At Sensors Expo 2017, Geoffroy Gosset, CEO and founder of e-peas, explains how a variety of energy harvesting techniques and low power solutions that his company supplies can answer this question.
Using the company’s power management ICs (PMICs), systems can be designed that run ARM processors continuously at low frequencies and draw less power than when microcontroller units (MCUs) operate at higher frequencies and turn on from sleep modes.
For photovoltaic cells it’s the AEM10940 and AEM10941.
For thermoelectric EH applications, it’s the AEM20940.
For piezoelectric and RF EH applications, it’s the AEM30940.
The ICs use a patented cold start technique to achieve 3 µW, 50 mV coldstart in photovoltaic applications, 15 µW, 50 mV coldstart in the thermoelectric system, 3 µW, 380 mV cold start in the piezoelectric system and -18.8 dB coldstart in the RF application. The leakage current in these designs is less than 400 nA. The PMICS can harvest energy efficiently (up to 90% efficiently) at power levels up to 500 mW. The ICs provide the ability to switch to a primary battery or ultracapacitor in the system to guarantee that it works 24/7.
The PMICs provide a complete power management system. For example, e-peas’ AEM10940 harvests the available input power (from 1 μW to 50 mW) from a photovoltaic (PV) cell or thermoelectric generator (TEG), boosts the voltage to charge a storage element, such as a Li-Ion battery, a thin film battery or a super- or conventional capacitor, provides the low voltage supply to drive an MCU at 1.8 V and a high voltage supply to drive a radio transceiver as well as integrating all the active elements for powering a typical wireless sensor.