ST1R508B

Overview

The ST1R508B is a power thermistor inrush current limiter manufactured by Littelfuse Inc. This component features a nominal resistance of 1.5 Ohms with a tolerance of ±20%. It is rated to handle a maximum steady-state current of 8 Amperes. The physical dimensions are specified as 0.780 inches, which equates to 19.81 millimeters in diameter. These specifications define the electrical and mechanical characteristics for circuit protection applications.

Feature Summary

• Functions as a power thermistor designed specifically for limiting inrush current within electronic circuits.

Applications

• Inrush current limiting in power supply inputs
• Circuit protection against initial surge currents

Procurement Notes

Verify the specific Littelfuse datasheet for the ST1R508B to confirm all electrical ratings and mechanical dimensions prior to integration. Ensure that the thermal environment and steady-state current requirements align with the 8 A rating. Cross-reference the 1.5 Ohm resistance value against the design schematic to guarantee proper circuit functionality and protection levels.

Selection Notes

Select this component when a 1.5 Ohm initial resistance is required to manage startup surges. The 8 A continuous current rating must accommodate the operational load without overheating. Verify that the 19.81 mm form factor fits the available board space or mounting configuration. Confirm compatibility with the target voltage levels and ambient temperature conditions.

Part Context

This part belongs to the category of power thermistors used for inrush current limiting. It serves as a protective element that reduces high initial current spikes during power-up phases. The device operates based on temperature-dependent resistance characteristics to safeguard downstream components from damage caused by excessive surge currents.

Replacement Considerations

Consult official Littelfuse documentation for verified substitute part numbers. Do not assume generic equivalents possess identical thermal or electrical performance characteristics without explicit manufacturer confirmation.