The MSM6585 is an version-up product of the MSM5205 voice synthesis IC. Mainly improved points
are improvement for the precision of an internal DA converter, a built-in low-pass filter, and
expansion on the sampling frequency. The MSM6585 does not include a control circuit to drive an
external memory similar to the MSM5205. Therefore, the MSM6585 can be connected with not only
semiconductor memories, but other memory media (CD-ROM, etc.) by the control of CPU.
FEATURES
• 4-bit ADPCM method
• Built-in 12-bit DA converter
• Built-in low-pass filter (LPF) (–40dB/oct)
• Sampling frequencies: 4k/8k/16k/32kHz
• Master clock frequency (ceramic oscillator) : 640kHz
• Voice data synthesis : Supported by voice analysis editing tools AR76-202 and AR203
• Package options :
18-pin plastic DIP (DIP18-P-300-2.54) (Product name : MSM6585RS)
24-pin plastic SOP (SOP24-P-430-1.27-K) (Product name : MSM6585 GS-K)
30-pin plastic SSOP (SSOP30-P-56-0.65-K) (Product name : MSM6585 GS-AK)
DIFFERENCES BETWEEN MSM6585 AND MSM5205
MSM6585MSM5205
• Master clock frequency:640kHz384kHz
• Sampling frequency:4k/8k/16k/32kHz4k/6k/8kHz
• ADPCM bit length:4-bit3-bit/4-bit
• DA Converter:12-bit10-bit
• Low-pass filter:Included (–40dB/oct)Not included
• Overflow preventing circuit:IncludedNot included
When data is shared with the MSM5205, note that the D3 to D0 selection timings of the MSM6585
and MSM5205 are different. (Refer to DIFFERENCES BETWEEN MSM6585 AND MSM5205.)
TIMING DIAGRAM
VCK (O)
RESET (I)
D3 - D0 (I)
IC internalD3 - D0
selection timings
AOUT, DAO (O)
t
VCK
t
W(RST)
t
H
ADPCM1 ADPCM2ADPCMN
t
S
t
VCK/8
ADPCM
N+1
The VCK clock rising and falling edges are reversed between the MSM5205 and the MSM6588, as
indicated in DIFFERENCES BETWEEN MSM6585 AND MSM5205.
Note that the MSM6585 cannot accept data if the MSM5205 controls to repeat valid and invalid each
half cycle, when the MSM5205 is replaced with the MSM6585.
The relationship of the sampling frequencies on S1 and S2, and the cutoff frequencies are
listed below.
MSM6585
S1
S2
L
H
L
H
L
L
H
H
Sampling frequency (f
4 kHz
8 kHz
16 kHz
32 kHz
SAM
)
Cutoff frequency (f
1.6 kHz
3.2 kHz
6.4 kHz
12.8 kHz
CUT
)
2.AOUT Connecting Circuit
Connect a 0.01mF capacitor to the AOUT pin. The circuit diagram is as shown below.
MSM6585
AOUT
0.01mF
AmplifierSpeaker
Even when the DAO pin is used, connect a 0.01mF capacitor to the AOUT pin. This capacitor is used
for the improvement of a voice quality.
3.Voice Output
The MSM6585 has two voice output pins. The DAO is direct output pin from the internal DA
converter. The AOUT is a pin to output a voice after which the DAO output passed a built-in LPF.
3.1DA Converter Output Waveform
The output amplitude from the DA converter is max. (4095/4096) ¥ VDD and becomes a stair step
waveform synchronized with the sampling frequency. The DAO output impedance varies in the
ranges from 10kW to 40kW. Therefore, determine the filter constant so that the resistor variation does
not
have influence on the cutoff frequency of the filter.
The cutoff frequency of the low-pass filter varies in proportion to the sampling frequency.
The following figure shows the low-pass filter characteristics in the sampling frequency
8kHz.
0
–20
–40
Damping factor (dB)
–60
MSM6585
4.Oscillation
Following show external circuit diagrams using a ceramic resonator, KBR-640B made by
Kyocera Corp. and CSB640P made by Murata MFG. Co., Ltd.
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
0.58 TYP.
Notes for Mounting the Surface Mount Type Package
The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which
are very susceptible to heat in reflow mounting and humidity absorbed in storage.
Therefore, before you perform reflow mounting, contact Oki’s responsible sales person for the
product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
0.19 TYP.
Notes for Mounting the Surface Mount Type Package
The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which
are very susceptible to heat in reflow mounting and humidity absorbed in storage.
Therefore, before you perform reflow mounting, contact Oki’s responsible sales person for the
product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).