AN8807SB Datasheet, PDF (9/10 Pages) Panasonic Semiconductor – Three-Beam Method Head Amplifier IC for CD-ROM

ICs for CD/CD-ROM Player
AN8807SB
• BDO Detection
BDO is detected by the low speed detection circuit and high speed detection circuit. The high speed detection circuit is
incorporated. On the other hand, the capacitor of the low speed detection circuit must be connected to Pin13. The capacity value
is 2200pF and it is recommended that it should be connected for VCC. When the capacity value of Pin13 is increased, BDO is
detected with large RF missing rate. When it is decreased, BDO can be detected with small RF missing rate.
BDO present=H
BDO absent=L
• OFTR Detection
OFTR detection reversely corresponds with BDO detection. However, its detection method is the same as for BDO. Capacitor
for the low speed detection must be connected to Pin15. It is recommended that it should be connected to VCC at 2200pF in the
same way as for Pin13. The relation between the capacity value and OFTR detection timing is as the same for BDO.
OFTR=H
Off from OFTR=L
• APC
170mV
21 LD OFF
VCC
10µF +
10Ω
–
2
LD
1
3
PD
LD ON/OFF
Figure 5 : APC
The reference voltage of LD is approx. 170mV fixed.
• Reference Supply
Servo reference supply is incorporated. Pin20 outputs VCC/2, and has approx. 3mA of current capacity for sink/source. It is
recommended that it should be given 1µF to 10µF of capacity in addition.
• Vibration Detection
The AN8807SB has a wind comparator of approx. ±75 mV. Abnormal vibration components of tracking error are detected and
the data for whether vibration is present or not is outputted to Pin22.