LC vs SC SFP ：What's the difference?

Small Form-factor Pluggable (SFP) transceivers are often used in both telecommunication and data communications applications. Their main task is to interface between networking devices (like switches or routers) and the cables connecting them. SFP connectors, such as LC and SC, however, refer to the different types of connectors that can be used to plug the SFP module into the fiber optic cable, which carries data in the form of light from one point to another in the network.

LC (Lucent Connector) SFP and SC (Standard Connector) SFP both serve this purpose but have distinct design and usage differences:

1. Physical Design: LC is a small form-factor connector that uses a 1.25 mm ferrule and employs a retaining tab mechanism similar to an RJ45 connector. SC is a larger connector type that uses a 2.5 mm ferrule and a push-pull coupler system for coupling.

2. Size and Density: LC’s smaller size allows it to fit into tight router interfaces or densely packed patch panels, offering double the port density than SC connectors. SC connectors, because of their bigger size, offer less port density.

3. Insertion Loss: LC connectors often have lower insertion loss (loss of power in the signalwhen light is transferred through the connector) than SC connectors, making them a better choice for high-precision optical applications.

4. Application: The smaller, more modern LC connector is widely used in contemporary applications such as data centers, server rooms, and telecom closets. In contrast, the SC connector, being older and bigger, is found in older telecom applications and analog systems.

5. Convenience: LC connectors are designed with a convenient latch mechanism instead of the SC's push-pull system, making them easier to operate in tight spaces.

6. Compatibility: Some transceiver modules may only support a specific connector type. For instance, SFP and SFP+ transceivers typically use LC connectors due to its smaller form factor.

Remember that choosing between LC and SC isn't just a matter of personal preference but depends primarily on the networking hardware and the scale of the network. While SC was very popular in the past, LC connectors have become more widespread due to their compact size and improved reliability. Consequently, before deciding on an SFP, aspects like requisite applications, network specifications, and future expansion plans should be considered.

What do LC and SC sfp represent respectively?

What is lc SFP?

· LC Connectors:Developed by Lucent Technologies, which is now owned by Nokia, the Lucent Connectors are comparatively newer and also use the push and pull mechanism. At times, these connectors are also referred to as the smaller version of SC connectors as they employ latches with small ferrules. The LC connectors initially received a slow response in the market due to the high licensing fees involved; however, today they are widely used in data applications and high-density patch applications.

The acronym LC in LC SFP stands for Lucent Connector, named after the company that developed it. It is a type of fiber optic connector used for optical signal transmission. The LC connector utilizes a small form factor, using a 1.25mm ferrule (a cylindrical fitting to encase the fiber) which is half the size of the standard fiber optic cable connector, the SC (Standard connector), which uses a 2.5mm ferrule.

An LC SFP (Small Form-factor Pluggable) is a type of compact, hot-pluggable transceiver module that comes with LC connectors. This type of SFP is designed to be used in data communication and telecommunication networks and can support Gigabit Ethernet, Fiber Channel, Synchronous Optical Network (SONET), and other communication standards.

The LC SFP has a high-density connector design, meaning it can fit more connectors into a single standard space (usually represented as 'U' in networking contexts). This makes it ideal for situations where space utilization is a crucial factor, such as in server rooms or data centers.

At the functional level, the LC SFP module is responsible for converting the electrical signal from a networking device into an optical signal for fiber optic transmission. After reaching the other end of the fiber optic line, it then converts the optical signal back into an electrical signal readable by another networking device.

Conclusively, the LC SFP offers reliable, high-speed data transfer over long distances making it a commonly used module in many networking environments, particularly those needing to maximize space efficiency. It is used widely in single-mode systems for its performance and ease of installation in high-density applications. Its smaller connector size and "push and click" mechanism have made it a standard in most current SFP transceivers in the networking industry.

LC SFPtransceiver means 1000BASE SFP transceiver with LC connectors, which includes 1000BASE-SX SFP, 1000BASE-MX SFP, 1000BASE-LX SFP, 1000BASE-EX SFP, 1000BASE-ZX SFP, 1000BASE-EZX SFP, 1000BASE-BX SFP and CWDM/DWDM SFP transceiver modules. Different protocols have varied requirement for transmission medium, operation temperature, supporting DOM or not, and etc. 1000BASE-SX SFPis designed for transmission within near area, while LC SFP LX transceiver for long-haul transmission.

What is sc SFP?

· SC Connectors:SC is an abbreviation for Subscriber Connector. These connectors are also known as Standard Connectors or Square Connectors. The connectors were first introduced in the 1980s by the laboratories of Nippon Telegraph and Telephone (NTT) and were the first to enter the market after ceramic ferrules. SC connectors stand out due to their push and pull design featuring a locking tab. These connectors are widely chosen for their inexpensiveness and reliable design. SC connectors are suited for telecommunication and data transfer applications, and are employed in passive and point-to-point optical networking.

