Finisar Corporation – November 2018 Rev. B2 Page 1
Product Specification
25G SFPwire® SFP+ Active Optical Cable
FCCG125SD1Cxx
PRODUCT FEATURES
Hot-pluggable SFP+ cable ends
Supports 25.7813 Gb/s bit rate
Connectivity Diagnostics®
SFI limiting interface
Input equalization and output
emphasis controls
Single 3.3V power supply
Low power dissipation
0° C to 70° C Temperature range
Rigid pull-tab with LED light
APPLICATIONS
25G Ethernet for Intra- and Inter-Rack
data center interconnection
Finisar 25G SFPwire®, FCCG125SD1Cxx, are SFP+ Active Optical Cables designed
for use in 25G Ethernet links. Finisar 25G SFPwire® are equipped with Connectivity
Diagnostics®, a Finisar’s technology solution enabling real-time performance monitoring
and troubleshooting. The electrical interface of Finisar 25G SFPwire® is compliant with
SFF-8431[1], and the receiver side is limiting.
Finisar 25G SFPwire® provides non-adaptive input equalization and output emphasis
controls as per SFF-8472[2]. The mechanical specifications of the 25G SFPwire® SFP+
ends are compatible with SFF-8432[3].
The 25G SFPwire® is RoHS compliant per Directive 2011/65/EU[4,5].
PRODUCT SELECTION
FCCG125SD1Cxx
Cable Length Options (Orange Jacket Cables)
xx = Z5 0.5m
xx = 05 5m
xx = 01 1.0m
xx = 07 7m
xx = A5 1.5m
xx = 09 9m
xx = 02 2.0m
xx = 10 10m
xx = B5 2.5m
xx = 15 15m
xx = 03 3.0m
xx = 20 20m
xx = C5 3.5m
xx = 30 30m
Please contact Finisar for Aqua-color jacket or custom length options.
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 2
I. Pin Descriptions
Pin
Symbol
Name/Description
1
VEET
Transmitter Ground (Common with Receiver Ground)
2
TFAULT
Transmitter Fault.
3
TDIS
Transmitter Disable. Laser output disabled on high or open.
4
SDA
2-wire Serial Interface Data Line
5
SCL
2-wire Serial Interface Clock Line
6
MOD_ABS
Module Absent. Grounded within the module
7
RS0
No connection required
8
RX_LOS
Loss of Signal indication. Logic 0 indicates normal operation.
9
RS1
No connection required
10
VEER
Receiver Ground (Common with Transmitter Ground)
11
VEER
Receiver Ground (Common with Transmitter Ground)
12
RD-
Receiver Inverted DATA out. AC Coupled
13
RD+
Receiver Non-inverted DATA out. AC Coupled
14
VEER
Receiver Ground (Common with Transmitter Ground)
15
VCCR
Receiver Power Supply
16
VCCT
Transmitter Power Supply
17
VEET
Transmitter Ground (Common with Receiver Ground)
18
TD+
Transmitter Non-Inverted DATA in. AC Coupled.
19
TD-
Transmitter Inverted DATA in. AC Coupled.
20
VEET
Transmitter Ground (Common with Receiver Ground)
Notes:
1. Circuit ground is internally isolated from chassis ground.
2. Open collector/drain output, which should be pulled up with a 4.7k – 10k Ohms resistor on the host
board if intended for use. Pull up voltage should be between 2.0V to Vcc + 0.3V.
3. A high output indicates a transmitter fault caused by either the TX bias current or the TX output power
exceeding the preset alarm thresholds. A low output indicates normal operation. In the low state, the
output is pulled to <0.8V.
4. Laser output disabled on TDIS >2.0V or open, enabled on TDIS <0.8V.
5. Internally pulled down per SFF-8431 Rev 4.1.
6. LOS is open collector output. Should be pulled up with 4.7k – 10k on host board to a voltage between
2.0V and 3.6V. Logic 0 indicates normal operation; logic 1 indicates loss of signal.
7. Internally connected.
Figure 1. Diagram of Host Board Connector Block Pin Numbers and Names.
VeeT
VeeT
VeeR
VeeR
TD-
TD+
RD+
RD-
VccT
VccR
VeeT
VeeR
TX_Fault
SDA
SCL
MOD_ABS
RS0
RX_LOS
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
Towards
ASIC
Towards
Bezel
TX_Disable
RS1
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 3
II. Absolute Maximum Ratings
Exceeding the limits below may damage the active optical cable permanently.
Parameter
Symbol
Min
Typ
Max
Unit
Ref.
Maximum Supply Voltage
Vcc
-0.5
4.0
V
Storage Temperature
TS
-5
75
C
1
Case Operating Temperature
TA
0
70
C
Relative Humidity
RH
0
85
%
2
Notes:
1. Assumes no mechanical load force on the unit. Ensuring no mechanical load force requires a cable
bend radius of >105 mm within 100 mm of either cable and SFP+ end and >60 mm on the rest of the
cable. Cable is rated for the storage temperature range is -20 to 75°C.
Non-condensing.
III. Electrical Characteristics (each cable end, TOP = 0 to 70 C, VCC = 3.14 to 3.46 Volts)
Parameter
Symbol
Min
Typ
Max
Unit
Ref.
