IEC 62024-2:2008

Overview - IEC 62024-2:2008 (Rated current of inductors for DC‑DC converters)

IEC 62024-2:2008 defines standardized measuring methods for the rated direct current limits of small high‑frequency inductors used in DC‑DC converters. The standard enables consistent comparison of current ratings published by different manufacturers by specifying how to measure two primary limits caused solely by DC: DC saturation and temperature rise. It applies to leaded and surface‑mount inductors with dimensions per IEC 62025‑1 (typically up to ≈12 mm × 12 mm footprint) and generally rated below 22 A (though larger currents may be covered if dimensions conform).

Key topics and technical requirements

• Scope and applicability
  • Focus on inductors for PCB‑mounted DC‑DC converters, telecom and small switching power supplies.
  • Applies to SMD and leaded parts within stated dimensional limits.
• Definitions
  • DC saturation limited current: DC that causes inductance to decrease to a specified limit.
  • Temperature rise limited current: DC that produces a specified temperature rise due to self‑heating.
• Standard atmospheric/test conditions
  • Normal test range: 15 °C–35 °C, RH 25%–75%, pressure 86–106 kPa.
  • Reference (referee) conditions: 20 °C ±2 °C, RH 60%–70%.
• Measuring methods
  • DC saturation method: small‑signal AC superimposed on DC; measure inductance drop vs DC.
  • Temperature rise method: two accepted measurement approaches - resistance‑substitution and thermocouple methods; includes fixture/jig guidance (printed‑wiring board or lead‑wire).
  • Test circuits, compensation, and calculation procedures are specified to ensure repeatability.
• Quality conformance and specification
  • Procedures for inspection and how rated current is determined and reported.
  • Guidance for information to appear on product detail specifications and catalogs.

Practical applications and users

• Who uses IEC 62024-2:
  • Inductor manufacturers for standardized datasheet ratings.
  • Component engineers / test labs validating current ratings.
  • Power supply and PCB designers selecting inductors for DC‑DC converters and switching supplies.
  • Procurement and quality assurance teams comparing vendor claims.
• Practical value:
  • Ensures comparable, repeatable current ratings across suppliers.
  • Helps designers avoid saturation or overheating in converter designs by choosing inductors rated under consistent test methods.

Related standards

• IEC 62025-1 - dimensions and non‑electrical characteristics for small inductors (normative reference).
• IEC 60068-1 - environmental testing (standard atmospheric conditions reference).
• IEC 62024 series - other parts cover additional electrical characteristics and measuring methods.

Keywords: IEC 62024-2, rated current of inductors, DC to DC converters, DC saturation, temperature rise, SMD inductors, inductor current rating, measuring methods, IEC standard.