A power efficient buck‐boost converter by reusing the coil inductor for wireless bio‐implants

Abstract

Summary In this paper, a buck‐boost converter circuit for wireless power transfer via inductive links in bio‐implantable systems is presented. The idea is based on reusing the power receiver coil to design a regulator. This method employs five switches to utilize the coil inductor in a frequency other than the power‐receiving signal frequency. Reusing the coil inductor decreases the on‐chip regulator area and makes it suitable for bio‐implants. Furthermore, in the proposed technique, the regulator efficiency becomes almost independent of the coil receiving voltage amplitude. The proposed concept is employed in a buck‐boost regulator, and simulation results are provided. For a 10 MHz received signal with the amplitude variation within 3 ~ 6 V and with the converter switching rate of 200 kHz, the achieved maximum efficiency is 78%. The proposed regulator can also deliver 10 μA to 4 mA to its load while its output voltage varies from 0.6 to 2.3 V. Simulations of the proposed converter are performed in Cadence‐Spectre using TSMC 0.18 μm CMOS technology. Copyright © 2017 John Wiley & Sons, Ltd.

A wirelessly powered low‐power digital temperature sensor

“…However, the requirement of a wired power connection considerably curtails the applicability of electronic systems in certain applications where wired power link is just not feasible such as biomedical implants or autonomous wireless sensor systems. [1][2][3][4] This is where wireless power transfer (WPT) has gradually become a necessity. One of the most ubiquitous users of WPT, the radiofrequency identification (RFID) tags, touched $10B in 2015, while further miniaturization of these tags, by taking advantage of microfabrication of integrated circuits technology, is opening entirely new application paradigms, 5 which enables the development of wireless systems with integrated sensors providing multiparameter information about a product from the time of its manufacturing till delivery, adding value to the consumers and producers and maximizing yield.…”

“…The enormous increase in wireless signal bandwidths, their ranges, and improvements in their power efficiencies have seen a parallel increase in their application in existing and in entirely new scenarios. However, the requirement of a wired power connection considerably curtails the applicability of electronic systems in certain applications where wired power link is just not feasible such as biomedical implants or autonomous wireless sensor systems . This is where wireless power transfer (WPT) has gradually become a necessity.…”

Wireless charging for cardiac pacemakers based on class‐D power amplifier and a series–parallel spider‐web coil

“…A new technique was developed to utilize a buck‐boost converter circuit for IC–WPT by Barati and Yavari et al 37 A regulator was designed to depend on power re‐consumption at the receiving coil, thus reducing the on‐chip area of the regulator and making it appropriate for BMIs with low power consumption. In this design procedure, the voltage at the receiver coil would not affect the regulator's efficiency nor reduce its degradation.…”

Transmission range extension strategy of parity–time‐symmetry‐based wireless power transfer system by a boost converter

“…Kato et al and Li et al 15,16 explained how to maximize efficiency by using a DC-DC converter for impedance matching, but a communication device between transmitting circuit and receiving circuit is needed. Barati et al 17 adds a buck-boost converter into the secondary side and realizes reusing the power receiver coil, making it more applicable for bio-implants. Based on the above research, a novel PT-symmetry-based MCR-WPT system with a boost converter in secondary side is proposed in this article to further extend transmission distance.…”