cxa1992br Sony Electronics, cxa1992br Datasheet - Page 16

• Manufacturer Part Number: cxa1992br
• Description: Rf Signal Processing Servo Amplifier
• Manufacturer: Sony Electronics

Description of Functions
RF Amplifier
The photo diode currents input to the input pins (PD1 and PD2) are each I-V converted through a 58k
equivalent resistor by the PD I-V amplifiers. These signals are added by the RF summing amplifier, and the
photo diode (A + B + C + D) current-voltage converted voltage is output to the RFO pin. An eye-pattern check
can be performed at this pin.
The low frequency component of the RFO output voltage is V
V
RFO
= –2.2 {–58k (iPD1 + iPD2) + V1 + V2 – 2V3} + V3.
V1 = V2 = V3 are set , and V
= –
1k
3.3µ
22k
10k
C
D
A
B
(VA + VB – 2V3) +V3
iPD1
iPD2
PD1
PD2
38
39
VC
VC
RFO
PD1 IV AMP
PD2 IV AMP
= 127.6k
58k
58k
– 16 –
V1
V2
VA 10k
VB 10k
(iPD1 + iPD2) + V3
RFO
= 2.2
34
(V
RF_M
V3
A
RF SUMMING AMP
+ V
22k
B
) = 127.6k
33
RF_O
FOK
DEFECT
(iPD1 + iPD2).
CXA1992BR