CXA1992BR
• Focus error amplifier offset adjustment (when adjusting the IC offset)
The offset adjustment is performed by comparing the FEO when the focus servo is OFF with the reference
level.
The FEO and reference level are compared by the window comparator, and the comparison results are output
from SENS1 and SENS2. (ADDRESS D11001110D6)
Adjust the offset so that SENS1 and SENS2 are both High.
Set the reference level to the center ±20mV.
25mV
<
40mV
<
50mV
Reference level width
Variable voltage per step Variable voltage per 2 steps
• Focus bias fine adjustment
Fine adjustment is performed by turning the focus bias adjustment switches (IFB1 to IFB6) ON and OFF while
monitoring a DSP jitter meter with the microcomputer.
The 6-bit focus bias adjustment switches are controlled with commands.
• When performing conventional focus bias adjustment
Fix the focus bias adjustment switches to the desired settings. (for example, IFB6 ON)
In this condition, adjust the focus bias by turning a volume connected to FE_BIAS (Pin 40).
[Example circuit]
VCC
40
FE_BIAS
Volume 47k
3.9k
VEE
– 18 –
SONY [ SONY CORPORATION ]
