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Mixing speech synthesis of four channels with  serial ROM interface LSI



package dimension figure

ML224xx package

The ML22420/ML22460 are speech synthesis LSIs with external speech data ROM. Speech playback is possible using general-purpose Flash memory and P2ROM™. Since the memory is directly controlled through the built-in memory IF, no burden is imposed on the microcontroller.
A high-precision converter and a FIR type low-pass filter are used for the speech output section to achieve the highest quality in this class. The built-in monaural speaker amplifier eliminates the cumbersome circuit design related to the amplifier. The ML22420 supports SPI/IF and the ML22460 supportsI2C/IF so that the device can be selected according to the customer's system.


  • With built-in 16bit DA converter of Audio class
  • FIR type low-pass filter
  • With built-in for speaker drive amplifier
  • External analog voice input and analog mixing
  • CPU command interface
    ML22420: SPI, ML22460:I2C
  • Mixing function of four channels possible to playback simultaneously?


  • Household electrical appliances
  • Voice guidance of industrial equipment
  • Voice information of fees and time
  • IH cooking heater
  • Compact portable devices
  • General consumer equipment, and so on


Parameter Specification
Part number ML22420/ML22460
Speech synthesis method 4bit ADPCM2
8bit non-linear PCM
8bit PCM, 16bit PCM
(The method of each phrase can be specified.)
Sampling Frequency
Fosc = at 4.096MHz
4.0k, 5.3k, 6.4k, 8.0k, 10.7k, 12.0k, 12.8k ,
16.0k, 21.3k, 24.0k, 25.6k ,32.0k, 48.0kHz
(The method of each phrase can be specified.)
*Restricted in part by the number of mixing.
Speaker amplifier output 0.7W (at 8Ω, 5V)
Number of playback phrases Max.1024 phrases 000h to 3FFh
Exnternal ROM Memory gto Max.128M
Other Functions Volume control function(49steps, MUTE)
Repeat function
Operating Power Supply Voltage +2.7V to +5.5V
Original oscillatory frequency 4.096MHz
Operating Temperature Range -40°C to +85°C
Package 30pin plastic SSOP
(two direction lead type and 0.65mm pitch)

Block Diagram


ML22420 Block Diagram

Typical Application Example

ML22420 series application circuit (at DVDD=SPVDD=5V)

Typical application example