ST5R006B

Overview

The Littelfuse ST5R006B is a thermistor-based inrush current limiter designed to mitigate high initial surge currents during power application. It features a nominal resistance of 5 Ohms with a tolerance of ±20%. The device supports a continuous current rating of 6 A and has a physical dimension of 0.775 inches (19.68mm). This component functions by exhibiting higher resistance at lower temperatures, which naturally limits the inrush current before heating up to allow normal operation.

Feature Summary

• Provides effective mitigation of high initial surge currents when power is applied to circuits
• Utilizes thermistor technology to dynamically adjust resistance based on temperature changes
• Designed for robust protection of sensitive electronic components against transient overcurrent events

Applications

• Power supply input stages requiring surge current limitation
• Consumer electronics circuit protection
• Industrial control systems managing capacitive loads

Procurement Notes

Verify the specific ordering suffix 'B' against official Littelfuse documentation to ensure correct packaging or variant specifications. Confirm that the 5 Ohm resistance and 6 A current ratings align precisely with your circuit design requirements. Cross-reference the physical dimensions of 0.775 inches to validate mechanical fit within the intended assembly. Ensure compliance with relevant safety standards applicable to inrush current limiters in your target market.

Selection Notes

Select this component when the application demands a passive solution for limiting inrush current without active control circuitry. The 5 Ohm resistance value should be evaluated against the specific voltage and capacitance parameters of the load to ensure adequate surge suppression. Consider the thermal recovery time and steady-state heat dissipation capabilities relative to the operating environment. Verify that the 6 A continuous current rating exceeds the maximum expected operational current under all conditions.

Part Context

The ST5R006B belongs to the Littelfuse ST series of inrush current limiters. These devices are engineered to protect downstream components from damage caused by high inrush currents typical in systems with large capacitive loads or transformers. The series offers various resistance and current ratings to accommodate diverse circuit requirements while maintaining reliable performance over repeated power cycles.

Replacement Considerations

Consult official Littelfuse substitution guides for verified alternatives. Ensure any replacement maintains equivalent resistance, current handling, and dimensional constraints.