Alpha Bridge ASFP28-25G-SR

Features

  • Compliant to 3by 25GBASE-SR.
  • 25Gb/s 10GE optical interface.
  • 25G 850nm VCSEL 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: 0 to 70°C.
  • All-metal housing for superior EMI performance.
  • 25G electrical interface (OIF CEI-28G-VSR).
  • Maximum power consumption 0W.
  • Advanced firmware allow customer system encryption information to be stored in transceive.
  • 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-SR

Parameter Symbol Min Max Unit
Storage Temperature Tc 40 85 °C
Operating Case Temperature Tc 0 70 °C
Supply Voltage Vcc 0 3.6 V
Relative Humidity RH 5 85 %
Damage Threshold THd 3.4   dBm

Recommended Operating Conditions ASFP28-25G-SR

Parameter Symbol Min Typical Max Units
Operating Case Temperature Tc 0   70 °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 Distances ASFP28-25G-SR

Fiber type 850nm OFL Bandwidth Supported Distances (meters)
  50μm MMF OM4 3500 MHz-km   0.5 to 100
  50μm MMF OM3 2000 MHz-km   0.5 to 70

Diagnostics ASFP28-25G-SR

Parameter Symbol Min Typical Max Unit
Operating Case Temperature TOP 0   +70 °C
Power Supply Voltage Vcc 3.135 3.3 3.465 V
Data Rate, each Lane     10.3125 11.2 Gb/s
Control Input Voltage High   2   Vcc V
Control Input Voltage Low   0   0.8 V
Link Distance with (OM3 MMF) D_MMF     150 m
Link Distance (SMF) D_SMF     2 km

Transmitter Electro-optical Characteristics ASFP28-25G-SR

Parameter Symbol Min. Typical Max Units
Operating Date Rate   9.95 11.3 Gbps  
Input Reference Clock Rate     Not Required    
Output Optical Power Pout 1 ---             4 dBm  
Extinction Ratio ER 9   dB  
Center Wavelength °C 1530 1565 nm  
Sidemode Supression ratio SSRmin 30     dB
Relative Intensity Noise RIN --- ---          -130 dB/Hz  
Output Eye Compliant with IEEE802.3ae
Differential Input Voltage VDIFF 0.12 --- 1.0
Transmit Fault Output-Low TX_FAULTL 0.0 --- 0.5
Transmit Fault Output-High TX_FAULTH 2.4 --- Vcc
TX_DISABLE Assert Time t_off --- --- 10
TX_DISABLE Negate Time t_on --- --- 2
Time to initialize t_init --- --- 300
Interrupt assert delay Interrupt _on --- --- 200
Interrupt negate delay Interrupt_off --- --- 500
P_Down/RST assert delay P_Down/RST_on     100
Mod_NR assert delay Mod_nr_on     1
Mod_NR negate delay Mod_nr_off     1
P-Down reset time   10    
RX_LOS assert delay t_loss_on     100
RX_LOS negate delay t_loss_off     100

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

Receiver Electro-optical Characteristics ASFP28-25G-SR

Parameter Test Point Min Typical Max Units Notes
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 TP4 TP4   10   %   At 1MHz
Mismatch            
        See CEI- 28G-    
Differential Return Loss (SDD22) TP4     VSR Equation dB  
        13-19    
Common Mode to Differential conversion       See CEI- 28G-    
and Differential to Common Mode TP4     VSR Equation dB  
conversion (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 λr 840 850 860 nm  
Damage Threshold   3.4     dBm 3
Average Receiver Power   -10.3     dBm 4
Average Receiver Power (Overload)       2.4 dBm 5
Receiver Power (OMA) (Overload)       3 dBm 6
Stressed Receiver Sensitivity (OMA)       -5.2 dBm 7
Receiver Reflectance       -12 dB  
LOS Assert LOSA -30     dBm  
LOS Deassert LOSD     -12 dBm  
LOS Hysteresis LOSH 0.5     dB  

(SRSTC)

Stressed Receiver Sensitivity Test Condition (Note 8)
Stressed Eye Closure (SEC) SEC 4.3 dB
Stressed Eye J2 Jitter J2 0.39 UI
Stressed Eye J4 Jitter J4 0.53 UI
OMA of each Aggressor Lane   3 dBm
Stressed Receiver Eye Mask Definition {X1, X2, X3, Y1, Y2, Y3} - Hit ratio 1.5x10- 5 hits per sample     {0.28, 0.5, 0.5, 0.33, 0.33, 0.4}  
  • Note: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 an optical input signal having this average power level on one The receiver does not have to operate correctly at this input power.
  • Average receive power (min) is informative and not the principal indicator of signal strength. A received power below this value cannot be compliant; however, a value above this does not ensure
  • If TX ER < 5.68dB.
  • If TX ER > 68dB.
  • Measured with conformance test signal at TP3 for BER specified in 3bm 95.1.1.
  • These test conditions are for measuring stressed receiver They are not characteristics of the receiver.

Block Diagram of Transceiver

  • The SFP28 25G is a single-rate module with an operating range of 0.5m to 70m/100m over OM3/OM4 MMF (Table 1), respectively, compliant with IEEE802.3by 25GBASE-SR optical specs.
  • The module optical connection is duplex LC and shall be compatible with SFP+ 28Gbps and backward compatible with legacy 10G SFP+ pluggable. The SFP28 SR 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 SR 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-SR 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-SR

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-SR

Model Number Part Number Reach Input/Output Signal Detect Voltage Temperature
ASFP28-25G-SR OPAX-MX1-85-CT 100m AC/AC TTL 3.3V 0°C to 70 °C
DOWNLOAD BROCHURE
Scroll to Top