Alpha Bridge ASFP28-25G-LR

Features

  • Compliant to 3by 25GBASE-LR.
  • Up to 25.78Gb/s data links.
  • 25G 1310nm DFB transmitter.
  • 25G PIN photo-detector.
  • 2-wire interface for management specifications compliant with SFF-8472 digital diagnostic monitoring interface for optical transceivers.
  • Operating case temperature: -40 to 85°C.
  • All-metal housing for superior EMI performance.
  • 25G electrical interface (OIF CEI-28G-VSR).
  • Maximum power consumption 5W.
  • Advanced firmware allow customer system encryption information to be stored in transceiver.
  • RoHS compliant.

Applications

  • High-speed storage area networks.
  • Computer cluster cross-connect.
  • Custom high-speed data pipes.
  • Inter Rack Connection.

Absolute Maximum Ratings ASFP28-25G-LR

Parameter Symbol Min Max Unit
Storage Temperature Tc 40 85°C °C
Operating Case Temperature Tc -40 85 °C
Supply Voltage Vcc 0 3.6 V
Relative Humidity RH 5 85 %
Damage Threshold THd 3.0   dBm

Recommended Operating Conditions ASFP28-25G-LR

Parameter Symbol Min. Typ. Max. Units
Case Operating Temperature Tc -40   85 °C
Power Supply Voltage Vcc 3.135 3.3 3.465 V
Data Rate, each Lane     25.78125   Gb/s
Data Rate Accuracy   -100   100 ppm
Control Input Voltage High   2   Vcc V
Control Input Voltage Low   0   0.8 V
Link Distance with G.652 D 0.002   10 km

Digital Diagnostics Functions ASFP28-25G-LR

Parameter Symbol Accuracy Unit Notes
Temperature monitor absolute error DMI_Temp ± 3 °C Over operating Temp
Supply voltage monitor absolute error DMI_VCC ±0.1 V Full operating range
RX power monitor absolute error DMI_RX ± 2 dB dB 1
Bias Current monitor DMI_Ibias ± 10% mA  
Laser power monitor absolute error DMI_TX ± 2 dB dB 1

Notes: Due to measurement accuracy of different single mode fibers, there could be an additional +/-1 dB fluctuation, or a +/- 3 dB total accuracy.

Electrical Characteristics ASFP28-25G-LR

Parameter Symbol Min Typical Max Unit Notes
Power Consumption       3.5 W  
Supply Current Icc     1.1 A  
Transceiver Power-on Initialization Time       2000 ms 1

Notes: Power-on initialization time is the time from when the power supply voltages reach and remain above the minimum recommended operating supply voltages to the time when the module is fully functional.

Optical Characteristics ASFP28-25G-LR

Parameter           Symbol Min Typical Max Unit Notes
Wavelength Assignment L0 1264.5 1271 1277.5 nm
L1 1284.5 1291 1297.5 nm  
L2 1304.5 1311 1317.5 nm  
L3 1324.5 1331 1337.5 nm  

Transmitter Electro-optical Characteristics ASFP28-25G-LR

Parameter Symbol Min. Type Max. Units Note
Power Consumption       1.5 W  
Supply Current Icc     450 mA  
Overload Differential Voltage pk-pk TP1a 900     mV  
Common Mode Voltage (Vcm) TP1 -350   2850 mV 1
Differential Termination Resistance Mismatch   TP1       10   %   At 1MHz
        See CEI-28G-    
Differential Return Loss (SDD11) TP1     VSR Equation dB  
        13-19    
Common Mode to Differential conversion       See CEI-28G-    
and Differential to Common Mode TP1     VSR Equation dB  
conversion (SDC11, SCD11)       13-20    
    See CEI-28G-        
Stressed Input Test TP1a VSR Section        
    13.3.11.2.1        
Center Wavelength t 1295   1325 nm  
Side Mode Suppression Ratio SMSR 30     dB  
Average Optical Power Pavg -7 --- 2 dBm  
OMA POMA -4   2.2 dBm 2
Launch Power in OMA minus Transmitter     -5       dBm  
and Dispersion Penalty (TDP)          
Transmitter Dispersion Penalty TDP     2.7 dB
Extinction Ratio ER 3.5 --- --- dB
Relative Intensity Noise RIN20OMA     -130 dB/Hz
Optical Return Loss Tolerance TOL --- --- 20 dB
Transmitter Reflectance RT     -26 dB
Average Launch Power OFF Transmitter Poff     -30 dBm

