Hirose DF40TC-40DP-0.4V(58) — 0.40 mm Pitch, 40-Position Mezzanine Header
The Hirose DF40TC-40DP-0.4V(58) is a 40-position, 2-row header from the DF40T series of board-to-board mezzanine connectors. It uses a 0.016" (0.40mm) pitch and stands 0.045" (1.14mm) above the board after soldering, making it suitable for ultra-compact, low-profile stacking applications in portable electronics, wearables, and handheld devices where z-height is at a premium. The connector is a surface-mount header with outer shroud contacts — this is the plug side of the mating pair. The connector is ROHS3 compliant.
40 Positions vs 30 and 50 — Choosing the Right Circuit Count
The DF40T series offers this 40-position header alongside 30-position (DF40TC-30DP-0.4V(58)) and 50-position (DF40TC-50DP-0.4V(51) or DF40TC-50DP-0.4V(58)) siblings, all sharing the same 0.016" (0.40mm) pitch, 0.045" (1.14mm) height, and gold flash plating. Because the footprint, stack height, and contact finish are identical across these three variants, a board layout designed for one can accommodate the others with only a pad-count change — useful if the design needs to scale signal count without a board respin.