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25G SFP28

FSJMLB31-K20C(I)

SFP28 25Gb/s LR 20km DDM

Product Features:
l ​Supports 25.78Gb/s aggregate bit rate;
l 1310nm DFB Laser transmitter and PIN/TIA receiver;
l Maximum link length of 20km on;
l Single Mode Fiber (SMF);
l Hot-pluggable SFP28 footprint;
l Duplex LC receptacles;
l Single +3.3V±5% power supply;
l Maximum power dissipation < 1.2W;
l Compliant with SFF-8472 & IEEE 802.3cc;
l Fully RoHS Compliant;
l Case operating temperature;
Commercial: 0°C to +70°C
Industrial: -40°C to +85°C

Overview


I. Pin Diagram

image 

Pinout of Connector Block on Host Board

II.Pin Descriptions

Pin

Symbol

Name/Description

Ref.

1

V

EET

Transmitter Ground (Common with Receiver Ground)

1

2

T

FAULT

Transmitter Fault.

2

3

T

DIS

Transmitter Disable. Laser output disabled on high or open.

3

4

SDA

2-wire Serial Interface Data Line

4

5

SCL

2-wire Serial Interface Clock Line

4

6

MOD_ABS

Module Absent. Grounded within the module

4

7

RS0

No connection required


8

LOS

Loss of Signal indication. Logic “0” indicates normal operation.

5

9

RS1

No connection required


10

V

EER

Receiver Ground (Common with Transmitter Ground)

1

11

V

EER

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

V

EER

Receiver Ground (Common with Transmitter Ground)

1

15

V

CCR

Receiver Power Supply


16

V

CCT

Transmitter Power Supply


17

V

EET

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

V

EET

Transmitter Ground (Common with Receiver Ground)

1

 

Notes:

1. Circuit ground is internally isolated from chassis ground.

2. TFAULT is an open collector/drain output, which is pulled up with a 4.7kΩ – 10kΩ resistor on the

host board, but is grounded inside the SFP+ cable plug.

3. Laser output disabled on TDIS >2.0V or open, enabled on TDIS <0.8V.

4. Should be pulled up with 4.7kΩ – 10kΩ on host board to a voltage between 2.0V and 3.6V.

MOD_ABS pulls line low to indicate module is plugged in.

5. LOS is open collector output. Should be pulled up with 4.7kΩ – 10kΩ on host board to a voltage

between 2.0V and 3.6V. Logic 0 indicates normal operation; logic 1 indicates loss of signal.

III. Absolute Maximum Ratings

Parameter

Symbol

Min

Type

Max

Unit

Ref.

Maximum Supply Voltage

Vcc

-0.5


3.6

V


Storage Temperature

TS

-40


85


Relative Humidity

RH

0


85

%


 

Notes:

1.Limited by the fiber cable jacket, not the activeends.

2.Non-condensing

 

IV. Optical Characteristics

Parameter

Symbol

Min.

Typ.

Max.

Unit

Ref.

Transmitter

Signaling rate(range)

Sr


25.7825±100ppm


GBd


Center Wavelength

λc

1260


1355

nm


Optical Return Loss Tolerance




20

nm


Average Output Power

Pavg

-4


2

dBm


Optical Modulation Amplitude

TxOMA

-4



dBm


Extinction Ratio

ER

3.5



dB


Side Mode Suppression Ratio

SMSR

30



dB


Transmitter OFF Output Power

POff



-30

dBm


Transmitter and Dispersion Penalty

TDP



2.7

dB


Transmitter eye mask definition {X1, X2, X3, Y1, Y2, Y3} Hit ratio 5×10-5 hits per sample.


{0.31, 0.4, 0.45, 0.34, 0.38, 0.4}



Receiver

Signaling rate(range)

Sr


25.7825±100ppm


GBd


Center Wavelength

λc

1260


1355

nm


Receiver Sensitivity(OMA)

SOMA



-12

dBm

1

Receiver Reflectance

Rfl



-26

dBm


Loss of Signal Assert

PA

-30



dBm


Loss of Signal De-assert

PD



-17

dBm


LOS Hysteresis

PD- PA

 0.5



dB


Note:

1. 1. Measured at 25.78125Gb/s, ER>3.5dBm, PRBS 2 31 -1 and BER better than or equal to 5x10-5.

V. Digital Diagnostic Memory Map

image 

VI. Digital Diagnostic Monitoring Information

Parameter

Unit

Accuracy

Case Temperature

±3

Supply Voltage

V

±3%

Tx Bias Current

mA

±10%

Tx Optical Power

dB

±3

Rx Optical Power

dB

±3

VII. Electrical Interface Characteristics

Parameter

Symbol

Min

Type

Max

Unit

Ref.

Supply Voltage

Vcc

3.135

3.3

3.465

V


Supply Current

Icc



300

mA

Commercial



350

mA

Industrial

Transmitter

Input differential impedance

Rin


100


Ω

1

Single-ended Data Input Swing

Vin

90


450

mVp-p

p


Transmit Disable Voltage

VD

2


VCCHOST

V


Transmit Enable Voltage

VEN

Vee


Vee+0.8

V


Transmit Fault Assert Voltage

V FA

2


VCCHOST

V


Transmit Fault De-Assert Voltage

V FDA

Vee


Vee+0.4

V


Receiver

Single-ended Data Output Swing

Vout

200


450

mVp-p

 

2

LOS Fault

VLOS_fault

2


VccHOST

V

3

LOS Normal

VLOS_norm

Vee


Vee+0.4

V

3

Notes:

1. Connected directly to TX data input pins.AC coupling from pins into laser driver IC.

2. LOS is an open collector output. Should be pulled up with 4.7kΩ – 10kΩ on the host board. Normal operation is logic 0; loss of signal is logic 1. Maximum pull-up voltage is 5.5V.

VIII. Recommended Interface Circuit

image 

IX. Mechanical Dimensions (mm)

image 

SFP wire mechanical drawing (Unit: mm)

feature


Product Features

Supports 25.78Gb/s aggregate bit rate

1310nm DFB Laser transmitter and PIN/TIA receiver

Maximum link length of 20km on

Single Mode Fiber (SMF)

Hot-pluggable SFP28 footprint

Duplex LC receptacles

Single +3.3V±5% power supply

Maximum power dissipation < 1.2W

Compliant with SFF-8472 & IEEE 802.3cc

Fully RoHS Compliant

Case operating temperature

Commercial: 0°C to +70°C

Industrial: -40°C to +85°C


Applications

Compliance

Data Center Backbone

SFP28 MSA.

Ethernet Switches

IEEE802.3cc

High-speed Servers

SFF-8431

High-performance Computing Clusters

SFF-8432

Specifications


Ordering Information

Package

Product part NO.

Distance

Temperature Range

FSJMLB31-K20C

25.78125

1310

20km

FSJMLB31-K20I

25.78125

1310

20km

*For availability of additional cable lengths, please contact Fibridge.