msm9831 Oki Semiconductor, msm9831 Datasheet - Page 18

• Manufacturer Part Number: msm9831
• Description: Voice Synthesis Lsi With On-chip 384kbit Mask Rom
• Manufacturer: Oki Semiconductor

CONNECTING THE MSM9831 TO SPEAKER DRIVING AMPLIFIER
The MSM9831 uses a current output type D/A converter.
When the MSM9831 is connected to a voltage input type amplifier, it is required to convert the voice signal that is
output as "change of current" into the voice signal that is output as "change of voltage".
The connection between the MSM9831 and MSC1157 (OKI speaker driving amplifier) when a resistor is used for
the above conversion is described below.
CIRCUIT CONNECTION EXAMPLE 1: WHEN V
CIRCUIT CONNECTION EXAMPLE 2: WHEN V
1 Semiconductor
P1.2
P1.1
P1.0
P1.2
P1.1
P1.0
CLK
(Ceramic oscillation is selected)
(External clock is selected)
ST
PI
PDWN
ST
PI
PDWN
XT
GND
GND
V
V
DD
DD
THE MSC1157 IS 2.5V
THE MSC1157 IS 1.5V
+5V
+3V
AOUT
AOUT
XT
XT
XT
DD
DD
4.096MHz
= 5.0V AND THE AMPLITUDE OF AIN OF
= 3.0V AND THE AMPLITUDE OF AIN OF
47nF
47nF
P-P
P-P
Ain
STBY
Ain
STBY
SEL
SEL
GND
GND
V
V
CC
CC
+5V
+3V
SP
SP
VR
SP
SP
VR
+
+
–
–
MSM9831-xxx
+
+
FEDL9831-02
–
–
+
–
+
–
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