Ultra-Low-Profile Twisted Core Inductor for Vertical Power Delivery Voltage Regulator

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 ² 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.