MS2212103B

Inrush Current Limiters (ICL) Overview

The MS2212103B is a radial-leaded Negative Temperature Coefficient (NTC) thermistor inrush current limiter from the Vishay Ametherm MegaSurge series. It provides surge protection for electronic circuits by limiting initial charging currents. Key electrical parameters include a resistance of 120 Ohms at 25°C with a tolerance of ±25%. The device supports a maximum steady-state current of 3 A and has a peak current rating of 30 A. It features a maximum energy absorption capacity of 220 J at 25°C and a dissipation factor of 75.4 mW/°C. The component measures 23.00 mm (0.906 inches) in diameter with a lead spacing of 7.80 mm.

Inrush Current Limiters (ICL) Feature Summary

• Utilizes NTC thermistor technology to dynamically reduce resistance as temperature rises, effectively suppressing high inrush currents during power-up.
• Designed with a robust radial-leaded package suitable for through-hole mounting on printed circuit boards.
• Certified by UL for safety compliance in industrial and commercial applications.

Inrush Current Limiters (ICL) Applications

• Protection of switching power supplies against high initial charging currents
• Surge suppression in AC/DC converter input stages
• Inrush current limiting for transformer primary windings

Inrush Current Limiters (ICL) Procurement Notes

Verify the specific suffix 'B' against the manufacturer's official datasheet to confirm if it denotes a specific packaging variant or mechanical dimension change compared to the base MS2212103 model. Ensure that the thermal environment allows for proper heat dissipation given the 75.4 mW/°C dissipation factor. Confirm that the 3 A steady-state current rating meets the operational requirements of the target circuit under all expected load conditions.

Inrush Current Limiters (ICL) Selection Notes

Select this component when a 120 Ohm cold resistance is required to limit inrush while maintaining low steady-state loss. The 220 J energy rating must exceed the calculated energy stress of the application's capacitive load. Consider the 23 mm diameter for available board space and the 7.80 mm lead pitch for PCB layout compatibility. Ensure the operating temperature range aligns with the thermistor's thermal characteristics to prevent premature aging or failure.

Inrush Current Limiters (ICL) Part Context

This part belongs to the MegaSurge MS22 series, which is engineered for high-energy inrush current limiting applications. The series is characterized by its ability to handle significant peak currents while providing stable resistance values. The MS2212103B represents a specific resistance-current combination within this family, optimized for medium-power supply protection scenarios requiring reliable surge suppression.

Inrush Current Limiters (ICL) Replacement Considerations

Direct substitutes may include other Vishay Ametherm parts with similar 120 Ohm resistance and 3 A current ratings, such as variants within the MS22 series. Cross-referencing with other manufacturers requires matching the 120 Ohm resistance, 3 A steady-state current, 220 J energy rating, and physical dimensions (23 mm diameter, 7.80 mm pitch). Verify that any alternative part holds equivalent UL certification if safety compliance is critical.