Pulse Electronics recently announced the launch of its first high frequency inductor series designed specifically for Quasi Resonant Converters. PH9499.xxxCNL is a 0.95uH–1.25uH/3.5Arms series of inductors optimized for the 800kHz – 1.2MHz frequency of operation, typical of this topology. Litz wire is used to limit the ratio of AC to DC resistance to 1.25 at 1MHz, so that the converter maximizes the benefit of its low (22mOhms MAX) DC resistance.
PH9499.xxxCNL was primarily designed for power modules converting directly from 48 V to silicon core voltages. Through its compact size (11.2×9.75×7.6mm MAX) and its 1.1mm stand-off design feature that allows components to be mounted beneath the inductor, a power density of over 240W/in3 can be achieved in the resultant power module design. Additionally, an industry leading 6% inductance tolerance is achieved to maximize the benefits of the resonant topology. This tight tolerance, which arises from the selected number of winding turns, results in a high saturation current (>18A) so a high overcurrent can be supported for a short duration without compromising performance.
“Many families of inductors claim to be market leaders, due to their ultra-low DCR specification, without publishing any data on their high frequency core and copper losses. While solutions such as molded inductors are very compact in their construction as magnetic material is pressed directly around the winding coil, their high frequency resistance can be multiples of their DC resistance and their iron powder material becomes lossy at MHz frequency of operation. The PH9499 series addresses these limitations by using a high frequency grade, low core loss, ferrite material and a fine gauge litz wire, especially selected to optimise the performance of your module, allowing you to achieve over 90% efficiency,” said Gerard Healy Product Marketing, Specialized Power PBU, Pulse Electronics
As the typical application for this inductor may require that the part is subjected to several passes though the reflow oven (both during the mounting of the components on the module and the mounting of the module in the end application), the PH9499 series has been qualified to withstand 4 passes of the IPC/JEDEC J-STD-20E lead free reflow profile.
For further information about Pulse inductive solutions, please see https://www.pulseelectronics.com/wp-content/uploads/2021/02/Power-Inductors-Overview-021021.pdf