Set of custom magnetics developed for quasi-resonant primary side current-mode controllers for LED lighting introduced by Wurth Electronics Midcom

These magnetics are targeted for use in Integral LED Driver applications such as LED Bulbs Light engines as well as low power, LED Drivers and Electronic Control Gear for LEDs.

The magnetics developed include custom-wound transformers for isolated applications and a custom-wound inductor for non-isolated applications, including flyback transformers in the 4 and 10W power range for isolated LED lighting applications and a less than 1mH inductor with an auxiliary winding for non-isolated buck-boost applications.Standard drum core inductors are used for the input filtering and EMI reduction.

The high-performing, low-leakage inductance transformers are designed to meet reinforced insulation requirements defined by IEC61347 and can withstand a dielectric voltage of 3000VRMS for one minute for a primary circuit at a working voltage of 400VDC. The operating temperature of these custom magnetics is -40°C to +125°C.

“Custom magnetics from Wurth Electronics Midcom are ideally suited for use with the NCL30080 series of quasi-resonant primary-side current mode controllers from ON Semiconductor”, said Bernie Weir, product line applications manager at ON Semiconductor. “Wurth provided excellent, timely support in delivering a range of magnetic solutions that meet our form factor and performance targets.”

The NCL30080 series – including NCL30080, NCL30081, NCL30082, and NCL30083 - incorporate a novel control method to precisely regulate a constant LED current from the primary side, removing the need for secondary side feedback circuitry The family includes versions with thermal foldback, 5-step log-dimming, analog/digital dimming, and softstart.

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