Alpha Bridge ASF28-F-20-AK

Features

  • Transmission data rate up to 25.78Gbps
  • 850nm VCSEL laser
  • PIN photo-detector
  • Internal CDR on both transmitter and receiver channels
  • Hot-pluggable SFP28 form factor
  • Up to 70m on OM3 MMF and 100m on OM4 MMF
  • Digital diagnostics functions are available (optional)
  • Operating case temperature range 0°C to +70°C
  • 3V power supply voltage
  • RoHS-6 compliant
  •  

Applications

  • IEEE 802.3by 25GBASE-SR

Absolute Maximum Ratings

Parameter Symbol Min. Max. Units Note
Supply Voltage Vcc 0 3.6 V  
Storage Temperature TS -40 85 °C  
Case Operating Temperature Tc 0 70 °C  
Relative Humidity RH 5 85 % 1

Recommended Operating Conditions

Parameter Symbol Min. Typical Max. Units Note
Supply Voltage Vcc 3.13 3.3 3.47  V  
Supply Current Icc     300 mA  
Fiber Length on 50/125μm high-bandwidth (OM3) MMF       70 m  
Fiber Length on 50/125μm high-bandwidth (OM4) MMF       100 m  

Diagnostics Specification

Parameter Range Units Accuracy Calibration
Temperature 0 to +70 °C ±3°C Internal / External
Voltage 3.0 to 3.6       V ±3% Internal / External
Bias Current 0 to 20 mA ±10% Internal / External
TX Power -8 to 3 dBm ±3dB Internal / External
RX Power -14 to 0 dBm ±3dB Internal / External

Transmitter Electro-optical Characteristics

Parameter Symbol Min Type Max Units Notes
Data Rate BR   25.78   Gbps  
Centre Wavelength λc 840 1310 860 nm  
Spectral Width (-20dB) σ     0.6 nm  
Average Output Power Pavg -8.4   2.4 dB  
Optical Power OMA POMA -6.4   3 dBm  
Extinction Ratio ER 2     dB  
Differential data input swing VIN,PP 40     1000 mV  
 Input Differential Impedance ZIN 90 100   110 Ω  
 TX Disable  Disable   2.0   Vcc V
 Enable   0   0.8 V  
 TX Fault  Fault   2.0   Vcc V
 Normal   0   0.8 V  

Transmitter Electro-optical Characteristics

Parameter Symbol Min Type Max Units Notes
 Data Rate BR   25.78   Gbps  
 Centre Wavelength λc 840 1310 860 nm  
 Spectral Width (-20dB) σ     0.6 nm  
 Average Output Power Pavg -8.4   2.4 dB  
 Optical Power OMA POMA -6.4   3 dBm  
 Extinction Ratio ER 2     dB  
 Differential data input swing VIN,PP 40     1000 mV  
 Input Differential Impedance ZIN 90 100   110 Ω  
 TX Disable  Disable   2.0   Vcc V
 Enable 0   0.8 V  
 TX Fault  Fault   2.0   Vcc V
 Normal 0   0.8 V  

Receiver Electro-optical Characteristics

Parameter Symbol Min Type Max Units Notes
Data rate BR   25.78   Gbps  
Centre Wavelength λc 840 850 860 nm  
Receiver Sensitivity (OMA) Psens     -10 dBm  
Stressed Sensitivity (OMA)       -5.2 dBm  
Receiver Power (OMA)       3 dBm  
LOS De-Assert LOSD     -13 dBm  
LOS Assert LOSA -30     dBm  
LOS Hysteresis   0.5     dB  
Differential data output swing Vout,PP 300   850 mV  
 LOS High 2.0   Vcc V  
Low   0.8 V  

Pin Descriptions

Pin Logic Symbol Name/Description Note
1   VeeT Module Transmitter Ground 1
2 LVTTL-O TX_Fault Module Transmitter Fault 2
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_ABS 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

Ordering Information

Part Number Model Number Length (M) Voltage Temperature
   ASF28-F-20-AK Active Optical Cable 20 3.3V 0°C to 70 °C
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