What is VITA 57.4 FMC+? 

Meet the Connector: VITA 57.4 FMC+

57.4 FMC+, the VITA 57.4 standard, provides specifications describing an I/O mezzanine module with connection to an FPGA (Field Programmable Gate Array) or other device with reconfigurable I/O capability. 57.4 is the latest extension of the FMC (VITA 57.1) standard and defines the FMC+ (FPGA Mezzanine Card) specification, which handles higher data rates and more complex I/O requirements than the original FMC standard, supporting applications that require more high-speed serial transceivers. Additionally, the current standard defines enhanced pin counts for additional data channels, making them ideal for advanced FPGA applications such as high-performance computing and data processing in industries like defense, telecommunications, and instrumentation.

The original FMC standard specified connectors with up to 160 pins and 10 high-speed serial lanes. As newer FPGAs arrived that supported significantly more high-speed transceivers, FMC+ connectors evolved to support up to 560 pins, accommodating more data channels and I/O functionality.

FMC+™ employs a larger connector from Samtec’s SEARAY™ family of high-speed, high-density arrays. This High Serial Pin Connector (HSPC) has 560 pins arranged in a 14×40 array. While new FMC+™ cards can only plug into new FMC+™ carriers due to their larger connectors, original FMC™ cards will also fit thanks to a customized polarization system providing true backward compatibility.

Design Notes

Standardization

Today’s 57.4 standard originated as the 57.1 standard, released by the VITA (VMEbus International Trade Association) consortium in 2008. The goal of FMC was to create a modular, flexible standard that allowed different I/O modules to interface directly with FPGA boards using high-speed, low-latency connections. FMC allowed system designers to integrate FPGAs with various custom or off-the-shelf I/O solutions without the need for additional backplane connections, simplifying the development of embedded systems.

The VITA 57.4 FMC+ standard was ratified in 2016 and introduced several key improvements to meet the growing demands of modern FPGA systems, including increased pin count (to 560), more data channels, and I/O functionality.

FMC+ also expanded the number of high-speed transceivers (gigabit transceivers) from 10 (in FMC) to as many as 24, enabling support for higher data bandwidth.

FMC+ is backward compatible with the original FMC standard, allowing existing FMC modules to be used on newer FMC+ carriers. This allows engineers to easily upgrade to higher-performance FPGA systems without redesigning the entire platform.

Smith’s Interconnect’s VITA 57.1- and 57.4-compliant optical FMC boards offer up to 120 Gb/s of full-duplex throughput for use with the latest generation of FPGA front-end processing boards.

High-speed connectors for I/O mezzanine modules

• Supporting up to 10 Gb/s transmission with adaptive equalized I/O
• Supporting single ended and differential signaling up to 2 Gb/s
• Numerous I/O available

Mounting type

The FMC+ modules (mezzanine cards) are mounted directly on top of an FPGA carrier board using specialized connectors. This creates a compact and modular design where the mezzanine card (FMC+ card) sits above the FPGA board, making it easier to swap or upgrade I/O modules.

The FMC+ standard uses high-density connectors that are specifically designed to maintain signal integrity at high data rates (up to 28 Gb/s per lane). These connectors provide stable mechanical attachment and electrical connectivity between the carrier board and the FMC+ mezzanine module.

Contacts

Pins: Up to 560

Mechanical properties

• Minimal size
• Scalable from low end to high performance applications
• Conduction and ruggedized support
• The standard describes options to create modules for operating in a range of environments from passively cooled to fully ruggedized conduction cooled.

Electrical properties

• Supporting up to 10 Gb/s transmission with adaptive equalized I/O
• Supporting a wide range of signaling standards
• System configurable I/O functionality
• FPGA intimacy

Markets and Applications

Aerospace, defense, telecommunications, and instrumentation.

Suppliers

Samtec, Smiths Interconnect

Related Products

Mezzanine connectors

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