{"id":2066,"date":"2026-07-24T16:30:01","date_gmt":"2026-07-24T08:30:01","guid":{"rendered":"https:\/\/www.trafopsu.com\/?p=2066"},"modified":"2026-07-24T16:49:23","modified_gmt":"2026-07-24T08:49:23","slug":"2-kw-integrated-llc-resonant-transformer-design-guide-using-a-dmegc-dmr59-pqi35-28-core","status":"publish","type":"post","link":"https:\/\/www.trafopsu.com\/pt\/2-kw-integrated-llc-resonant-transformer-design-guide-using-a-dmegc-dmr59-pqi35-28-core\/","title":{"rendered":"Guia de conce\u00e7\u00e3o de um transformador ressonante LLC integrado de 2 kW utilizando um n\u00facleo DMEGC DMR59 PQI35\/28"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Next-generation high-density power supply units (PSUs) for data centers, AI servers, and industrial electronics demand ultra-high conversion efficiency (&gt;98.5%) and high-power density (&gt;90 W\/inch\u00b3). As switching frequencies push into the <strong>200 kHz \u2013 500 kHz<\/strong>&nbsp;regime, conventional wound transformers suffer from high proximity effect losses, excessive leakage inductance variance, and thermal bottlenecks.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This Application Note presents a comprehensive design methodology for a <a href=\"https:\/\/www.trafopsu.com\/pt\/category\/products\/planar-transformers\/\"><strong><u><strong>2 kW high-power-density integrated LLC resonant transformer<\/strong><\/u><\/strong><\/a>&nbsp;utilizing the <strong>DMEGC DMR59 Mn-Zn ferrite core<\/strong>&nbsp;in a <strong>PQI35\/28 (PQI35\/11.4 assembly)<\/strong>&nbsp;geometry. By deploying an interleaved multi-layer FR4 planar PCB winding strategy, optimized resonant inductance integration, and low-loss ferrite selection, the transformer achieves a peak DC-DC stage efficiency exceeding <strong>98.8%<\/strong>&nbsp;with a maximum temperature rise under 50\u00b0C.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>1. Material Selection: DMEGC DMR59 Core Characteristics<\/strong><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Selecting the correct ferrite material is fundamental to minimizing core losses (Pv) at switching frequencies above 200 kHz. <strong>DMEGC DMR59<\/strong>\u00a0is a high-frequency, ultra-low-loss Manganese-Zinc (Mn-Zn) power ferrite specially engineered for high-density LLC and phase-shifted converters.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img fetchpriority=\"high\" decoding=\"async\" width=\"693\" height=\"305\" src=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image.png\" alt=\"\" class=\"wp-image-2069\" style=\"width:800px;height:auto\" srcset=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image.png 693w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-300x132.png 300w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-18x8.png 18w\" sizes=\"(max-width: 693px) 100vw, 693px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Key Performance Comparison<\/strong><strong><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Core Loss Minimum (Pv)<\/strong>: DMR59 features a negative temperature coefficient of power loss up to 100\u00b0C, reaching its absolute minimum loss density around 80\u00b0C \u2013 100\u00b0C\u2014matching the typical full-load thermal operating window of modern server PSUs.<\/li>\n\n\n\n<li><strong>High-Frequency Performance<\/strong>: Compared to traditional materials like DMR44 or N97, DMR59 maintains significantly lower volumetric losses under Bm=50 mT at f=300 kHz\u2212500 kHz.<\/li>\n\n\n\n<li><strong>High Saturation Flux Density (Bs)<\/strong>: Exceeds 510 mT at 25\u00b0C and 410 mT at 100\u00b0C, offering robust saturation margins during startup, transient load steps, and hold-up events.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>2. Integrated LLC Resonant Transformer Geometry &amp; Planar Mechanical Construction<\/strong><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O <strong>PQI35\/28<\/strong>&nbsp;core set (combining PQ35 and planar PQI core halves) offers an optimized balance between magnetic cross-sectional area (Ae) and total height, fitting seamlessly into standard <strong>1U chassis limits (40 mm outer height)<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img decoding=\"async\" width=\"693\" height=\"324\" src=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-1.png\" alt=\"\" class=\"wp-image-2070\" style=\"width:800px;height:auto\" srcset=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-1.png 693w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-1-300x140.png 300w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-1-18x8.png 18w\" sizes=\"(max-width: 693px) 100vw, 693px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Key Structural Innovations<\/strong><strong><\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Interleaved Multi-Layer Planar PCB Windings: By adopting an 8:2 primary-to-secondary turns ratio across 6-to-8 PCB layers with full interleaving (P-S-P-S), the AC copper losses (I2RAC) caused by skin effect and eddy currents are dramatically suppressed.