The AD8027ARTZ is a low distortion high speed Operational Amplifier with rail-to-rail input and output that operate on low supply voltages and is optimized for high-performance and a wide dynamic signal range. The AD8027 has low noise (4.3nV/√Hz, 1.6pA/√Hz) and low distortion (120dBc at 1MHz). In applications that use a fraction of or use the entire input dynamic range and require low distortion. The rail-to-rail input amplifier has an input stage that switches from one differential pair to another as the input signal crosses a threshold voltage, which causes distortion. The AD8027 has unique feature that allows the user to select the input crossover threshold voltage through the disable/select pin. This feature controls the voltage at which the complementary transistor input pairs switch. The AD8027 also has intrinsically low crossover distortion.