749118205

Overview

The Würth Elektronik 749118205 is an offline pulse transformer designed for AC/DC converter applications, specifically LED drivers. It features a primary inductance of 0.9mH and a turns ratio of 19:1:1. The component offers 4000Vrms isolation voltage and operates at a frequency of 132kHz. Electrical characteristics include a primary DC resistance of 4.3Ω, secondary DC resistance of 26mΩ, and leakage inductance of 175µH. It utilizes through-hole mounting with dimensions of 18 x 16.5 x 18mm and supports a temperature range from -40°C to +125°C.

Feature Summary

• Provides high-voltage isolation suitable for offline power conversion circuits
• Engineered for compatibility with specific AC/DC controller chipsets
• Supports through-hole installation for robust PCB integration

Applications

• LED driver circuits
• AC/DC switched-mode power supplies (SMPS)
• Offline power conversion systems

Procurement Notes

Verify the manufacturer part number 749118205 against official Wurth Elektronik documentation to ensure authenticity. Confirm that the required specifications, including the 19:1:1 turns ratio and 4000Vrms isolation rating, align with your circuit design requirements before procurement. Ensure compliance with RoHS directives if applicable to your manufacturing standards.

Selection Notes

Select this component when designing AC/DC converters requiring 4000Vrms isolation and a 19:1:1 turns ratio. It is optimized for use with NCP101x and NCP105x controllers. Consider the 132kHz operating frequency and 0.9mH primary inductance for magnetic design compatibility. Verify that the through-hole package fits the mechanical constraints of the target enclosure.

Part Context

This transformer belongs to the WE-UNIT series by Würth Elektronik, which focuses on offline power applications. The series is designed to meet relevant safety standards and dielectric requirements for AC/DC converters. It serves as a critical magnetic component for isolating primary and secondary sides in non-isolated or isolated power supply topologies.

Replacement Considerations

Cross-reference with other WE-UNIT series transformers if pinout or electrical parameters differ. Verify compatibility with NCP101x/NCP105x controllers when substituting. Ensure replacement parts maintain the 4000Vrms isolation and 19:1:1 turns ratio.

FAQ

What is the isolation voltage rating of the 749118205?

The component provides 4000Vrms isolation voltage.

Which controller chipsets is this transformer designed for?

It is designed for use with On Semiconductor NCP101x and NCP105x chipsets.