Since the inception of computer boards, optimizing board real estate has consistently posed challenges for designers. Space constraints often prevent the inclusion of all desired functionalities, prompting inventive solutions. Mezzanine cards have become a prevalent method for expanding available board space, enhancing capabilities, and improving modularity. Over time, numerous approaches have been developed, with many tailored to specific board layouts, while others have achieved industry-standard status.
The first non-VMEbus standard established by VITA was VITA 4 IP modules, which were based on the widely adopted IndustryPack® from GreenSpring Computers. Subsequently, VITA has introduced standards for M-modules (VITA 12), PMC (IEEE 1386, VITA 32), XMC (VITA 42), and FMC (VITA 57) – each of which has gained substantial popularity within the embedded computing industry.
In October 2025, VITA announced the ratification by ANSI and VITA of the ANSI/VITA 93.0-2025 standard for small form factor mezzanines. The VITA 93 standard, referred to as QMC, is designed for both performance and flexibility. QMC defines a mezzanine card form factor that is significantly smaller than the popular XMC form factor. QMC was developed specifically to support various carrier-card formats for use in a wide range of deployed environments, supporting both air- and conduction-cooled designs in commercial, industrial, space, or military-grade rugged environments. Multiple modules can be installed on various carrier card form factors, including 3U/6U Eurocards (VPX, CompactPCI, VME, etc.), VNX+, PCIe expansion cards, and others. QMC supports high-speed serial data links through its host carrier interface, along with its user-defined I/O interface.
QMC addresses the need in the market for a small-form-factor I/O mezzanine. Its function is much the same as the earlier IP Module, PMC, and XMC standards in that it provides connectors and interfaces for both the carrier-side connector as well as the I/O side, but in a much smaller form factor. The emergence of the VNX+ standard [VITA 90.0] drove the initial need for a smaller-form-factor mezzanine with backplane I/O capability, but it was soon realized that this new form factor would have significant utility across many form factors and deployed environments.
“QMC represents a revolutionary change in small form factor mezzanine cards,” stated Mark Littlefield, VITA 93 Working Group Chair and Director, System Products at Elma Electronic. “The need for a smaller-form-factor mezzanine has been challenging the industry for years, and QMC brings a much-needed standards-based solution to the industry.” VITA 93 started as a study group that spent considerable time surveying the industry to gather information and requirements for small mezzanine cards. This then turned into the VITA 93 working group that started with a clean slate to develop the VITA 93 QMC standard.
“The versatility of QMC modules will serve a broad range of industries and applications,” explained Robert Greenfield, VITA 93 Working Group Co-Chair and Director of Business Development at Acromag. “The combination of high-performance connectors, rugged design, scalability, and variable stack heights offers endless possibilities for modular expansion of I/O and signal processing capabilities.” Acromag has been a provider of mezzanine cards across multiple form factors for many years. Their expertise made a significant contribution to the development of the final standard.
“The publication of the VITA 93 QMC standard is a milestone for the embedded systems industry,” commented Jan Zimmermann, General Manager, TEWS Technologies GmbH. “It opens new opportunities for innovation in rugged, deployed applications across aerospace, defense, industrial, and transportation markets. At TEWS Technologies, we believe QMC will play a defining role in the next generation of embedded computing, and we are committed to shaping this future with a strong and growing portfolio of QMC modules and carriers.” Small-form-factor cards and mezzanine modules are widely utilized throughout Europe. TEWS Technologies contributed its extensive expertise in this market to the working group.
“The VITA 93 standard represents three years of collaboration among leading experts in mezzanine card technology, including PMC and XMC,” said Joe Norris, VITA 93 Working Group Co-Chair and President of Technobox, Inc. “Our goal was to build a strong, open market that benefits suppliers and customers alike. We focused on cost, manufacturability, interoperability, cooling performance, scalability, and simplicity – all essential to making this standard a success,” Norris added. “The result is a platform that sets the stage for real business growth across the industry.” Technobox has been a pioneer in mezzanine module technology. The depth of knowledge in mezzanines provided by Technobox was instrumental in refining the QMC standard.
Ancillary standards on the way
The VITA 93 working group continues to work on ancillary standards for QMC. VITA 93.1 and VITA 93.2 will define the mechanical details of two mezzanine cards with front-panel I/O. These I/O cards are intended to be used on carrier cards or rear transition modules to break out the QMC I/O signals to industry standard connectors that fit through the carrier card’s face plate or rear-transition module panels. The work on these projects is moving quickly and will be published in the coming months.
QMC standard-based products
Members of the ecosystem are launching new products based on the QMC standard.
Acromag announced the QMC Series plus PCIe/VPX carrier boards and evaluation carriers. (QMC Series I/O Modules for VITA 93 Small Form Factor Mezzanine | Acromag) (Figure 1.)
- QMC350: Analog input, 20 channels, 1 MSPS 16-bit A/D
- QMC440: Digital input, 32 optically-isolated channels
- QMC450: Digital output, 32 isolated solid-state relays
- QMC510: Octal serial communication, programmable RS-232/422/485 ports
- QMC520: Quad isolated serial communication, programmable RS-232/422/485 ports
- QMC730: Multifunction I/O, A/D, D/A, DIO, counter/timers
- QPCe7210: PCIe carrier, one QMC site
TEWS Technologies announced a portfolio of QMC modules, a TPCE210 dual-site PCIe carrier, and a QMC Starter Kit (TQMC400 + TPCE210 + drivers). (VITA 93 – QMC | TEWS Technologies GmbH) (Figure 2.)
- TPCE210: PCI Express x4, Gen 2, Dual QMC Carrier
- TQMC400: 4 Channel Full-Modem RS232/RS422/RS485 Programmable Serial Interface
- TQMC401: 4 Channel High Speed Sync/Async Serial Interface
- TQMC600: Reconfigurable FPGA with Digital I/O
- TQMC700: Reconfigurable FPGA with AD/DA & Digital I/O
- TQMC701: 8 Single-Ended/Differential A/D Channels, 4 D/A Channels and 16 Digital I/O Channels
- TQMC800: 1 Channel 1000BASE-T Ethernet
Additional announcements are expected in the coming weeks and months.
The QMC Community website offers an up-to-date selection of announcements, articles, webinars, and white papers that provide comprehensive information on designing with QMCs. Designers seeking to expand their knowledge are encouraged to consult this resource first (www.vita.com/QMC). A thorough discussion of QMC took place during a panel session at Embedded Tech Trends in January 2025. Related videos and presentations can be accessed through the Embedded Tech Trends website (www.embeddedtechtrends.com).
The ANSI/VITA 93.0-2025 standard is available for purchase at the VITA Online Store (www.vita.com/Standards).
