AN8806SB Datasheet, PDF (9/10 Pages) Panasonic Semiconductor – Three-Beam Method Head Amplifier IC for CD Player

ICs for CD/CD-ROM Player
AN8806SB
• 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 this 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
VCC
LD OFF
21 _{10µF +}
10Ω
–
2
LD
1
4
PD
LDP
3
LD ON/OFF
Figure 5 : APC
By connecting Pin4 to OPEN or GND, the reference voltage of LD can be switched. Connection to OPEN makes the reference
voltage approx. 170mV and connection to GND makes it approx. 140mV.
• 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 AN8806SB has a wind comparator of approx. ±75mV. Abnormal vibration components of tracking error are detected and
the data for whether vibration is present or not is outputted to Pin22.