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MSM9831-xxx

¡ 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.

P1.2

P1.1

P1.0

ST

PI

PDWN

AOUT

+5V

47nF

+5V

+

–

+

–

+

–

XT

XT

GND

Ain

SP

SP

VR

STBY

GND

SEL

4.096MHz

(Ceramic oscillation is selected)

P1.2

P1.1

P1.0

ST

PI

PDWN

AOUT

+3V

47nF

+3V

+

–

+

–

+

–

XT

GND

Ain

SP

SP

VR

STBY

GND

SEL

(External clock input is selected)

CLK

XT