CXA1992 SONY [Sony Corporation], CXA1992 Datasheet - Page 24

• Manufacturer Part Number: CXA1992
• Description: RF Signal Processing Servo Amplifier
• Manufacturer: SONY [Sony Corporation]

Tracking and Sled Servo
The above figure shows a block diagram of the tracking and sled servo.
The capacitor connected between Pins 9 and 10 is a time constant to cut the high-frequency gain when TG2 is
OFF. The peak frequency of the tracking phase compensation is approximately 1.2kHz when a 510kΩ
resistance is connected to Pin 11. In the CXA1992AR, TG1 and TG2 are inter-linked switches.
To jump tracks in FWD and REV directions, turn TM3 or TM4 ON. During this time, the peak voltage applied to
the tracking coil is determined by the TM3 or TM4 current and the feedback resistance from Pin 12. To be
more specific,
The FWD and REV sled kick is performed by turning TM5 or TM6 ON. During this time, the peak voltage
applied to the sled motor is determined by the TM5 or TM6 current and the feedback resistance from Pin 15;
The values of the current for each switch are determined by the resistance connected between Pin 17 and V
When this resistance is 60kΩ :
As is the case with the FE signal, the TE signal is switched to pass through a low-pass filter formed by the
internal resistance (100kΩ) and the capacitance connected to Pin 50.
0.047µ
100k
0.033µ
Track jump peak voltage = TM3 (or TM4) current
Sled kick peak voltage = TM5 (or TM6) current
TM3 (or TM4) = ±11µA, and TM5 (or TM6) = ±22µA.
47k
0.022µ
150k
45
47
48
10
46
50
49
9
BUFFER AMP
TDFCT
TEO
LPFI
TEI
TGU
TG2
ATSC
TZC
100k
TE
470k
TZC
+
–
TG2
DFCT
100k
100k
GAIN
WINDOW
COMPARATOR
BALANCE
WINDOW
COMPARATOR
1k
20k
1k
TM1
Tracking Phase
Compensation
680k
680k
TGH
TGL
BALH
BALL
ATSC
11
FSET
66p
– 24 –
TG1
510k
0.015µ
feedback resistance
TM7
10k
feedback resistance value
TM6
TM5
TM4
TM3
22µA
22µA
11µA
11µA
90k
SLED ON/OFF
CONTROL
SENS
SELECTOR
47k
TM2
TA_M
TA_O
SL_O
26
25
19
16
15
14
12
13
SL_M
SL_P
100k
SENS2
SENS1
LOCK
82k
TRACKING
COIL
8.2k
SLED MOTOR
3.3µ
22µ
15k
CXA1992AR
M
EE
.