Philips HTS5000W/12, Service Manual

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EN 54 HTS5000W 9. Exploded View & Module PWR 04-01 Non-Wireless
13 Volume chip M62429FP
A serial driven volumechip is used in the ampli
fi
erdesign. Control of this device is fully done by 2 lines out of the RX module. A clock
and data signal is coming from pin 12 and 14 of 1103; these lines are on 3.3Vdc logic level. However, the volumechip operates on 5V
logic. Therefore, transistors 7120 and 7121 form a level converter. The chip M62429 from Renesas has to receive a serial 10 bits data
signal to set the desired attenuation (see below datap volume code)
Note: At start-up the chip is in its initial maximum attenuation of – 83dB // so, when powering up the surroundreceiver with the mains
plug, no sound at all will be heard in the speakers. The transmitter in the DVD player has to send a valid volume data and clockstream
to the receiver to set a volume. Of course, if the surroundreceiver starts up from standby, the volumesetting will be at its last value (The
volumechip is continuously powered from the 5Vdc when the surroundreceiver is in standby condition)
The DVD set sends every 4 seconds the last volumesetting to the receiver, this assures reliable volumesetting under all conditions.