Converters with Multiphase Magnetics: TLVR vs CL and the Novel Optimized Structure

Conventional multiphase DC-DC converters can be upgraded for better performance, for example with coupled inductors (CL) or recently introduced trans-inductor voltage regulator (TLVR). This paper derives and verifies more accurate current slew rates for a TLVR in steady-state and transient, and then compares the relative performance of TLVR and CL. A general Figure of Merit (FOM) is proposed for an easy comparison of the different options. A novel notch coupled inductor (NCL) magnetic structure is proposed, maximizing the FOM. For a similar transient and size, both TLVR and NCL converters were built, confirming a dramatic improvement due to proposed NCL concept.