AN8808SB Datasheet, PDF (7/10 Pages) Panasonic Semiconductor – Three-Beam Method Head Amplifier IC for CD supporting the hologram pick-up

ICs for CD/CD-ROM Player
AN8808SB
The VCBA is for focus balance adjustment. Connecting 47kΩ of an external resistance to Pin29, signal ratio between A + C
and B + D can be controlled as shown in Table 1.
Table 1
A+C
B+D
VC
B+D
A+C
1.5V
0.14
7.0
2.5V
1.0
1.0
3.5V
7.0
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
20kΩ
Subtraction
26 –
25
+
20kΩ
30
–
+
Figure 3 : Tracking Error Amplifier