and quad low voltage operational amplifiers with rail−to−rail output swing. These amplifiers are a cost−effective solution for applications where low power consumption and space saving packages are critical. Specification tables are provided for operation from power supply voltages at 2.7 V and 5 V. Rail−to−Rail operation provides improved signal−to−noise preformance. Ultra low quiescent current makes this series of amplifiers ideal for portable, battery operated equipment. The common mode input range includes ground making the device useful for low−side current−shunt measurements. The ultra small packages allow for placement on the PCB in close proximity to the signal source thereby reducing noise pickup.