LC78626E Datasheet, PDF (18/32 Pages) Sanyo Semicon Device – DSP for Compact Disk Players

LC78626E
(3) The TJ Mode
The relationships between the acceleration pulse, deceleration pulse, and brake interval are as shown in the table
below.
Command
1 TRACK JUMP IN (OUT) #1
1 TRACK JUMP IN (OUT) #2
1 TRACK JUMP IN (OUT) #3
1 TRACK JUMP IN (OUT) #4
2 TRACK JUMP IN (OUT)
4 TRACK JUMP IN (OUT)
16 TRACK JUMP IN (OUT)
32 TRACK JUMP IN (OUT)
64 TRACK JUMP IN (OUT)
128 TRACK JUMP IN (OUT)
256 TRACK JUMP IN (OUT)
TRACK JUMP BRAKE
When in the conventional track jump mode
a
b
c
233 µs
233 µs
60 ms
0.5 TRACK
JUMP period
233 µs
60 ms
0.5 TRACK
JUMP period
233 µs
This period
does not exist
0.5 TRACK
JUMP period
233 µs
60 ms TOFF =“L”
during period C
None
2 TRACK
JUMP period
466 µs
9 TRACK
JUMP period
7 TRACK
JUMP period
18 TRACK
JUMP period
14 TRACK
JUMP period
36 TRACK
JUMP period
28 TRACK
JUMP period
72 TRACK
JUMP period
56 TRACK
JUMP period
TOFF is high during the period over
which 256 tracks elapse and pulses a
and b are not produced.
There is no a or b period.
60 ms
60 ms
60 ms
60 ms
60 ms
60 ms
60 ms
When in the new track jump mode.
a
b
c
Same as in the conventional mode.
0.5 TRACK
JUMP period
The same
as for a
60 ms
0.5 TRACK
JUMP period
The same
as for a
This period
does not exist
0.5 TRACK
JUMP period
The same
as for a
60 ms TOFF =“L”
during period C
1 TRACK
JUMP period
The same
as for a
60 ms
2 TRACK
JUMP period
The same
as for a
60 ms
9 TRACK
JUMP period
The same
as for a
60 ms
Same as in the conventional mode.
Same as in the conventional mode.
Same as in the conventional mode.
Same as in the conventional mode.
Same as in the conventional mode.
* The 256 TRACK CHECK does not produce an actuator drive signal as shown in the table above, rather because the mode is such that the TES signal is
counted when the tracking loop is off, it is necessary to provide a feed to the feed motor.
* When the track jump sequence (a, b, c) is completed, the servo command register is reset automatically.
* When a new command has been input when the track jump is in process, that command is executed at that instant.
* In the 1 TRACK JUMP #3 command there is no brake period (period c), but rather caution is warranted because it is necessary to generate the brake
mode using an external circuit.
* Although in the 2TRACK JUMP IN (OUT) of the new track jump mode the brake period (period c) did not exist for the LC78620E/21E/25E ICs, in this IC
period C has been changed to 60 ms.
Slip detector
High during the brake interval
No. 5692-18/32