CXA2555Q
Center Voltage Generation Circuit
The center voltage of VR = (Vcc + GND)/2 is supplied. The maximum current is approximately ±3mA
VCC
VCC
40k
Vc Buffer
25
VR
Vc
16
40k
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.
VCC
56k
8k
100µ
LD
10
10k
PD
2
1k
1
10k
55k
56k
10µ
1µ
100
500
10k
1.25V
– 18 –
SONY [ SONY CORPORATION ]
