The History And Evolution Of D‑Sub Connectors

Introduction

D‑Sub connectors—so‑named for the distinctive D‑shaped metal shell—first rolled off the Cannon production line in 1952, instantly shrinking the size of multi‑pin interconnects used in early computers and instrumentation. Over seven decades they have morphed from “miniature” curiosities into an everyday workhorse found on factory floors, test benches, aircraft cockpits, and even legacy desktop PCs.

1. From Mainframes to Microcomputers

Early D‑Subs offered reliable shielding and a secure mechanical latch at a time when most connectors were still screw‑terminals. As computing moved from room‑sized mainframes to personal machines in the 1980s, the compact shell sizes (A through E) mapped neatly to common signal counts, making D‑Sub the default external I/O for serial, parallel and video ports. The familiar thumbscrews ensured a vibration‑proof link—critical for industrial and military electronics long before USB existed.

2. Standard Pin Counts and Their Signature Uses

9‑pin (DE‑9) – Often mislabeled “DB9,” this connector became synonymous with RS‑232 serial ports on PCs, PLCs, CNC machines and networking gear thanks to its small footprint and simple point‑to‑point wiring.
15‑pin (HD‑15/DA‑15) – Better known as the VGA connector, the three‑row “high‑density” 15‑pin carried analog video from the 1987 IBM PS/2 right through the flat‑panel era and is still embedded in KVM switches and projectors. (Connecteur secondaire D)
25‑pin (DB‑25) – The original parallel‑port workhorse for printers and SCSI‑1 peripherals; it also hosted full‑handshake RS‑232 on early modems and routers.
37‑pin (DC‑37) – With 19 + 18 contacts, this larger shell served multi‑drop SCSI chains, aerospace data buses and industrial control harnesses where extra grounds and shields were essential.

These variants—“9pin, 15pin,25pin,37pin d sub connectors” in many catalog searches—share identical mating geometry, letting engineers mix densities and genders with off‑the‑shelf hoods, backshells and board brackets. en.wikipedia.org

3. Ruggedization: The Rise of d sub waterproof connectors

When control cabinets migrated outdoors, the industry answered with IP‑rated d sub waterproof connectors. Modern IP67 D‑Subs integrate O‑ring seals, stainless hardware and over‑molded backshells so they can survive wash‑downs, salt‑spray and daily thermal cycling—without abandoning legacy pinouts or tooling. Engineers keep the EMI shielding of the classic metal shell while gaining dustproof and waterproof integrity in harsh‑environment robots, traffic systems and subsea sensors.

Connecteurs circulaires miniatures étanches IP68 M12 4 broches pour transmission de puissance

4. Why D‑Sub Connectors Still Matter

Proven design: Decades of field data mean predictable impedance, retention force and vibration resistance.
Massive ecosystem: Millions of crimp, solder‑cup, press‑fit and IDC parts in every plating and orientation keep costs low and supply chains resilient.
Scalability: From micro‑D for satellites to combo‑D carrying power + coax + fiber, the format adapts to new protocols without a new mechanical envelope.
Serviceability: Through‑hole footprints and captive screws make replacements possible with a screwdriver—no hot‑air rework required.

Conclusion
Whether you need drop‑in 9pin, 15pin,25pin,37pin d sub connectors for a legacy board spin or robust d sub waterproof connectors for an outdoor kiosk, the humble D‑Sub remains a flexible, future‑proof choice.

Ready to spec your next connector? Talk to YW Connectors today, request free samples, or send us your drawing for a fast quotation—let’s build reliable links together!