




25G SFP28 LR Transceiver for 20km SMF Links, 1310nm Duplex LC
SFP28-25-13-20(LR)-LCD
- Broad Multi-Brand Compatibility
- Flexible Customization Support
- Tested for Reliable Performance
- Fast Response & Delivery
- Professional Technical Support
The FC-LINK SFP28 25G 1310nm 20km LR LC DX transceiver is a high-performance solution for duplex optical data communications, supporting data rates of 25.78Gbps. It features an SFP+ 20-pin connector for hot-pluggable capability and provides digital diagnostic monitoring through an I2C interface. The module includes built-in dual clock and data recovery (CDR) for enhanced signal integrity.Designed for single-mode fiber, this transceiver operates at a nominal wavelength of 1310nm. The transmitter section integrates a high-performance 1310nm DFB laser, compliant with Class 1 laser safety standards (IEC 60825). The receiver section is equipped with an InGaAs detector pre-amplifier (IDP) housed in an optical header, paired with a limiting post-amplifier IC for reliable and efficient performance.
| SPECIFICATIONS | |||
|---|---|---|---|
| Product Model | SFP28-25-13-20(LR)-LCD | Manufacturer Brand | FC-LINK |
| Package Type | SFP28 | Optical Connector | Duplex LC |
| Max Data Rate | 25.78G | Channel Data Rate | 10.31Gbps |
| Effective Transmission Distance | 20km | ||
| Wavelength | 1310nm | Operating Voltage | 3.3V |
| Fiber Type | SMF | Core Size | 9/125µm |
| Transmitter Type | DFB-LD | Receiver Type | CDR |
| TX Power | -7~2dbm | Receiver Sensitivity | <9.5dBm |
| Digital Diagnostic Monitoring(DDM) | YES | Receiver Overload | 2dBm |
| Power Consumption | <1.2W(Standard) <1.5W(Industrial) | Protocols | SFF-8402 |
| Operating Temperature(Commercial) | 0℃~+70℃ | Storage Temperature(Commercial) | -40℃~+85℃ |
| Operating Temperature(Industrial) | -40℃~+85℃ | Storage Temperature(Industrial) | -40℃~+85℃ |

Server-to-Switch Data Center Links
Used for 10G/25G/100G optical uplinks between servers and top-of-rack switches in high-density data center deployments.

Building-to-Building Campus Backbone
Suitable for 1G/10G fiber links between office buildings, campus distribution rooms, and backbone aggregation points.

Access-to-Core Enterprise Uplinks
Designed for switch uplinks from access to aggregation or core layers in enterprise and campus network architectures.