 Note: Average optical power shall be measured using the methods specified in TIA/EIA-455-95.

Receiver Electro-optical Characteristics ASFP28-25G-LR

Parameter Symbol Min. Type Max. Units Note
Differential Voltage, pk-pk TP4     900 mV  
Common Mode Voltage (Vcm) TP4 -350   2850 mV 1
Common Mode Noise, RMS TP4     17.5 mV  
Differential Termination Resistance Mismatch TP4     10 % At 1MHz
        See CEI-28G-    
Differential Return Loss (SDD22) TP4     VSR Equation dB  
        13-19    
Common Mode to Differential conversion and       See CEI-28G-    
Differential to Common Mode conversion TP4     VSR Equation dB  
(SDC22, SCD22)       13-21    
Common Mode Return Loss (SCC22) TP4     -2 dB 2
Transition Time, 20 to 80% TP4 9.5       ps  
Vertical Eye Closure (VEC) TP4     5.5 dB  
Eye Width at 10-15 probability (EW15) TP4 0.57     UI  
Eye Height at 10-15 probability (EH15) TP4 228     mV  
Center Wavelength r 1295   1325 nm  
Damage Threshold THd 3     dBm 3
Average Receive Power   -14   2 dBm  
Receive Power (OMA)       2.2 dBm  
  Receiver Sensitivity (OMA)   SEN       -12   dBm for BER =
Stressed Receiver Sensitivity (OMA)     -9.5 dBm 4 5x10-5
Receiver Reflectance RR   -26  
LOS Assert LOSA -30    
LOS Deassert LOSD   -15  
LOS Hysteresis LOSH 0.5    
Receiver Electrical 3 dB upper Cutoff        
Vertical Eye Closure Penalty, each Lane 2.5 dB
Stressed Eye J2 Jitter 0.27 UI
Stressed Eye J4 Jitter 0.39 UI
SRS Eye Mask Definition {X1, X2, X3, Y1, Y2, Y3} Hit ratio 5x10-5 per sample   {0.31, 0.4, 0.45, 0.34, 0.38, 0.4}
  • Notes: Vcm is generated by the Specification includes effects of ground offset voltage From 250MHz to 30GHz.
  • The receiver shall be able to tolerate, without damage, continuous exposure to a modulated optical input signal having this power level on one lane. The receiver does not have to operate correctly at this input power.
  • Measured with conformance test signal at receiver input for BER = 5×10-5.
  • Vertical eye closure penalty, stressed eye J2 jitter, stressed eye J4 jitter, and SRS eye mask definition are test conditions for measuring stressed receiver They are not the required characteristics of the receiver.

