As the use of digital audio players and mobile phones equipped with music playback functions grows, demands for systems equipped with digital audio functions, such as MP3, has also been increasing. Oki successfully integrates the speaker amplifier, achieving a highly functional, low cost chip with the smallest size packaging in the world.

Oki's ML2011 is compliant with all MP3 formats including MPEG 1 Audio Layer III, MPEG 2 Audio Layer III and MPEG2.5, enabling users to replay a wide range of sounds from fully compressed voice to high-quality music. The 8ohm speaker amplifier has an output of 650mW and is designed to operate on 5V. Naturally, the chip is compliant with the MP3 decoder. It comes in two sizes: the world's smallest packaging of 3.6mm x 4.2mm W-CSP, or a 5mm x 6mm QFN package for easy mounting.
Oki also offers the ML2011 reference board, and SoundLib, the sample software for use in embedding. Users can easily connect the ML2011 reference board to their existing system, offering an environment for easy development and evaluation of the software. The use of SoundLib enables users to reduce the time needed for developing embedded software.

While a sound generator replays musical note files by combining pre-installed instrument sounds, the ML2011, because it is compliant with MP3, can replay both voice and vocals with music accompaniment. In addition, compared to speech LSIs, ML2011 provides better sound quality sound effects and can compress the data by 50%.

ML2841, a sound chip equipped with a 64 polyphonic sound generator and an MP3 decoder. Oki succeeded in reducing the power consumption of long-period MP3 playback on mobile phones down to 32mW, a decrease of approximately 80% compared to previous products.

Oki succeeded in reducing three notable parameters for the ML2841. First, it decreased the MP3 decoder power consumption from 57mW to 5mW. Secondly, by applying a digital amplifier, it reduced the headphone amplifier power consumption down to 32mW, an 80% decrease. Finally, it reduced the total cost by utilizing the mobile phone platform and optimizing specifications as necessary. With these achievements, Oki completed an experiment to play back music for 30 hours non-stop by connecting the chip to a GSM mobile phone platform and a 1000mAh battery. Theoretically, it can extend playback time to 60 hours by improving the software for the mobile phone platform.

The chip consist of a low power consumption MP3 decoder, an SRS 3D surround, an equalizer and a 64 polyphonic sound generator. With a super-small package of 4.16 X 4.16mm, it is best suited to achieving audio functions on mobile phones. Oki also upgraded its tool to create multimedia communication data files (MCDF) compliant to be compliant with ML2841, which enables users to create their own multimedia content. The tool can be downloaded from: https://www.oki.com/jp/sisc/swingnringercp/