A Highly Reliable SIMO Converter Using Hybrid Starter and Overcharging Protector for Energy Harvesting Systems

Oh-Kyong Kwon,Seong-Kwan Hong,Jae-Hyung Jung

doi:10.1109/access.2020.3021230

Oh-Kyong Kwon, Seong-Kwan Hong + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.3021230

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Journal: IEEE Access	Publication Date: Jan 1, 2020
Citations: 1	License type: CC BY 4.0

Affiliation: Hanyang University

Abstract

This paper proposes a highly reliable single-inductor multi-output (SIMO) converter for energy harvesting systems, which is controlled by the power management controller (PMC) including the hybrid starter, overcharging protector (OCP), and switch controller (SWC). The proposed hybrid starter employs the power-on-reset to accurately control the activated and deactivated moments of the SWC, thus generating a system supply voltage (V SYS ) within the stable operating voltage range. The proposed OCP employs the diode-connection and Schmitt trigger schemes to monitor the voltage of a storage device (V STG ) in real time, thereby protecting the IC from being damaged without using either a capacitor or Zener diode, which causes the additional area or reverse leakage current, respectively. The proposed SIMO converter with the PMC was fabricated using 0.18-μm CMOS process. The measurement results show that VSYS values at the activated and deactivated moments of the SWC are 1.798 V and 1.510 V, respectively, both of which are within the stable system voltage range for 1.8 V devices. In addition, the measured maximum V STG is 5.892 V, which is much lower than an absolute maximum rated voltage of 9.2 V for 5 V devices. Furthermore, the measurement results reveal that the hybrid starter allows the proposed SIMO converter to be properly restarted immediately after VSYS is shorted to ground, while the OCP safely protects the SIMO converter even when the storage device is removed from the IC while charging. Therefore, the proposed SIMO converter with the PMC is suitable for energy harvesting systems that require high reliability.

Highlights

The energy harvesting systems, which use harvesters as inputs to obtain various energies from the ambient environment, have become increasingly useful for Internet of Things (IoT) applications including wearable and implantable devices
This paper proposes a highly reliable single-inductor multi-output (SIMO) converter for energy harvesting systems, which is controlled by the power management controller (PMC) including the hybrid starter, overcharging protector (OCP), and switch controller (SWC)
This paper proposes a highly reliable SIMO converter for energy harvesting systems, which is controlled by the PMC including the hybrid starter, OCP, and SWC

Summary

Introduction

The energy harvesting systems, which use harvesters as inputs to obtain various energies from the ambient environment, have become increasingly useful for Internet of Things (IoT) applications including wearable and implantable devices. The proposed SIMO converter has two inputs (VSTG for the storage device and VHAR for the harvester) and three outputs (VSYS for the 1.8 V system supply voltage, VLOAD for the 3.3 V output load, and VSTG).

Results

Conclusion