Energy-Efficient Start-up Power Management for Batteryless Biomedical Implant Devices

Abstract

This paper presents a solar energy harvesting power management using the high-efficiency switchedcapacitor DC-DC converter for biomedical implant applications. By employing an on-chip start-up circuit with parallel connected Photovoltaic (PV) cells, a small efficiency improvement can be obtained when compared with the traditional stacked photodiode methodology to boost the harvested voltage while preserving a single-chip solution. The PV cells have been optimised in the PC1D software and the optimal parameters modelled in the Cadence environment. A cross-coupled circuit with level shifter loop is also proposed to improve the overall step up voltage output and hybrid converter increases the start-up speed by 23.5%. The proposed system is implemented in a standard 0.18-μm CMOS technology. Simulation results show that the 4-phase start-up and crosscoupled with level-shifter can achieve a maximum efficiency of 60%.

A Self-tracked High-dielectric Wireless Power Transfer System for Neural Implants

“…The transmitter is perfectly tuned at 1.5 GHz as revealed by the S11. The proposed method yields significantly improved power transfer efficiency (η = 1×10 -3 ) for implantable devices than traditional WPT methods at a 10-cm distance [2].…”

“…The mechanical mismatch and micro-motion introduced by the interconnection between the device in the brain tissue and the connector mounted on the skull (i.e. tether), can be minimized by using a wireless power system (WPT) [2].…”

Energy-Efficient Start-up Dickson Charge Pump for Batteryless Biomedical Implant Devices

“…The amount of useful power that can be scavenged from energy harvesters is strongly dependant on external environmental or human body conditions [1].This can be particularly challenging for implantable biomedical applications that require a constant voltage and current to its electronics components. Consequently, to ensure that power is reliably supplied to an implantable integrated circuits and systems from an unreliable input power source, an effective power management unit or DC-DC converter is required [2,3].…”

Flexible Wirelessly Powered Implantable Device

“…On the other hand, photovoltaic wireless power harvesting is being considered as a novel approach for many biomedical applications [7,8]. This technique is based on the conversion of light into electricity using photovoltaic cells.…”