XOCECO LC-20Y15, Service Manual

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2. Inner block diagram of LA72700 stereo decoder
Descriptions of the pins:
No. Pin name Connections No. Pin name Connections
3 PCSTFILT VCO PLL filter 11 SDA IIC data input
4 PCPLDET Driving level test 12 SCL IIC clock input
5 PISIF SIF signal test 24 PCALCFIL ALC filter
6 GND GND 25/26 R/L OUT TVF_R/L output
9 SIF DEMOD SIF demodulator 27 PCREC Reference voltage
10 MUTE Mute (DC=5V) 31 VCC 9V power
3. R2S15900SP audio processor with surround stereo
The audio signal from YPrPb/YcrCb or VGA input interface is selective sent to R2S15900SP through the
multi-channel selector HEF4052BT, while the audio signal from the AV inputs is sent to R2S15900SP
directly.
After the processing of bass, treble, balance and AVL by R2S15900S, all these processed audio signals
will be output to audio amplifier TPA1517 (for 15 inch models) or AN5277 (for other models) to amplify,
then the amplified signal will be sent to the speaker to output. The Fig.1-3 is the block diagram of
AN5277.