What This 40-Position Mezzanine Plug Does
Pitch, Stack Height, and the Footprint Decision
The 0.80mm pitch is the tightest common mezzanine pitch — it saves board real estate but demands careful trace routing between pads on the PCB. The 8mm mated stacking height is a fixed dimension: the plug's own height above board is 0.309" (7.85mm), so the receptacle half must sit at the complementary height to hit the 8mm total. If your board stack needs a different gap, the Free Height family includes other heights — but this part number locks the z-height at 8mm. The 40 positions match a 40-circuit BOM line; there is no 38- or 42-position variant in this pitch class.