IEC 61754-37:2025

Overview - IEC 61754-37:2025 (Type MDC connector family)

IEC 61754-37:2025 specifies the mechanical interface dimensions for the Type MDC connector family, a compact multi-fibre connector used in fibre optic interconnecting devices and passive components. The standard (Edition 1.0, 2025) defines plug, adaptor and active-device receptacle interfaces for duplex and quadruplex configurations, including both PC (physical contact) and APC (8° angled PC) optical endfaces. It provides dimensional tables, diagrams and intermateability rules to ensure mechanical compatibility across manufacturers and equipment.

Key technical topics and requirements

• Mechanical interface dimensions: Detailed dimensional tables and figures for duplex and quadruplex plugs, adaptors and receptacles (including pitch, radii and diameters).
• Ferrule characteristics: Uses two spring‑loaded 1.25 mm nominal OD ferrules per duplex plug; ferrule compression force for buffered fibre specified (5.0 N to 6.0 N) and guidance for non‑spring‑loaded designs.
• Optical endface types: Distinct interfaces for PC and APC (8° angled) ferrules; APC receptacles mate with APC plugs and PC with PC.
• Alignment and latching:
  • Optical alignment by a resilient split sleeve.
  • Push‑pull coupling latching mechanism described; Annex C gives additional MDC latch details.
• Interface identifiers: The standard defines interfaces 37-1 through 37-6 (duplex plug PC/APC, duplex adaptor, duplex receptacle, quadruplex adaptor and quadruplex receptacle) and provides a plug-to-adaptor/receptacle intermateability table.
• Ancillary information: Annex A (additional adaptor dimensional variants), Annex B (oriented fibre core location) and normative pin gauge and active device receptacle dimensions.

Practical applications and who uses this standard

IEC 61754-37 is essential for:

• Connector and cable manufacturers designing Type MDC plugs, adaptors and receptacles to ensure cross‑vendor compatibility.
• Optical transceiver and active device designers integrating MDC receptacles into modules and line cards.
• Data centre and telecom equipment engineers specifying compact multi‑fibre connector interfaces for high‑density cabling systems.
• Test labs and conformity bodies verifying mechanical interchangeability and connector mating performance.
• Systems integrators and installers selecting components that comply with standardized pitch, latch and ferrule interface criteria.

Using this standard reduces mechanical incompatibility, accelerates product development and supports reliable high‑density fibre deployments.

Related standards

Relevant normative references (cited by IEC 61754-37):

• IEC 61754-1 - General guidance for fibre optic connector interfaces
• IEC 61755-3-1 / 3-2 - Ferrule optical interface specifications (PC and APC)
• IEC 60794-2-50 - Indoor cable family specification for terminated assemblies
• IEC 63267 series - Multimode ferrule interfaces

Keywords: IEC 61754-37, MDC connector, fibre optic connector interfaces, duplex MDC, quadruplex MDC, PC/APC ferrule, connector mechanical dimensions, connector pitch, split sleeve alignment.