<\/li>\n\n\n\n<li>Controlled Inter-layer Capacitance: FR4 ring spacers and Kapton insulation foils (20 \u00b5m \u2013 50 \u00b5m) are inserted between PCB winding layers to maintain precise air gap spacing, minimizing inter-winding common-mode parasitic capacitance (Ccm) and reducing EMI noise.<\/li>\n\n\n\n<li>Integration with Synchronous Rectification (SR): The planar secondary output copper planes directly interface with secondary-side power MOSFETs (e.g., 80V OptiMOS \/ GaN devices), minimizing termination resistance and terminal parasitic inductance.<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>3. Electrical &amp; Design Specifications<\/strong><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Below is the summary of electrical parameters for the 2 kW PQI35\/28 transformer designed for an LLC half-bridge DC-DC stage:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img decoding=\"async\" width=\"693\" height=\"585\" src=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-2.png\" alt=\"\" class=\"wp-image-2071\" style=\"aspect-ratio:1.1846367422489588;width:800px;height:auto\" srcset=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-2.png 693w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-2-300x253.png 300w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-2-14x12.png 14w\" sizes=\"(max-width: 693px) 100vw, 693px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>4. Performance Validation &amp; Thermal Breakdown<\/strong><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>4.1 Stage Efficiency Curve<\/strong><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When deployed in a 400V to 48V LLC converter with Gallium Nitride (CoolGaN\u2122) primary switches and Low-RDSon OptiMOS\u2122 synchronous rectifiers:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Peak Efficiency:<\/strong>&nbsp;<strong>98.85%<\/strong>&nbsp;at 50% load (1000 W).<\/li>\n\n\n\n<li><strong>Full-Load Efficiency:<\/strong>&nbsp;<strong>98.42%<\/strong>&nbsp;at 100% load (2000 W).<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"693\" height=\"267\" src=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-3.png\" alt=\"\" class=\"wp-image-2072\" style=\"aspect-ratio:2.595559160498834;width:800px;height:auto\" srcset=\"https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-3.png 693w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-3-300x116.png 300w, https:\/\/www.trafopsu.com\/wp-content\/uploads\/2026\/07\/image-3-18x7.png 18w\" sizes=\"(max-width: 693px) 100vw, 693px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>4.2 Thermal Profile Under 1U Forced Air Flow<\/strong><strong><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Ambient Temperature (<\/strong>Tamb<strong>):<\/strong>&nbsp;25\u00b0C (Simulated 45\u00b0C maximum operating environment).<\/li>\n\n\n\n<li><strong>Core Hotspot (DMEGC DMR59):<\/strong>&nbsp;~68\u00b0C at 2000 W full continuous load.<\/li>\n\n\n\n<li><strong>PCB Winding Hotspot:<\/strong>&nbsp;~73\u00b0C&nbsp;at secondary SR output termination.<\/li>\n\n\n\n<li><strong>Thermal Reserve:<\/strong>&nbsp;&gt;25\u00b0C clearance below the 100\u00b0C maximum thermal margin, preventing runaway core heating.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>5. Thermal Management &amp; Layout Recommendations<\/strong><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To replicate these benchmark results on your custom PCB design:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Direct Thermal Vias:<\/strong>&nbsp;Place dense arrays of thermal micro-vias (0.3 mm diameter, pitch 0.8 mm) beneath the planar transformer footprint to transfer heat directly to the bottom aluminum heatsink or chassis.<\/li>\n\n\n\n<li><strong>Airflow Channeling:<\/strong>&nbsp;Ensure forced air from the enclosure fan is piped across the PQI35 magnetic core sides and the secondary synchronous rectification MOSFETs.<\/li>\n\n\n\n<li><strong>Symmetrical Current Paths:<\/strong>&nbsp;Maintain equal-length current traces for parallel secondary windings to prevent localized current crowding and unbalanced thermals.