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Электронный компонент: HFCT-5006

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Agilent HFCT-5951xx/HFCT-5952xx
Single Mode Laser Small Form Factor
Transceivers for ATM, SONET OC-12/
SDH STM-4 (L4.1)
Part of the Agilent METRAK family
Data Sheet
Description
The HFCT-5951xx/HFCT-5952xx
transceivers are high
performance, cost effective
modules for serial optical data
communications applications
specified for a signal rate of
622 Mb/s. They are designed to
provide SONET/SDH compliant
links for 622 Mb/s long reach
links.
All modules are designed for
single mode fiber and operate at
a nominal wavelength of 1300
nm. They incorporate high
performance, reliable, long
wavelength optical devices and
proven circuit technology to give
long life and consistent service.
The transmitter section consists
of a Distributed Feedback Laser
(DFB) packaged in conjunction
with an optical isolator for
excellent back reflection
performance. The transmitter has
full IEC 825 and CDRH Class 1
eye safety.
Features
HFCT-5951xx/HFCT-5952xx are
compliant to the long reach
SONET OC12/SDH STM-4 (L4.1)
specifications
Multisourced 2 x 5 and 2 x 10
package styles with LC receptacle
Single +3.3 V power supply
Temperature range:
HFCT-595xNL/NG: 0C to
+70C
Wave solder and aqueous wash
process compatible
Manufactured in an ISO9002
certified facility
Performance
HFCT-5951xx/HFCT-5952xx:
Links of 40 km with 9/125 m SMF
Fully Class 1 CDRH/IEC 825
compliant
Pin Outs:
HFCT-5951xx 2 x 5
HFCT-5952xx 2 x 10
Applications
SONET/SDH equipment
interconnect,
STS-12/SDH STM-4 rate
Long reach (up to 40 km)
ATM links
The receiver section uses a
MOVPE grown planar PIN
photodetector for low dark
current and excellent
responsivity.
A pseudo-ECL logic interface
simplifies interface to external
circuitry.
These transceivers are supplied
in the new industry standard
2 x 5 and 2 x 10 DIP style
footprint with the LC fiber
connector interface and are fully
compliant with SFF Multi Source
Agreement (MSA).
2
Functional Description
Receiver Section
Design
The receiver section contains an
InGaAs/InP photo detector and
a preamplifier mounted in an
optical subassembly. This optical
subassembly is coupled to a
postamp/decision circuit.
The postamplifier is ac coupled
to the preamplifier as illustrated
in Figure 1. The coupling
capacitors are large enough to
pass the SONET/SDH test
pattern at 622 MBd without
significant distortion or
performance penalty. If a lower
signal rate, or a code which has
significantly more low frequency
content is used, sensitivity, jitter
and pulse distortion could be
degraded.
Figure 1 also shows a filter
function which limits the
bandwidth of the preamp output
signal. The filter is designed to
bandlimit the preamp output
noise and thus improve the
receiver sensitivity.
These components will reduce
the sensitivity of the receiver as
the signal bit rate is increased
above 622 Mb/s.
The device incorporates a
photodetector bias circuit. This
output must be connected to V
CC
and can be monitored by
connecting through a series
resistor (see application
section).
Figure 1. Receiver Block Diagram
Noise Immunity
The receiver includes internal
circuit components to filter
power supply noise. However
under some conditions of EMI
and power supply noise,
external power supply filtering
may be necessary (see
application section).
The Signal Detect Circuit
The signal detect circuit works
by sensing the peak level of the
received signal and comparing
this level to a reference. The SD
output is low voltage TTL.
TRANS-
IMPEDANCE
PRE-
AMPLIFIER
FILTER
GND
AMPLIFIER
PECL
OUTPUT
BUFFER
TTL
OUTPUT
BUFFER
DATA OUT
SIGNAL
DETECT
CIRCUIT
SD
DATA OUT
PHOTODETECTOR
BIAS
3
Figure 2. Simplified Transmitter Schematic
Functional Description
Transmitter Section
Design
The transmitter section uses a
distributed feedback (DFB) laser
as its optical source, see Figure
2. The source is packaged in
conjunction with an optical
isolator to provide excellent
back reflection performance. The
package has been designed to be
compliant with IEC 825 eye
safety requirements under any
single fault condition. 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.
