ST2R510B

Overview

The ST2R510B is a power thermistor inrush current limiter manufactured by Littelfuse Inc. It features a nominal resistance of 2.5 Ohms with a tolerance of ±20% at 25°C. The component supports a maximum steady-state current of 10 A and has an axial leaded package with a length of 30.50 mm (1.201 inches). This device is designed to limit high initial current surges during power-up events.

Feature Summary

• Functions as a power thermistor for inrush current limiting applications
• Provides surge protection through resistive heating characteristics
• Utilizes an axial leaded package for through-hole mounting

Applications

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

Procurement Notes

Verify the obsolete status of this specific part number before initiating procurement processes. Confirm availability through authorized distributors or secondary market channels, as Littelfuse may have discontinued production. Ensure that any substitute components meet the original electrical specifications and thermal requirements for the intended application.

Selection Notes

Select this component based on its 2.5 Ohm resistance value and 10 A steady-state current rating. Consider the physical dimensions of the 30.50 mm package for board layout constraints. Evaluate the thermal performance and recovery time characteristics relative to the system's duty cycle and ambient temperature conditions.

Part Context

This component belongs to the Littelfuse power thermistor family, specifically designed for circuit protection against inrush currents. These devices are commonly used in electronic equipment where large capacitive loads or transformers are connected to AC or DC sources, preventing damage to switches and rectifiers during startup.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation due to the obsolete status of the ST2R510B. Engineers should consult Littelfuse technical support or distributor catalogs for equivalent legacy replacements that match the 2.5 Ohm resistance and 10 A current ratings.