Overview
IEC 61754-3:1996 specifies the interface dimensions for type LSA family of connectors, establishing mechanical and mating interfaces to ensure interchangeability and reliable mating performance. This IEC International Standard defines the plug and adaptor geometry, ferrule size and endface requirements, coupling method (screw coupling) and key mechanical tolerances for the single‑position LSA connector family.
Key topics and technical requirements
- Scope: Standard interface dimensions for the Type LSA connector family.
- Connector type: Parent connector is a single‑position plug with a nominal 2.5 mm ferrule diameter, screw coupling nut and ferrule spring force toward the optical axis. A single male key limits relative rotation.
- Defined interfaces:
- Interface 3‑1: Plug connector interface - screw coupling
- Interface 3‑2: Adaptor connector interface - screw coupling
Interface 3‑1 is specified to mate with Interface 3‑2.
- Mechanical details and limits (selected values from the standard):
- Ferrule nominal diameters and tolerance grades for Ø A (detailed tolerance table included in the standard; envelope condition per ISO 8015).
- Ferrule spring force requirement: must be less than 20 N when compressed.
- Thread: M5.5 × 0.5 (plug) and matching M5.5 × 0.5‑6G (adaptor).
- Adaptor acceptance: feature must accept a gauge pin to 12.2 mm depth with withdrawal force 3 N min, 10 N max.
- Ferrule endface geometry: dimensions for convex spherical polishing with **eccentricity