LC78622NE
• CLV mode
In CLV mode the LC78622NE detects the disk speed from the HF signal and provides proper linear speed using
several different control schemes by switching the DSP internal modes. The PWM reference period corresponds to
a frequency of 7.35 kHz. The V/P pin outputs a high level during rough servo and a low level during phase control.
+
–
Internal mode
CLV
CLV
V/P
High
High
Low
Rough servo (velocity too low)
Rough servo (velocity too high)
Phase control (PCK locked)
High
Low
Low
High
PWM
PWM
• Rough servo gain switching
MSB
LSB
0
Command
RES = low
1
1
0
0
1
1
0
0
1
1
0
0
0
0
DISC 8 SET
DISC 12 SET
1
●
For 8 cm disks, the rough servo mode CLV control gain can be set about 8.5 dB lower than the gain used for 12 cm
disks.
• Phase control gain switching
MSB
LSB
1
Command
RES= low
1
1
1
1
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
1
1
0
CLV PHASE COMPARATOR DIVISOR: 1/2
CLV PHASE COMPARATOR DIVISOR: 1/4
CLV PHASE COMPARATOR DIVISOR: 1/8
NO CLV PHASE COMPARATOR DIVISOR USED
0
1
0
●
The phase control gain can be changed by changing the divisor used by the dividers in the stage immediately
preceding the phase comparator.
No. 6015-11/31
SANYO [ SANYO SEMICON DEVICE ]