Block Diagram of Transceiver

  • This 1310 nm DFB 25Gb/s SFP28 LR transceiver is designed to transmit and receive optical data over single mode optical fiber for link length up to 10km.
  • The module optical connection is duplex LC and shall be compatible with SFP+ 28Gbps and backward compatible with legacy 10G SFP+ pluggable. The SFP28 LR module is a dual directional device with a transmitter and receiver plus a control management interface (2-wire interface) in the same physical package. 2-wire interface is used for serial ID, digital diagnostics and module control function.
  • The module operates by a single +3.3V power supply. LVCMOS/LVTTL global control signals, such as Module Present, Reset, Interrupt and Low Power Mode, are available with the modules. The SFP28 LR module electrical interface is compliant to OFI CEI-VSR-28G-VSR. It has been designed to meet the harshest external operating conditions including temperature, humidity and EMI interference. The module offers very high functionality and feature integration, accessible via a two-wire serial interface.
  • The transmitter converts 25Gbit/s serial PECL or CML electrical data into serial optical data compliant with the 25GBASE-LR standard. An open collector compatible Transmit Disable (Tx_Dis) is provided. Logic “1”or no connection on this pin will disable the laser from transmitting. Logic “0” on this pin provides normal operation. The transmitter has an internal automatic power control loop (APC) to ensure constant optical power output across supply voltage and temperature variations. An open collector compatible Transmit Fault (Tx_Fault) is provided. TX_Fault is module output contact that when high, indicates that the module transmitter has detected a fault condition related to laser operation or safety. The TX_Fault output contact is an open drain/collector and shall be pulled up to the Vcc_Host in the host with a resistor in the range 4.7-10 kΩ. TX_Disable is a module input contact. When TX_Disable is asserted high or left open, the SFP28 module transmitter output shall be turned off. This contact shall be pulled up to VccT with a 4.7 kΩ to 10 kΩ resistor.
  • The receiver converts 25Gbit/s serial optical data into serial PECL/CML electrical data. An open collector compatible Loss of Signal is provided. Rx_LOS when high indicates an optical signal level below that specified in the relevant standard. The Rx_LOS contact is an open drain/collector output and shall be pulled up to Vcc_Host in the host with a resistor in the range 4.7-10 kΩ, or with an active termination. Power supply filtering is recommended for both the transmitter and receiver. The Rx_LOS signal is intended as a preliminary indication to the system in which the SFP28 is installed that the received signal strength is below the specified range. Such an indication typically points to non- installed cables, broken cables, or a disabled, failing or a powered off transmitter at the far end of the cable.

Pin Descriptions ASFP28-25G-LR

PIN Logic Symbol Name / Description Note
1   VeeT Module Transmitter Ground 1
2 LVTTL-O TX_Fault Module Transmitter Fault  
3 LVTTL-I TX_Dis Transmitter Disable; Turns off transmitter laser output  
4 LVTTL-I/O SDA 2-Wire Serial Interface Data Line 2
5 LVTTL-I SCL 2-Wire Serial Interface Clock 2
6   MOD_DEF0 Module Definition, Grounded in the module  
7 LVTTL-I RS0 Receiver Rate Select  
8 LVTTL-O RX_LOS Receiver Loss of Signal Indication Active LOW  
9 LVTTL-I RS1 Transmitter Rate Select (not used)  
10   VeeR Module Receiver Ground 1
11   VeeR Module Receiver Ground 1
12 CML-O RD- Receiver Inverted Data Output  
13 CML-O RD+ Receiver Data Output  
14   VeeR Module Receiver Ground 1
15   VccR Module Receiver 3.3 V Supply  
16   VccT Module Receiver 3.3 V Supply  
17   VeeT Module Transmitter Ground 1
18 CML-I TD+ Transmitter Non-Inverted Data Input  
19 CML-I TD- Transmitter Inverted Data Input  
20   VeeT Module Transmitter Ground 1

Optical Receptacle Cleaning Recommendations


All fiber stubs inside the receptacle portions were cleaned before shipment. In the event of contamination of the optical ports, the recommended cleaning process is the use of forced nitrogen. If contamination is thought to have remained, the optical ports can be cleaned using a NTT international Cletop® stick type and HFE7100 cleaning fluid.  Before the mating of patch-cord, the fiber end should be cleaned up by using Cletop® cleaning cassette.

Ordering Information ASFP28-25G-LR

Model Number Part Number Reach Input/Output Signal Detect Voltage Temperature
ASFP28-25G-LR OPAX-S10-13-IB 10km AC/AC TTL 3.3V -40°C to 85 °C
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