GAOTek SFP Transceiver with 4.25Gb/s (5km)

This 4.25Gb/s 1310nm SFP (Small form-factor pluggable) Transceiver is used with Single-mode optical fiber to reach up to 3.11 miles (5km) transmission distance.




This 4.25Gb/s 1310nm SFP (Small form-factor pluggable) Transceiver is used with Single-mode optical fiber to reach up to 3.11 miles (5km) transmission distance. It also has a DFB (Distributed Feedback) type transmitter, PIN type receiver, an LD (Laser Driver), a limiting amplifier and digital diagnostic monitor. It is compatible with 1x, 2x, 4x Fiber Channel with data rates 1.06Gb/s, 2.125Gb/s and 4.25Gb/s. The SFP Transceiver is a Class 1 laser safety product which complies with US FDA regulations, SFF-8472 and RoHS standards.

Key Features:

  • Up to 3.11 miles (5km) transmission distance.
  • Up to 4.25Gb/s data links.
  • 1310nm DFB transmitter and PIN Photo-detector.
  • Unique enhanced digital diagnostic monitoring interface.
  • Duplex LC/UPC type pluggable optical interface.
  • Low power dissipation.
  • Metal enclosure, for lower EMI.
  • Single +3.3V power supply
  • RoHS compliant and lead-free.
  • Compliant with SFF-8472
  • Commercial case operating temperature range: 32°F to 158°F (0°C to +70°C)
  • Extended case operating temperature range: 14°F to 176°F (-10°C to +80°C)
  • Industrial case operating temperature range: -40°F to 185°F (-40°C to +85°C)


Technical Specifications:

Protocol 2-Wire Serial communication Protocol
Working Range Up to 3.11 miles (5km)
Memory 256-byte memory map in EEPROM
Standards SFF-8472, SFF-8431 and SFP MSA.

1x,2x,4x FC

Class 1 laser safety

RoHS compliant.

Data rate 4.25Gb/s
Wavelength 1310nm
Fiber Optic Cable 9/125µm Single-mode
Transmitter DFB
Receiver PIN
Connector LC
Digital Diagnostics Monitoring Enabled
Transmitter output optical Power -6 dBm to -1 dBm
Receiver Sensitivity Data rate at 1.06Gb/s -22 dBm
Data rate at 2.125Gb/s -21 dBm
Data rate at 4.25Gb/s -18 dBm
Receiver Input Saturation Power 0.5 dBm
Supply Voltage 3.3V
Transmitter Differential Line Input Impedance 100Ω
Dimensions 2.3in x 0.54in x 0.33in (L 58.4mm x W13.7mm x   H 8.5mm)
Relative Humidity 5% to 95% Non-condensing

5% to 70% (Recommended)

Storage Temperature -40 °F to 185 °F (-40°C to 85°C)

Case Operating Temperature

Commercial 32°F to 158°F (0°C to +70°C)
Extended 14°F to 176°F (-10°C to +80°C)
Industrial -40°F to 185°F (-40°C to +85°C)


Additional Information:


Ideal to be used on applications such as

  • 4xFC at 4.25Gbps
  • 2xFC at 2.125 Gbps
  • 1xFC at 1.0625Gbps
  • 1000 Base-LX Ethernet

Ordering Information:

Product ID Data rate(Gb/s) Media Wavelength Transmission Distance Temperature Range Supply Current


4.25 Single -mode fiber 1310nm 3.11 miles (5km) Commercial

32°F to 158°F

(0°C to +70°C)

330 mA


4.25 Single -mode fiber 1310nm 3.11 miles (5km) Extended

14°F to 176°F

(-10°C to +80°C)


330 mA


4.25 Single -mode fiber 1310nm 3.11 miles (5km) Industrial

-40°F to 185°F

(-40°C to +85°C)


330 mA

Digital Diagnostics Functions:

  • GAOTek GAO-SFP-117 series transceivers support the 2-wire serial communication protocol as defined in the SFP MSA1. It is very closely related to the E2PROM defined in the GBIC standard, with the same electrical specifications.
  • Additionally, GAOTek SFP Transceivers provide a unique enhanced digital diagnostic monitoring interface which allows real-time access to device operating parameters such as transmitter optical power, receiver optical power, transceiver temperature, transceiver supply voltage and laser bias current. It defines an alarm system and warning flags, which alerts the end users when particular operating parameters are outside of a factory set normal range.
  • Standard SFP Serial id provides access to identification information that describes the transceiver’s capabilities, standard interfaces, manufacturer and other information.
  • SFP MSA defines a 256-byte memory map in EEPROM that is accessible over a 2 wire serial interface at the 8 bit address 1010000X (A0h). The interface is identical to, and is thus fully backward compatible with both the GBIC Specification and the SFP Multi Source Agreement.
  • The operating and diagnostics information is monitored and reported by a Digital Diagnostics Transceiver Controller (DDTC) inside the transceiver, which is accessed through a 2-wire serial interface. The memories are organized as a series of 8-bit data words that can be addressed individually or sequentially.
  • Digital diagnostics for the GAO-SFP-117 are internally calibrated by default.

