The MAS 3507D is a single-chip MPEG layer 2/3 audio decoder for use in audio broadcast or memory-based playback applications. Due to embedded memories, the embedded DC/DC up-converter, and the very low power consumption, the MAS 3507D is ideally suited for portable electronics.

In MPEG 1 (ISO 11172-3), three hierarchical layers of compression have been standardized. The most sophisticated and complex, layer 3, allows compression rates of approximately 12:1 for mono and stereo signals while still maintaining CD audio quality. Layer 2 (widely used in DVB, ADR, and DAB) achieves a compression of 8:1 providing CD quality.

Features

– Serial asynchronous MPEG bit stream input (SDI)

– Parallel (PIO-DMA) Input

– Broadcast and multimedia operation mode

– Automatic locking to given data rate in broadcast mode

– Data request triggered by ’demand signal’ in multi media mode

– Output audio data delivered (in various formats) via an I2S bus (SDO)

– Digital volume / stereo channel mixer / Bass / Treble

– Output sampling clocks are generated and controlled internally.

– Ancillary data provided via I2C interface

– Status information accessible via PIO pins or I2C

– “CRC Error” and “MPEG Frame Synchronization” Indicators at Pins in serial input mode

– Power management for reduced power consumption at lower sampling frequencies

– Low power dissipation (30 mW @ fs ≤ 12 kHz, 46 mW @ fs ≤ 24 kHz, 86 mW @ fs > 24 kHz @ 2.7 V)

– Supply voltage range: 1.0 V to 3.6 V due to built-in DC/DC converter (1-cell/2-cell battery operation)

– Adjustable power supply supervision

– Power-off function

– Additional functionality achievable via download software (CELP voice Decoder, ADPCM encoder /decoder)