AFCT-5971ALZ Avago Technologies US Inc., AFCT-5971ALZ Datasheet - Page 2

• Manufacturer Part Number: AFCT-5971ALZ
• Description: TXRX FE SM LASER 125MBS 2X5
• Manufacturer: Avago Technologies US Inc.

Specifications of AFCT-5971ALZ

• Applications: Ethernet
• Data Rate: 125MBd
• Wavelength: 1300nm
• Voltage - Supply: 3.1 V ~ 3.5 V
• Connector Type: LC Duplex
• Mounting Type: Through Hole
• Data Rate Max: 0.125Gbps
• Supply Voltage: 3.3V
• Wavelength Typ: 1300nm
• Leaded Process Compatible: Yes
• Optical Fiber Type: TX/RX
• Data Transfer Rate: 155Mbps
• Optical Rise Time: 2/2.2ns
• Optical Fall Time: 2/2.2ns
• Operating Temperature Classification: Industrial
• Peak Wavelength: 1360/1580nm
• Package Type: DIP With Connector
• Operating Supply Voltage (min): 3.1V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.5V
• Output Current: 50mA
• Operating Temp Range: -40C to 85C
• Mounting: Snap Fit To Panel
• Pin Count: 10
• Product: Transceiver
• Maximum Rise Time: 2 ns, 2.2 ns
• Maximum Fall Time: 2 ns, 2.2 ns
• Maximum Output Current: 50 mA
• Operating Supply Voltage: 3.1 V to 3.5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Package / Case: DIP-10 with Connector
• Function: Applications specified for signal rate of 125 MBd, for Fast Ethernet, and Singlemode Fiber.
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: Singlemode Glass
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Functional Description
Transmitter Section
Design
A schematic diagram for the transmitter is shown in Fig-
ure 2. The AFCT-5971LZ/ALZ 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 nor-
mal operating conditions. The optical output is con-
trolled 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 modula-
tion, eye diagram and extinction ratio over temperature,
supply voltage and operating life.
Functional Description
Receiver Section
Design
The receiver section for the AFCT-5971LZ/ALZ con-
tains an InGaAs/InP photo detector and a preamplifier
mounted in an optical subassembly. This optical subas-
sembly is coupled to a postamp/decision circuit on a
circuit board. The design of the optical assembly is such
that it provides better than 14 dB Optical Return Loss
(ORL).
The postamplifier is ac coupled to the preamplifier as
illustrated in Figure 1. The coupling capacitors are large
enough to pass the EFM test pattern at 125 MBd with-
out significant distortion or performance penalty.
Figure 1 also shows a filter function which limits the
bandwidth of the preamp output signal. The filter is de-
signed to bandlimit the preamp output noise and thus
improve the receiver sensitivity.
Figure 1. Receiver Block Diagram
2
TRANS-
IMPEDANCE
PRE-
AMPLIFIER
GND
FILTER
AMPLIFIER
CIRCUIT
SIGNAL
DETECT
LVPECL
OUTPUT
BUFFER
LVPECL
OUTPUT
BUFFER
These components will reduce the sensitivity of the re-
ceiver as the signal bit rate is increased above 155 Mb/s.
Noise Immunity
The receiver includes internal circuit components to
filter power supply noise. However under some condi-
tions of EMI and power supply noise, external power
supply filtering may be necessary (see Application Sec-
tion).
The Signal Detect Circuit
The signal detect circuit works by sensing the level of
the received signal and comparing this level to a refer-
ence. The SD output is low voltage PECL.
Figure 2. Simplified Transmitter Schematic
DATA
DATA
LVPECL
INPUT
DATA OUT
DATA OUT
SD
MODULATOR
LASER
LASER BIAS
LASER BIAS
CONTROL
DRIVER
LASER
FP
(rear facet monitor)
PHOTODIODE