SG303

Inrush Current Limiters (ICL) Overview

The SG303 is a negative temperature coefficient (NTC) thermistor inrush current limiter from the Vishay Ametherm SURGE-GARD series. Designed for PCB mounting with radial kinked leads, this component limits initial surge currents during power-up. It features a nominal resistance of 2.5 Ohms with a tolerance of ±15% and a steady-state current rating of 3 A. The device supports a maximum voltage of 265 VAC and operates within a temperature range of 0°C to +65°C.

Inrush Current Limiters (ICL) Feature Summary

• Utilizes NTC thermistor technology to provide high initial resistance that decreases as temperature rises, effectively limiting inrush current.

Inrush Current Limiters (ICL) Applications

• Protection for switching power supplies
• Limiting surge current in AC/DC converters
• Inrush current control in general electronic equipment

Inrush Current Limiters (ICL) Procurement Notes

Verify the specific ordering suffix against the official datasheet to ensure correct lead configuration and packaging. Confirm that the thermal environment allows for proper heat dissipation, as the component's resistance changes significantly with temperature. Ensure the PCB layout accommodates the radial kinked lead spacing to prevent mechanical stress during soldering.

Inrush Current Limiters (ICL) Selection Notes

Select the SG303 when the circuit requires a 2.5 Ohm cold resistance and can handle up to 3 A steady-state current. Compare the energy absorption capability against the expected surge profile of the application. Ensure the operating voltage does not exceed the 265 VAC rating. Consider the physical dimensions and lead style compatibility with the target printed circuit board design.

Inrush Current Limiters (ICL) Part Context

This component belongs to the SG series of inrush current limiters manufactured by Vishay / Ametherm under the SURGE-GARD trademark. These devices are specialized NTC thermistors designed specifically for protecting sensitive electronics from high initial charging currents. The series offers various resistance and current ratings to suit different power levels.

Inrush Current Limiters (ICL) Replacement Considerations

Direct replacements must match the 2.5 Ohm resistance, 3 A current rating, and 265 VAC voltage specification. Verify that alternative components support radial kinked leads and fit the same PCB footprint. Check that the replacement part has equivalent energy handling capabilities and operates within the same temperature range.