SC in SC SFP refers to the ‘Standard Connector,’ which is a type of fiber optic connector utilized in optical signal transmission. The SC connector uses a 2.5mm ferrule with a push-pull coupling mechanism, ensuring a secure connection once installed. In terms of physical design, the SC connector is bigger than its LC counterpart.

When we talk about SC SFP, we're referring to a Small Form-factor Pluggable transceiver that employs SC connectors. This kind of transceiver is a compact, hot-pluggable module that interfaces between a networking device and a fiber optic cable. SC SFPs are used in both telecommunication and data communication applications, supporting different communication standards, ranging from Gigabit Ethernet to Fibre Channel and Synchronous Optical Networking (SONET), among others.

Much like other types of SFPs, the SC SFP’s function is to convert electrical signals from a network device into optical signals that can be transferred through a fiber optic line. Upon reaching the destination, the SC SFP converts the optical signal back into an electrical signal that the receiving network device can interpret.

The SC SFP, due to its larger connector size, offers less port density compared to LC SFPs. This might be a disadvantage in space-constrained, high-density environments. However, they are easy to handle due to their push-pull design which ensures a secure connection.

Although SC connectors were highly popular in the past, they are being largely replaced in many modern applications by smaller, higher-density connectors such as LC. Nevertheless, SC connectors are still found in some older system applications and continue to be relevant wherever compatibility with legacy systems is necessary.

To sum it up, both LC and SC SFP transceivers serve the same function, their main difference lies in physical design and connector size. Depending on the specific application and network hardware, the decision between the two types would be made considering factors like port density, connector compatibility, and whether high-density packaging is a requirement for the specific network setup.

A Few Important Fiber Optic Devices to Connect LC and SC Connectors

The choice of LC and SC connectors will entirely depend on your application requirements. However, the following are a few devices that you may need while using these connectors.

· Media Converters: These devices enable signal conversion, and are largely used in networks that use both copper and fiber optic cables. There are copper to fiber, fiber to copperand fiber to fiber media converters to choose from. Nowadays, these converters are equipped with SFP transceivers, and they support LC and SC connectors.

· Network Switches: They are the most important network hardware, which connects different devices in the network. There are different types of network switches to choose from. Industrial switches, PoE switches, hardened switches, and so on are a few popular ones. Today, it is quite easy to find network switches with LC and SC SFP transceivers.

· High Definition Transmitters and Receivers: High definition serial digital interface (HD-SDI) is a standard for digital video transmission lines. These enable the transfer of unencrypted and uncompressed video and audio signals. HD-SDI converters, HDMI video systems, and HD-CVI, HD-AHD, and HD-TVI installation kitsare examples of High Definition transmitters and receivers.

SFP SC vs LC: How They Differ From Each Other

After having a basic understanding of SC and LC connectors, the next question is: what the difference between SC and LC? In general, the difference between LC and SC connectors lies in size, processing and connector history.

· Size: LC is half of the size of SC. In fact, an SC adapter is exactly the same size as the duplex LC adapter. Therefore, LC is becoming more and more common in the central office. Because in the central office, the density of the packaging is an important cost factor.

· Handling: Although there is a very innovative, real “push-pull LC” available, with the same handling power as SC. SC is a real “push-pull connector”, and LC is a “lock connector”.

· The history of the connector: LC is “younger” than SC, while SC is spreading wider around the world than LC. LC, however, is catching up.

As we all know, the main difference between SFP LC and SFP SC transceiver lies in the connector. Among the different types of SFPs with LC connector, 1000BASE-SX SFP and 1000BASE-LX SFP transceivers are most commonly used. We take these two transceivers as an example. The 1000BASE-SX SFP LC transceiver is suitable for multimode fiber cables less than 550 meters. The LC SFP LX transceiver is suitable for 10km single-mode optical fiber cables and supports multimode fiber. The 1000BASE-SX LC SFP transceiver standard is designed to support low cost multimode optical fiber operation in horizontal and short length backbone applications. The LC SFP LX transceiver standard is designed to support a longer multimode building optical fiber backbone network and a single mode campus backbone network. The cost of the LC SFP LX transceiver exceeds that of the 1000BASE-SX SFP LC transceiver.

Conclusion

Fiber optic communication is set to grow significantly in the years to come. It is making its presence felt in industries like defense, healthcare, railways, oil and gas, and so on. The choice of the right cables and cable connectors as well as fiber optic devices is important to ensure a precise connection. The pointers in this white paper will help when it comes to choosing between the SFP SC and SFP LC transceivers. However, if you are unsure about the right fiber optic devices, you can always get in touch with the team at VERSITRON, which is a market leader in fiber optics. The company provides various types of fiber optic devices such as copper to fiber media converters, fiber optic network switches, high definition transmitters and receivers, and so on.