The OPAx387 are unity-gain stable, precision, operational amplifiers featuring state-of-the-art, zero-drift technology. The use of proprietary zero-drift circuitry gives the benefit of low input offset voltage over time and temperature, as well as lower 1/f noise component. As a result of the high PSRR, the devices work well in applications that run directly from battery power without regulation. The OPAx387 family is optimized for full rail-to-rail input, allowing for low-voltage, single-supply operation or split-supply use. These miniature, high-precision, low-noise amplifiers offer high-impedance inputs that have a common-mode range 100 mV beyond the supplies without input crossover distortion, and a rail-to-rail output that swings within 5 mV of the supplies under normal test conditions. The OPAx387 precision amplifiers are designed for upstream analog signal-chain applications in low or high gains, as well as downstream signal-chain functions, such as DAC buffering.