An area-efficient hybrid high-voltage charge pump design for IoT applications

A new hybrid charge pump topology is proposed to achieve high voltage DC supply in a TSMC 0.13 μm BCD technology. The design incorporates a hybrid cross-coupled and serial-parallel topologies which permits the use of MEM capacitors through-out the design and, thus, minimizes the overall area required for the same voltage gain. The paper proposes a new zero-reversion loss cross-coupled charge pump and a new serial-parallel charge pump design to reduce the overall area required for the charge pump by up to 50 % and provides a strong basis for different gain charge pump implementations.

I. Introduction

Sensors based IoT nodes are a new class device that will have a wide range of environmental and medical applications [1]. These are essentially miniature wireless sensors that either harvests power or run on a small battery. However, given the need to drive a sensor front-end, they have various supply voltage requirements. While various charge-pumps and power management circuits have been developed to boost the low harvested voltage (few hundreds of millivolts) to few volts [2] [3], not much has been done to address the need for a high voltage (>20V) on a stand-alone IoT. The size restriction on an environmental or implanted sensor makes it rather challenging to fit a high-voltage power-management-unit (PMU) on such a device. Considering a 3V Li-Ion battery, we designed the core charge-pump necessary for such a PMU.