digital audio playback system. It is comprised of a multibit sigmadelta
modulator, high performance digital interpolation filters,
and continuous-time differential current output DACs. Other
features include an on-chip clickless stereo attenuator and mute
capability, programmed through an SPI compatible serial control
port. The AD1955 is fully compatible with all known DVD audio
formats including 192 kHz as well as 96 kHz sample frequencies
and 24 bits. It is also backward compatible by supporting 50 μs/
15 μs digital de-emphasis intended for “redbook” compact discs,
as well as de-emphasis at 32 kHz and 48 kHz sample rates.
The AD1955 has a very flexible serial data input port that
allows for glueless interconnection to a variety of ADCs, DSPs,
SACD decoders, external digital filters, AES/EBU receivers, and
(continued on page 12)