The ML2250 family is a group of speech synthesizer LSIs which provide the industry's highest playback time and sound quality in a compact space. The ML2250 family includes readable and writable Flash ROM products and playback-only mask ROM products. Since all these products are compatible from each other, the mask ROM products can be operated when mounted on a circuit board for the Flash memory products. This enables, for instance, the use of a Flash memory product instead of a mask product on a prototype board for reducing the manhours in evaluating the sound quality of sound data.
The ML2250 family also features a loop function for continuous playback of a single sound and a "2-channel mixing function" for simultaneous playback of separate sounds to provide a wide range of expressions. For example, the loop playback of a babbling stream sound can be used simultaneously with random playback of chirping sounds of birds to create a natural environment sound which continues almost endlessly.
Circuit design is also easy. Sound playback is possible by simply connecting 5 ports for the MPU, 2 ports for the amplifier, and the power supply circuit. Moreover, there is no need to provide a D/A converter and a low-pass filter, which are normally required on the output side, since both of these are already incorporated in these LSIs.

Built-in Mask ROM Products: ML2251, ML2252, ML2253, ML2254, ML2256-xxx

These are speech synthesizer LSIs with an integrated mask ROM. We provide 5 different products by ROM size. (Refer to the table.)

Built-in Flash Memory Products: ML22Q54, ML22Q58

These are speech synthesizer LSIs with integrated 4-Mbit/8-Mbit Flash memory. Writing of speech data can be easily performed by using dedicated tools. The Flash memory products are suitable for cases where mask ROM products cannot be used such as low-volume production of a variety of products and for applications requiring a short delivery time. Since the circuit configuration is identical to the mask ROM products, these LSIs can also be used for evaluation purposes.

Data Sheet (Digests) [PDF]

When detailed data sheets are required, please send the mail form. In the column for requested documents of the form, please write "Detailed version."

ROM Capacity and Maximum Sound Generating Time

Features and Main Specifications

• 8-bit /16-bit PCM, 8-bit non-linear PCM, 2-bit /4-bit ADPCM2
• Serial input/parallel input selectable
• Edit ROM function
• 2-channel mixing function
• Sampling frequencies:
  4.0kHz, 5.3kHz, 6.0kHz, 6.4kHz, 8.0kHz, 10.6kHz, 12.0kHz, 12.8kHz, 16.0kHz, 21.3kHz, 24.0kHz, 25.6kHz, 32.0kHz, 42.7kHz, 48kHz
• Maximum of phrases: 256 phrases
• Built-in volume control function (2-ch independent, 29 steps and "mute")
• External audio data input is possible
• Built-in 14-bit D/A converter
• Low-pass filter: Digital filter

Product Characterisitcs

Ο: Supported

-: Not supported

Block Diagram

Example of Application Circuit