PRELIMINARY DATA SHEET
– Low power dissipation (30 mW at fs
≤
12 kHz,
46 mW at fs
≤
24 kHz, 86 mW at fs > 24 kHz at
2.7 V)
– Supply voltage range: 2.7 V to 3.6 V
– Adjustable built-in DC/DC up-converter for one-cell
and two-cell battery operation (typically down to
V
bat
= 0.9 V)
– Adjustable power supply supervision
– Power-off function
1. Introduction
The WorldSpace system is a satellite-based digital
radio service for direct-to-home transmission of digital
radio programs. The coverage areas of this service are
Africa, South America, and parts of Asia.
The MAS 3506D is the source decoder of Micronas’
StarMan chip set that is designed for the reception of
WorldSpace signals. The MAS 3506D extracts one
Service Component (SC) of an incoming digital World-
Space Broadcast Channel (BC) and decodes
MPEG 1/2/2.5 Layer 3
1)
encoded audio data con-
tained in the selected Service Component. The Ser-
vice Control Header (SCH) information from the
Broadcast Channel is accessible via the embedded
fast mode serial control interface. The MAS 3506D
provides digital audio data output in I
2
S and similar for-
mats. An embedded digital buffer-controlled loop
recovers the sampling frequency of the audio signal
and generates a synchronized 24.576 MHz clock sig-
nal which is used as an oversampling clock for D/A
converters. A block diagram of the MAS 3506D is
shown in Figure 1–2 on page 5.
1)
1.2. System Overview
The Micronas StarMan chip set consists of the channel
decoder DRD 3515A and the MPEG Layer 3 audio
decoder MAS 3506D. All essential analog and digital
building blocks for WorldSpace reception are provided
by the chip set. Together with an L-band tuner and an
appropriate microcontroller this set creates a complete
StarMan radio receiver (Figure 1–1)
MPEG 2.5 is a compatible extension of MPEG 2
audio, defined in ISO/IEC 13818-3.2 that covers
additionally very low sampling frequencies down to
8 kHz.
Aux1/2
AM/FM
(analog)
Receiver,
Tape Player
MAS 3506D
BC
I
2
S
SC-out
1.1. Features of the MAS 3506D
– Single-chip WorldSpace Broadcast Channel bit-
stream demultiplexer
– ISO MPEG 1/2/2.5 Layer 3 decoder
– ISO MPEG compliance tests passed
– Data processing by a high-performance RISC DSP
core (MASC)
– Download feature provides additional functionality
– Self-synchronized operation
– Output audio data delivered (in various formats) via
an I
2
S bus (SDO)
– Digital volume control and stereo channel mixer
– Automatic soft-mute function
– WorldSpace SCH-data output via I
2
C interface
– MPEG ancillary data provided via I
2
C interface
– Status information accessible via PIO pins or I
2
C
– “CRC Error”, “MPEG Frame Synchronization” and
“BC-Frame-Synchronization” indicators
– Power management for reduced power consump-
tion at lower sampling frequencies
WorldSpace
Tuner
IF input
DRD 3515A
analog out
I
2
C
System
Controller
Fig. 1–1:
Standard application of the StarMan chip set
Since the DRD 3515A also contains an audio amplifier
for headphone or small loudspeaker operation, only a
minimum of external components is necessary. The
additional inputs for analog signals (e.g. conventional
AM/FM receiver, tape etc.) make the amplifier accessi-
ble to these audio sources and thus considerably sim-
plify the design of complete radio receivers.
The analog audio output of the WorldSpace signal can
be connected to an external stereo amplifier for higher
power or quality. Also a digital audio signal in standard
I
2
S format is provided for high-end applications that
may require an external D/A converter.
4
Micronas
MICRONAS [ MICRONAS ]
