The Hirose DF12NC-50DS-0.5V(51) is a 50-position, 2-row receptacle with center strip contacts from the DF12 series, designed for board-to-board mezzanine stacking. The receptacle accepts the matching DF12 series plug headers to achieve mated stacking heights of 3.5mm, 4mm, or 5mm from a single part number, which simplifies inventory when your BOM calls for multiple board gaps.
The solder retention feature keeps the part anchored during reflow without a secondary hold-down, which matters when your pick-and-place line runs at speed. Surface mount termination with a 2.70mm height above board fits standard mezzanine clearance envelopes; the 0.50mm pitch means the outer rows sit close to the board edge, so check your keep-out zones.
Against the DF12NB-60DS-0.5V(51), the 50-position DF12NC-50DS-0.5V(51) trades 10 circuits for the same 0.50mm pitch and 2.70mm height — the 60-position sibling is a direct drop-in for higher I/O density if your BOM allows the extra lines. The DF12NB(3.0)-50DS-0.5V(51) shares the 50-position count but drops to a 2.20mm height, which changes the mated stack by 0.50mm — useful when your board gap is tighter than the standard 3.5mm minimum. The DF12NC-30DS-0.5V(51) cuts to 30 positions at the same height and pitch, a cost-saver if your signal count fits 30 lines.