Samsung SC-D351, Service Manual

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Circuit Operating Description
13-10 Samsung Electronics
13-4-5 PRML Block H/W Demand matter
At PRML BLOCK, it is Control Signal of Micro Processor to Serial Enable/Data/Clock. In each mode star (SP-
PB, LP gas-PB, SP-Forward/Reverse Search, LP gas-Search, SP-Slow, LP gas-slow etc) You must be made to
carry out data control. moreover, Head S/W Pulse is inputted, the signal of the High section of an incoming
signal (Envelope Output) and the Low section is divided at the time of reproduction, and signal processing is
realized continuously as You have to become Control. In response to the control signal of Power Down from
DV-1chip (Channel Block), PB-High, and Adaptive High, operation is stopped between Recording Time
(Power Down), and normal signal processing operation is control(ed) between Playback Time. You have to
perform Playback operation by making and supplying 41.85MHz PB Clock and PB Data by DV-1chip (Channel
Block). When the unstable incoming signal by the 41.85MHz signal is inputted from a PREAMP way from DV-
1chip (Channel Block) (Search Mode or tape damage etc), this signal and it is made to perform stable in
reproduction operation. PREAMP to Differential Function(s), such as the supply receptacle AGC, Dropout,
Analog qualizer, Digital Equalizer, 1+D, and Viterbi, are carried out for the reproduction print-out signal of
input (DIP, DIN). PB data of 41.85Mbps(es) is supplied by DV-1chip (Channel Block). X2 process must be
performed for 20.925MHz which is the highest frequency of a reproduction signal to a reproduction signal,
and 41.85MHz PB clock must be supplied by DV-1chip (Channel Block). ATF Signal Processor is performed
from a reproduction print-out signal, and it is ATF of F0/F1 (465kHz)/F2 (697.5kHz).ATF Error Signal for
coltrol is made.It supplies by Micro Processor and must be made to have to use by the object for Capstan
Control.A two-sort power supply (3.3Vdc and 1.8Vdc) is supplied from DC/DC.
It uses with a power supply of operation and the standard power supply of block required for control of the
signal for control with the exterior. Internal 1.8V regulator can be operated by Exterior option (pull up or pull
down). At this time, the external country can be used in the 3.3V single country.