Design for Stress, Not Only Resistance

Design for stress, not only resistance

When failure is not an option, resistance and wattage aren't enough, In mission-critical systems, temperature, environment, pulse loading, frequency and qualification requirements drive real-world resistor performance and reliability.

Environment

Match resistor to the operating environment

• Corrosive sulfur-bearing atmospheres
• Vacuum & space exposure
• Repeated thermal cycling and wide temperature excursions

Design considerations

• Sulfur-resistant terminations & materials
• ASTM E595 low-outgassing compliance
• Proven stability under thermal stress

Key takeaway Environmental stress can accelerate drift, degradation & failure before power limits are reached.

Qualification

Materials → Processes→ Screening/testing → Reliability verification → Traceability

MIL-spec requirements for reliability

• MIL-PRF-55342 - film resistors
• MIL-PRF-39007 - wirewound resistors

Key takeaway Qualification verifies reliability and consistency in demanding environments - ensuring mission-ready reliability in critical applications

Other design factors

Temperature Resistance drift can

Pulse energy Inrush & transients can damage undersized resistors

Frequency Parasitics can affect high-frequency performance

Key takeaway These factors influence accuracy, design robustness, and reliability

Mission-critical applications

Avionics Flight control computers

Space Satellites & GPS systems

Militarv Radar & sonar

Vishay resistor technology highlights

Design consideration

• TCR stability
• Power handling
• Temperature Capability
• High-Frequency Performance
• Pulse Capability
• Key Advantage
• MIL Qualification

Thin film M/D55342 E/H

• Excellent
• Low to Moderate
• Up to +150°C
• Non-inductive
• Moderate
• Precision & low noise
• MIL-PRF-55342

Thick film M/D55342 RCWPM

• Good
• Low to Moderate
• Up to +150°C
• General-purpose
• Moderate
• Sulfur resistance & proven reliability
• MIL-PRF-55342

Wirewound RWR

• Application-dependent
• High
• Up to +250°C
• Type N non-inductive option
• Excellent
• High power & pulse endurance
• MIL-PRF-39007

RWR TCRvaries by resistance value and construction

Mouser & Vishay logos

Published: 2026-09-25 © 2026 Mouser Electronics, Inc.