ST7R004B

Overview

The ST7R004B is a radial lead inrush current limiter manufactured by Littelfuse Inc. It features a nominal resistance of 7 Ohms with a tolerance of ±20%. The component has a continuous current rating of 4 Amperes and measures 15.24mm (0.600 inches) in length. Designed for PCB mounting, it serves as a passive electronic component to manage initial surge currents.

Feature Summary

• Provides inrush current limiting functionality
• Radial lead termination style for through-hole mounting

Applications

• Power supply input stages
• Transformer primary circuits
• Capacitive load protection

Procurement Notes

Verify the obsolete status and non-cancelable nature of this component before procurement planning. Confirm regional shipping restrictions and tariff applicability. Ensure design-in decisions account for end-of-life management strategies due to discontinuation from manufacturing.

Selection Notes

Select this component based on the specific requirement for a 7-ohm resistance value at 4 amperes. Consider the physical dimensions of 15.24mm for board layout constraints. Evaluate thermal performance requirements against the continuous current rating for the target application environment.

Part Context

This part belongs to the inrush current limiter category within Littelfuse's portfolio. It is designed to protect sensitive downstream components from high initial charging currents. The product line supports various industrial and commercial power applications requiring surge mitigation.

Replacement Considerations

As this product is no longer manufactured, identify alternative inrush current limiters with matching 7-ohm resistance and 4A current ratings. Verify package compatibility and thermal characteristics when sourcing substitutes.