Supply Voltage
Vcc
3.14
3.46
V
Supply Current
Icc
310
mA
Transmitter
Input differential impedance
Rin
100

1
Differential data input swing
Vin,pp
180
700
mV
Transmit Disable Voltage
VD
2
Vcc
V
Transmit Enable Voltage
VEN
Vee
Vee+ 0.8
V
Receiver
Differential data output swing
Vout,pp
300
850
mV
2
Data output rise time, fall time
tr
28
ps
3
LOS Fault
VLOS fault
2
VccHOST
V
4
LOS Normal
VLOS norm
Vee
Vee+0.8
V
4
Power Supply Noise Tolerance
VccT/VccR
Per SFF-8431 Rev 4.1
mVpp
5
Notes:
1. Connected directly to TX data input pins. AC coupling from pins into laser driver IC.
2. Into 100 differential termination.
3. 20 – 80% . Measured with Module Compliance Test Board and OMA test pattern. Use of four 1’s
and four 0’s in sequence in the PRBS^9 is an acceptable alternative[1].
4. LOS is an open collector output. Should be pulled up with 4.7k – 10k on the host board.
Normal operation is logic 0; loss of signal is logic 1. Maximum pull-up voltage is 5.5V.
5. Testing methodology per [1].
IV. Input Equalization and Output Emphasis Controls
Finisar FCCG125SD1Cxx provide non-adaptive input equalization and output
emphasis controls, allowing the host to select pre-set levels of optimization of the electrical
high-speed signals of the transceiver’s transmitter input and receiver output, via the 2-wire
communication, as defined in the SFF-8472[2].
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 4
V. General Specifications
Parameter
Symbol
Min
Typ
Max
Units
Ref.
Bit Rate
BR
25.78125
Gb/s
Bit Error Ratio
BER
10-8
1
Notes: 1. Pre-FEC, tested with a PRBS 231 – 1.
VI. Connectivity Diagnostics® Technology
Finisar FCCG125SD1Cxx are equipped with Connectivity Diagnostics®, which
combines the pull-tabs’ LED lights with the out-of-band signaling between the transceivers
at the two ends of the AOC. Three features are currently implemented:
Helps locate the other end of the AOC. Manually pushing-in
either pull tab will light up their LED lights on both ends.
Reports the health status of the AOC. Any Digital Diagnostic
Monitoring warning/alarm events, transmitter’s fault or
receiver’s loss of signal, will light up the pull-tab LED lights
of both ends.
Allows the host to control the AOC pull-tabs’ LED lights.
Writing a command via the 2-wire communication interface
of the near-end AOC transceiver will light up the pull-tabs’
LED lights of both ends.
A detailed description of Connectivity Diagnostics® is provided in Finisar’s
Application Note AN-2158[6].
VII. Environmental Specifications
The following table shows the operating temperature range of the FCCG125SD1Cxx:
Parameter
Symbol
Min
Typ
Max
Units
Ref.
Case Operating Temperature
Top
0
70
°C
VIII. Regulatory Compliance
The FCCG125SD1Cxx SFPwire®, which contains laser devices, is a Class 1 laser
product and complies with 21CFR 1040.10 and 1040.11 except for deviations pursuant to
Laser Notice No. 50, dated June 24, 2007, and it complies with EN(IEC) 60825 Edition
1.2 regulations. The 25G SFPwire® is RoHS compliant per Directive 2011/65/EU[4,5].
Copies of certificates are available at Finisar Corporation upon request.
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 5
VIX. Mechanical Specifications
The FCCG125SD1Cxx SFPwire SFP+ cable ends are compatible with the SFF-8432
specifications and provide a rigid pull tab whose color is opaque, when the embedded LED
light is not lit up, or amber, when illuminated.
Figure 2. FCCG125SD1Cxx Mechanical Dimensions.
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 6
FCCG125SD1Cxx SFPwire® cable details
Description
Min
Typ
Max
Units
Notes
Jacket Material
PVC
PVC
Jacket Color
Orange
Aqua available upon
request
Flammability Rating
OFNR
Plenum Cable option
available upon request
Outer Diameter
2.8
3.0
3.2
mm
Tensile Load (Short Term)
200
N
Tensile Load (Long Term)
100
N
Crush Resistance
10
N/mm
FOTP-41
Impact Resistance
0.5
N·m
FOTP-25
Flexing
300
Cycles
FOTP-104
Twist Bend
Exceeds FOTP-85
Cable to SFP+ Plug Connection
90
Newtons
Bend Radius (Short Term)
25
mm
Bend Radius (Long Term)
30
mm
Durability
100
Cycle Min
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 7
X. PCB Layout and Bezel Recommendations
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 8
Figure 3.
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 9
Figure 4.
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 10
XI. Host - Active optical cable end Interface Block Diagram
Figure 5.
FCCG125SD1Cxx Product Specification
Finisar Corporation - November 2018 Rev. B2 Page 11
XII. References
1. “Specifications for Enhanced 8.5 and 10 Gigabit Small Form Factor Pluggable Module
‘SFP+ ‘”, SFF Document Number SFF-8431, Revision 4.1.
2. “Improved Pluggable Formfactor”, SFF Document Number SFF-8432, Revision 4.2,
April 18, 2007.
3. Directive 2011/65/EU of the European Parliament and of the Council “on the restriction
of the use of certain hazardous substances in electrical and electronic equipment”.
Certain products may use one or more exemption as allowed by the directive.
4. “Application Note AN-2038: Finisar Implementation of RoHS Compliant
Transceivers”, Finisar Corporation, January 21, 2005.
5. “Diagnostic Monitoring Interface for Optical Transceivers”, SFF Document Number
SFF-8472, revision 12.2, November 21, 2014.
6. “Application Note AN-2158: Finisar’s Connectivity Diagnostics® for Active Optical
Cables” Finisar Corporation, rev. B5, April 2017.
XIII. For More Information
Finisar Corporation
1389 Moffett Park Drive
Sunnyvale, CA 94089-1133
Tel. 1-408-548-1000
Fax 1-408-541-6138
sales@finisar.com
www.finisar.com