DVD PLAYER DIGITAL SERVO & DSP IC
S5L1454A
sampling rage = fs +
+
X
K0
K
D
Y
Average Value Filter Configuration
TIMING DIAGRAM (For example: When LD on & LENS down)
FOKB
FOD LD on
FE
SENSE
down
tOFa
¢º¢º FOCUS/TRACKING INPUT GAIN ADJUSTMENT
Summary
The object of the focus/tracking input gain adjustment is to select the appropriate input gain using H/W before
sampling, according to the size of the FE and TE signals input into the servo part. This allows you to use the
ADC's full input range and raises the quantized data's ability for decomposition.
Input signal : FE, TE
Output signal : FEin, TEin(internal signal) or FOD, TRD (external signal)
FE
(from RF)
INPUT GAIN
AMP
pin
x(-N)
fs
FE
+
+
FEin FOCUS LOOP
FILTER
FinG/TinG
Fofst Fbias
COMMAND
manual setting : DPRW(BC) cmd
Automatic control : focus → DDT (A1) cmd
tracking → TBA (B3) cmd
FOD
pin
23