LG GDR-8161B Service Manual page 15

3-3-2. TE for DVD-RAM, CD (DPP)
F1
49
F2
50
E2
51
E1
52
A
57
D
58
C
59
B
60
TE signal for DVD-RAM 2.6G,4.7G is programmable by DPP.
In case of DVD-RAM,sub spot(sub beam) is amplified by 1.17times and 1.9times in case of CD and add into
main spot(main beam).
The reason of adding sub is that controling offset(Offset cancel) which is occurred at lens shift.
Beam adjustment for center voltage(1.65V) of TE signal is done by adding TE signal which feed into IC201
111pin during initialization to offset.
IC101
DVD-RAM 2.6G, 4.7G : x1.17
CD : x1.9
AMP
AMP
DPPG
DPD
Tracking error Circuit
TEG
x1
TESEL
1.65V
IC201
1.65Vpp.
Center voltage
=1.65V
A/D
111
18
TE
Offset
Add
1.65V
Bal.
Detect
23