Samsung DVD-709, Service Manual

Page: 63 / 179

Circuit Descriptions
6-6 Samsung Electronics
6-2 RF
6-2-1 RIC1 (KS1461)
KS1461 is combined with KS1452 and KS1453 as bipolar IC developed for DVD SERVO system.
Main features include DVD waveform equalizing, CD waveform equalizing, focus error signal generation, 3-beam
tracking error signal generation, DPD 1-beam tracking error, defect, envelope, MIRR output, etc. after receiving the
pick-up output converted into I/V.
6-2-1 (a) Basic Potentiometer
KS1461 uses a single power method and each circuit is based on V of 2.5V.
V (Pin 12, 20, 24, 67) terminal is needed for IC, which uses the peripheral V.
6-2-1(b) RF signal
Fig. 6-11 shows the flow of signal generated by the pick-up.
A, B, C, D signals detected from pick-up are converted in to RF signal(A+B+C+D) via RF summing AMP.
Fig. 6-12 shows the waveform-equalizing block diagram for the RF signal.
It outputs to EQout (Pin 86) terminal by initially changing switching AMP gain of DVD and CD, and then adjust-
ing the level in RF SUM & AGC. It controls RF SUM & AGC gain by means of Pin 89-95 and interfaces with PWM
signal, (output from PWM terminal of KS1453, via low-pass filter to adjust boost gain and peak frequency.
EQout terminal is connected with EQin (Pin 86).
PICK-UP
RE SUM
& AGC
RF EG
DPD
TE
Mhx
ENV
FOK
DEFECT
TESEL
TE
ABCD
SUM
FE
ALPC
MIRR
%
^
&
*
5
6
7
8
3
4
104
104
104
104
? . m
474
104
RFAGCO EQIN MIRRI
G
,
y
I
i
T
F
P
[
d
MIRR
TE
RFEQO
A
B
C
D
E F LD PD
w
E
ABCD
FE
DFCT1
DFCT2
FOKB
ENV
103
ABCDI
Fig. 6-11