PCIE x8 to MXM adapter card

• A low-cost adapter card that can connect PCIE to MXM for testing MXM boards.
• Four-layer PCB design, area 100x100mm, free sample available.
• Three display output interfaces are designed, and the circuits have all passed the test.
• Supports standard MXM cards and Blue Sky special MXM cards (special-shaped cards).

Some things to note

• This project is under the GPL 3.0 protocol. Please work together to maintain the open source environment.
• This project is for DIY and learning purposes only.
• Due to the impedance control requirements of PCIE and display interfaces, please use the JLC2313 stacked structure when designing the board, otherwise it may cause abnormal functions.
• The adapter card comes with a 3+1 Pin fan interface. The V2 version uses the PWM signal that comes with some boards to control the speed. (The V3 version does not seem to be used.) The V4 version adds a cheap temperature control circuit based on NTC.
• The adapter card provides PCIE 8Pin auxiliary power supply, which must be connected when the board power is greater than 75W.
• An external power supply interface for special-shaped cards is also provided.
• The riser card only provides physical connection. If you encounter problems that cannot be used, please check the board itself. (NVIDIA has restricted MXM transfer after the 20 series, and the driver cannot be installed.)
• MXM transfer may require operations including but not limited to modifying INF and VBIOS. Please make sure you have sufficient understanding of them.
• The description of the individual signals is marked in the schematic.
• Due to the accuracy loss bug of LCEDA, there will be a bunch of errors in the DRC check, ignore it. Design rules are okay.
• The BOM has been verified and the BOM generated by the system can be used directly.
• If used for a long time, it is recommended to choose the immersion gold process, as spray tin will oxidize.
• V1 has been deprecated, don't ask why there is no V1.
• The PCB in the project does not include the silk screen image on the back ( this is a ghost if it can be opened )

Change log

• 22.1.5 (V3) has designed a circuit that supports temperature and speed control. It has not been tested on the board. If you have tested it, you can send me a private message. Don't try it, it doesn't work
• 22.5.1 (V4) The temperature control circuit has been redesigned and has been verified to be feasible. The packaging of the power supply interface of the special-shaped card has been changed, and a version with process edges (V4.1) suitable for standard SMT has been added.

Actual pictures (V2 version)

• Full picture of the board
  
• Three display outputs, 1DP 1HDMI 1DVI-I (including VGA)
  
• MXM slot, height is 7.8mm, copper pillar uses 5.5mm, M3
  
• HDMI and DP both add ESD protection
  
• The differential signals of the display interface have been matched to equal lengths and are matched to less than 3mil.
  
• PCIE only performs internal equal length processing, and the coupling capacitor is placed close to the gold finger.
  
• Fan interface and PCIE 8Pin auxiliary power supply
  
• Auxiliary power supply interface for special-shaped cards