HFCT-5964ATG NEL [Nel Frequency Controls,inc], HFCT-5964ATG Datasheet - Page 3

• Manufacturer Part Number: HFCT-5964ATG
• Description: ATG Single Mode Laser Small Form Factor Transceivers for ATM, SONET OC-3 /SDH STM-1 Part of the Agilent METRAK family
• Manufacturer: NEL [Nel Frequency Controls,inc]

Functional Description
Transmitter Section
Design
A schematic diagram for the
transmitter is shown in Figure 2.
The HFCT-5964TL/TG/NL/NG/
ATL/ATG incorporates an FP
laser as its optical source. All
part numbers have 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 detects 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.
Figure 2. Simplified Transmitter Schematic
3
P
P
B
B
DATA
DATA
MON
MON
MON
MON
(+)
(-)
(+)
(-)
LVPECL
INPUT
The transmitter also includes
monitor circuitry for both the
laser diode bias current and
laser diode optical power.
MODULATOR
LASER
LASER BIAS
LASER BIAS
CONTROL
DRIVER
LASER
FP
(rear facet monitor)
PHOTODIODE