Electronic Connector Selection Guide: Pitch, Current, Mating Cycles
How to select board-to-board, wire-to-board and I/O connectors by pitch, current rating, voltage, mating cycles, environment and termination.
Electrical and mechanical requirements
Define the number of contacts, pitch, rated current per contact and working voltage first. Verify contact resistance and current-carrying derating when multiple contacts are loaded simultaneously.
Consider mating cycles, locking mechanism, polarization (to prevent reversed insertion) and retention for vibration environments.
Environment and termination
Match IP rating, operating temperature and plating (gold for low-level signals and high cycles, tin for cost-sensitive power) to the application.
Choose termination style—SMT, through-hole, crimp or IDC—based on assembly process and repairability, and confirm footprint and mating-harness availability.
Frequently Asked Questions
Gold or tin contact plating?
Gold suits low-level signals and high mating cycles; tin is cost-effective for higher-current, lower-cycle power contacts.
Why derate connector current?
When many contacts carry current at once, heat accumulates; per-contact current should be derated below the single-contact rating.