Hitachi CL43WP910TAN, Service Manual

Page: 9 / 77

AUDIO OUTPUT
The left and right signals are output from pins 1 and 2 of the PSA1 connector and are then
applied to audio amplifier I402(TDA7482) and I403(TDA7482) via the attenuation networks
R459 / R461 & R466 / R468.
The left and right output stage consists of two TDA7482 which are Class-D amplifier which
in this case is driven to give 15W per channel @ 10% thd. The power output is limited by
the Vcc supply to pin 13.
The TDA7482 has mute control line on pin 10. This control input is high when the outputs
are active and low when muted.
Headphone
The left and right signals are output from pins 1 and 2
of the PSA1 connector and are then applied
to Headphone amplifier I404(TDA2822N) via the attenuation networks R473 /R474 & R479 / R480
The TDA2822N has dual low-voltage power amplifier.
Class-D
Amp.
TDA7482
R466
R473
R479
Class-D
Amp.
TDA7482
Front L
(PSA1 pin1)
R459
R468
R461
I402
I403
Front L
Speaker
Front R
Speaker
R480 R474
Head Phone
Amp
TDA2822N
To Head
Phone
Terminal
Front R
(PSA1 pin2)
I404
Fig.3 Sound output circuit Diagram