AN8807SB
ICs for CD-ROM Player
s
Operational Description
(The values shown below are design values when supply voltageV
CC
=5V.)
• RF Amplifier
As shown in Figure 1, RF signals are generated by three-beam method pick-up. Equivalent resistance to RFOUT (Pin7) is
57.6kΩ, when resistance between RF– and RFOUT is 12kΩ.
Light level
48kΩ
12kΩ
36
–
+
48kΩ
10kΩ
10kΩ
6
R
RF
Dark level
7
A
D
B
C
–
+
35
–
+
R
RF (T)
= 48kΩ
×
R
RF
10kΩ
Figure 1 : RF Amplifier
• Focus Error Amplifier
As shown in Figure 2, the operation result of (A+C) – (B+D) is outputted to FEOUT (Pin27). Equivalent resistance to FEOUT
is 96kΩ, when resistance between FE and FEOUT is 20kΩ.
20kΩ
48kΩ
VCBA
36
R
FE
A+ C
–
+
48kΩ
28
27
A
D
B
C
–
20kΩ
–
+
+
B+D
35
–
+
×
2
f
C
=30kHz
29
V
C
–
+
Figure 2 : Focus Error Amplifier
PANASONIC [ PANASONIC SEMICONDUCTOR ]
