skip to main content

This content will become publicly available on July 1, 2023

Title: An Inductor-First Single-Inductor Multiple-Output Hybrid DC-DC Converter With Integrated Flying Capacitor for SoC Applications
With the increasing complexity of highly integrated system on chips (SoCs), the power management system (PMS) is required to provide several power supplies efficiently for individual blocks. This paper presents a single-inductor multiple outputs (SIMO) an inductor-first hybrid converter that generates three outputs between 0.4V and 1.6V from a 1.8V input. The proposed multiple-output hybrid power stage can improve the conversion efficiency by reducing inductor current while extending the output voltage range compared with the existing hybrid topologies. In addition, the proposed converter employs an on-chip switched-capacitor power stage (SCPS) with a dual switching frequency technique, resulting in a fast response time, low cross-regulation, and reduced number of on-chip pads. Measurement results show that the converter achieves a peak efficiency of 87.5% with a maximum output current of 450mA. The converter is integrated with a fast voltage regulation loop with a 500MHz system clock to achieve less than 0.01mA/mV cross-regulation and a maximum 20mV overshoot at full-load transient response. The design is fabricated in the standard 180nm CMOS technology
; ; ; ; ;
Award ID(s):
Publication Date:
Journal Name:
IEEE transactions on circuits and systems
Sponsoring Org:
National Science Foundation
More Like this
  1. To improve the power delivery in System-on-Chips (SoCs), this paper proposes a single-input-multi-output (SIMO) hybrid converter to obtain fast response time, low cross-regulation, and 87% peak efficiency by using a multi-output hybrid power stage and dual-switching-frequency technique. The multiple-output hybrid power stage improves the conversion efficiency without sacrificing the output voltage range, and the dual-switching-frequency technique enhances the response time and cross-regulation performance. The proposed SIMO hybrid converter achieves 87.5% peak efficiency with an output voltage range from 0.4V to 1.6V for all outputs and a total maximum load current of 450mAAdditionally, it achieves less than 0.01mA/mV cross-regulation and less than 20mV overshoot at full-load step transient response.
  2. 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 onmore »the order of 10μs (over 100× faster than previous works).« less
  3. 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.
  4. A high-voltage-gain dc-dc converter topology is proposed for renewable energy applications. The proposed coupled-inductor-based high-gain dc-dc converter features reduced input current ripple. The semiconductor elements voltage spikes due to the leakage inductance are prevented through the use of a clamping circuit. The Clamping circuit helps recover the leakage inductance stored energy, which causes voltage spikes on the switch. This results in the selection of elements with lower voltage ratings. Power switches with lower voltage ratings lead to lower conduction losses and improved system efficiency. The DC component of the inductor magnetizing current is zero. Consequently, no energy is stored in the inductor core, and the losses are further reduced.
  5. A new high-voltage-gain non-isolated dc-dc topology for applications in renewable energies is proposed. A coupled inductor with three windings is used to increase the proposed topology voltage gain. In addition to increasing the voltage gain, the proposed topology also has other prominent features including continuous input current and zero dc magnetizing inductance current, which reduces the losses and size of coupled inductor core. Furthermore, the continuous input current guarantees a low-volume input filter, which is essential for renewable energy applications. The leakage inductor stored energy is recycled via the diode and capacitor and transferred to the converter output for increasing the efficiency and reducing voltage stresses on the converter components.