EN 140401-804:2011/A1:2013

Overview

The EN 140401-804:2011/A1:2013 standard, developed by the European Committee for Electrotechnical Standardization (CENELEC), provides a detailed specification for fixed low power film high stability Surface-Mount Device (SMD) resistors with a rectangular shape. It focuses on resistors classified under stability classes 0.1 and 0.25, ensuring precise resistance values over time and under stable environmental conditions.

This standard applies primarily to fixed resistors used in electronic circuits, where low power dissipation and high stability are crucial. The amendment A1 issued in 2013 updates the original 2011 version to reflect the latest technical requirements, including dimensional tolerances, coding systems, and ordering information.

Key Topics

• Resistor Types and Stability Classes
  The standard covers rectangular SMD resistors with high stability film technology, designed for fixed low power applications. It specifies two main stability classes:

  • Class 0.1 – exceptionally low deviation over time
  • Class 0.25 – tight but slightly less stringent tolerance

• Dimensions and Styles
  The document details size variants, including popular industry styles and their corresponding dimensions in millimeters:

  • RR1005M (0402 metric)
  • RR1608M (0603 metric)
  • RR2012M (0805 metric)
  • RR3216M (1206 metric)
  • RR5025M (2010 metric)
    Each style has specified length, width, and height tolerances essential for compatibility in surface mounting processes.

• Resistance Coding System (RKMG)
  The standard endorses use of the RKMG code system, which replaces decimal points with SI-prefix letters-R, K, M, G-to simplify resistance value representation. This ensures clear ordering and identification, especially in automated electronic order processing without spaces.

• Amendments and Updates
  The 2013 amendment clarifies aspects such as:

  • No spaces in ordering codes for electronic processing
  • Updated tolerance and termination dimensions
  • Fail-safe coding conventions for failure rate indications

Applications

• Electronic Circuitry
  Fixed low power film high stability SMD resistors according to EN 140401-804:2011/A1:2013 are used in precision circuits where resistance stability over time is critical-such as timing circuits, filters, and sensor signal conditioning.

• Consumer Electronics and Industrial Devices
  Their compact sizes and high reliability make these resistors suitable for densely packed PCB layouts in consumer electronics, automotive applications, and industrial automation equipment.

• Test and Measurement Instruments
  Because of their tight tolerance and temperature stability, these resistors are preferred in test instrumentation and calibration devices where precise electrical characteristics are mandatory.

Related Standards

• EN 60062
  Provides the coding system for resistor values using the RKMG scheme referenced in EN 140401-804 updates.

• General SMD Resistor Standards
  Other European and international standards cover general characteristics of SMD components, but EN 140401-804 is specifically tailored for fixed low power film resistors with high stability.

• CENELEC and IEC Norms
  This standard aligns with broader CENELEC and IEC norms for electronic components, ensuring interoperability and compliance across European markets.

By adhering to EN 140401-804:2011/A1:2013, manufacturers and users can ensure that low power film SMD resistors meet stringent quality, dimensional, and stability requirements-critical for modern electronics requiring long-term performance and reliability.