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SUMIT, SUMIT-ISM, UEMF Industry Standard


SUMIT is an electromechanical connectorization specification that enables all common serial and legacy chipset expansion busses for next generation products. It is a stackable, I/O-centric, serial expansion approach that is independent of any particular board form factor. It supports PCIe, USB, LPC, SMBus, and ExpressCard signals on a single high-speed connector. A second connector supports additional PCIe lanes.

Interface signals included in SUMIT:

  • Two x1 channels of PCI Express (including clock and card present)
  • One x4 channel of PCI Express (including clock and card present)
  • Three USB 2.0 channels
  • One ExpressCard channel
  • Two SPI/uWire channels
  • LPC interface with serial IRQ support
  • System Management Bus (SMBus)/I2C with SMD Alert
  • Reset and Wake On LAN (WAKE)

The SUMIT standard specifies Samtec's Q2 QMS/QFS Series in a one bank (52 pin) orientation for module stacking. Samtec specifically designed the QMS/QFS Series with a 15.24mm stack height for top and bottom board stacking. Q2 has triple the wipe of many high speed mezzanine interconnects making it appropriate for rugged applications.

For elevated board stack in applications where processors need bigger heat sinks; Samtec has created the ASP (application specific product) male QMS versions which mates to the female QFS for the 22mm mated height:

To obtain samples or information on the part numbers listed on this page, click on one of the links below:

Pricing and Delivery

SUMIT Connectors

Samtec PN Prints PADS
ASP-129637-01 PDF Print
ASP-129646-01 PDF Print
ASP-142781-01 PDF Print

Samtec also offers precision machined standoffs to limit the impact of tolerance stack up issues in stackable embedded applications.

Samtec is a member of Small Form Factor Special Interest Group (SFF-SIG). For more information on SFF-SIG, please click here.

Click here to view a white paper from VersaLogic on "Increasing Bandwidth and Connectivity in Small Form, High-Performance Embedded Applications: The I/O-Centric, High-Speed SUMIT Interconnect Standard."

For additional information, contact our Standards Group.

SUMIT is an interconnect and signaling bus specification only. For more information on the PCB form factor specification using the SUMIT standard, such as Pico-ITXe, Pico-I/O, and SUMIT-ISM, contact the Standards Group for more information.

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