The selection of Operational-Amplifier (op-amp) also constitutes an important part of the DAC2488 design.
In DAC2488, the Total Harmonic Distortion (THD) performance of an op-amp should be at most 0.0006% @ 3V output and the Noise performance should not exceed 6nV per Hz. An output buffer op-amp will help to drive a heavy load to provide a better noise immunity and to prevent loading affects on the analog portion of the system.
And lastly, signal pickup for those op-amp should have a low offset voltage (70uV) and minimal bias current（10pA,because it can make sure analogue stage can pickup all small audio signal from D/A and provide excellent DC performance. Although most audio systems are designed to operate within the audio band (100kHz), an op-amp should have a bandwidth exceeding 10MHz, this is because a low noise high bandwidth op-amp can slew fast enough to make up for the non-linear loss that are inherent to many musical outputs.