23
TEG
AMP
AMP
x1
DPPG
DPD
TESEL
40
39
37
36
F1
F2
E2
E1
IC101
1.65V
47
46
44
43
A
D
C
B
IC201
1.65V
A/D
TE
Offset
Add
Bal.
Detect
1.65Vpp.
Center voltage
=1.65V
DVD-RAM 2.6G, 4.7G : x1.17
CD : x1.9
111
14
3-3-2. TE for DVD-RAM, CD (DPP)
Tracking error Circuit
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.