Point of Load converters with coupled inductors for fast transient

Abstract

Abstract In today’s rapidly advancing technological landscape, the demand for high-speed operations extends to the communication sector, necessitating faster and more responsive devices. This thesis investigates the use of various inductor topologies in multiphase buck converters, which serve as critical power supplies for numerous components. The focus is on analyzing the transient behavior of different inductor configurations to enhance current rise time. Specifically, the study compares common discrete inductors (DL), coupled inductors (CL), notched coupled inductors (NCL), and Trans-Inductor Voltage Regulators (TLVR) in terms of their dynamic response, output voltage ripple, and efficiency. The research is divided into two phases: • Simulation: This phase evaluates the performance of all inductor couplings, examining their efficiency, dynamic response, power system rejection ratio, and stability. • Hardware Implementation: This phase focuses on two inductor couplings, DL and CL, to validate the simulation results concerning efficiency, stability, and voltage ripple through physical testing. The study was conducted with all topologies having similar stability margins. The results reveal that coupled inductors and their variants achieve higher efficiencies, with CL and NCL reaching a maximum efficiency of 95% compared to 91% for DL and TLVR. This trend was also observed in physical testing. In terms of transient performance, DL achieved the highest current slew rate of -19.59 Aμs−1 during load release. The voltage and current ripples in CL and NCL contained only high-frequency components, whereas DL and TLVR exhibited both high and low-frequency components. Additionally, the PSRR was better in CL, with a gain (Vout Vin) of 0 dB compared to DL, which had a gain of 60 dB.