A Multiload-Compatible DC–DC Converter With Permeability-Controlled Variable Inductor and Load-Aware Frequency Control for CPL Stability

DC-DC converter with resistive load (RL) or constant power load (CPL) requires different inductance to satisfy current ripple, efficiency, and stability. To achieve all the targets, a new perspective of using a permeability-controlled variable inductor (PCVI) and load-aware frequency control (LAFC) technique is proposed and employed in the buck converter for multi-load conditions. The key of this design is to achieve continuous conduction mode operation with high inductance for RL and maintain stability with low inductance for CPL via minor frequency variation. The magnetic core of PCVI consists of a ring-shaped ferrite wrapped with a passiveLCresonator. The PCVI incorporates two sets of windings: one serving as the inductor terminal integrated into the circuit, and the other connected to a compensation capacitor. This design provides the PCVI with a frequency-variation inductance by modifying the equivalent magnetic reluctance viaLCresonator. Besides, PCVI allows a voltage leap and sharp impedance variation within a minor frequency variation. The proposed converter features two decoupled control loops: a conventional output voltage loop and LAFC. The LAFC leverages output voltage ripple as feedback to dynamically tune the switching frequency, thereby mitigating voltage/current ripples and enhancing stability under high-power CPL scenarios without proportional-integral computation.