18DA472

Overview

The Vishay Ametherm 18DA472 is an NTC thermistor inrush current limiter (ICL) designed for PCB mounting. It belongs to the SURGE-GARD series and features a radial leaded package with straight leads. The component has a nominal resistance of 4.7 Ohms with a tolerance of 20%. It is rated for a steady-state current of 100 Joules energy absorption capability and operates within a temperature range of 0°C to +65°C. The physical dimensions include an 18mm diameter, with a width of approximately 6mm and a lead spacing of 7.8mm. The unit weighs 5.844 grams and is supplied in bulk packaging.

Feature Summary

• Utilizes negative temperature coefficient (NTC) technology to limit initial surge currents during power-up cycles.
• Provides robust protection for sensitive electronic components by reducing peak inrush current stress.
• Features a compact radial through-hole design suitable for standard printed circuit board assembly processes.

Applications

• Power supply input stages
• Transformer primary circuits
• Capacitor charging protection

Procurement Notes

Verify the specific voltage rating requirements against the official datasheet, as distributor summaries may omit critical maximum continuous voltage limits. Confirm that the 100J energy rating aligns with the application's surge profile. Ensure the operating temperature range of 0°C to +65°C meets environmental constraints. Check for RoHS compliance status if required by project specifications.

Selection Notes

Select this component when a 4.7 Ohm cold resistance is appropriate for the target circuit's impedance matching. Consider the 100J energy handling capacity relative to the system's stored energy levels. Evaluate the 18mm form factor for adequate thermal dissipation space on the PCB. Compare against higher or lower resistance variants in the SG or SL series if current limiting characteristics differ significantly from design needs.

Part Context

This part is part of Vishay Ametherm's precision thermistor portfolio, specifically engineered for inrush current limiting applications. The manufacturer specializes in various sizes and packages for both inrush limiting and temperature sensing. The 18DA472 represents a standard disc thermistor configuration within their broader product line, offering reliable performance for general-purpose power electronics protection.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult the manufacturer's cross-reference guide for equivalent models with matching electrical parameters such as 4.7 Ohm resistance and 100J energy rating.