Ultra-Low-Profile Twisted Core Inductor for Vertical Power Delivery Voltage Regulator
Adhistira M. Naradhipa, Feiyang Zhu, Qiang Li
Abstract
Cloud computing and artificial intelligence (AI) are pushing the power of microprocessors, requiring more than a thousand amperes of current. The vertical power delivery (VPD) architecture is emerging to provide ultra-high current to the microprocessors efficiently. With the VPD architecture, the voltage regulator modules (VRMs) are placed under the processor, requiring low-profile VRMs with high current density to comply with the processor platform’s form factor. However, magnetic components are usually the bottleneck to achieve high-density VRMs. This paper proposes a new twisted core coupled inductor structure, enabling low-profile VRM. The proposed inductor features a high peak current density of 1.63 A/mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with a height of 2 mm. Moreover, the proposed inductor achieves negative coupling with a single straight winding, resulting in an extremely small winding resistance. Only a single mold design is required to build the proposed twisted core inductor structure, which eases the fabrication complexity. The fabricated two-phase negative coupled inductor is experimentally verified and has a high current handling capability of up to 130 A.