A 170mV-to-1.8V Input Voltage Range DC-DC Boost Converter Using a 100nH Air-coil with Sub-μA Quiescent Current

This paper introduces a sub- $\mu$A DC-DC boost converter designed to function with input voltages between 170 mV and 1.8 V. The wide input voltage operating range of the proposed converter allows to extract most of the charge out of a supercapacitor, intermittently charged by a wireless powering system. It is the first converter working with this large (10x) input voltage range, while utilizing a mm-sized MRI-compatible 100 nH air-coil, making it well-suited for miniature active medical implants. By using the proposed peak current circuit, the converter can achieve $\sim$ ns on-time control with only $1 \mu \mathrm{A}$ of quiescent current. Despite the low-power consumption and large input voltage operating range, the peak current was regulated within 6.75% from its optimal value of 50 mA. Finally, the proposed DC-DC converter achieves a peak efficiency of ${9 5. 8 2 \%}$ even if using a miniature air-coil inductor.