The OPA1642AID is a ultra low distortion, low-noise, bi-polar input operational amplifier released by Texas Instruments. It is a dual-input, single-output, very low-noise (2.7 nV/sqrt Hz) amplifier that is capable of providing a high-performance audio circuit with a wide bandwidth. It has a low-noise maximum of 2.7 nV/sqrt Hz, and its input bias current is only 2.0 pA. This amplifier also features a low-distortion maximum of 0.00035%, with THD+N of 0.00005%. The device also features an amplifier offset voltage of only 3.0mV, and its common-mode rejection ratio (CMRR) is 104 dB. The OPA1642AID is suited for single-supply operation, and is capable of operating from a voltage as low as 1.8 V to a maximum of 5.5 V. This op amp can be used in audio preamplifiers, interstage amplifiers, line drivers, and microphone preamps.