Advancing Mezzanine Card Technology via QMC

What you’ll learn:

• VITA mezzanine card standards.
• Why VITA 93 QMC is important for new rugged applications.

As computer technology advances, the functional density of components increases, meaning that more functionality is packed into smaller spaces. This trend is evident across various levels of technology, from microprocessors to memory chips, and mezzanine cards or daughtercards are no exception.

To address the issue of more compact solutions, VITA, a non-profit rugged standards organization, has developed the VITA 93 QMC standard (see figure). Earlier VITA mezzanine standards include VITA 32 PMC, VITA 42 XMC, and VITA 57 FPGA Mezzanine Card (FMC).

Mezzanine Card Considerations

Mezzanine cards or daughtercards are small circuit boards that plug into a larger mainboard, providing additional functionality without increasing the overall size of the system. These cards are used in a variety of applications, including telecommunications, industrial automation, and consumer electronics. Mezzanine cards, which have been around for decades, are designed to augment board products that need the ability to add or exchange features.

For example, in telecommunications, mezzanine cards can be used to add extra ports or processing power to a network switch or router. This allows the device to handle more data and support more users without requiring a complete redesign of the hardware. Similarly, in industrial automation, daughtercards can be used to add specialized input/output (I/O) capabilities to a programmable logic controller (PLC), enabling it to interface with a wider range of sensors and actuators.

As components shrink, the design and manufacturing of mezzanine cards become more challenging. Engineers must carefully consider factors such as heat dissipation, signal integrity, and power consumption to ensure that the cards perform reliably in their intended applications.

Why VITA 93 QMC is Important

The VITA 93 QMC standard defines an emerging technology that takes this concept even further. VITA 93 defines a small-form-factor mezzanine that’s significantly smaller than XMC, with both host and I/O interface connectors.

The host interface supports modern high-speed serial fabrics for connectivity. Multiple modules can be installed on various carrier-card form factors, including 3U/6U Eurocards (VPX, CompactPCI, VME), VNX+, PCIe expansion cards, and many others. It’s suitable for deployment in commercial, industrial, space, or military-grade rugged environments with air- or conduction-cooled formats.

The standards working group, which originally started out in 2022 as the VITA 85.109 study group, came together to gather requirements from invested participants in the mezzanine supply chain. The study group was chartered to study and document the concept of a new Small Form Factor Mezzanine (SFFm) with certain characteristics not currently addressed by existing mezzanine standards. This was driven by a market need for a mezzanine with the following basic characteristics:

• Significantly smaller than XMC (specifically to be accommodated on the VITA 90 VNX+ form factor that was too small to accommodate any of the VITA mezzanines).
• Providing two interfaces:
  • A host/primary interface supporting PCIe speeds beyond Gen2.
  • An I/O/secondary interface to support either front-panel or backplane I/O.
• Able to be hosted on a range of carrier cards.
• Able to be deployed in either commercial, industrial, or military-grade rugged environments.

It was also desirable to make this new standard as broadly appealing as possible to multiple markets to drive up adoption, thus driving down costs and ultimately prices.

The resulting QMC standard represents the next frontier in the evolution of mezzanine cards. It offers even greater potential for advances in various high-tech industries.