XMC, known as Express Mezzanine Card, was created by VITA 42 and was designed to meet the requirements of high performance systems in rugged environments. XMC modules consist of Multi-Channel Fiber Optic I/O, FPGA-based Processing, Fibre Channel, Gigabit Ethernet, and Bulk Memory.

Following is a list of VITA 42 XMC standards:

• VITA 42.1 - XMC Parallel Rapid IO Protocol Layer Standard
• VITA 42.2 - XMC Serial Rapid IO Protocol Layer Standard
• VITA 42.3 - XMC PCI Express Protocol Layer Standard
• VITA 42.4 - XMC HyperTransport Protocol Layer Standard
• VITA 42.5 - XMC Aurora Pin Assignments
• VITA 42.10 - XMC General Purpose I/O Standard

Connector Specification
XMC specifies a Samtec SamArray® connector set for throughput. The YFS/YFW Series SamArray® system provides 114 pins in a 6 x 19 configuration (equating to 10 differential pairs in each direction), a 10mm stack height, and a 3.125 Gbps performance rating. Testing confirms that the SamArray® connector set can perform up to10 Gbps allowing for even faster speeds in the future.

XMC Connector Options
Several other XMC connector configurations are available allowing users to optimize their component choice.

For those who control both halves of the interface and want a “next generation solution” that is ROHS compliant, Samtec now offers SEARAY™ in a 6x19, 10mm solution.  

SEAM-19-03.5-S-06-2
SEAF-19-06.5-S-06-2

Note - Samtec’s SEAM/SEAF Series is not a VITA 42 recognized connector set, but is recognized by VITA 57.  For more information on VITA 57, please click here.

*In addition to the 10mm stack height versions, VITA 42 specifies a 12mm tall XMC connector set. The additional 2mm allows for improved airflow through the system.

For questions regarding the VITA 42 XMC standard and available parts, please contact us at XMC.

VITA 42 includes non-solderball XMC post-only connectors for paste-on-pad attachment. While these connectors provide acceptable attachment performance, Samtec recommends considering solderball equipped connectors for increased mechanical robustness. Samtec YFS/YFT Series SamArray® connectors with leaded solderballs are ideal for Military applications. For commercial users, RoHS compliant lead-free solderball versions are available.

In addition, the socket (female) side is available with either standard or low insertion/withdrawal force contacts. Standard contacts provide an added margin of protection in applications exposed to extreme shock and vibration. Low insertions/withdrawal force contacts are ideal for mainstream applications where cards may be installed by field personnel or see more frequent mating cycles.

• For more information regarding Samtec's YFS/YFT Series SamArray® insertion and withdrawal forces, click here.
• For more information regarding lead and lead free processing, click here.
• For Application Notes for ASP-105884-01/ASP-105885-01, click here.
• For Application notes for all products capable of XMC protocols, click here.
• For available white papers, click here.
• Click here to read a VITA overview.
• Click here for information on VITA 57
• Click here for information on "Mated Stack Height"