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Adaptive-coupled Inductors for Multiphase Voltage Regulators
Year: 2022 | Author: Feiyang Zhu | Paper: H-S2.2
Fig. 1. Multiphase buck with an adaptive-coupled inductor. (a) Equivalent circuit. (b) Inductor structure.
To solve this issue, this paper proposes an adaptive-coupled inductor structure as shown in Fig. 1. This is realized by applying a variable inductor in the additional winding loop of an indirect-coupled inductor. By varying the coupling coefficient during the steady-state operation and load transients, the proposed inductor structure can help the multiphase buck converter achieve a faster transient speed while maintaining the same steady-state current ripple, as compared with the traditional indirect-coupled inductor. The coupling coefficient in the proposed structure is self-adjusted according to the circuit working conditions. Therefore, the proposed structure can be easily implemented without increasing the control complexity and cost. Furthermore, the inductor size of Lc can be dramatically reduced.
A four-phase buck converter with the proposed inductor structure is experimentally tested, and a 25.6 % output voltage overshoot reduction can be realized by the proposed coupled inductor structure as shown in Fig. 2.
Fig. 2. Load transient response comparison. (a) Traditional coupled inductor. (b) Proposed coupled inductor.
