cxa1992ar Sony Electronics, cxa1992ar Datasheet - Page 31

• Manufacturer Part Number: cxa1992ar
• Description: Rf Signal Processing Servo Amplifier
• Manufacturer: Sony Electronics

Note that the time from the High to Low transition of FZC to the time command $08 is asserted must be
minimized. To do this, the software sequence shown in B is better than the sequence shown in A.
2. $1X (DFCT1 at SENS1 pin (Pin 25), DFCT2 at SENS2 pin (Pin 26))
These commands deal with switching TG1/TG2, brake circuit ON/OFF,
and the sled kick output.
The bit configuration is as follows:
TG1, TG2, TM7
The purpose of TG1 and TG2 is to switch the tracking servo gain Up/Normal. TG1 and TG2 are interlinked
switches. The brake circuit (TM7) is to prevent the frequently occurred phenomena where the merely 10-track
jump has been performed actually though a 100-track jump was intended to be done due to the extremely
degraded actuator settling caused by the servo motor exceeding the linear range after a 100 or 10-track jump.
For the prevention method, when the actuator travels radially; that is, when it traverses from the inner track to
the outer track of the disc and vice versa, the brake circuit utilizes the fact that the phase relationship between
the RF envelope and the tracking error is 180° out-of-phase to cut the unneeded portion of the tracking error
and apply braking.
D7
0
D6
0
Transfer $08
YES
YES
D5
FZC
F. OK ?
0
Latch
(A)
Fig. 5. Poor and good software command sequences
?
D4
1
NO
NO
TG1, TG2 Break
ON/OFF ON/OFF
D3
circuit
– 31 –
D2
D1
Sled kick
height
Transfer $08
YES
YES
FZC
F. OK ?
D0
Latch
(B)
?
(PS1)
Sled kick height
NO
NO
D1
0
0
1
1
(PS0)
D0
0
1
0
1
CXA1992AR
±1
±2
±3
±4