Industrial Switching in Harsh Environments
Applied in industrial Ethernet, automation systems, and outdoor cabinets where wider temperature tolerance and stable fiber communication are required.
| Absolute Maximum Ratings | |||||||||
| Parameter | Symbol | Unit | Min. | Max. | |||||
| Storage temperature range | Ts | °C | -45 | 85 | |||||
| Relative humidity | RH | % | 0 | 95 | |||||
| Input voltage | Vcc | V | 0 | 4 | |||||
| Recommended Operating Conditions | |||||||||
| Parameter | Symbol | Unit | Min. | Typ. | Max. | ||||
| Operating case temperature range | Tc | ℃ | -45 | - | 85 | ||||
| Supply voltage | Vcc | V | 3.135 | 3.3 | 3.465 | ||||
| Bit rate | BR | Gb/s | - | 25.78125 | - | ||||
| Max supported link length | L | km | - | - | 20 | ||||
| Electrical Characteristics | |||||||||
| Parameter | Symbol | Unit | Min. | Typ. | Max. | Note | |||
| Power dissipation | - | W | - | - | 1.2 | - | |||
| Transmitter | |||||||||
| Input differential impedance | RIN | Ω | - | 100 | - | - | |||
| Single ended data input swing | VIN | mVp-p | 90 | - | 450 | - | |||
| Tx_disable input voltage – low | VIL | V | -0.3 | - | 0.8 | - | |||
| Tx_disable input voltage – high | VIH | V | 2.0 | - | Vcc+0.3 | - | |||
| Tx_fault output voltage – low | VOL | V | -0.3 | - | 0.8 | - | |||
| Tx_fault output voltage – high | VOH | V | 2.0 | - | Vcc+0.3 | - | |||
| Receiver | |||||||||
| Output impedance (Differential) | Zout | V | - | 100 | - | - | |||
| Rx_LOS output voltage- low | VOL | V | -0.3 | - | 0.8 | - | |||
| Rx_LOS output voltage- high | VOH | V | 0.2 | - | Vcc+0.3 | - | |||
| Optical Transmitter/Receiver Characteristics | |||||||||
| Parameter | Symbol | Unit | Min. | Typ. | Max. | Note | |||
| Transmitter | |||||||||
| Center wavelength | λ | nm | 1295 | 1310 | 1325 | - | |||
| Data rate | B | Gb/s | - | 25.78 | - | - | |||
| Output Spectral Width | λ(-20dB) | nm | - | - | 1 | - | |||
| Optical output power | Po | dBm | -7 | - | 2 | - | |||
| Extinction ratio | ER | dB | 3.5 | - | - | - | |||
| Transmitterand dispersion penalty | TDP | dB | - | - | 3.2 | - | |||
| Receiver | |||||||||
| Operating Wavelength | λ | nm | 1260 | - | 1355 | - | |||
| Overload | - | dBm | 2 | - | - | - | |||
| Receiver sensitivity (OMA) | POMA | dBm | - | - | -11.3 | - | |||
| Optical return loss | ORL | dB | - | - | -26 | - | |||
| Signal detect threshold-de-assert | SD | dBm | - | - | -14 | - | |||
| LOS hysteresis | - | dB | 0.5 | - | - | - | |||
| Pin Configuration |
| Transceiver Pin Descriptions | |||||||||
| Pin No. | Symbol | Logic | Description | ||||||
| 1,20 | VEET | - | Transmitter ground(common with receiver ground) | ||||||
| 2 | TX fault | LVTTL output | Transmitter fault. low normal operation, high fault indication | ||||||
| 3 | TX disable | LVTTL input | Transmitter disable. laser output disabled on high or open | ||||||
| 4 | SDA | LVTTL input/output | Module definition 2.data line for serial ID | ||||||
| 5 | SCL | LVTTL input/output | Module definition 1.clock line for serial ID | ||||||
| 6 | MOD-ABS | - | Module definition 0.grounded within the module | ||||||
| 7 | RS0 | LVTTL input | Rate select 0, optionally controls SFP28 module receiver. LVTTL logic. | ||||||
| 8 | LOS | LVTTL output | Loss of signal indication. Logic 0 indicates normal operation. | ||||||
| 9 | RS1 | LVTTL input | Rate select 1, optionally controls SFP28 module transmitter. LVTTL logic. | ||||||
| 10,11,14 | VEER | - | Receiver ground(common with transmitter ground) | ||||||
| 12 | RD- | CML output | Receiver inverted DATA out.AC coupled | ||||||
| 13 | RD+ | CML output | Receiver non-inverted DATA out.AC coupled | ||||||
| 15 | VCCR | - | Receiver power supply | ||||||
| 16 | VCCT | - | Transmitter power supply | ||||||
| 18 | TD+ | CML input | Transmitter non-inverted DATA in.AC coupled | ||||||
| 19 | TD- | CML input | Transmitter inverted DATA in.AC coupled | ||||||

Performance Testing
Each module is tested before shipment to help ensure stable optical and electrical performance.

Compatibility Verification
Compatibility validation is available for major switch and router platforms.

Reliability Screening
Selected products support aging, temperature cycle, and stability testing for demanding applications.

Traceable Quality Control
Inspection and production records support more consistent quality control and batch traceability.



















