IEEE Access (Jan 2023)
Design, Analysis and Optimization of Magnetic-Core Solenoid Inductor for On-Chip Multi-Phase Buck Converter
Abstract
Due to heterogeneous integration, there is an increased demand for on-chip DC-DC converters to provide multiple voltage domains for efficient operation of the system. Towards this, planar magnetic-core based inductors gained popularity due to their increased inductance density for on-chip buck converter realization. To ensure proper operation of the converter, the magnetic-core should not saturate, and over-design of the inductor decreases the converter efficiency significantly. Also, the magnetic-core area budget is limited for on-chip design. This paper proposes an optimization framework to design an efficient multi-phase buck converter with the magnetic-core solenoid inductor for the given specifications. We investigate two cost-functions for optimization where Cost function1 considers only power loss reduction, whereas Cost function2 considers both power loss and inductor footprint. Full-wave simulations on commercial tool show that the optimized multi-phase buck converter with $500~mA$ load current achieves 88.13% and 88.06% efficiency for Cost function1 and Cost function2, respectively. The footprint for the optimized inductor with Cost function2 has a 10% reduction compared with the optimized inductor with Cost function1.
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