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CXA1372BQ/BS

Tracking Sled Servo

42

TZC

TZC

0.022µ

45

0.047µ

ATSC

BPF

100k

1k

1k

100k

ATSC

43

44

TE

22k

0.1µ

TE

TDFCT

470k

DFCT

680k

TG1

TG1

680K

10k

TM1

66P

Tracking

Phase

Compensation

8

9

0.033µ

TGU

TG2

20k

TG2

470k

10k

90k

TM7

11

12

TA–

13

SL+

14

15

SLO

SL–

TRACKING

COIL

100k

82k

22µ

3.3µ

15k

8.2k

0.015µ

M

SLED MOTOR

120k

100k

SSTOP

SSTOP

100k

1k

10k

TM2

TM6

TM5

22µA

22µA

TM4

TM3

11µA

11µA

16

510k

0.01µ

FSET

TAO

18

The above figure shows a block diagram of the tracking and sled servo.

The capacitor connected between Pins 8 and 9 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 510k

Ω

resistance connected to Pin 16.

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,

Track jump peak voltage = TM3 (or TM4) current

× feedback resistance

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;

Sled kick peak voltage = TM5 ( or TM6) current

× feedback resistance

The values of the current for each switch are determined by the resistance connected between Pin 17 and

GND. When this resistance is 120k

Ω:

TM3 ( or TM4) = ±11µA, and TM5 (or TM6) = ±22µA.

This current value is almost inversely proportional to the resistance and the variable range is approximately 5

to 40µA at TM3.

SSTOP is the ON/OFF detection signal for the limit SW of the linear motor's innermost track.

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 (470k

Ω) and the capacitor connected to Pin 44.

TM-1 was ON at DFCT in the CXA1082 and CXA1182, but it does not operate in the CXA1372.