Multimode 25gb/S Sfp28 Sr 850nm Fiber Optic Transceiver

Multimode 25gb/S Sfp28 Sr 850nm Fiber Optic Transceiver

Description of 25g sfp28 SR module

Sopto 850 nm VCSEL 25Gigabit SFP28 transceiver is designed to transmit and receive optical data over 50 μm multimode optical fiber (Table 1).

The SFP28 SR module electrical interface is compliant to SFI electrical specifications. The transmitter input and receiver output impedance is 100 Ohms differential. Data lines are internally AC coupled. The module provides differential termination and reduce differential to common mode conversion for quality signal termination and low EMI. SFI typically operates over 200 mm of improved FR4 material or up to about 150mm of standard FR4 with one connector.

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.

Table 1: SFP28 SR Operating Range for each Optical Fiber Type

Features of 25g SFP28 SR Module

● 25Gb/s serial optical interface

● 850nm VCSEL transmitter, PIN photo-detector

● Maximum link length of 70m on OM3 MMF and 100m on OM4 MMF

● 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

● Low power consumption

● Advanced firmware allow customer system encryption information to be stored in transceiver

● Cost effective SFP28 solution, enables higher port densities and greater bandwidth

● RoHS compliant

Applications

● 25GBASE-SR Ethernet

● High-speed storage area networks

● Computer cluster cross-connect

● Custom high-speed data pipes

● Inter Rack Connection

Specifications

Optical Characteristics

The following optical characteristics are defined over the Recommended Operating Environment unless otherwise specified.