More Like this

1. Analysis of Dual-Inductor Hybrid Converters for Extreme Conversion Ratios

   https://doi.org/10.1109/JESTPE.2020.2985116  

   Das, Ratul ; Seo, Gab-Su ; Le, Hanh-Phuc ( June 2020 , IEEE Journal of Emerging and Selected Topics in Power Electronics)

   This paper presents a dual-inductor hybrid (DIH) converter that is capable of efficient non-isolated DC-DC con- versions with extremely large voltage conversion ratios. The converter topology combines a switched-capacitor network and two interleaved inductors, that supports simple duty-cycle control for output regulation. In order to achieve complete soft charging for all flying capacitors, a method to optimally size the capacitors has been proposed and verified. A detailed analysis on the two inductor currents revealing a new and simple method to modulate them and its impacts on output regulation and efficiency are also provided and demonstrated in experiments. Employing the converter topology and design methods, a DIH converter prototype is implemented and measured for a wide range of operating voltages, providing a 1V-2V output from a 48-V input and a 1V-5V output from a 150V input with output currents up to 20A. The converter achieves 94.3% peak efficiency at 48V- to-2V/7A conversion and 93.7% at 150V-to-5V/18A conversion. 

   more » « less
2. A Regulated 48V-to-1V/100A 90.9%-Efficient Hybrid Converter for POL Applications in Data Centers and Telecommunication Systems

   Das, Ratul ; Le, Hanh-Phuc ( March 2019 , 2019 IEEE Applied Power Electronics Conference and Exposition (APEC))

   This paper describes the topology, fundamental operations, and key characteristics of a Dual-Phase Multi-Inductor Hybrid (DP-MIH) Converter for Point of Load (POL) telecommunication and data center applications. The circuit topology employs a unique configuration of switched-inductor and capacitor pairs to achieve complete soft charging and native voltage balancing of flying capacitors regardless of mismatches and variations in capacitor and inductor values. The converter topology and its operation are verified by a five-level DP-MIH converter prototype capable of delivering maximum load of 100A at 1V-5V regulated output voltages from a 48V input supply. It achieves 90.9% peak efficiency and 440 w/in3 power density for 48V-to-1V conversion and 95.3% and 2200W/in3 for a 48V-to-5V conversion. 

   more » « less
3. A 120V-to-1.8V 91.5%-Efficient 36-W Dual-Inductor Hybrid Converter with Natural Soft-charging Operations for Direct Extreme Conversion Ratios

   https://doi.org/10.1109/ECCE.2018.8557854  

   Das, Ratul ; Seo, Gab-Su ; Le, Hanh-Phuc ( September 2018 , 2018 IEEE Energy Conversion Congress and Exposition (ECCE))

   This paper presents a new dual inductor hybrid converter (DIHC) that is capable of efficient direct non-isolated DC-DC conversions with extremely large voltage conversion ratios. The converter employs two interleaved inductors and a switched-capacitor (SC) network to bring several significant topological benefits. Capacitance of the flying capacitors of this new topology can be optimally sized to achieve natural, complete soft-charging for all capacitors. This novel capacitor soft-charging feature is a key contribution of this work and can be exploited to overcome the limitations of conventional SC converters suffering from capacitor hard charging losses. The converter topology and its operation are verified in an 36-W converter prototype for 40-120V input to 0.9V-1.8V output up to 20A of current load that achieves peak efficiencies of 91.5% for 120V-to-1.8V and 87.3% for 120V-to-0.9V conversion. Its advantages and performance at extreme conversion ratios push the limit of point-of-load converters, reducing complexity and cost for bus voltage distributions, as well as enabling fewer conversion stages and thus higher efficiency for data centers and high-performance digital systems. 

   more » « less
4. An 80-W 94.6%-Efficient Multi-Phase Multi-Inductor Hybrid Converter

   Das, Ratul ; Seo, Gab-Su ; Maksimovic, Dragan ; and Le, Hanh-Phuc ( March 2019 , 2019 IEEE Applied Power Electronics Conference and Exposition (APEC))

   This paper presents a new Multi-Phase Multi-Inductor Hybrid (MP-MIH) converter that features high efficiency at large conversion ratios, while operating the switches with duty cycles larger than state-of-the-art hybrid topologies. In this converter, the capacitors are soft-charged and soft- discharged through three inductors operated in three interleaving phases. An experimental six-level three-phase converter prototype achieves 94.6% peak efficiency and 425 W/in3 power density for conversions from 48V to 1V-2V at loads of up to 40A. This multi-phase multi-inductor hybrid converter architecture can be extended to any number of switched-capacitor network levels to support wide range of input and output voltages and load currents in data centers, telecommunication and other high- performance digital systems. 

   more » « less
5. A 95%-Efficient 48V-to-1V/10A VRM Hybrid Converter Using Interleaved Dual Inductors

   https://doi.org/10.1109/ECCE.2018.8557715  

   Seo, Gab-Su ; Das, Ratul ; Le, Hanh-Phuc ( September 2018 , 2018 IEEE Energy Conversion Congress and Exposition (ECCE))

   This paper presents a new 48 V-to-1 V hybrid converter. The converter utilizes two interleaved inductors to achieve complete soft-charging of flying capacitors to efficiently support high output currents. This dual inductor hybrid converter (DIHC) features fewer number of switches and more effective switch utilization than a recently reported hybrid Dickson converter, leading to substantially less conduction losses presented by a smaller equivalent output impedance. Experimental results verify the converter's operation principles and advantages in a 300-kHz 20-W prototype achieving 95.02% peak efficiency and 225 W/in3 power density. Its advantages and performance promise a good candidate converter architecture for applications that require large conversion ratios and high output currents, such as data centers and high-performance digital systems. 

   more » « less