The AK4551 is a low voltage 20bit A/D & D/A converter for portable digital audio system. In the AK4551, the loss of accuracy form clock jitter is also improved by using SCF techniques for on-chip post filter. Analog signal input/output of the AK4551 are single-ended, therefore, any external filters are not required. The AK4551 is suitable for portable digital audio system, as the AK4551 is lower power dissipation and a smaller package than AK4519. FEATURES