High efficiency, highly integrated DC-DC converter for 48V data centers with standard CMOS and GaN devices

High efficiency, highly integrated DC-DC converter for 48V data centers with standard CMOS and GaN devices

HUA, YUAN (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Electronic Instrumentation)

Du, S. (mentor)
Serdijn, W.A. (graduation committee)
Manzaneque Garcia, T. (graduation committee)

Delft University of Technology

Electrical Engineering

2022-08-26

This thesis presents a 48V-to-1V 10-level dual inductor hybrid converter (DIHC) containing 11 on-chip switches and an off-chip Gallium Nitride (GaN) switch. Thanks to the 10-level Dickson switched-capacitor (SC) circuit, most of the voltage stress will be taken over by off-chip capacitors, which reduces the voltage stress of each switch to 4.8 V and takes full advantage of the voltage pressure on the 5-V on-chip transistors. This proposed structure is implemented in a 0.18-μm BCD process to convert 48-V input to 1-V output with up to 18-A current load. The post-layout simulations show that a peak power efficiency of 90.6% can be achieved at 5.2-A loading and the power density is about 2093 W/in3 considering the power stage volume.
This thesis also proposes a 48V/3V multi-resonant DC-DC converter for data center applications, consisting of a 3Φ-SC stage and a 4-to-1 series-parallel stage. Thanks to the multi-phase resonant operation mode, the converter uses fewer components to achieve the same voltage conversion ratio as the conventional two-phase SC converters, and can further improve the efficiency by realising soft-charging. This topology is simulated in cadence spectre, and achieves a peak efficiency of 96.94%, and 95.0% full load efficiency at 30-A load.

hybrid dc-dc converter
10-level
48V-to-1V
switched capacitor
GaN switch
5-V on-chip
resonant
multi-phase
voltage conversion ratio
soft-charging

http://resolver.tudelft.nl/uuid:cfd99eaf-b2c4-428e-983d-87e5c0318d13

Student theses

master thesis

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