18
3
5
4
2
25
21
19
20
22
Q102,
Q110
Q110
IC101
P/U
5V
For DVD
For CD
LDOFF
LDSEL
LDPWR0.1
LDRWR0.1
MD
MD
DVD-RAM 4.7G : about 0.77V
DVD-RAM 2.6G : about 0.68V
DVD-ROM : about 0.68V
CD : about 0.7V
CD
Q104
DESCRIPTION OF CIRCUIT
1. ALPC (Automatic laser power control)
1-1. ALPC Circuit Constitution
Dual laser power control for DVD and CD are provided.
The laser ON for DVD or CD can be selected by
¡
LDSEL
¡–
and the lasers ON/OFF are controlled by
¡
LDOFF
¡–
.
Laser power for DVD and CD can be programmable by
¡
LDPWR 0,1
¡–
ALPC (Automatic laser plower control)
DVD-RAM 4.7G : about 0.23V
DVD-RAM 2.6G : about 0.18V
DVD-ROM
: about 0.18V
CD
: about 0.19V