What the 4 mm stack height and 0.50 mm pitch mean for your board stack
The Hirose DF12NC(4.0)-30DP-0.5V(51) is a 30-position header from the DF12 series, designed for board-to-board mezzanine stacking at a fixed mated height of 4mm. The 0.50mm pitch packs the contacts tightly enough to route dense signal traces between layers, but the footprint demands careful trace escape — expect one signal per channel between vias on a standard 4-layer stack.
30 positions vs 40 or 50 — picking the right circuit count
This 30-position variant sits between the 40-position DF12NC(4.0)-40DP-0.5V(51) and the 50-position DF12NC(4.0)-50DP-0.5V(51) in the same DF12NC sub-family. If your BOM calls for 30 signal lines, this is the direct match; stepping to 40 or 50 positions means a longer connector body and a wider board footprint, but no change in the routing pitch or mating interface.
Active production — no end-of-life concern for this BOM line
There is no announced end-of-life or last-time-buy window, so it can be specified into new designs without an immediate obsolescence risk.