Circuit Descriptions
EN 33L11M1.1L LA 7.
2011-Jun-24
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div. table
7.3 Video
7.3.1 Video: Front-End
Key components for the tuner section are:
• Sharp Half NIM tuner VA1E1BF2403,
• Toshiba channel decoder TC90517 (external ISDB-T
channel decoder).
• Analog demodulator (using internal MT5363 analog
demodulator - pin AH35 VIP, AH37 VIN).
Refer to Figure 7-10
for details.
Figure 7-10 Front-end functional block diagram
7.4 Audio
In this chassis, audio processing is done by the following key
components:
• MT5363 micro-processor for input selection and audio
processing,
• TPA3123D2 class-D power amplifier for 2 x 10 W
amplification.
The audio profile (optimal setting per screen size and styling) is
stored at Option 10 (bit 0 to bit 4). Profile 1 for 32-inch Dali and
profile 2 for 40-inch Dali.
Table 7-1 Microprocessor control lines - 1 -
Table 7-2 Microprocessor control lines - 2 -
From uP At class D Usage
SW_MUTE SW_MUTE Will pull audio signals to LOW upon DC drops, help
to eliminate plop sound.
RESET_AUDIO A_STBY Control SHUTDOWN pin of class D amplifier:
ON/OFF the amplifier
MUTE MUTE Corresponding to the MUTE button on Remote
Control, to mute/unmute speakers
DC_PROT DC_PROT Detecting present of DC at speakers output and
feedback to uP. This will trigger TV into protection
mode. This is important to protect speakers
From uP
A_STBY
to class D Class D outputs
SW_MUTE LOW - MUTE
HIGH - Operating (unmute)
RESET_AUDIO LOW HIGH Operating (unmute)
HIGH LOW Class D shutdown (mute)
MUTE LOW - Operating (unmute)
HIGH - MUTE
DC_PROT LOW - DC detected -> set going to protection
HIGH - No DC -> normal operating
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