DATA
DATA
PECL
INPUT
LASER
MODULATOR
FP
LASER
LASER BIAS
DRIVER
LASER BIAS
CONTROL
PHOTODIODE
(rear facet monitor)
Note 1
B
MON
(+)
B
MON
(-)
Note 1
Note 1: THESE FUNCTIONS ONLY AVAILABLE ON 2 x 10 PINOUT DESIGN
P
MON
(+)
P
MON
(-)
Note 1
The transmitter section also
includes monitor circuitry for
both the laser diode bias current
and laser diode optical power.
4
DATA OUT
SIGNAL
DETECT
DATA IN
DATA IN
Tx DISABLE
B
MON
(+) Note 1
B
MON
(-) Note 1
P
MON
(+) Note 1
P
MON
(-) Note 1
QUANTIZER IC
LASER DRIVER
AND CONTROL
CIRCUIT
PIN PHOTODIODE
PREAMPLIFIER
SUBASSEMBLY
LASER
OPTICAL
SUBASSEMBLY
DATA OUT
LC
RECEPTACLE
R
X
SUPPLY
T
X
SUPPLY
R
X
GROUND
T
X
GROUND
PHOTO DETECTOR
BIAS Note 2
LASER BIAS
MONITORING
LASER DIODE
OUTPUT POWER
MONITORING
CASE
Note 3
Note 1: THESE FUNCTIONS ONLY AVAILABLE ON 2 x 10 PINOUT DESIGN
Note 2: CONNECTED TO R
X
V
CC
IN 2 x 5 DESIGN
Note 3: NOSE CLIP PROVIDES CONNECTION TO CHASSIS GROUND FOR BOTH EMI AND THERMAL DISSIPATION.
Note 1
Note 1
Package
The overall package concept for
the Agilent transceiver consists
of four basic elements; two
optical subassemblies and two
electrical subassemblies. They
are housed as illustrated in the
block diagram in Figure 3.
The package outline drawing
and pin out are shown in
Figures 4, 5 and 6. The details of
this package outline and pin out
are compliant with the multi-
source definition of the 2 x 5 and
2 x 10 DIP. The low profile of the
Agilent transceiver design
complies with the maximum
height allowed for the LC
connector over the entire length
of the package.
The electrical subassemblies
consist of high volume
multilayer printed circuit boards
on which the IC and various
surface-mounted passive circuit
elements are attached.
The receiver electrical
subassembly includes an
internal shield for the electrical
and optical subassemblies to
ensure high immunity to
external EMI fields.
The optical subassemblies are
each attached to their respective
transmit or receive electrical
subassemblies. These two units
are than fitted within the outer
housing of the transceiver that is
molded of filled nonconductive
plastic to provide mechanical
Figure 3. Block Diagram.
strength. The housing is then
encased with a metal EMI
protective shield. Four ground
connections are provided for
connecting the EMI shield to
signal ground.
The pcb's for the two electrical
subassemblies both carry the
signal pins that exit from the
bottom of the transceiver. The
solder posts are fastened into
the molding of the device and
are designed to provide the
mechanical strength required to
withstand the loads imposed on
the transceiver by mating with
the LC connectored fiber cables.
Although they are not connected
electrically to the transceiver, it
is recommended to connect
them to chassis ground.
5
DIMENSIONS IN MILLIMETERS (INCHES)
DIMENSIONS SHOWN ARE NOMINAL. ALL DIMENSIONS MEET THE MAXIMUM PACKAGE OUTLINE DRAWING IN THE SFF MSA.
Figure 4. HFCT-5951xx/5952xx Package Outline Drawing (2 x 10 Design shown)
TOP VIEW
13.59
(0.535)
MAX
13.59
0.535
+ 0
- 0.2
+0
-0.008
( )
15.0 0.2
(0.591 0.008)
6.25
(0.246)
10.16
(0.4)
9.6 0.2
(0.378 0.008)
1.07
(0.042)
1
(0.039)
1.78
(0.07)
20 x 0.5
(0.02)
0.25
(0.01)
4.06
(0.16)
9.8
(0.386)
MAX
48.2
(1.898)
FRONT VIEW
SIDE VIEW
BACK VIEW
19.5 0.3
(0.768 0.012)
1
(0.039)
10.8 0.2
(0.425 0.008)
3.81
(0.15)
1.07
(0.042)
1
(0.039)
1.78
(0.07)
20 x 0.5
(0.02)
0.25
(0.01)
3.81
(0.15)
9.8
(0.386)
MAX
48.2
(1.898)
SIDE VIEW
19.5 0.3
(0.768 0.012)
G MODULE - NO EMI NOSE SHIELD
20 x 0.25
(0.01)
BOTTOM VIEW
(PIN THICKNESS)
NOTE: END OF PINS
CHAMFERED