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Toshiba TLP511E User Manual

Page 38

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7-11

QV001

INPUT SELECTOR

CXA1855Q

VIDEO

RGB

LINEOUT

BUFFER

BUFFER

DAC

VOL / MUTE

SOUND OUT

SPEAKER

1.5W

VOLUME

MUTE

L

R

L

R

L

R

CXA1315M

QA01

M5222FP

QA02

TDA7056A

7-3-7. Audio Circuit

Fig. 7-3-12 shows the audio circuit block diagram.

Signal path from the QV001 to the LINE OUT terminal

is: QV001

®

transistor buffer

®

LINE OUT terminal.

Signal path from the QV001 to the speaker is as follows.

The audio signal developed from the QV001 becomes

one signal with its L and R signal components mixed.

The mixed audio signal enters the electrical volume IC

QA01 (M5222FP) and the output level is controlled

within a range of about 0 dB to –80 dB by an external

DC voltage (DAC). The audio signal thus controlled by

the IC QA01 is fed to the speaker amplifier IC QA02

(TDA7056A) and amplified by about 36 dB to drive the

speaker.

Fig. 7-3-12 Audio circuit block diagram

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