ST33001B

Overview

The ST33001B is an inrush current limiter (ICL) manufactured by Littelfuse Inc. It features a nominal resistance of 33 Ohms with a tolerance of ±20%. The device supports a maximum steady-state current of 1 A and has a diameter of 0.550 inches (13.97 mm). This component is designed to limit initial surge currents in electronic circuits.

Feature Summary

• Limits inrush current during power-up phases
• Provides stable resistance at operating temperature
• Compact radial leaded package design

Applications

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

Procurement Notes

Verify the obsolete status of this specific part number before procurement planning. Confirm availability through authorized distributors or secondary market suppliers, as Littelfuse may have discontinued production. Ensure replacement components meet identical electrical specifications for seamless integration into existing designs without re-qualification.

Selection Notes

Select this component for applications requiring precise inrush current limitation with a 1 A steady-state rating. The 33 Ohm resistance value suits circuits needing moderate initial impedance. Verify thermal management requirements for the 13.97 mm package size within the target enclosure constraints.

Part Context

This ICL belongs to Littelfuse's circuit protection portfolio, specifically addressing transient current management. It complements fuses and TVS diodes by managing startup surges rather than overcurrent faults or voltage spikes. The product line focuses on protecting sensitive downstream components from high initial charging currents.

Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation. Due to the obsolete status, engineers must identify equivalent ICLs with matching 33 Ohm resistance, 1 A current rating, and compatible package dimensions from other manufacturers.