Electrical interface characteristics:

Parameter Symbol Min Type Max Unit Note
Total Supply Current ICC A mA 1
Transmitter Disable Input-High VDISH 2 Vcc+0.3 V
Transmitter Disable Input-Low VDISL 0 0.8 V
Transmitter Fault Input-High VTxFH 2 Vcc+0.3 V
Transmitter Fault Input-Low VTxFL 0 0.8 V
Total Supply Current ICC B mA 1
LOSS Output Voltage-High VLOSH 2 Vcc+0.3 V LVTTL
LOSS Output Voltage-Low VLOSL 0 0.8 V


  1. A (TX)+ B (RX) = 330mA (Not include termination circuit)

Optical Characteristics:

Specification of Transmitter:

Parameter Symbol Min Type Max Unit Ref
Average Output Optical  Power POUT -6 -1 dBm 1
Center Wavelength λc 1270 1310 1360 nm DFB laser
Optical Extinction Ratio ER 6 dB
Side Mode Suppression Ratio SMSR 30 dB
Spectrum Bandwidth(-20dB) σ 1 nm
Transmitter OFF Output Power POff -45
Differential Line Input Impedance RIN 90 100 110
Output Eye Mask FC-PI-4 requirements


  1. Measure at 2^23-1 NRZ PRBS pattern.

Specification of Receiver:

Parameter Symbol Min Type Max Unit Ref
Receiver Sensitivity @ 1.06Gb/s RSENS1 – 22.0 dBm 1
Receiver Sensitivity @ 2.125Gb/s RSENS2 – 21.0 dBm 1
Receiver Sensitivity @ 4.25Gb/s RSENS3 – 18.0 dBm 1
Wavelength Range λC 1270 1610 nm PIN-TIA
Input Saturation Power (Overload) Psat 0.5 dBm
LOS Assert LOSA -35 dBm
LOS De -Assert LOSD -19 dBm
LOS Hysteresis 0.5 2 6 dB 2


  1. With worst-case extinction ratio. Measured with a PRBS 27-1 test pattern, BER<10-12
  2. When LOS de-asserted, the RX data+/- output is High-level (fixed)

Pin out of Connector Block on Host Board:

PIN Descriptions:

Pin Symbol Name/Description Note
1 VEET Transmitter Ground (Common with Receiver Ground) 1
2 TFault Transmitter Fault
3 TDis Transmitter Disable. 2
4 MOD_DEF(2) Module Definition 2. Data line for Serial ID. 3
5 MOD_DEF(1) Module Definition 1. Clock line for Serial ID. 3
6 MOD_DEF(0) Module Definition 0. Grounded within the module. 3
7 Rate Select No connection required 4
8 LOS Loss of Signal indication. Logic 0 indicates normal operation 5
9 VEER Receiver Ground (Common with Transmitter Ground) 1
10 VEER Receiver Ground (Common with Transmitter Ground) 1
11 VEER Receiver Ground (Common with Transmitter Ground) 1
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) 1
15 VCCR Receiver power Supply
16 VCCT Transmitter Power supply
17 VEET Transmitter Ground (Common with receiver Ground) 1
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) 1


  1. Circuit ground is internally isolated from ground.
  2. Laser output disabled when it is open or TDis > 2.0V, enabled on TDis < 0.8V.
  3. Should be pulled up with 4.7kΩ to 10kΩ on host board to a voltage between 2.0V and 3.6V.MOD_DEF (0) pulls the line low to indicate the module is plugged in.
  4. This is an optional input used to control the receiver bandwidth for compatibility with multiple data rates (most likely Fiber Channel 1x and 2x Rates).If implemented, the input will be internally pulled down with > 30kΩ resistor. The input states are:
  • Low (0 – 0.8V) : Reduced Bandwidth
  • (>0.8, < 2.0V) : Undefined
  • High (2.0 – 3.465V) : Full Bandwidth
  • Open : Reduced Bandwidth
  1. Loss of signal is open collector output.
  • It should be pulled up with 4.7 kΩ to 10 kΩ on host board to a voltage between 2.0V and 3.6V.
  • Logic 0 indicates normal operation.
  • Logic 1 indicates loss of signal.

Mechanical Dimensions:

Recommend Circuit Schematic:

Regulatory Compliance:

Feature Reference Performance
Laser Eye Safety FDA 21CFR 1040.10, 1040.11 IEC/EN 60825-1,2 Class 1 laser product
Component Recognition IEC/EN 60950, UL Compatible with standards
ROHS 2002/95/EC Compatible with standards
Electrostatic discharge(ESD) IEC/EN 61000-4-2 Compatible with standards
EMC EN61000-3 Compatible with standards
Electromagnetic Interference(EMI) FCC Part 15 Class B EN 55022 Class B (CISPR 22A) Compatible with standards