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.
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A 120V-to-1.8V 91.5%-Efficient 36-W Dual-Inductor Hybrid Converter with Natural Soft-charging Operations for Direct Extreme Conversion Ratios
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.
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- Award ID(s):
- 1810470
- NSF-PAR ID:
- 10094090
- Date Published:
- Journal Name:
- 2018 IEEE Energy Conversion Congress and Exposition (ECCE)
- Page Range / eLocation ID:
- 1266 to 1271
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)Efficient high-conversion-ratio power delivery is needed for many portable computing applications which require sub-volt supply rails but operate from batteries or USB power sources. In such applications, the power management unit should have a small volume, area, and height while providing fast transient response. Past work has shown favorable performance of hybrid switched-capacitor (SC) converters to reduce the size of needed inductor(s), which can soft-charge high-density SC networks while supporting efficient voltage regulation [1-5]. However, the hybrid approach has its own challenges including balancing the voltage of the flying capacitor and achieving safe but fast startup. Rapid supply transients, including startup, can cause voltage stress on power switches if flying capacitors are not quickly regulated. Past approaches such as precharge networks [3] or fast balancing control [5] have startup times that are on the order of milliseconds. This paper presents a two-stage cascaded hybrid SC converter that features a fast transient response with automatic flying capacitor balancing for low-voltage applications (i.e., 5V:0.4 to 1.2V from a USB interface). The converter is nearly standalone and all gate drive supplies are generated internally. Measured results show a peak efficiency of 96.9%, <; 36mV under/overshoot for 1A/μs load transients, and self-startup time on the order of 10μs (over 100× faster than previous works).more » « less
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Summary Inductive power transfer has become an emerging technology for its significant benefits in many applications, including mobile phones, laptops, electric vehicles, implanted bio‐sensors, and internet of things (IoT) devices. In modern applications, a direct current–direct current (DC–DC) converter is one of the essential components to regulate the output supply voltage for achieving the desired characteristics, that is, steady voltage with lower peak ripples. This paper presents a switched‐capacitor (SC) DC–DC converter using complementary architecture to provide a regulated DC voltage with an increased dynamic response. The proposed topology enhances the converter efficiency by decreasing the equivalent output resistance to half by connecting two symmetric SC single ladder converters. The proposed converter is designed using the standard 130‐nm BiCMOS process. The results show that the proposed architecture produces 327‐mV DC output with a rise time of 60.1 ns and consumes 3.449‐nW power for 1.0‐V DC supply. The output settling time is 43.6% lower than the single‐stage SC DC–DC converter with an input frequency of 200 MHz. The comparison results show that the proposed converter has a higher power conversion efficiency of 93.87
% and a lower power density of 0.57 mW/mm2compared to the existing works.
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/ECCE.2018.8557854
