The wrong PCB connector choice can cause intermittent connections, overheating, or mechanical failure. This guide covers the 5 key dimensions of connector selection.
1. Pitch — The Fundamental Dimension
Pitch is the center-to-center distance between adjacent pins. Common values:
- 2.54mm (0.1″) — Universal standard, most headers and IDC connectors
- 2.00mm — JST PH, PHR series; common in consumer electronics
- 1.25mm — JST GH, Molex PicoBlade; space-constrained designs
- 1.00mm — FPC/FFC connectors, board-to-board
- 0.50mm — Ultra-compact board-to-board
2. Current Rating Per Contact
Don’t just look at the connector’s “rated current” — that’s often per contact under ideal conditions. Derate by 30-50% for multi-contact connectors, especially if all pins carry power.
3. Mating Cycle Durability
How many times can you plug and unplug before the contact resistance degrades? Consumer connectors: 30-100 cycles. Industrial connectors: 500-10,000+ cycles.
4. Environmental Sealing
IP67-rated connectors are essential for outdoor, automotive, and washdown environments. TE and Amphenol offer extensive sealed connector families.
5. Termination Style
Through-hole vs. surface mount vs. crimp vs. IDC — each affects assembly cost and reliability.