HFCT-5760TL/TP/NL/NP/ATL/ATP/ANL/ANP
Single Mode OC-3/STM-1 Small Form Factor Pluggable Transceivers
Part of the Avago METRAK family
Data Sheet
Description
The HFCT-5760xxx Small Form Factor
Pluggable LC optical transceivers are high
performance, cost effective modules for serial
data transmission at a signal rate of 155 Mbit/
s. The transceivers are compliant with SONET/
SDH and the Small Form Factor Pluggable
(SFP) Multi-Source Agreement (MSA)
specifications. They are designed for
intermediate and long reach applications at 155
Mbit/s.
The transceivers operate at a nominal
wavelength of 1300 nm over single mode fiber.
The transmitter section incorporates a highly
reliable Fabry Perot (FP) laser and uses an
MOVPE grown planar PIN photodetector for low
dark current and excellent responsivity on the
receiver section.
Features
• Compliant with ITU-T G.957 STM-1 S1.1 (15 km) and
L1.1 (40 km) Optical Interface
• Compliant with Telcordia GR253 OC3 IR-1 (15 km) and
LR-1 (40 km) Optical Interface
• Multi-Source Agreement (MSA) compliant SFP
package
• Hot-pluggable
• Multirate operation from
125 Mb/s to 155 Mb/s
• Operating case temperature ranges:
-40 to +85 °C (ATL/ATL/ANL/ANP)
-10 to +85 °C (TL/TP/NL/NP)
• Optional extended de-latch for high density
applications
- standard de-latch
- bail de-latch
• Manufactured in an ISO 9001 “compliant facility”
• Single +3.3 V power supply
• Class 1 CDRH/IEC 825 eye safety compliant
• LC Duplex fiber connector
Applications
OC-3 SFP transceivers are designed for ATM LAN and
WAN applications such as:
•
•
•
•
•
ATM switches and routers
SONET/SDH switch infrastructure
xDSL applications
Metro edge switching
Suitable for Fast Ethernet applications
Related Products
• HFCT-596xx LC SFF PTH transceivers
• HDMP-3001 Ethernet Over SONET/SDH Mapper
Functional Description
Receiver Section
Design
The receiver section for the HFCT-5760xxx
contains an InGaAs/InP photo detector and a
preamplifier mounted in an optical
subassembly. This optical subassembly is
coupled to a postamplifier/decision circuit on a
circuit board.
The postamplifier is ac coupled to the
preamplifier. The coupling capacitors are large
enough to pass the SONET/SDH test pattern at
155 Mb/s 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.
There is 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.
Loss of Signal
The Loss of Signal (LOS) output indicates that
the optical input signal to the receiver does not
meet the minimum detectable level for
compliant signals. When LOS is high it
indicates loss of signal. When LOS is low it
indicates normal operation. The Loss of Signal
thresholds are set to indicate a definite optical
fault has occurred (eg., disconnected or broken
fiber connection to receiver, failed transmitter).
Transmitter Section
Design
A schematic diagram for the transceiver is
shown in Figure 1. The HFCT-5760xxx
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.
Tx Fault
The HFCT-5760xxx module features a transmit
fault control signal output which when high
indicates a laser transmit fault has occurred
and when low indicates normal laser operation.
A transmitter fault condition can be caused by
deviations from the recommended module
operating conditions or by violation of eye
safety conditions. A fault is cleared by cycling
the Tx Disable control input.
Tx Disable
The HFCT-5760xxx accepts a transmit disable
control signal input which shuts down the
transmitter. A high signal implements this
function while a low signal allows normal laser
operation. In the event of a fault (eg., eye
safety circuit activated), cycling this control
signal resets the module. The Tx Disable
control should be actuated upon initialization of
the module.
2
Module Description
The transceiver meets the Small Form Pluggable
(SFP) industry standard package utilizing an
integral LC-Duplex optical interface connector.
The hot-pluggable capability of the SFP package
allows the module to be installed at any time -
with the host system operating and on-line.
This allows for system configuration changes or
maintenance without system down time. The
HFCT-5760xxx uses a reliable 1300 nm FP
laser source and requires a 3.3 V dc power
supply for optimal design.
Module Diagrams
Figure 1 illustrates the major functional
components of the HFCT-5760xxx. The
connection diagram of the module is shown in
Figure 4. Figure 2 depicts the external
configuration of the module. Figure 3 depicts
the MSA recommended power supply filter.
Installation
The HFCT-5760xxx can be installed in or
removed from any Multisource Agreement
(MSA) - compliant Small Form Pluggable port
regardless of whether the host equipment is
operating or not. The module is simply
inserted, electrical interface first, under finger
pressure. Controlled hot-plugging is ensured by
design and by 3-stage pin sequencing at the
electrical interface. The module housing makes
initial contact with the host board EMI shield
mitigating potential damage due to Electro-
Static Discharge (ESD). The 3-stage pin
contact sequencing involves (1) Ground, (2)
Power, and then (3) Signal pins, making contact
with the host board surface mount connector in
that order.
TRANS-
IMPEDANCE
PRE-
AMPLIFIER
FILTER
AMPLIFIER
OUTPUT
BUFFER
ELECTRICAL INTERFACE
DATA OUT
DATA OUT
LOS
PHOTODIODE
LASER
BIAS
CONTROL
MODULATOR
&
SAFETY
CIRCUITRY
DATA IN
DATA IN
TX_DISABLE
TX_FAULT
FP
LASER
LASER
DRIVER
MOD-DEF (2)
EEPROM
MOD-DEF (1)
MOD-DEF (0)
Figure 1. Transceiver functional diagram
3
1 µH
3.3 V
10 µF
0.1 µF
1 µH
3.3 V
V
CC
,T
0.1 µF
4.7 K to 10 K
Tx Dis
Tx_FAULT
SO+
SOÒ
50 W
50 W
Tx_DISABLE
Tx_FAULT
TD+
TDÒ
TX GND
0.01 µF
V
CC
,R
0.01 µF
100
0.01 µF
AMPLIFICATION
&
QUANTIZATION
0.01 µF
100
LASER DRIVER
& SAFETY
CIRCUITRY
4.7 K to 10 K
HFCT-5760xx
PROTOCOL
IC
SI+
SIÒ
Rx_LOS
4.7 K to 10 K
10 µF
50 W
50 W
0.1
µF
RD+
RDÒ
Rx_LOS
RX GND
MOD_DEF2
PC MASTER
4.7 K to
10 K
4.7 K to
10 K
MOD_DEF1
MOD_DEF0
4.7 K to
10 K
EEPROM
3.3 V
Figure 2. Recommended application configuration
1 µH
V
CC
T
0.1 µF
1 µH
V
CC
R
0.1 µF
10 µF
0.1 µF
10 µF
3.3 V
SFP MODULE
HOST BOARD
NOTE: INDUCTORS MUST HAVE LESS THAN 1
SERIES RESISTANCE PER MSA.
Figure 3. MSA required power supply filter
4
20
19
18
17
16
15
14
13
12
11
V
EE
T
TD-
TD+
V
EE
T
V
CC
T
V
CC
R
V
EE
R
RD+
RD-
V
EE
R
TOP OF BOARD
1
2
3
4
5
6
7
8
9
10
V
EE
T
Tx FAULT
TxDISABLE
MOD-DEF(2)
MOD-DEF(1)
MOD-DEF(0)
RATE SELECT
LOS
V
EE
R
V
EE
R
BOTTOM OF BOARD
(AS VIEWED THROUGH TOP OF BOARD)
Figure 4. Connection diagram of module printed circuit board
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