AN8807SB Datasheet, PDF (7/10 Pages) Panasonic Semiconductor – Three-Beam Method Head Amplifier IC for CD-ROM

ICs for CD/CD-ROM Player
AN8807SB
The VCBA is for focus balance adjustment. Connecting 47kΩ of external resistance toPin299, signal ratio between A+C and
B+D can be controlled as shown in Table 1.
VC
1.5V
2.5V
3.5V
Table 1
A+C
B+D
0.14
1.0
7.0
B+D
A+C
7.0
1.0
0.14
• Tracking Error Amplifier
As shown in Figure 3, the tracking error amplifier receives the output currents E and F of three-beam method pin photo diode
for sub-beam detection, and outputs the operation result of E–F to TEOUT (Pin25).
VREF
32
470kΩ
fC6100kHz
E
33
VREF
31
–
+
470kΩ
VCBA
F
34
–
+
VCBA
Subtraction
26 –
25
+
20kΩ
30
–
+
Figure 3 : Tracking Error Amplifier