OKI Starts Shipping Samples of High-quality Speech LSIs
Improvement of hearing experience by adjusting playback speed and tone
[Reference] Characteristics, specifications and shipping schedule for ML2272X Series
- Adjustment of playback speed and tone
Playback speed can be adjusted from 0.5 to 2 times the original speed while playback tone can be set from -20% to + 20%. Playback speed and voice tone can be set separately, thereby, enabling voice speed to be increased while maintaining the tone. With this function, the LSI can be used in products aimed at the elderly, language education devices, educational toys and emergency warning systems.
- Higher voice quality
The chip offers voice quality that is the highest in the speech devices market, by using a 16-bit D/A converter and improved digital filters.
- Built-in speaker amplifier
By including a speaker amplifier in the chip, the number of components required for implementation is reduced, resulting in smaller board size and lower total cost. Additionally, since there is no need to design any complex analog circuit around the amplifier, design requirements are reduced while maintaining high voice quality.
- Variety of compatible products
The ML2272X Series includes three types of LSIs depending on the memory size: ML22725(16M bit), ML22724 (8M bit) and ML22723 (4M bit).
The ML2272X Series is compatible with the ML2282X Series and can be used on the same board. Unlike the voice speed and tone adjustment functions in the ML2272X Series, the ML2282X Series has a function to simultaneously play back two sound and voice signals. In addition, the ML22420 and ML22460, which enable longer playback time by interfacing to an external large-capacity memory and recording voice data by interfacing to Flash memory, are also members of this compatible lineup.
- OKI's proprietary P2ROM™ Memory Technology
As with previous models, the ML2272X Series also uses OKI's P2ROM memory technology. P2ROM has unique advantages that are not achieved by other ROM memory technologies: short manufacturing lead time, eliminate unnecessary mask costs, and production in small amounts (from 500 units).
Major specifications
| ML2272X | ML2282X | ML22420 | ML22460 | |
|---|---|---|---|---|
| Playback time | ML22725 / ML22825(16M bit) 17min ML22724 / ML22824(8M bit) 8min ML22723 / ML22823(4M bit) 4min |
(Depends on external memory) | ||
| Voice speed change | 0.5 - 2.0 times (150 steps) |
— | — | — |
| Voice tone change | ±20% (40 steps) | — | — | — |
| Simultaneous playback | 1 | 2 | 4 | |
| Number of phrases | 4096 phrases | |||
| Voice processing | 4bit OKI ADPCM2, 8bit PCM, 8bit non linear, 16bit PCM | |||
| Sampling frequency | 4.0k - 48.0kHz (When voice speed/tone adjustment function is not used) |
|||
| D/A Converter | 16bit D/A converter (Digital LPF included) | |||
| Built-in speaker amplifier | 0.7W (Speaker resistance 8 Ω, when VDD=5V) TBD
External analog input: 1ch |
|||
| CPU Interface | 3 line serial | I2C | ||
| Oscillation frequency | 4.096 MHz | |||
| Power supply voltage | +2.7 to +5.5 V | |||
| Operating temperature | 0 - 70°C
(Option: -40 to +85°C) |
-40 - 85°C | ||
| Package | 30 pin SSOP (7.6mm x 9.7mm) | |||
| Evaluation tool | Sound device control board | |||
Volume shipment schedule
- ML2272X
- June 2008
- ML2282X
- May 2008
- ML22420
- June 2008
- * Information in the press releases is current on the date of the press announcement, but is subject to change without prior notice.