Circuit Description - Harman Kardon FL8380 Service Manual

FUNCTION DESCRIPTION
Tracking System
E
A B
C D
F
PDIC
The tracking error output of E and F is given to Pin 25 (TEOUT). C8 is required for
oscillation-proof. R10 is chosen such that TEOUT of Pin 25 become 1.4Vp-p.
During alignment procedure, the DSP IC (MN662790) will adjust the tracking balance
voltage V from Pin 31. V
TBAL
within 0.5 V.
The tracking gain will change according to the type of disc. For normal disc or CDR disc,
V is set to V
GCTRL REF2
focus gain is changed too.
R15
32
R14
31
varies with reference to the center voltage V
TBAL
; for CDRW disc V
GCTRL
To Focus System
GCTRL
28 21
V
GCTRL
C2
is set to V - 0.75 V. At the same time, the
REF2
17
V V
REF1 REF2
Subtraction
TBAL
23
30 25
R10
C15 C5
R5
V
TEOUT
TBAL
(=1.65 V)
REF2
FL8380
TEN
24
C8