DATA SHEET
MAS 35x9F
In MPEG 1 (ISO 11172-3), three hierarchical layers of
compression have been standardized. The most
sophisticated and complex, layer 3, allows compres-
sion rates of approximately 12:1 for mono and stereo
signals while still maintaining CD audio quality. Layer 2
(widely used, e.g., in DVD) achieves a compression of
8:1 without significant losses in audio quality.
The MAS 35x9F supports the “Advanced Audio Cod-
ing” (AAC) that is defined as a part of MPEG 2. AAC
provides compression rates up to 16:1. It defines sev-
eral profiles for different applications. This IC decodes
the “low complexity profile” that is especially optimized
for portable applications.
The MAS 35x9F also implements a voice encoder and
decoder that is compliant to the ITU Standard G.729
Annex A.
SC4 is a proprietary Micronas speech codec technol-
ogy that can be downloaded to the MAS 35x9F, to
allow recording and playing back speech at various
sampling rates.
MPEG Layer 2/3, AAC Audio Decoder,
G.729 Annex A Codec
Release Note: Revision bars indicate significant
changes to the previous edition. This data sheet
applies to the MAS 35x9F version B4.
1. Introduction
The MAS 35x9F is a single-chip, low-power MPEG
layer 2/3 and MPEG2-AAC audio stereo decoder. It
also contains the G.729 Annex A speech compression
and decompression technology for use in memory-
based or broadcast applications. Additional functional-
ity is achievable via download software (e.g., CELP
voice decoder, Micronas SC4 (ADPCM) encoder/
decoder).
The MAS 35x9F decoding block accepts compressed
digital data streams as serial bit streams or in parallel
format, and provides serial PCM and S/PDIF output of
decompressed audio. In addition to the signal process-
ing function, the IC incorporates a high-performance
stereo D/A converter, headphone amplifiers, a stereo
A/D converter, a microphone amplifier, and two DC/DC
converters.
Thus, the MAS 35x9F provides a true
“all-in-one”
solution that is ideally suited for highly optimized mem-
ory-based portable music players with integrated
speech recording and playback function.
Micronas
June 30, 2004; 6251-505-1DS
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MICRONAS [ MICRONAS ]
