High Performance BU94702AKV MP3 Encoder/Decoder


ROHM has recently announced the development of a USB audio decoder IC that enables audio playback of MP3 files from CD-ROM and USB memory using just a single chip, making it ideal for a variety of equipment, including AV receivers, radio players, and stereo component systems.

USB and SD memory cards are receiving increased attention as a storage medium for audio and multimedia files due to their fast read/write speeds, greater convenience, and easier portability compared with CDs and DVDs. Steadily decreasing costs are another reason they are becoming more mainstream. ROHM offers a lineup of single-chip USB audio decoders for different file formats, along with a well-received series for car audio featuring greater ESD resistance. The number and type of applications utilizing USB and SD memory is only expected to grow in the future, for example by adding encoding capability that allows the user to record and listen to music while driving without requiring dedicated equipment.

The BU94702AKV meets market needs by enabling MP3 and CD-ROM playback and USB memory recording on a single chip. Additional features include USB/SD memory card host functionality, MP3/AAC/WMA decoder, FAT file system, and a music search function (file browser) that allows track selection during playback. Also, built-in LDO and DAC circuits enable easy configuration of an audio system by simply connecting a power supply audio amp, and speakers. Compact and lightweight, the VQFP80 package makes it possible to add audio functionality to a wide range of applications beyond audio-only devices, such as alarm clocks, relaxation products (i.e. massage chairs), electronic dictionaries, and digital cameras. 

■Key Features

  1. USB 2.0 Full Speed Host I/F function
  2. SD memory card I/F (SPI)
  3. 2×MP3 encoding function (compatible with MPEG-1 Layer 3)
  4. MP3, WMA, and AAC decoder
  5. CD-ROM decoder
  6. Song search function (file browsing) during playback
  7. Reads and writes other types of files (besides music)

■Block Diagram

Block Diagram


  • FAT File System
    A memory system developed by Microsoft designed to determine the position and order of a specific file stored in a memory device such as A PC HDD or Flash memory. The FAT file system allows the OS to determine the status of each file within a cluster as well as find an unallocated cluster for new files.