cxa2555q Sony Electronics, cxa2555q Datasheet - Page 18

• Manufacturer Part Number: cxa2555q
• Description: Rf Amplifier For Cd Player/cd-rom
• Manufacturer: Sony Electronics

APC Circuit
When the laser diode is driven by a constant current, the optical power output has extremely large negative
temperature characteristics.
The APC circuit is used to maintain the optical power output at a constant level. The laser diode current is
controlled according to the monitor photodiode output.
APC is ON by connecting APC_ON pin to GND; it is OFF by connecting the pin to Vcc.
Center Voltage Generation Circuit
The center voltage of VR = (Vcc + GND)/2 is supplied. The maximum current is approximately ±3mA
PD
2
10k
8k
40k
40k
V
CC
55k
Vc Buffer
1.25V
10k
10k
V
CC
56k
– 18 –
56k
25
1k
16
VR
1
100µ
V
LD
CC
1µ
10µ
Vc
10
100
500
CXA2555Q