<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>6. Conclusion &amp; Custom Planar Transformer Solutions<\/strong><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O <strong>PQI35\/28 2 kW integrated LLC resonant transformer design<\/strong>&nbsp;utilizing the <strong>DMEGC DMR59 ferrite core<\/strong>&nbsp;provides an industrial-grade blueprint for ultra-dense, high-efficiency power converters. Its low core losses at elevated temperatures, combined with the low AC copper losses of interleaved planar windings, make it an effective option for modern AI server power supplies and high-power DC-DC converters.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Related reading: <\/strong><a href=\"https:\/\/www.trafopsu.com\/pt\/high-power-llc-resonant-transformer-solutions-from-500w-to-6kw\/\"><u>High-Power LLC Resonant Transformer Solutions: From 500 W to 6 kW<\/u><\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Custom Magnetic Component Design and Manufacturing Services at <\/strong><a href=\"https:\/\/www.trafopsu.com\/pt\"><strong><u><strong>TrafoPSU<\/strong><\/u><\/strong><\/a><strong><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.trafopsu.com\/pt\"><u>TrafoPSU<\/u><\/a>&nbsp;is a China-based <a href=\"https:\/\/www.trafopsu.com\/pt\/about-us\/\"><u>custom magnetic components manufacturer<\/u><\/a>&nbsp;specializing in high-frequency magnetic engineering, custom planar transformers, integrated inductors, and high-power-density magnetics. As a <a href=\"https:\/\/www.trafopsu.com\/pt\/productcategory\/\"><u>transformer and inductor manufacturer<\/u><\/a>, we support electrical design, prototyping, validation, and volume production for customers seeking a custom transformer manufacturer in China.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>OEM\/ODM Prototyping:<\/strong>&nbsp;Custom primary\/secondary turns ratios, planar PCB stackups, and integrated resonant chokes.<\/li>\n\n\n\n<li><strong>Material Sourcing:<\/strong>&nbsp;Certified DMEGC ferrite cores (DMR59, DMR95, DMR52), TDK, and Ferroxcube materials.<\/li>\n\n\n\n<li><strong>Testing &amp; Quality Assurance:<\/strong>&nbsp;Complete 100% automated electrical testing, HIPOT isolation checks, and thermal profiling.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Related magnetic component capabilities include engineering and production support for a <a href=\"https:\/\/www.trafopsu.com\/pt\/category\/products\/inductors-and-chokes\/\"><u>nanocrystalline common mode choke<\/u><\/a>&nbsp;or a <a href=\"https:\/\/www.trafopsu.com\/pt\/category\/products\/inductors-and-chokes\/\"><u>custom high current inductor<\/u><\/a>&nbsp;used in EMI filtering, energy storage, and high-current power conversion.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.trafopsu.com\/pt\/contact-us\/\"><u>Contact our application engineering team<\/u><\/a>&nbsp;to request engineering samples or discuss how this 2 kW PQI35\/28 planar transformer design can be tailored to your voltage, frequency, thermal, and topology requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>As unidades de alimenta\u00e7\u00e3o (PSUs) de alta densidade de \u00faltima gera\u00e7\u00e3o para centros de dados, servidores de IA e eletr\u00f3nica industrial exigem uma efici\u00eancia de convers\u00e3o ultra-elevada (&gt;98,5%) e uma elevada densidade de pot\u00eancia (&gt;90 W\/polegada\u00b3). \u00c0 medida que as frequ\u00eancias de comuta\u00e7\u00e3o atingem o intervalo de 200 kHz a 500 kHz, os transformadores convencionais com enrolamentos sofrem de elevadas perdas por efeito de proximidade, varia\u00e7\u00e3o excessiva da indut\u00e2ncia de fuga e estrangulamentos t\u00e9rmicos. Esta Nota de Aplica\u00e7\u00e3o apresenta [\u2026]<\/p>","protected":false},"author":7,"featured_media":2074,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2066","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-application"],"_links":{"self":[{"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/posts\/2066","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/comments?post=2066"}],"version-history":[{"count":3,"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/posts\/2066\/revisions"}],"predecessor-version":[{"id":2076,"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/posts\/2066\/revisions\/2076"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/media\/2074"}],"wp:attachment":[{"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/media?parent=2066"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/categories?post=2066"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.trafopsu.com\/pt\/wp-json\/wp\/v2\/tags?post=2066"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}