An Ultimate Introduction of 10G SFP+ Transceiver Modules

The 10G SFP+ transceiver modules are compact and hot-pluggable devices and have the digital optical monitoring capability for strong diagnostic capabilities. The 10G SFP+ transceiver module is a significant component in the field of optical communication. It belongs to the SFP series and has a rate of up to 10Gbps. SFP+ modules are widely used in 10G Ethernet, SONET/SDH, Fiber Channel and other applications due to their advantages such as small size, low cost, and high density.

Physical Characteristics

• It has a small size, typically about the size of a thumb, which allows for high-density installations in network equipment such as switches, routers, and optical line terminals.
• The host side connector interface is standardized 20 pins gold finger, enabling easy insertion and removal from the device port, facilitating quick replacement and upgrades without shutting down the entire network system. And the media side connector interface is LC for optical fiber or RJ45 for twisted pair.

Function and Working Principle

• SFP+ optical modules are mainly used to convert electrical signals into optical signals for transmission over fiber optic cables and vice versa.
• Inside the module, there is a LDD (Laser Diode Driver) and a TOSA (Transmitter Optical Subassembly, a laser and some optical components) in the Tx side, a LA (Limiting Amplifier) and a ROSA (Receiver Optical Subassembly, a photodetector and some optical components) in the Rx side. All of those components are managed by a microcontroller and some associated circuits.

SFP+ Transceiver Modules Standards

• In order to ensure that optical modules of different types and from different manufacturers can be interconnected and interoperable, SFP+ modules support a variety of communication standards.
• The basic standard for SFP+ transceiver is MSA (Multi Source Agreement), including SFF-8431, SFF-8432 and SFF-8472 …. The MSA defines the SFP+ electrical specification, physical dimension, management interface and other details. All the SFP+ transceiver must compliant with the MSA.
• Besides MSA, when SFP+ apply in an application, the corresponding standards should be compliant also. For example, IEEE802.3 standards in Ethernet, ITU-T standards in SONET/SDH.

SFP+ Type and Specification

SFP+ types can be classified by the transmission media, distance, application and so on.

• SFP+ 10GBASE – T

‘10G’ stands for a transmission rate of 10 gigabits per second (10Gbps), ‘BASE’ indicates baseband transmission, and ‘T’ represents Twisted – Pair. SFP+ 10GBASE – T has a RJ-45 connector and uses CAT5e/CAT6A/CAT7 cables. It supports 10Gbps data rate up to 30m link length and back compatible with 100Mbps and 1.25Gbps up to 100m link length.

• SFP+ 10GBASE-SR Multimode module

‘SR’ is the abbreviation of ‘Short – Range’. This application is mainly used for MMF and the link length is up to 300m at 10Gbps data rate. Its wavelength is 850nm and the transmitter uses VCSEL to save power consumption and cost.

• SFP+ 10GBASE-LRM MMF/SMF module

‘LRM’ means ‘Long Reach Multimode’. This module transmitter wavelength is 1310nm, single mode fiber can be used as the media but mostly multimode is used. Both the multimode fiber and single mode fiber can be used as the transmission media. The SFP+ LRM support 220m link length over OM1 and OM2 fiber and 300m over SMF.

 

• SFP+ 10GBase – LR Single mode module

‘LR’ is the abbreviation of ‘Long – Range’. It also has a transmission rate of 10Gbps, but it is used for single-mode fiber and can achieve transmission over longer distances (such as 10km or even farther) using a 1310nm DFB laser. It is often used in scenarios such as backbone links of campus networks or connections in metropolitan area networks.

• SFP+ 10GBase – ER Single mode module

‘ER’ is the abbreviation of ‘Extended – Range’. It is an Ethernet standard used for ultra-long-distance single-mode fiber transmission. Tx side uses a 1550nm an EML laser and the Rx side uses a PIN receiver, supports 40km link length.

• SFP+ 10GBase- ZR Single mode

SFP+ 10GBase – ZR is an enhanced SFP+ 10GBase – ER, the transmission distance is much longer than ‘ER’ up to 80km over SMF. Tx side is the same with ‘ER’ but the Rx side uses a high sensitivity APD receiver to meet link budget. The Max. input power to the Rx side should below -5dBm to protect the APD to be damaged.

• Fiber Channel SFP+

Fiber Channel is different from Ethernet and has its own independent set of protocol systems, specifically designed for high-speed data transmission scenarios such as Storage Area Networks (SAN). The Fiber Channel SFP+ supported data rate is different from the Ethernet. The FC application includes 1GFC, 2GFC, 4GFC, 8GFC, 16GFC and 32GFC, corresponding data rate are 1.065Gbps, 2.125Gbps, 4.25Gbps, 8.50Gbps, 14.025Gbps, 28.05Gbps. The Fiber Channel SFP+ support the 8GFC or 16GFC, and it is compatible with the lower rate application.

 

SFP+ with WDM Technology

• SFP+ CWDM optical module

The SFP+ CWDM optical module is a coarse wavelength division multiplexing optical module, which is usually used together with single-mode optical fibers. This type of optical module saves optical fiber resources by adopting CWDM technology. Compared with DWDM, CWDM doesn’t need wavelength control technology, its power consumption is much lower than DWDM.

• SFP+ DWDM Optical Module

The SFP+ DWDM optical module is a dense wavelength division multiplexing optical module. It is used together with single-mode optical fibers and has a maximum transmission distance of up to 80 km, making it suitable for long-distance data transmission. This optical module can meet the requirements for ultra-long-distance transmission with EDFA system.

SFP+ BIDI Optical Module

The SFP+ BIDI optical module is a single-fiber bi-directional optical module that adopts WDM technology. It uses different wavelengths for upstream and downstream transmission and needs to be used in pairs to ensure normal operation. The advantage of this optical module is that it can reduce the amount of optical fibers used in network deployment, or double the network capacity by replacing the duplex module with the BIDI module, thus greatly reducing the deployment cost of the network.

 

SFP+ Operating Temperature

The SFP+ transceiver operating temperature has 3 grades. The operating temperature means the case temperature but not the environment temperature.

Commercial: -5 ~ +70℃

Extended: -10 ~ +80℃

Industrial: -40 ~ +85℃

Conclusion

There are numerous types of SFP+ optical modules. They can be considered from several aspects such as the type of transmission media (RJ-45 cable, MMF, SFM), transmission distance (300m, 10km, 40km,80km), and application systems (Fiber Channel, CWDM, DWDM, BIDI).