afct-5944lz-gz Avago Technologies, afct-5944lz-gz Datasheet - Page 3

• Manufacturer Part Number: afct-5944lz-gz
• Description: Single Mode Sff Transceivers For Sonet Oc-48/sdh Stm-16 Multirate Operation Part Of The Avago Technologies
• Manufacturer: Avago Technologies

Figure 2. Simplified Transmitter Schematic
3
Functional Description
Transmitter Section
Design
A schematic diagram for the transmitter is shown in
Figure 2. The AFCT-5944LZ/ALZ/GZ/AGZ incorporates
an FP laser and has been designed to be compliant with
IEC 825 eye safety requirements under any single fault
condition and CDRH under normal operating conditions.
The optical output is controlled by a custom IC that de-
tects the laser output via the monitor photodiode. This
IC provides both dc and ac current drive to the laser to
ensure correct modulation, eye diagram and extinction
ratio over temperature, supply voltage and operating life.
The transmitters also include monitor circuitry for both
the laser diode bias current and laser diode optical
power.
B
B
P
P
DATA
DATA
MON
MON
MON
MON
(+)
(-)
(+)
(-)
INPUT
PECL
MODULATOR
LASER
LASER BIAS
LASER BIAS
CONTROL
DRIVER
LASER
FP
(rear facet monitor)
PHOTODIODE