HFCT-5760TP Avago Technologies US Inc., HFCT-5760TP Datasheet - Page 2

• Manufacturer Part Number: HFCT-5760TP
• Description: Fiber Optic Transmitters, Receivers, Transceivers OC3 SFP IR -10 to +8 5 non-DMI
• Manufacturer: Avago Technologies US Inc.

Specifications of HFCT-5760TP

• Function: Singlemode Small Form Factor Pluggable Transceivers with LC Connector.
• Product: Transceiver
• Data Rate: 155 Mbps
• Wavelength: 1300 nm
• Maximum Rise Time: 2.5 ns
• Maximum Fall Time: 2.5 ns
• Operating Supply Voltage: 3.1 V to 3.5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 10 C
• Package / Case: SFP-20
• Optical Fiber Type: TX/RX
• Data Transfer Rate: 155Mbps
• Optical Rise Time: 2.5ns
• Optical Fall Time: 2.5ns
• Operating Temperature Classification: Commercial
• Peak Wavelength: 1360nm
• Package Type: SFP
• Operating Supply Voltage (min): 3.1V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.5V
• Operating Temp Range: -10C to 85C
• Mounting: Snap Fit To Panel
• Pin Count: 20
• For Use With: Singlemode Glass
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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).
2
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.