ml22808 Oki Semiconductor, ml22808 Datasheet - Page 13

• Manufacturer Part Number: ml22808
• Description: Oki Adpcm Algorithm-based Speech Synthesis Lsi
• Manufacturer: Oki Semiconductor

Power Down Function
This LSI has the power down function. When in a power down state, all the circuits including the oscillator
circuit stop operating, thus minimizing the supply current. When supplying an external clock to the XT pin, tie
the pin at a “L” level during power down.
The figure below shows a equivalent circuit to an oscillator circuit.
The Initial Status at Reset Input and the Status at Power Down of Output Pins
The status of relative output pins at reset input and power down is shown below.
Voice Synthesis Algorithm
The ML22804/ML22808-xxx contain four algorithm types to match the characteristic of playback voice: 4-bit
ADPCM2 algorithm, 8-bit straight ADPCM2 algorithm, 8-bit non-linear PCM algorithm, and 16-bit straight
PCM algorithm.
Key feature of each algorithm is described in the table below.
OKI Semiconductor
OKI 4-bit ADPCM2
OKI 8-bit Nonlinear
PCM
8-bit PCM
16-bit PCM
Voice synthesis
algorithm
(During power down = “L”)
Power down signal
output pin
Digital
BUSY
NCR
Normal voice waveform
components inclusive
Applied waveform
sound effect etc.
High-frequency
“H” level
“H” level
State
XT
approx. 1 MΩ
OKI’s specific speech synthesis algorithm of improved
waveform follow-up with improved 4-bit ADPCM.
Algorithm, which plays back mid-range of waveform as 10-bit
equivalent voice quality.
Normal 8-bit PCM algorithm
Normal 16-bit PCM algorithm
output pin
Analog
AOUT
XT
ML22808/ML22804/ML22802-XXX
Feature
Master clock inside the
LSI
GND level
State
FEDL2280XDIGEST-03
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