Buck converter with higher than 87% efficiency over 500nA to 20mA load current range for IoT sensor nodes by Clocked Hysteresis Control

Ultra-low power energy harvesting and power management circuits for IoT applications

“…Moreover, the large size of batteries makes them an inadequate solution to power PMC within IoT smart nodes. In this aspect, energy harvester powered PMC garners a considerable attention as it features energy-autonomous IoT smart nodes, and avoid the maintenance cost of recharging and/or replacement of batteries and their bulky size [2,6,9,21,30,[37][38][39]. The use of energy harvesting elements (EHL) as an energy source for PMC within bio-sensors and autonomous implantable systems was considered by many literatures the adequate solution [2,4,5,22,30,[40][41][42][43][44][45][46][47][48][49][50][51].…”

“…Recent progress in IC technology and design techniques, especially in ultralow power circuits domain, has led the appearance of fully integrated autonomous and implantable SoC with high performance regarding power consumption, silicon area and power efficiency. Many applications have taken advantages of such a progress including the internet of things (IoT) wearable devices, smart nodes and biomedical sensors, which become an emerging technology nowadays (Figure 1-1) [6][7][8][9][10][11][12][13][14][15][16]. The rapid growth of IoT devices and applications due to the increase of people needs, increases the number of integrated blocks within the IoT SoC.…”

“…These smart nodes, are usually implemented as IoT SoC and includes power management circuit (PMC), energy sources, signal processing, communication blocks and sensors and/or actuators, as illustrated in Figure 1-1. Energy harvesting systems garners a considerable attention as it features energy-autonomous IoT smart nodes, and avoid the maintenance cost of recharging and/or replacement of batteries and their bulky size [1,[4][5][6][7][8][9][10].…”

“…The need of MPPT, along with the DC-DC converter rises from the harvester nature dependency and load power variability, especially at a regulated output voltage. The solar energy can be harvested using inductive based [4,16,19,20] or switched capacitor-based DC-DC converter [2,3,5,6,9,13,14,21]. However, the latter is a more suitable solution for fully-integrated IoT SoC, such as smart nodes and body-area-network (BAN), avoiding bulky off-chip inductors.…”