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.

VIDEO

L

 

R

QV001

RGB INPUT SELECTOR

L CXA1855Q

R

LINEOUT

R BUFFER

L

 

BUFFER

 

QA01

M5222FP

 

 

 

 

VOLUME

 

 

 

 

 

 

 

 

 

 

DAC

VOL / MUTE

 

 

 

 

MUTE

 

 

 

CXA1315M

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

QA02

TDA7056A

 

 

 

 

 

SOUND OUT

 

SPEAKER

 

 

 

 

 

 

 

1.5W

 

 

 

 

 

 

 

Fig. 7-3-12 Audio circuit block diagram

7-11

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Toshiba TLP510U, TLP511E, TLP510E, TLP511U manual Audio Circuit, Audio circuit block diagram